macrovision/macrovision.js

let selected = null;
let prevSelected = null;
let selectedEntity = null;
let prevSelectedEntity = null;

let entityIndex = 0;

let firsterror = true;

let clicked = null;
let movingInBounds = false;
let dragging = false;
let clickTimeout = null;
let dragOffsetX = null;
let dragOffsetY = null;

let preloaded = new Set();

let panning = false;
let panReady = true;
let panOffsetX = null;
let panOffsetY = null;

let shiftHeld = false;
let altHeld = false;

let entityX;
let canvasWidth;
let canvasHeight;

let dragScale = 1;
let dragScaleHandle = null;

let dragEntityScale = 1;
let dragEntityScaleHandle = null;

let scrollDirection = 0;
let scrollHandle = null;

let zoomDirection = 0;
let zoomHandle = null;

let sizeDirection = 0;
let sizeHandle = null;

let worldSizeDirty = false;

let rulerMode = false;

let rulers = [];

let currentRuler = undefined;

const tagDefs = {
    "anthro": "Anthro",
    "feral": "Feral",
    "taur": "Taur",
    "naga": "Naga",
    "goo": "Goo"
}

math.createUnit("humans", {
    definition: "5.75 feet"
});

math.createUnit("story", {
    definition: "12 feet",
    prefixes: "long"
});
math.createUnit("stories", {
    definition: "12 feet",
    prefixes: "long"
});
math.createUnit("buses", {
    definition: "11.95 meters",
    prefixes: "long"
});
math.createUnit("marathons", {
    definition: "26.2 miles",
    prefixes: "long"
});
math.createUnit("timezones", {
    definition: "1037.54167 miles",
    prefixes: "long",
    aliases: ["timezone", "timezones"]
});
math.createUnit("nauticalMiles", {
    definition: "6080 feet",
    prefixes: "long",
    aliases: ["nauticalMile", "nauticalMiles"]
});
math.createUnit("fathoms", {
    definition: "6 feet",
    prefixes: "long",
    aliases: ["fathom", "fathoms"]
});

math.createUnit("earths", {
    definition: "12756km",
    prefixes: "long",
    aliases: ["earth", "earths", "Earth", "Earths"]
});
math.createUnit("lightsecond", {
    definition: "299792458 meters",
    prefixes: "long"
});
math.createUnit("lightseconds", {
    definition: "299792458 meters",
    prefixes: "long"
});

math.createUnit("parsec", {
    definition: "3.086e16 meters",
    prefixes: "long"
})
math.createUnit("parsecs", {
    definition: "3.086e16 meters",
    prefixes: "long"
})
math.createUnit("lightyears", {
    definition: "9.461e15 meters",
    prefixes: "long"
})
math.createUnit("AU", {
    definition: "149597870700 meters"
})
math.createUnit("AUs", {
    definition: "149597870700 meters"
})
math.createUnit("dalton", {
    definition: "1.66e-27 kg",
    prefixes: "long"
});
math.createUnit("daltons", {
    definition: "1.66e-27 kg",
    prefixes: "long"
});
math.createUnit("solarradii", {
    definition: "695990 km",
    prefixes: "long"
});
math.createUnit("solarmasses", {
    definition: "2e30 kg",
    prefixes: "long"
});
math.createUnit("galaxy", {
    definition: "105700 lightyears",
    prefixes: "long"
});
math.createUnit("galaxies", {
    definition: "105700 lightyears",
    prefixes: "long"
});
math.createUnit("universe", {
    definition: "93.016e9 lightyears",
    prefixes: "long"
});
math.createUnit("universes", {
    definition: "93.016e9 lightyears",
    prefixes: "long"
});
math.createUnit("multiverse", {
    definition: "1e30 lightyears",
    prefixes: "long"
});
math.createUnit("multiverses", {
    definition: "1e30 lightyears",
    prefixes: "long"
});

math.createUnit("footballFields", {
    definition: "57600 feet^2",
    prefixes: "long"
});

math.createUnit("people", {
    definition: "75 liters",
    prefixes: "long"
});
math.createUnit("shippingContainers", {
    definition: "1169 ft^3",
    prefixes: "long"
});
math.createUnit("olympicPools", {
    definition: "2500 m^3",
    prefixes: "long"
});
math.createUnit("oceans", {
    definition: "700000000 km^3",
    prefixes: "long"
});
math.createUnit("earthVolumes", {
    definition: "1.0867813e12 km^3",
    prefixes: "long"
});
math.createUnit("universeVolumes", {
    definition: "4.2137775e+32 lightyears^3",
    prefixes: "long"
});
math.createUnit("multiverseVolumes", {
    definition: "5.2359878e+89 lightyears^3",
    prefixes: "long"
});

math.createUnit("peopleMass", {
    definition: "80 kg",
    prefixes: "long"
});
math.createUnit("cars", {
    definition: "1250kg",
    prefixes: "long"
});
math.createUnit("busMasses", {
    definition: "15000kg",
    prefixes: "long"
});
math.createUnit("earthMass", {
    definition: "5.97e24 kg",
    prefixes: "long"
});

math.createUnit("kcal", {
    definition: "4184 joules",
    prefixes: "long"
})
math.createUnit("foodPounds", {
    definition: "867 kcal",
    prefixes: "long"
})
math.createUnit("foodKilograms", {
    definition: "1909 kcal",
    prefixes: "long"
})
math.createUnit("peopleEaten", {
    definition: "125000 kcal",
    prefixes: "long"
})
math.createUnit("villagesEaten", {
    definition: "1000 peopleEaten",
    prefixes: "long"
})
math.createUnit("townsEaten", {
    definition: "10000 peopleEaten",
    prefixes: "long"
})
math.createUnit("citiesEaten", {
    definition: "100000 peopleEaten",
    prefixes: "long"
})
math.createUnit("metrosEaten", {
    definition: "1000000 peopleEaten",
    prefixes: "long"
})

math.createUnit("barn", {
    definition: "10e-28 m^2",
    prefixes: "long"
})
math.createUnit("barns", {
    definition: "10e-28 m^2",
    prefixes: "long"
})

math.createUnit("points", {
    definition: "0.013888888888888888888888888 inches",
    prefixes: "long"
})
math.createUnit("beardSeconds", {
    definition: "10 nanometers",
    prefixes: "long"
})
math.createUnit("smoots", {
    definition: "5.5833333 feet",
    prefixes: "long"
})
math.createUnit("furlongs", {
    definition: "660 feet",
    prefixes: "long"
})
math.createUnit("nanoacres", {
    definition: "1e-9 acres",
    prefixes: "long"
})
math.createUnit("barnMegaparsecs", {
    definition: "1 barn megaparsec",
    prefixes: "long"
})
math.createUnit("firkins", {
    definition: "90 lb",
    prefixes: "long"
})
math.createUnit("donkeySeconds", {
    definition: "250 joules",
    prefixes: "long"
})
math.createUnit("HU", {
    definition: "0.75 inches",
    aliases: [
        "HUs",
        "hammerUnits"
    ]
});

const defaultUnits = {
    length: {
        metric: "meters",
        customary: "feet",
        relative: "stories",
        quirky: "smoots"
    },
    area: {
        metric: "meters^2",
        customary: "feet^2",
        relative: "footballFields",
        quirky: "nanoacres"
    },
    volume: {
        metric: "liters",
        customary: "gallons",
        relative: "olympicPools",
        volume: "barnMegaparsecs"
    },
    mass: {
        metric: "kilograms",
        customary: "lbs",
        relative: "peopleMass",
        quirky: "firkins"
    },
    energy: {
        metric: "kJ",
        customary: "kcal",
        relative: "peopleEaten",
        quirky: "donkeySeconds"
    }
}

const unitChoices = {
    length: {
        "metric": [
            "angstroms",
            "millimeters",
            "centimeters",
            "meters",
            "kilometers",
        ],
        "customary": [
            "inches",
            "feet",
            "yards",
            "miles",
            "nauticalMiles",
        ],
        "relative": [
            "humans",
            "stories",
            "buses",
            "marathons",
            "timezones",
            "earths",
            "lightseconds",
            "solarradii",
            "AUs",
            "lightyears",
            "parsecs",
            "galaxies",
            "universes",
            "multiverses"
        ],
        "quirky": [
            "beardSeconds",
            "points",
            "smoots",
            "furlongs",
            "HUs",
            "fathoms",
        ]
    },
    area: {
        "metric": [
            "cm^2",
            "meters^2",
            "kilometers^2",
        ],
        "customary": [
            "feet^2",
            "acres",
            "miles^2"
        ],
        "relative": [
            "footballFields"
        ],
        "quirky": [
            "barns",
            "nanoacres"
        ]
    },
    volume: {
        "metric": [
            "milliliters",
            "liters",
            "m^3",
        ],
        "customary": [
            "floz",
            "cups",
            "pints",
            "quarts",
            "gallons",
        ],
        "relative": [
            "people",
            "shippingContainers",
            "olympicPools",
            "oceans",
            "earthVolumes",
            "universeVolumes",
            "multiverseVolumes",
        ],
        "quirky": [
            "barnMegaparsecs"
        ]
    },
    mass: {
        "metric": [
            "kilograms",
            "milligrams",
            "grams",
            "tonnes",
        ],
        "customary": [
            "lbs",
            "ounces",
            "tons"
        ],
        "relative": [
            "peopleMass",
            "cars",
            "busMasses",
            "earthMass",
            "solarmasses"
        ],
        "quirky": [
            "firkins"
        ]
    },
    energy: {
        "metric": [
            "kJ",
            "foodKilograms"
        ],
        "customary": [
            "kcal",
            "foodPounds"
        ],
        "relative": [
            "peopleEaten",
            "villagesEaten",
            "townsEaten",
            "citiesEaten",
            "metrosEaten",
        ],
        "quirky": [
            "donkeySeconds"
        ]
    }
}
const config = {
    height: math.unit(1500, "meters"),
    x: 0,
    y: 0,
    minLineSize: 100,
    maxLineSize: 150,
    autoFit: false,
    drawYAxis: true,
    drawXAxis: false,
    autoMass: "off",
    autoFoodIntake: false,
    autoPreyCapacity: false
}

const availableEntities = {

}

const availableEntitiesByName = {

}

const entities = {

}

function constrainRel(coords) {
    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    const worldHeight = config.height.toNumber("meters");

    if (altHeld) {
        return coords;
    }
    return {
        x: Math.min(Math.max(coords.x, -worldWidth / 2 + config.x), worldWidth / 2 + config.x),
        y: Math.min(Math.max(coords.y, config.y), worldHeight + config.y)
    }
}

// not using constrainRel anymore
function snapPos(coords) {
    return {
        x: coords.x,
        y: (!config.lockYAxis || altHeld) ? coords.y : (Math.abs(coords.y) < config.height.toNumber("meters")/20 ? 0 : coords.y)
    };
}

function adjustAbs(coords, oldHeight, newHeight) {
    const ratio = math.divide(newHeight, oldHeight);

    const x = (coords.x - config.x) * ratio + config.x;
    const y = (coords.y - config.y) * ratio + config.y;

    return { x: x, y: y};
}

function pos2pix(coords) {
    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    const worldHeight = config.height.toNumber("meters");

    const x = ((coords.x - config.x) / worldWidth + 0.5) * (canvasWidth - 50) + 50;
    const y = (1 - (coords.y - config.y) / worldHeight) * (canvasHeight - 50) + 50;

    return { x: x, y: y };
}

function pix2pos(coords) {
    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    const worldHeight = config.height.toNumber("meters");

    const x = (((coords.x - 50) / (canvasWidth - 50)) - 0.5) * worldWidth + config.x;
    const y = (1 - ((coords.y - 50) / (canvasHeight - 50))) * worldHeight + config.y;
    return { x: x, y: y };
}

function updateEntityElement(entity, element) {
    const position = pos2pix({ x: element.dataset.x, y: element.dataset.y });
    const view = entity.view;

    element.style.left = position.x + "px";
    element.style.top = position.y + "px";
    element.style.setProperty("--xpos", position.x + "px");
    element.style.setProperty("--entity-height", "'" + entity.views[view].height.to(config.height.units[0].unit.name).format({ precision: 2 }) + "'");
    const pixels = math.divide(entity.views[view].height, config.height) * (canvasHeight - 50);
    const extra = entity.views[view].image.extra;
    const bottom = entity.views[view].image.bottom;
    const bonus = (extra ? extra : 1) * (1 / (1 - (bottom ? bottom : 0)));
    let height = pixels * bonus;

    // working around a Firefox bug here

    if (height > 17895698) {
        height = 0;
    }

    element.style.setProperty("--height", height + "px");
    element.style.setProperty("--extra", height - pixels + "px");

    element.style.setProperty("--brightness", entity.brightness);

    if (entity.views[view].rename)
        element.querySelector(".entity-name").innerText = entity.name == "" ? "" : entity.views[view].name;
    else
        element.querySelector(".entity-name").innerText = entity.name;

    const bottomName = document.querySelector("#bottom-name-" + element.dataset.key);

    bottomName.style.left = position.x + entityX + "px";
    bottomName.style.bottom = "0vh";
    bottomName.innerText = entity.name;

    const topName = document.querySelector("#top-name-" + element.dataset.key);

    topName.style.left = position.x + entityX + "px";
    topName.style.top = "20vh";
    topName.innerText = entity.name;

    if (entity.views[view].height.toNumber("meters") / 10 > config.height.toNumber("meters")) {
        topName.classList.add("top-name-needed");
    } else {
        topName.classList.remove("top-name-needed");
    }
    updateInfo();
}

let ratioInfo

function updateInfo() {
    let text = ""
    if (config.showRatios) {
        if (selectedEntity !== null && prevSelectedEntity !== null && selectedEntity !== prevSelectedEntity) {
            let first = selectedEntity.currentView.height;
            let second = prevSelectedEntity.currentView.height;
    
            if (first.toNumber("meters") < second.toNumber("meters")) {
                text += selectedEntity.name + " is " + math.format(math.divide(second, first), { precision: 5 }) + " times smaller than " + prevSelectedEntity.name;
            } else {
                text += selectedEntity.name + " is " + math.format(math.divide(first, second), { precision: 5 })+ " times taller than " + prevSelectedEntity.name;
            }

            text += "\n";

            let apparentHeight = math.multiply(math.divide(second, first), math.unit(6, "feet"));

            if (config.units === "metric") {
                apparentHeight = apparentHeight.to("meters");
            }

            text += prevSelectedEntity.name + " looks " + math.format(apparentHeight, { precision: 3}) + " tall to " + selectedEntity.name + "\n";

            if (selectedEntity.currentView.capacity && prevSelectedEntity.currentView.weight) {
                const containCount = math.divide(selectedEntity.currentView.capacity, math.divide(prevSelectedEntity.currentView.weight, math.unit("80kg/people")));
                
                if (containCount > 0.1) {
                    text += selectedEntity.name + " can fit " + math.format(containCount, { precision: 1 }) + " of " + prevSelectedEntity.name + " inside them" + "\n"
                }
                
            }
    
        }
    }

    if (config.showHorizon) {
        if (selectedEntity !== null) {
            const y = document.querySelector("#entity-" + selectedEntity.index).dataset.y;
            const R = math.unit(1.27560e+7, "meters")
            const h = math.add(selectedEntity.currentView.height, math.unit(y, "meters"))

            const first = math.multiply(2, math.multiply(R, h))
            const second = math.multiply(h, h)

            const sightline = math.sqrt(math.add(first, second)).to(config.height.units[0].unit.name)

            sightline.fixPrefix = false
            text += selectedEntity.name + " could see for " + math.format(sightline, { precision: 3 }) + "\n"
        }
    }

    if (config.showRatios && config.showHorizon) {
        if (selectedEntity !== null && prevSelectedEntity !== null && selectedEntity !== prevSelectedEntity) {
            const y1 = document.querySelector("#entity-" + selectedEntity.index).dataset.y;
            const y2 = document.querySelector("#entity-" + prevSelectedEntity.index).dataset.y;
            const R = math.unit(1.27560e+7, "meters")
            const R2 = math.subtract(math.subtract(R, prevSelectedEntity.currentView.height), math.unit(y2, "meters"))
            const h = math.add(selectedEntity.currentView.height, math.unit(y1, "meters"))

            const first = math.pow(math.add(R, h), 2)
            const second = math.pow(R2, 2)

            const sightline = math.sqrt(math.subtract(first, second)).to(config.height.units[0].unit.name)

            sightline.fixPrefix = false
            text += selectedEntity.name + " could see " + prevSelectedEntity.name + " from " + math.format(sightline, { precision: 3 }) + " away\n"
        }
    }

    ratioInfo.innerText = text;
    
}

function pickUnit() {
    if (!config.autoUnits) {
        return;
    }

    let type = null;
    let category = null;
    
    const heightSelect = document.querySelector("#options-height-unit");

    currentUnit = heightSelect.value;

    Object.keys(unitChoices).forEach(unitType => {
        Object.keys(unitChoices[unitType]).forEach(unitCategory => {
            if (unitChoices[unitType][unitCategory].includes(currentUnit)) {
                type = unitType;
                category = unitCategory;
            }
        })
    })

    // This should only happen if the unit selector isn't set up yet.
    // It doesn't really matter what goes into it.
    if (type === null || category === null) {
        return "meters"
    }

    const choices = unitChoices[type][category].map(unit => {
        let value = config.height.toNumber(unit);
        if (value < 1) {
            value = 1 / value / value;
        }
        return [unit, value]
    })

    heightSelect.value = choices.sort((a, b) => {
        return a[1] - b[1]
    })[0][0]

    selectNewUnit();
}

function updateSizes(dirtyOnly = false) {
    updateInfo();

    if (config.lockYAxis) {
        if (config.groundPos === "very-high") {
            config.y = -config.height.toNumber("meters") / 12 * 5;
        } else if (config.groundPos === "high") {
            config.y = -config.height.toNumber("meters") / 12 * 4;
        } else if (config.groundPos === "medium") {
            config.y = -config.height.toNumber("meters") / 12 * 3;
        } else if (config.groundPos === "low") {
            config.y = -config.height.toNumber("meters") / 12 * 2;
        } else if (config.groundPos === "very-low") {
            config.y = -config.height.toNumber("meters") / 12;
        } else {
            config.y = 0;
        }
    }

    drawScales(dirtyOnly);

    let ordered = Object.entries(entities);

    ordered.sort((e1, e2) => {
        if (e1[1].priority != e2[1].priority) {
            return e2[1].priority - e1[1].priority;
        } else {
            return e1[1].views[e1[1].view].height.value - e2[1].views[e2[1].view].height.value
        }

    });

    let zIndex = ordered.length;

    ordered.forEach(entity => {
        const element = document.querySelector("#entity-" + entity[0]);
        element.style.zIndex = zIndex;
        if (!dirtyOnly || entity[1].dirty) {
            updateEntityElement(entity[1], element, zIndex);
            entity[1].dirty = false;
        }
        zIndex -= 1;
    });

    document.querySelector("#ground").style.top = pos2pix({x: 0, y: 0}).y + "px";


    drawRulers();
}

function drawRulers() {
    const canvas = document.querySelector("#rulers");

    /** @type {CanvasRenderingContext2D} */

    const ctx = canvas.getContext("2d");

    const deviceScale = window.devicePixelRatio;

    ctx.canvas.width = Math.floor(canvas.clientWidth * deviceScale);
    ctx.canvas.height = Math.floor(canvas.clientHeight * deviceScale);

    ctx.scale(deviceScale, deviceScale);
    
    rulers.concat(currentRuler ? [currentRuler] : []).forEach(rulerDef => {
        let x0 = rulerDef.x0;
        let y0 = rulerDef.y0;
        let x1 = rulerDef.x1;
        let y1 = rulerDef.y1;
        if (rulerDef.entityKey !== null) {
            const entity = entities[rulerDef.entityKey]
            const entityElement = document.querySelector("#entity-" + rulerDef.entityKey)
            x0 *= entity.scale;
            y0 *= entity.scale;
            x1 *= entity.scale;
            y1 *= entity.scale;
            x0 += parseFloat(entityElement.dataset.x)
            x1 += parseFloat(entityElement.dataset.x)
            y0 += parseFloat(entityElement.dataset.y)
            y1 += parseFloat(entityElement.dataset.y)
        }
        ctx.save();
        ctx.beginPath();
        const start = pos2pix({x: x0, y: y0});
        const end = pos2pix({x: x1, y: y1});
        ctx.moveTo(start.x, start.y);
        ctx.lineTo(end.x, end.y);
        ctx.lineWidth = 5;
        ctx.strokeStyle = "#f8f";
        ctx.stroke();
        const center = { x: (start.x + end.x) / 2, y: (start.y + end.y) / 2 };
        ctx.fillStyle = "#eeeeee";
        ctx.font = 'normal 24pt coda';
        ctx.translate(center.x, center.y);
        let angle = Math.atan2(end.y - start.y, end.x - start.x);

        if (angle < -Math.PI/2) {
            angle += Math.PI;
        }
        if (angle > Math.PI/2) {
            angle -= Math.PI;
        }
        ctx.rotate(angle);
        const offsetX = Math.cos(angle + Math.PI/2);
        const offsetY = Math.sin(angle + Math.PI/2);
        
        const distance = Math.sqrt(Math.pow(y1 - y0, 2) + Math.pow(x1 - x0, 2));
        const distanceInUnits = math.unit(distance, "meters").to(document.querySelector("#options-height-unit").value);
        const textSize = ctx.measureText(distanceInUnits.format({ precision: 3}));
        ctx.fillText(distanceInUnits.format({ precision: 3}), -offsetX * 10 - textSize.width / 2, -offsetY*10);
        ctx.restore();
    });
}

function drawScales(ifDirty = false) {
    const canvas = document.querySelector("#display");

    /** @type {CanvasRenderingContext2D} */

    const ctx = canvas.getContext("2d");

    const deviceScale = window.devicePixelRatio;

    ctx.canvas.width = Math.floor(canvas.clientWidth * deviceScale);
    ctx.canvas.height = Math.floor(canvas.clientHeight * deviceScale);

    ctx.scale(deviceScale, deviceScale);

    ctx.beginPath();
    ctx.rect(0, 0, ctx.canvas.width / deviceScale, ctx.canvas.height / deviceScale);

    switch(config.background){
        case "black":
            ctx.fillStyle = "#000";
            break;
        case "dark":
            ctx.fillStyle = "#111";
            break;
        case "medium":
            ctx.fillStyle = "#333";
            break;
        case "light":
            ctx.fillStyle = "#555";
            break;
    }
    ctx.fill();


    if (config.drawYAxis || config.drawAltitudes !== "none") {
        drawVerticalScale(ifDirty);
    }
    if (config.drawXAxis) {
        drawHorizontalScale(ifDirty);
    }
}

function drawVerticalScale(ifDirty = false) {
    if (ifDirty && !worldSizeDirty)
        return;
    function drawTicks(/** @type {CanvasRenderingContext2D} */ ctx, pixelsPer, heightPer) {
        let total = heightPer.clone();
        total.value = config.y;
        let y = ctx.canvas.clientHeight - 50;

        let offset = total.toNumber("meters") % heightPer.toNumber("meters");

        y += offset / heightPer.toNumber("meters") * pixelsPer;
        total = math.subtract(total, math.unit(offset, "meters"));

        for (; y >= 50; y -= pixelsPer) {
            drawTick(ctx, 50, y, total.format({ precision: 3 }));
            total = math.add(total, heightPer);
        }
    }

    function drawTick(/** @type {CanvasRenderingContext2D} */ ctx, x, y, label, flipped=false) {
        const oldStroke = ctx.strokeStyle;
        const oldFill = ctx.fillStyle;

        x = Math.round(x);
        y = Math.round(y);

        ctx.beginPath();
        ctx.moveTo(x, y);
        ctx.lineTo(x + 20, y);
        ctx.strokeStyle = "#000000";
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo(x + 20, y);
        ctx.lineTo(ctx.canvas.clientWidth - 70, y);
        if (flipped) {
            ctx.strokeStyle = "#666666";
        } else {
            ctx.strokeStyle = "#aaaaaa";
        }
        
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo(ctx.canvas.clientWidth - 70, y);
        ctx.lineTo(ctx.canvas.clientWidth - 50, y);
        ctx.strokeStyle = "#000000";
        ctx.stroke();

        const oldFont = ctx.font;
        ctx.font = 'normal 24pt coda';
        ctx.fillStyle = "#dddddd";

        ctx.beginPath();
        if (flipped) {
            ctx.textAlign = "end";
            ctx.fillText(label, ctx.canvas.clientWidth - 70, y + 35)
        } else {
            ctx.fillText(label, x + 20, y + 35);
        }
        ctx.textAlign = "start";
        

        ctx.font = oldFont;
        ctx.strokeStyle = oldStroke;
        ctx.fillStyle = oldFill;
    }

    function drawAltitudeLine(ctx, height, label) {
        const pixelScale = (ctx.canvas.clientHeight - 100) / config.height.toNumber("meters");
        const y = ctx.canvas.clientHeight - 50 - (height.toNumber("meters") - config.y) * pixelScale;
        if (y < ctx.canvas.clientHeight - 100) {
            drawTick(ctx, 50, y, label, true);
        }
    }

    const canvas = document.querySelector("#display");

    /** @type {CanvasRenderingContext2D} */

    const ctx = canvas.getContext("2d");

    const pixelScale = (ctx.canvas.clientHeight - 100) / config.height.toNumber();

    let pixelsPer = pixelScale;
    heightPer = 1;


    if (pixelsPer < config.minLineSize) {
        const factor = math.ceil(config.minLineSize / pixelsPer);
        heightPer *= factor;
        pixelsPer *= factor;
    }

    if (pixelsPer > config.maxLineSize) {
        const factor = math.ceil(pixelsPer / config.maxLineSize);
        heightPer /= factor;
        pixelsPer /= factor;
    }

    if (heightPer == 0) {
        console.error("The world size is invalid! Refusing to draw the scale...");
        return;
    }
    heightPer = math.unit(heightPer, document.querySelector("#options-height-unit").value);
    


    ctx.beginPath();
    ctx.moveTo(50, 50);
    ctx.lineTo(50, ctx.canvas.clientHeight - 50);
    ctx.stroke();
    ctx.beginPath();
    ctx.moveTo(ctx.canvas.clientWidth - 50, 50);
    ctx.lineTo(ctx.canvas.clientWidth - 50, ctx.canvas.clientHeight - 50);
    ctx.stroke();

    if (config.drawYAxis) {
        drawTicks(ctx, pixelsPer, heightPer);
    }

    if (config.drawAltitudes == "atmosphere" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(8, "km"), "Troposphere");
        drawAltitudeLine(ctx, math.unit(17.5, "km"), "Ozone Layer");
        drawAltitudeLine(ctx, math.unit(50, "km"), "Stratosphere");
        drawAltitudeLine(ctx, math.unit(85, "km"), "Mesosphere");
        drawAltitudeLine(ctx, math.unit(675, "km"), "Thermosphere");
        drawAltitudeLine(ctx, math.unit(10000, "km"), "Exosphere");
    }
    
    if (config.drawAltitudes == "orbits" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(7, "miles"), "Cruising Altitude");
        drawAltitudeLine(ctx, math.unit(100, "km"), "Edge of Space (Kármán line)");
        drawAltitudeLine(ctx, math.unit(211.3, "miles"), "Space Station");
        drawAltitudeLine(ctx, math.unit(369.7, "miles"), "Hubble Telescope");
        drawAltitudeLine(ctx, math.unit(1500, "km"), "Low Earth Orbit");
        drawAltitudeLine(ctx, math.unit(20350, "km"), "GPS Satellites");
        drawAltitudeLine(ctx, math.unit(35786, "km"), "Geosynchronous Orbit");
        drawAltitudeLine(ctx, math.unit(238900, "miles"), "Lunar Orbit");
        drawAltitudeLine(ctx, math.unit(57.9e6, "km"), "Orbit of Mercury");
        drawAltitudeLine(ctx, math.unit(108.2e6, "km"), "Orbit of Venus");
        drawAltitudeLine(ctx, math.unit(1, "AU"), "Orbit of Earth");
        drawAltitudeLine(ctx, math.unit(227.9e6, "km"), "Orbit of Mars");
        drawAltitudeLine(ctx, math.unit(778.6e6, "km"), "Orbit of Jupiter");
        drawAltitudeLine(ctx, math.unit(1433.5e6, "km"), "Orbit of Saturn");
        drawAltitudeLine(ctx, math.unit(2872.5e6, "km"), "Orbit of Uranus");
        drawAltitudeLine(ctx, math.unit(4495.1e6, "km"), "Orbit of Neptune");
        drawAltitudeLine(ctx, math.unit(5906.4e6, "km"), "Orbit of Pluto");
        drawAltitudeLine(ctx, math.unit(2.7, "AU"), "Asteroid Belt");
        drawAltitudeLine(ctx, math.unit(123, "AU"), "Heliopause");
        drawAltitudeLine(ctx, math.unit(26e3, "lightyears"), "Orbit of Sol");
    }
    
    if (config.drawAltitudes == "weather" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(1000, "meters"), "Low-level Clouds");
        drawAltitudeLine(ctx, math.unit(3000, "meters"), "Mid-level Clouds");
        drawAltitudeLine(ctx, math.unit(10000, "meters"), "High-level Clouds");
        drawAltitudeLine(ctx, math.unit(20, "km"), "Polar Stratospheric Clouds");
        drawAltitudeLine(ctx, math.unit(80, "km"), "Noctilucent Clouds");
        drawAltitudeLine(ctx, math.unit(100, "km"), "Aurora");
    }
        
    if (config.drawAltitudes == "water" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(12100, "feet"), "Average Ocean Depth");
        drawAltitudeLine(ctx, math.unit(8376, "meters"), "Milkwaukee Deep");
        drawAltitudeLine(ctx, math.unit(10984, "meters"), "Challenger Deep");
        drawAltitudeLine(ctx, math.unit(5550, "meters"), "Molloy Deep");
        drawAltitudeLine(ctx, math.unit(7290, "meters"), "Sunda Deep");
        drawAltitudeLine(ctx, math.unit(592, "meters"), "Crater Lake");
        drawAltitudeLine(ctx, math.unit(7.5, "meters"), "Littoral Zone");
        drawAltitudeLine(ctx, math.unit(140, "meters"), "Continental Shelf");
    }
        
    if (config.drawAltitudes == "geology" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(35, "km"), "Crust");
        drawAltitudeLine(ctx, math.unit(670, "km"), "Upper Mantle");
        drawAltitudeLine(ctx, math.unit(2890, "km"), "Lower Mantle");
        drawAltitudeLine(ctx, math.unit(5150, "km"), "Outer Core");
        drawAltitudeLine(ctx, math.unit(6370, "km"), "Inner Core");
    }
        
    if (config.drawAltitudes == "thicknesses" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(0.335, "nm"), "Monolayer Graphene");
        drawAltitudeLine(ctx, math.unit(3, "um"), "Spider Silk");
        drawAltitudeLine(ctx, math.unit(0.07, "mm"), "Human Hair");
        drawAltitudeLine(ctx, math.unit(0.1, "mm"), "Sheet of Paper");
        drawAltitudeLine(ctx, math.unit(0.5, "mm"), "Yarn");
        drawAltitudeLine(ctx, math.unit(0.0155, "inches"), "Thread");
        drawAltitudeLine(ctx, math.unit(0.1, "um"), "Gold Leaf");
        drawAltitudeLine(ctx, math.unit(35, "um"), "PCB Trace");
    }
        
    if (config.drawAltitudes == "airspaces" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(18000, "feet"), "Class A");
        drawAltitudeLine(ctx, math.unit(14500, "feet"), "Class E");
        drawAltitudeLine(ctx, math.unit(10000, "feet"), "Class B");
        drawAltitudeLine(ctx, math.unit(4000, "feet"), "Class C");
        drawAltitudeLine(ctx, math.unit(2500, "feet"), "Class D");
    }

    if (config.drawAltitudes == "races" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(100, "meters"), "100m Dash");
        drawAltitudeLine(ctx, math.unit(26.2188/2, "miles"), "Half Marathon");
        drawAltitudeLine(ctx, math.unit(26.2188, "miles"), "Marathon");
        drawAltitudeLine(ctx, math.unit(161.734, "miles"), "Monaco Grand Prix");
        drawAltitudeLine(ctx, math.unit(500, "miles"), "Daytona 500");
        drawAltitudeLine(ctx, math.unit(2121.6, "miles"), "Tour de France");
    }

    if (config.drawAltitudes == "olympic-records" || config.drawAltitudes == "all") {
        drawAltitudeLine(ctx, math.unit(2.39, "meters"), "High Jump");
        drawAltitudeLine(ctx, math.unit(6.03, "meters"), "Pole Vault");
        drawAltitudeLine(ctx, math.unit(8.90, "meters"), "Long Jump");
        drawAltitudeLine(ctx, math.unit(18.09, "meters"), "Triple Jump");
        drawAltitudeLine(ctx, math.unit(23.30, "meters"), "Shot Put");
        drawAltitudeLine(ctx, math.unit(72.30, "meters"), "Discus Throw");
        drawAltitudeLine(ctx, math.unit(84.80, "meters"), "Hammer Throw");
        drawAltitudeLine(ctx, math.unit(90.57, "meters"), "Javelin Throw");
    }  
}

// this is a lot of copypizza...

function drawHorizontalScale(ifDirty = false) {
    if (ifDirty && !worldSizeDirty)
        return;
    function drawTicks(/** @type {CanvasRenderingContext2D} */ ctx, pixelsPer, heightPer) {
        let total = heightPer.clone();
        total.value = math.unit(-config.x, "meters").toNumber(config.unit);

        // further adjust it to put the current position in the center

        total.value -=  heightPer.toNumber("meters") / pixelsPer * (canvasWidth + 50) / 2;
        let x = ctx.canvas.clientWidth - 50;


        let offset = total.toNumber("meters") % heightPer.toNumber("meters");

        x += offset / heightPer.toNumber("meters") * pixelsPer;
        total = math.subtract(total, math.unit(offset, "meters"));

        for (; x >= 50 - pixelsPer; x -= pixelsPer) {
            // negate it so that the left side is negative
            drawTick(ctx, x, 50, math.multiply(-1, total).format({ precision: 3 }));
            total = math.add(total, heightPer);
        }
    }

    function drawTick(/** @type {CanvasRenderingContext2D} */ ctx, x, y, label) {
        ctx.save()

        x = Math.round(x);
        y = Math.round(y);

        ctx.beginPath();
        ctx.moveTo(x, y);
        ctx.lineTo(x, y + 20);
        ctx.strokeStyle = "#000000";
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo(x, y + 20);
        ctx.lineTo(x, ctx.canvas.clientHeight - 70);
        ctx.strokeStyle = "#aaaaaa";
        ctx.stroke();

        ctx.beginPath();
        ctx.moveTo(x, ctx.canvas.clientHeight - 70);
        ctx.lineTo(x, ctx.canvas.clientHeight - 50);
        ctx.strokeStyle = "#000000";
        ctx.stroke();

        const oldFont = ctx.font;
        ctx.font = 'normal 24pt coda';
        ctx.fillStyle = "#dddddd";

        ctx.beginPath();
        ctx.fillText(label, x + 35, y + 20);

        ctx.restore()
    }
    const canvas = document.querySelector("#display");

    /** @type {CanvasRenderingContext2D} */

    const ctx = canvas.getContext("2d");

    let pixelsPer = (ctx.canvas.clientHeight - 100) / config.height.toNumber();

    heightPer = 1;

    if (pixelsPer < config.minLineSize * 2) {
        const factor = math.ceil(config.minLineSize * 2/ pixelsPer);
        heightPer *= factor;
        pixelsPer *= factor;
    }

    if (pixelsPer > config.maxLineSize * 2) {
        const factor = math.ceil(pixelsPer / 2/ config.maxLineSize);
        heightPer /= factor;
        pixelsPer /= factor;
    }

    if (heightPer == 0) {
        console.error("The world size is invalid! Refusing to draw the scale...");
        return;
    }
    heightPer = math.unit(heightPer, document.querySelector("#options-height-unit").value);
    

    ctx.beginPath();
    ctx.moveTo(0, 50);
    ctx.lineTo(ctx.canvas.clientWidth, 50);
    ctx.stroke();
    ctx.beginPath();
    ctx.moveTo(0,  ctx.canvas.clientHeight - 50);
    ctx.lineTo(ctx.canvas.clientWidth , ctx.canvas.clientHeight - 50);
    ctx.stroke();

    drawTicks(ctx, pixelsPer, heightPer);
}

// Entities are generated as needed, and we make a copy
// every time - the resulting objects get mutated, after all.
// But we also want to be able to read some information without 
// calling the constructor -- e.g. making a list of authors and
// owners. So, this function is used to generate that information.
// It is invoked like makeEntity so that it can be dropped in easily,
// but returns an object that lets you construct many copies of an  entity,
// rather than creating a new entity.
function createEntityMaker(info, views, sizes, forms) {
    const maker = {};

    maker.name = info.name;
    maker.info = info;
    maker.sizes = sizes;

    maker.constructor = () => makeEntity(info, views, sizes, forms);
    maker.authors = [];
    maker.owners = [];
    maker.nsfw = false;

    Object.values(views).forEach(view => {
        const authors = authorsOf(view.image.source);
        if (authors) {
            authors.forEach(author => {
                if (maker.authors.indexOf(author) == -1) {
                    maker.authors.push(author);
                }
            });
        }
        const owners = ownersOf(view.image.source);
        if (owners) {
            owners.forEach(owner => {
                if (maker.owners.indexOf(owner) == -1) {
                    maker.owners.push(owner);
                }
            });
        }

        if (isNsfw(view.image.source)) {
            maker.nsfw = true;
        }
    });

    return maker;
}

// This function serializes and parses its arguments to avoid sharing
// references to a common object. This allows for the objects to be 
// safely mutated.

function makeEntity(info, views, sizes, forms = {}) {
    const entityTemplate = {
        name: info.name,
        identifier: info.name,
        scale: 1,
        rotation: 0,
        info: JSON.parse(JSON.stringify(info)),
        views: JSON.parse(JSON.stringify(views), math.reviver),
        sizes: sizes === undefined ? [] : JSON.parse(JSON.stringify(sizes), math.reviver),
        forms: forms,
        init: function () {
            const entity = this;

            Object.entries(this.forms).forEach(([formKey, form]) => {
                if (form.default) {
                    this.defaultForm = formKey;
                }
            });

            Object.entries(this.views).forEach(([viewKey, view]) => {
                view.parent = this;
                if (this.defaultView === undefined) {
                    this.defaultView = viewKey;
                    this.view = viewKey;
                    this.form = view.form;
                }

                if (view.default) {
                    if (forms === {} || this.defaultForm === view.form) 
                    {
                        this.defaultView = viewKey;
                        this.view = viewKey;
                        this.form = view.form;
                    }
                }

                // to remember the units the user last picked

                view.units = {};

                if (config.autoMass !== "off" && view.attributes.weight === undefined) {
                    let base = undefined;
                    switch(config.autoMass) {
                        case "human":
                            baseMass = math.unit(150, "lbs")
                            baseHeight = math.unit(5.917, "feet")
                            break
                        case "quadruped at shoulder":
                            baseMass = math.unit(80, "lbs")
                            baseHeight = math.unit(30, "inches")
                            break
                    }

                    const ratio = math.divide(view.attributes.height.base, baseHeight)
                    view.attributes.weight = {
                        name: "Mass",
                        power: 3,
                        type: "mass",
                        base: math.multiply(baseMass, Math.pow(ratio, 3))
                    }
                }

                if (config.autoFoodIntake && view.attributes.weight !== undefined && view.attributes.energyNeed === undefined) {
                    view.attributes.energyIntake = {
                        name: "Food Intake",
                        power: 3,
                        type: "energy",
                        base: math.unit(2000 * view.attributes.weight.base.toNumber("lbs") / 150, "kcal")
                    }
                }

                if (config.autoCaloricValue && view.attributes.weight !== undefined && view.attributes.energyWorth === undefined) {
                    view.attributes.energyNeed = {
                        name: "Caloric Value",
                        power: 3,
                        type: "energy",
                        base: math.unit(860 * view.attributes.weight.base.toNumber("lbs"), "kcal")
                    }
                }

                if (config.autoPreyCapacity !== "none" && view.attributes.weight !== undefined && view.attributes.capacity === undefined) {
                    view.attributes.capacity = {
                        name: "Capacity",
                        power: 3,
                        type: "volume",
                        base: math.unit((config.autoPreyCapacity == "same-size" ? 1 : 0.05) * view.attributes.weight.base.toNumber("lbs") / 150, "people")
                    }
                }

                Object.entries(view.attributes).forEach(([key, val]) => {
                    Object.defineProperty(
                        view,
                        key,
                        {
                            get: function () {
                                return math.multiply(Math.pow(this.parent.scale, this.attributes[key].power), this.attributes[key].base);
                            },
                            set: function (value) {
                                const newScale = Math.pow(math.divide(value, this.attributes[key].base), 1 / this.attributes[key].power);
                                this.parent.scale = newScale;
                            }
                        }
                    );
                });
            });

            this.sizes.forEach(size => {
                if (size.default === true) {
                    if (Object.keys(forms).length > 0) {
                        if (this.defaultForm !== size.form) {
                            return;
                        }
                    }
                    this.views[this.defaultView].height = size.height;
                    this.size = size;
                }
            });

            if (this.size === undefined && this.sizes.length > 0) {
                this.views[this.defaultView].height = this.sizes[0].height;
                this.size = this.sizes[0];
                console.warn("No default size set for " + info.name);
            } else if (this.sizes.length == 0) {
                this.sizes = [
                    {
                        name: "Normal",
                        height: this.views[this.defaultView].height
                    }
                ];
                this.size = this.sizes[0];
            }

            this.desc = {};

            Object.entries(this.info).forEach(([key, value]) => {
                Object.defineProperty(
                    this.desc,
                    key,
                    {
                        get: function () {
                            let text = value.text;

                            if (entity.views[entity.view].info) {
                                if (entity.views[entity.view].info[key]) {
                                    text = combineInfo(text, entity.views[entity.view].info[key]);
                                }
                            }

                            if (entity.size.info) {
                                if (entity.size.info[key]) {
                                    text = combineInfo(text, entity.size.info[key]);
                                }
                            }

                            return { title: value.title, text: text };
                        }
                    }
                )
            });

            Object.defineProperty(
                this,
                "currentView",
                {
                    get: function() {
                        return entity.views[entity.view];
                    }
                }
            )

            this.formViews = {};
            this.formSizes = {}

            Object.entries(views).forEach(([key, value]) => {
                if (value.default) {
                    this.formViews[value.form] = key;
                }
            });

            Object.entries(views).forEach(([key, value]) => {
                if (this.formViews[value.form] === undefined) {
                    this.formViews[value.form] = key;
                }
            });

            this.sizes.forEach(size => {
                if (size.default) {
                    this.formSizes[size.form] = size;
                }
            })

            this.sizes.forEach(size => {
                if (this.formSizes[size.form] === undefined) {
                    this.formSizes[size.form] = size;
                }
            });

            Object.values(views).forEach(view => {
                if (this.formSizes[view.form] === undefined) {
                    this.formSizes[view.form] = { name: "Normal", height: view.attributes.height.base, default: true, form: view.form };
                }
            });


            delete this.init;
            return this;
        }
    }.init();

    return entityTemplate;
}

function combineInfo(existing, next) {
    switch (next.mode) {
        case "replace":
            return next.text;
        case "prepend":
            return next.text + existing;
        case "append":
            return existing + next.text;
    }

    return existing;
}

function clickDown(target, x, y) {
    clicked = target;
    movingInBounds = false;
    const rect = target.getBoundingClientRect();
    let entX = document.querySelector("#entities").getBoundingClientRect().x;
    let entY = document.querySelector("#entities").getBoundingClientRect().y;
    dragOffsetX = x - rect.left + entX;
    dragOffsetY = y - rect.top + entY;

    x = x - dragOffsetX;
    y = y - dragOffsetY;
    if (x >= 0 && x <= canvasWidth && y >= 0 && y <= canvasHeight) {
        movingInBounds = true;
    }


    clickTimeout = setTimeout(() => { dragging = true }, 200)
    target.classList.add("no-transition");
}

// could we make this actually detect the menu area?

function hoveringInDeleteArea(e) {
    return e.clientY < document.querySelector("#menubar").clientHeight;
}

function clickUp(e) {

    if (e.which != 1) {
        return;
    }

    clearTimeout(clickTimeout);

    if (clicked) {
        clicked.classList.remove("no-transition");
        if (dragging) {
            dragging = false;

            if (hoveringInDeleteArea(e)) {
                removeEntity(clicked);
                document.querySelector("#menubar").classList.remove("hover-delete");
            }
        } else {
            select(clicked);
        }
        clicked = null;
    }

}

function deselect(e) {
    if (rulerMode) {
        return;
    }
    if (e !== undefined && e.which != 1) {
        return;
    }

    if (selected) {
        selected.classList.remove("selected");
    }
    if (prevSelected) {
        prevSelected.classList.remove("prevSelected");
    }

    document.getElementById("options-selected-entity-none").selected = "selected";
    document.getElementById("delete-entity").style.display = "none";
    clearAttribution();

    selected = null;
    clearViewList();
    clearEntityOptions();
    clearViewOptions();

    document.querySelector("#delete-entity").disabled = true;

    document.querySelector("#grow").disabled = true;
    document.querySelector("#shrink").disabled = true;
    document.querySelector("#fit").disabled = true;
}

function select(target) {
    
    if (prevSelected !== null) {
        prevSelected.classList.remove("prevSelected");
    }

    prevSelected = selected;
    prevSelectedEntity = selectedEntity;
    deselect();
    selected = target;
    selectedEntity = entities[target.dataset.key];

    updateInfo();

    document.getElementById("options-selected-entity-" + target.dataset.key).selected = "selected";

    if (prevSelected !== null && config.showRatios && selected !== prevSelected) {
        prevSelected.classList.add("prevSelected");
    }
    selected.classList.add("selected");

    displayAttribution(selectedEntity.views[selectedEntity.view].image.source);

    configFormList(selectedEntity, selectedEntity.form);
    configViewList(selectedEntity, selectedEntity.view);
    configEntityOptions(selectedEntity, selectedEntity.view);
    configViewOptions(selectedEntity, selectedEntity.view);

    document.querySelector("#delete-entity").disabled = false;

    document.querySelector("#grow").disabled = false;
    document.querySelector("#shrink").disabled = false;
    document.querySelector("#fit").disabled = false;
}

function configFormList(entity, selectedForm) {
    const label = document.querySelector("#options-label-form");
    const list = document.querySelector("#entity-form");

    list.innerHTML = "";


    if (selectedForm === undefined) {
        label.style.display = "none";
        list.style.display = "none";
        return;
    }

    label.style.display = "block";
    list.style.display = "block";

    Object.keys(entity.forms).forEach(form => {
        const option = document.createElement("option");
        option.innerText = entity.forms[form].name;
        option.value = form;

        if (form === selectedForm) {
            option.selected = true;
        }
        
        list.appendChild(option);
    });
}

function configViewList(entity, selectedView) {
    const list = document.querySelector("#entity-view");

    list.innerHTML = "";

    list.style.display = "block";

    Object.keys(entity.views).forEach(view => {
        if (Object.keys(entity.forms).length > 0) {
            if (entity.views[view].form !== entity.form) {
                return;
            }
        }
        const option = document.createElement("option");
        option.innerText = entity.views[view].name;
        option.value = view;

        if (isNsfw(entity.views[view].image.source)) {
            option.classList.add("nsfw")
        }

        if (view === selectedView) {
            option.selected = true;

            if (option.classList.contains("nsfw")) {
                list.classList.add("nsfw");
            } else {
                list.classList.remove("nsfw");
            }
        }
        
        list.appendChild(option);
    });
}

function clearViewList() {
    const list = document.querySelector("#entity-view");

    list.innerHTML = "";
    list.style.display = "none";
}

function updateWorldOptions(entity, view) {
    const heightInput = document.querySelector("#options-height-value");
    const heightSelect = document.querySelector("#options-height-unit");

    const converted = config.height.toNumber(heightSelect.value);

    setNumericInput(heightInput, converted);
}

function configEntityOptions(entity, view) {
    const holder = document.querySelector("#options-entity");

    document.querySelector("#entity-category-header").style.display = "block";
    document.querySelector("#entity-category").style.display = "block";

    holder.innerHTML = "";

    const scaleLabel = document.createElement("div");
    scaleLabel.classList.add("options-label");
    scaleLabel.innerText = "Scale";

    const scaleRow = document.createElement("div");
    scaleRow.classList.add("options-row");

    const scaleInput = document.createElement("input");
    scaleInput.classList.add("options-field-numeric");
    scaleInput.id = "options-entity-scale";

    scaleInput.addEventListener("change", e => {
        try {
            const newScale = e.target.value == 0 ? 1 : math.evaluate(e.target.value); 
            if (typeof(newScale) !== "number") {
                toast("Invalid input: scale can't have any units!")
                return;
            }
            entity.scale = newScale;
        } catch {
            toast("Invalid input: could not parse " + e.target.value)
        }


        entity.dirty = true;
        if (config.autoFit) {
            fitWorld();
        } else {
            updateSizes(true);
        }
        updateEntityOptions(entity, entity.view);
        updateViewOptions(entity, entity.view);
    });

    scaleInput.addEventListener("keydown", e => {
        e.stopPropagation();
    })

    setNumericInput(scaleInput, entity.scale);

    scaleRow.appendChild(scaleInput);
    holder.appendChild(scaleLabel);
    holder.appendChild(scaleRow);

    const nameLabel = document.createElement("div");
    nameLabel.classList.add("options-label");
    nameLabel.innerText = "Name";

    const nameRow = document.createElement("div");
    nameRow.classList.add("options-row");

    const nameInput = document.createElement("input");
    nameInput.classList.add("options-field-text");
    nameInput.value = entity.name;

    nameInput.addEventListener("input", e => {
        entity.name = e.target.value;
        entity.dirty = true;
        updateSizes(true);
    })

    nameInput.addEventListener("keydown", e => {
        e.stopPropagation();
    })

    nameRow.appendChild(nameInput);

    holder.appendChild(nameLabel);
    holder.appendChild(nameRow);

    configSizeList(entity);

    document.querySelector("#options-order-display").innerText = entity.priority;
    document.querySelector("#options-brightness-display").innerText = entity.brightness;
    document.querySelector("#options-ordering").style.display = "flex";
}

function configSizeList(entity) {
    const defaultHolder = document.querySelector("#options-entity-defaults");

    defaultHolder.innerHTML = "";

    entity.sizes.forEach(defaultInfo => {
        if (Object.keys(entity.forms).length > 0) {
            if (defaultInfo.form !== entity.form) {
                return;
            }
        }
        const button = document.createElement("button");
        button.classList.add("options-button");

        button.innerText = defaultInfo.name;

        button.addEventListener("click", e => {
            if (Object.keys(entity.forms).length > 0) {
                entity.views[entity.formViews[entity.form]].height = defaultInfo.height;
            } else {
                entity.views[entity.defaultView].height = defaultInfo.height;
            }
            entity.dirty = true;
            updateEntityOptions(entity, entity.view);
            updateViewOptions(entity, entity.view);
            if (!checkFitWorld()) {
                updateSizes(true);
            }

            if (config.autoFitSize) {
                let targets = {};
                targets[selected.dataset.key] = entities[selected.dataset.key];
                fitEntities(targets);
            }

        });

        defaultHolder.appendChild(button);
    });
}

function updateEntityOptions(entity, view) {
    const scaleInput = document.querySelector("#options-entity-scale");
    setNumericInput(scaleInput, entity.scale);

    document.querySelector("#options-order-display").innerText = entity.priority;
    document.querySelector("#options-brightness-display").innerText = entity.brightness;
}

function clearEntityOptions() {
    document.querySelector("#entity-category-header").style.display = "none";
    document.querySelector("#entity-category").style.display = "none";
    /*
    const holder = document.querySelector("#options-entity");

    holder.innerHTML = "";

    document.querySelector("#options-entity-defaults").innerHTML = "";
    document.querySelector("#options-ordering").style.display = "none";
    document.querySelector("#options-ordering").style.display = "none";*/
}

function configViewOptions(entity, view) {
    const holder = document.querySelector("#options-view");

    document.querySelector("#view-category-header").style.display = "block";
    document.querySelector("#view-category").style.display = "block";

    holder.innerHTML = "";

    Object.entries(entity.views[view].attributes).forEach(([key, val]) => {
        const label = document.createElement("div");
        label.classList.add("options-label");
        label.innerText = val.name;

        holder.appendChild(label);

        const row = document.createElement("div");
        row.classList.add("options-row");

        holder.appendChild(row);

        const input = document.createElement("input");
        input.classList.add("options-field-numeric");
        input.id = "options-view-" + key + "-input";

        const select = document.createElement("select");
        select.classList.add("options-field-unit");
        select.id = "options-view-" + key + "-select"

        Object.entries(unitChoices[val.type]).forEach(([group, entries]) => {
            const optGroup = document.createElement("optgroup");
            optGroup.label = group;
            select.appendChild(optGroup);
            entries.forEach(entry => {
                const option = document.createElement("option");
                option.innerText = entry;
                if (entry == defaultUnits[val.type][config.units]) {
                    option.selected = true;
                }
                select.appendChild(option);
            })
        });


        input.addEventListener("change", e => {
            const raw_value = input.value == 0 ? 1 : input.value;
            let value
            try {
                value = math.evaluate(raw_value).toNumber(select.value);
            } catch {
                try {
                    value = math.evaluate(input.value)
                    if (typeof(value) !== "number") {
                        toast("Invalid input: " + value.format() + " can't convert to " + select.value)
                        value = undefined
                    }
                } catch {
                    toast("Invalid input: could not parse: " + input.value)
                    value = undefined
                }
            }
            if (value === undefined) {
                return;
            }
            input.value = value
            entity.views[view][key] = math.unit(value, select.value);
            entity.dirty = true;
            if (config.autoFit) {
                fitWorld();
            } else {
                updateSizes(true);
            }
            updateEntityOptions(entity, view);
            updateViewOptions(entity, view, key);
        });

        input.addEventListener("keydown", e => {
            e.stopPropagation();
        })

        if (entity.currentView.units[key]) {
            select.value = entity.currentView.units[key];
        } else {
            entity.currentView.units[key] = select.value;
        }

        select.dataset.oldUnit = select.value;

        setNumericInput(input, entity.views[view][key].toNumber(select.value));

        // TODO does this ever cause a change in the world?
        select.addEventListener("input", e => {
            const value = input.value == 0 ? 1 : input.value;
            const oldUnit = select.dataset.oldUnit;
            entity.views[entity.view][key] = math.unit(value, oldUnit).to(select.value);
            entity.dirty = true;
            setNumericInput(input, entity.views[entity.view][key].toNumber(select.value));

            select.dataset.oldUnit = select.value;
            entity.views[view].units[key] = select.value;

            if (config.autoFit) {
                fitWorld();
            } else {
                updateSizes(true);
            }

            updateEntityOptions(entity, view);
            updateViewOptions(entity, view, key);
        });

        row.appendChild(input);
        row.appendChild(select);
    });

}

function updateViewOptions(entity, view, changed) {
    Object.entries(entity.views[view].attributes).forEach(([key, val]) => {
        if (key != changed) {
            const input = document.querySelector("#options-view-" + key + "-input");
            const select = document.querySelector("#options-view-" + key + "-select");

            const currentUnit = select.value;
            const convertedAmount = entity.views[view][key].toNumber(currentUnit);
            setNumericInput(input, convertedAmount);
        }

    });
}

function setNumericInput(input, value, round = 6) {
    if (typeof value == "string") {
        value = parseFloat(value)
    }
    input.value = value.toPrecision(round);
}

function getSortedEntities() {
    return Object.keys(entities).sort((a, b) => {
        const entA = entities[a];
        const entB = entities[b];
        const viewA = entA.view;
        const viewB = entB.view;
        const heightA = entA.views[viewA].height.to("meter").value;
        const heightB = entB.views[viewB].height.to("meter").value;
        return heightA - heightB;
    });
}

function clearViewOptions() {
    document.querySelector("#view-category-header").style.display = "none";
    document.querySelector("#view-category").style.display = "none";
}

// this is a crime against humanity, and also stolen from
// stack overflow
// https://stackoverflow.com/questions/38487569/click-through-png-image-only-if-clicked-coordinate-is-transparent

const testCanvas = document.createElement("canvas");
testCanvas.id = "test-canvas";

function rotate(point, angle) {
    return [
        point[0] * Math.cos(angle) - point[1] * Math.sin(angle),
        point[0] * Math.sin(angle) + point[1] * Math.cos(angle)
    ];
}

const testCtx = testCanvas.getContext("2d");
function testClick(event) {

    testCtx.save();

    const target = event.target;
    if (rulerMode) {
        return;
    }

    // Get click coordinates

    let w = target.width;
    let h = target.height;
    let ratioW = 1, ratioH = 1;

    // Limit the size of the canvas so that very large images don't cause problems)
    if (w > 1000) {
        ratioW = w / 1000;
        w /= ratioW;
        h /= ratioW;
    }
    if (h > 1000) {
        ratioH = h / 1000;
        w /= ratioH;
        h /= ratioH;
    }

    // todo remove some of this unused stuff

    const ratio = ratioW * ratioH;
    const entity = entities[target.parentElement.dataset.key];

    const angle = entity.rotation;

    var x = event.clientX - target.getBoundingClientRect().x,
        y = event.clientY - target.getBoundingClientRect().y,
        alpha;

    [xTarget,yTarget] = [x,y];

    [actualW, actualH] = [target.getBoundingClientRect().width, target.getBoundingClientRect().height];

    xTarget /= ratio;
    yTarget /= ratio;

    actualW /= ratio;
    actualH /= ratio;

    testCtx.canvas.width = actualW;
    testCtx.canvas.height = actualH;

    testCtx.save();

    // dear future me: Sorry :(

    testCtx.resetTransform();



    testCtx.translate(actualW/2, actualH/2);
    testCtx.rotate(angle);
    testCtx.translate(-actualW/2, -actualH/2);
    testCtx.drawImage(target, (actualW/2 - w/2), (actualH/2 - h/2), w, h);
    testCtx.fillStyle = "red";
    testCtx.fillRect(actualW/2,actualH/2,10,10);

    testCtx.restore();

    testCtx.fillStyle = "red";
    alpha = testCtx.getImageData(xTarget, yTarget, 1, 1).data[3];
    testCtx.fillRect(xTarget, yTarget, 3, 3);

    // If the pixel is transparent,
    // retrieve the element underneath and trigger its click event
    if (alpha === 0) {
        const oldDisplay = target.style.display;
        target.style.display = "none";
        const newTarget = document.elementFromPoint(event.clientX, event.clientY);
        newTarget.dispatchEvent(new MouseEvent(event.type, {
            "clientX": event.clientX,
            "clientY": event.clientY
        }));
        target.style.display = oldDisplay;
    } else {
        clickDown(target.parentElement, event.clientX, event.clientY);
    }
    testCtx.restore();
}

function arrangeEntities(order) {
    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    let sum = 0;
    order.forEach(key => {
        const image = document.querySelector("#entity-" + key + " > .entity-image");
        const meters = entities[key].views[entities[key].view].height.toNumber("meters");

        let height = image.height;
        let width = image.width;

        if (height == 0) {
            height = 100;
        }
        if (width == 0) {
            width = height;
        }

        sum += meters * width / height;
    });

    let x = config.x - sum / 2;

    order.forEach(key => {

        const image = document.querySelector("#entity-" + key + " > .entity-image");
        const meters = entities[key].views[entities[key].view].height.toNumber("meters");

        let height = image.height;
        let width = image.width;

        if (height == 0) {
            height = 100;
        }
        if (width == 0) {
            width = height;
        }

        x += meters * width / height / 2;
        document.querySelector("#entity-" + key).dataset.x = x;
        document.querySelector("#entity-" + key).dataset.y = config.y;
        x += meters * width / height / 2;

    })

    fitWorld();
    updateSizes();
}

function removeAllEntities() {
    Object.keys(entities).forEach(key => {
        removeEntity(document.querySelector("#entity-" + key));
    });
}

function clearAttribution() {
    document.querySelector("#attribution-category-header").style.display = "none";
    document.querySelector("#options-attribution").style.display = "none";
}

function displayAttribution(file) {
    document.querySelector("#attribution-category-header").style.display = "block";
    document.querySelector("#options-attribution").style.display = "inline";
    const authors = authorsOfFull(file);
    const owners = ownersOfFull(file);
    const citations = citationsOf(file);
    const source = sourceOf(file);

    const authorHolder = document.querySelector("#options-attribution-authors");
    const ownerHolder = document.querySelector("#options-attribution-owners");
    const citationHolder = document.querySelector("#options-attribution-citations");
    const sourceHolder = document.querySelector("#options-attribution-source");

    if (authors === []) {
        const div = document.createElement("div");
        div.innerText = "Unknown";
        authorHolder.innerHTML = "";
        authorHolder.appendChild(div);
    } else if (authors === undefined) {
        const div = document.createElement("div");
        div.innerText = "Not yet entered";
        authorHolder.innerHTML = "";
        authorHolder.appendChild(div);
    } else {
        authorHolder.innerHTML = "";

        const list = document.createElement("ul");
        authorHolder.appendChild(list);
        authors.forEach(author => {
            const authorEntry = document.createElement("li");
            if (author.url) {
                const link = document.createElement("a");
                link.href = author.url;
                link.innerText = author.name;
                link.rel = "noreferrer no opener";
                link.target = "_blank";
                authorEntry.appendChild(link);
            } else {
                const div = document.createElement("div");
                div.innerText = author.name;
                authorEntry.appendChild(div);
            }
            list.appendChild(authorEntry);
        });

    }

    if (owners === []) {
        const div = document.createElement("div");
        div.innerText = "Unknown";
        ownerHolder.innerHTML = "";
        ownerHolder.appendChild(div);
    } else if (owners === undefined) {
        const div = document.createElement("div");
        div.innerText = "Not yet entered";
        ownerHolder.innerHTML = "";
        ownerHolder.appendChild(div);
    } else {
        ownerHolder.innerHTML = "";

        const list = document.createElement("ul");
        ownerHolder.appendChild(list);
        owners.forEach(owner => {
            const ownerEntry = document.createElement("li");
            if (owner.url) {
                const link = document.createElement("a");
                link.href = owner.url;
                link.innerText = owner.name;
                link.rel = "noreferrer no opener";
                link.target = "_blank";
                ownerEntry.appendChild(link);
            } else {
                const div = document.createElement("div");
                div.innerText = owner.name;
                ownerEntry.appendChild(div);
            }
            list.appendChild(ownerEntry);
        });

    }

    if (citations === [] || citations === undefined) {

    } else {
        citationHolder.innerHTML = "";

        const list = document.createElement("ul");
        citationHolder.appendChild(list);
        citations.forEach(citation => {
            const citationEntry = document.createElement("li");
            const link = document.createElement("a");
            link.style.display = "block";
            link.href = citation;
            link.innerText = new URL(citation).host;
            link.rel = "noreferrer no opener";
            link.target = "_blank";
            citationEntry.appendChild(link);
            list.appendChild(citationEntry);
        })
    }

    if (source === null) {
        const div = document.createElement("div");
        div.innerText = "No link";
        sourceHolder.innerHTML = "";
        sourceHolder.appendChild(div);
    } else if (source === undefined) {
        const div = document.createElement("div");
        div.innerText = "Not yet entered";
        sourceHolder.innerHTML = "";
        sourceHolder.appendChild(div);
    } else {
        sourceHolder.innerHTML = "";
        const link = document.createElement("a");
        link.style.display = "block";
        link.href = source;
        link.innerText = new URL(source).host;
        link.rel = "noreferrer no opener";
        link.target = "_blank";
        sourceHolder.appendChild(link);
    }
}

function removeEntity(element) {
    if (selected == element) {
        deselect();
    }
    if (clicked == element) {
        clicked = null;
    }

    const option = document.querySelector("#options-selected-entity-" + element.dataset.key);
    option.parentElement.removeChild(option);

    delete entities[element.dataset.key];
    const bottomName = document.querySelector("#bottom-name-" + element.dataset.key);
    const topName = document.querySelector("#top-name-" + element.dataset.key);
    bottomName.parentElement.removeChild(bottomName);
    topName.parentElement.removeChild(topName);
    element.parentElement.removeChild(element);

    selectedEntity = null;
    prevSelectedEntity = null;
    updateInfo();
}

function checkEntity(entity) {
    Object.values(entity.views).forEach(view => {
        if (authorsOf(view.image.source) === undefined) {
            console.warn("No authors: " + view.image.source);
        }
    });
}

function preloadViews(entity) {
    Object.values(entity.views).forEach(view => {
        if (Object.keys(entity.forms).length > 0) {
            if (entity.form !== view.form){
                return;
            }
        }
        if (!preloaded.has(view.image.source)) {
            let img = new Image();
            img.src = view.image.source;
            preloaded.add(view.image.source);
        }
    });
}

function displayEntity(entity, view, x, y, selectEntity = false, refresh = false) {
    checkEntity(entity);

    // preload all of the entity's views

    preloadViews(entity);

    const box = document.createElement("div");
    box.classList.add("entity-box");

    const img = document.createElement("img");
    img.classList.add("entity-image");
    img.addEventListener("dragstart", e => {
        e.preventDefault();
    });

    const nameTag = document.createElement("div");
    nameTag.classList.add("entity-name");
    nameTag.innerText = entity.name;
    box.appendChild(img);
    box.appendChild(nameTag);

    const image = entity.views[view].image;
    img.src = image.source;

    if (image.bottom !== undefined) {
        img.style.setProperty("--offset", ((-1 + image.bottom) * 100) + "%")
    } else {
        img.style.setProperty("--offset", ((-1) * 100) + "%")
    }

    img.style.setProperty("--rotation", (entity.rotation * 180 / Math.PI) + "deg")

    box.dataset.x = x;
    box.dataset.y = y;

    img.addEventListener("mousedown", e => { if (e.which == 1) { testClick(e); if (clicked) { e.stopPropagation() } } });
    img.addEventListener("touchstart", e => {
        const fakeEvent = {
            target: e.target,
            clientX: e.touches[0].clientX,
            clientY: e.touches[0].clientY,
            which:  1
        };
        testClick(fakeEvent);
        if (clicked) { e.stopPropagation() }
    });

    const heightBar = document.createElement("div");
    heightBar.classList.add("height-bar");

    box.appendChild(heightBar);

    box.id = "entity-" + entityIndex;
    box.dataset.key = entityIndex;
    entity.view = view;

    if (entity.priority === undefined)
        entity.priority = 0;
    if (entity.brightness === undefined)
        entity.brightness = 1;

    entities[entityIndex] = entity;
    entity.index = entityIndex;

    const world = document.querySelector("#entities");
    world.appendChild(box);

    const bottomName = document.createElement("div");
    bottomName.classList.add("bottom-name");
    bottomName.id = "bottom-name-" + entityIndex;
    bottomName.innerText = entity.name;

    bottomName.addEventListener("click", () => select(box));

    world.appendChild(bottomName);

    const topName = document.createElement("div");
    topName.classList.add("top-name");
    topName.id = "top-name-" + entityIndex;
    topName.innerText = entity.name;

    topName.addEventListener("click", () => select(box));

    world.appendChild(topName);

    const entityOption = document.createElement("option");
    entityOption.id = "options-selected-entity-" + entityIndex;
    entityOption.value = entityIndex;
    entityOption.innerText = entity.name;

    document.getElementById("options-selected-entity").appendChild(entityOption);
    entityIndex += 1;
    if (config.autoFit) {
        fitWorld();
    }

    if (selectEntity)
        select(box);

    entity.dirty = true;

    if (refresh && config.autoFitAdd) {
        let targets = {};
        targets[entityIndex - 1] = entity;
        fitEntities(targets);
    }
    if (refresh)
        updateSizes(true);
}


window.onblur = function () {
    altHeld = false;
    shiftHeld = false;
}

window.onfocus = function () {
    window.dispatchEvent(new Event("keydown"));
}

// thanks to https://developers.google.com/web/fundamentals/native-hardware/fullscreen

function toggleFullScreen() {
    var doc = window.document;
    var docEl = doc.documentElement;

    var requestFullScreen = docEl.requestFullscreen || docEl.mozRequestFullScreen || docEl.webkitRequestFullScreen || docEl.msRequestFullscreen;
    var cancelFullScreen = doc.exitFullscreen || doc.mozCancelFullScreen || doc.webkitExitFullscreen || doc.msExitFullscreen;

    if (!doc.fullscreenElement && !doc.mozFullScreenElement && !doc.webkitFullscreenElement && !doc.msFullscreenElement) {
        requestFullScreen.call(docEl);
    }
    else {
        cancelFullScreen.call(doc);
    }
}

function handleResize() {
    const oldCanvasWidth = canvasWidth;
    entityX = document.querySelector("#entities").getBoundingClientRect().x;
    canvasWidth = document.querySelector("#display").clientWidth - 100;
    canvasHeight = document.querySelector("#display").clientHeight - 50;

    const change = oldCanvasWidth / canvasWidth;

    updateSizes();
}

function prepareSidebar() {
    const menubar = document.querySelector("#sidebar-menu");

    [
        {
            name: "Show/hide sidebar",
            id: "menu-toggle-sidebar",
            icon: "fas fa-chevron-circle-down",
            rotates: true
        },
        {
            name: "Fullscreen",
            id: "menu-fullscreen",
            icon: "fas fa-compress"
        },
        {
            name: "Clear",
            id: "menu-clear",
            icon: "fas fa-file"
        },
        {
            name: "Sort by height",
            id: "menu-order-height",
            icon: "fas fa-sort-numeric-up"
        },
        {
            name: "Permalink",
            id: "menu-permalink",
            icon: "fas fa-link"
        },
        {
            name: "Export to clipboard",
            id: "menu-export",
            icon: "fas fa-share"
        },
        {
            name: "Import from clipboard",
            id: "menu-import",
            icon: "fas fa-share",
            classes: ["flipped"]
        },
        {
            name: "Save Scene",
            id: "menu-save",
            icon: "fas fa-download",
            input: true
        },
        {
            name: "Load Scene",
            id: "menu-load",
            icon: "fas fa-upload",
            select: true
        },
        {
            name: "Delete Scene",
            id: "menu-delete",
            icon: "fas fa-trash",
            select: true
        },
        {
            name: "Load Autosave",
            id: "menu-load-autosave",
            icon: "fas fa-redo"
        },
        {
            name: "Load Preset",
            id: "menu-preset",
            icon: "fas fa-play",
            select: true
        },
        {
            name: "Add Image",
            id: "menu-add-image",
            icon: "fas fa-camera"
        },
        {
            name: "Clear Rulers",
            id: "menu-clear-rulers",
            icon: "fas fa-ruler"
        }
    ].forEach(entry => {
        const buttonHolder = document.createElement("div");
        buttonHolder.classList.add("menu-button-holder");
        const button = document.createElement("button");
        button.id = entry.id;
        button.classList.add("menu-button");
        const icon = document.createElement("i");
        icon.classList.add(...entry.icon.split(" "));

        if (entry.rotates) {
            icon.classList.add("rotate-backward", "transitions");
        }

        if (entry.classes) {
            entry.classes.forEach(cls => icon.classList.add(cls));
        }

        const actionText = document.createElement("span");
        actionText.innerText = entry.name;
        actionText.classList.add("menu-text");

        const srText = document.createElement("span");
        srText.classList.add("sr-only");
        srText.innerText = entry.name;

        button.appendChild(icon);
        button.appendChild(srText);

        buttonHolder.appendChild(button);
        buttonHolder.appendChild(actionText);

        if (entry.input) {
            const input = document.createElement("input");
            buttonHolder.appendChild(input);
            input.placeholder = "default";
            input.addEventListener("keyup", e => {
                if (e.key === "Enter") {
                    const name = document.querySelector("#menu-save ~ input").value;
                    if (/\S/.test(name)) {
                        saveScene(name);
                    }
                    updateSaveInfo();
                    e.preventDefault();
                }
            })
        }

        if (entry.select) {
            const select = document.createElement("select");
            buttonHolder.appendChild(select);
        }

        menubar.appendChild(buttonHolder);
    });
}

function checkBodyClass(cls) {
    return document.body.classList.contains(cls);
}

function toggleBodyClass(cls, setting) {
    if (setting) {
        document.body.classList.add(cls);
    } else {
        document.body.classList.remove(cls);
    }
}

const backgroundColors = {
    "none": "#00000000",
    "black": "#000",
    "dark": "#111",
    "medium": "#333",
    "light": "#555"
}

const settingsData = {
    "show-vertical-scale": {
        name: "Vertical Scale",
        desc: "Draw vertical scale marks",
        type: "toggle",
        default: true,
        get value() {
            return config.drawYAxis;
        },
        set value(param) {
            config.drawYAxis = param;
            drawScales(false);
        }
    },
    "show-horizontal-scale": {
        name: "Horiziontal Scale",
        desc: "Draw horizontal scale marks",
        type: "toggle",
        default: false,
        get value() {
            return config.drawXAxis;
        },
        set value(param) {
            config.drawXAxis = param;
            drawScales(false);
        }
    },
    "show-altitudes": {
        name: "Altitudes",
        desc: "Draw interesting altitudes",
        type: "select",
        default: "none",
        disabled: "none",
        options: [
            "none",
            "all",
            "atmosphere",
            "orbits",
            "weather",
            "water",
            "geology",
            "thicknesses",
            "airspaces",
            "races",
            "olympic-records",
        ],
        get value() {
            return config.drawAltitudes;
        },
        set value(param) {
            config.drawAltitudes = param;
            drawScales(false);
        }
    },
    "lock-y-axis": {
        name: "Lock Y-Axis",
        desc: "Keep the camera at ground-level",
        type: "toggle",
        default: true,
        get value() {
            return config.lockYAxis;
        },
        set value(param) {
            config.lockYAxis = param;
            if (param) {
                config.y = 0;
                updateSizes();
                document.querySelector("#scroll-up").disabled = true;
                document.querySelector("#scroll-down").disabled = true;
            } else {
                document.querySelector("#scroll-up").disabled = false;
                document.querySelector("#scroll-down").disabled = false;
            }
        }
    },
    "axis-spacing": {
        name: "Axis Spacing",
        desc: "How frequent the axis lines are",
        type: "select",
        default: "standard",
        options: [
            "dense",
            "standard",
            "sparse"
        ],
        get value() {
            return config.axisSpacing;
        },
        set value(param) {
            config.axisSpacing = param;
            const factor = {
                "dense": 0.5,
                "standard": 1,
                "sparse": 2
            }[param];
            config.minLineSize = factor * 100;
            config.maxLineSize = factor * 150;
            updateSizes();
        }
    },
    "ground-type": {
        name: "Ground",
        desc: "What kind of ground to show, if any",
        type: "select",
        default: "black",
        disabled: "none",
        options: [
            "none",
            "black",
            "dark",
            "medium",
            "light",
        ],
        get value() {
            return config.groundKind;
        },
        set value(param) {
            config.groundKind = param;
            document.querySelector("#ground").style.setProperty("--ground-color", backgroundColors[param])
        }
    },
    "ground-pos": {
        name: "Ground Position",
        desc: "How high the ground is if the y-axis is locked",
        type: "select",
        default: "bottom",
        options: [
            "very-high",
            "high",
            "medium",
            "low",
            "very-low",
            "bottom",
        ],
        get value() {
            return config.groundPos;
        },
        set value(param) {
            config.groundPos = param;
            updateSizes();
        }
    },
    "background-brightness": {
        name: "Background Color",
        desc: "How bright the background is",
        type: "select",
        default: "medium",
        options: [
            "black",
            "dark",
            "medium",
            "light",
        ],
        get value() {
            return config.background;
        },
        set value(param) {
            config.background = param;
            drawScales();
        }
    },
    "auto-scale": {
        name: "Auto-Size World",
        desc: "Constantly zoom to fit the largest entity",
        type: "toggle",
        default: false,
        get value() {
            return config.autoFit;
        },
        set value(param) {
            config.autoFit = param;
            checkFitWorld();
        }
    },
    "auto-units": {
        name: "Auto-Select Units",
        desc: "Automatically switch units when zooming in and out",
        type: "toggle",
        default: false,
        get value() {
            return config.autoUnits;
        },
        set value(param) {
            config.autoUnits = param;
        }
    },
    "zoom-when-adding": {
        name: "Zoom On Add",
        desc: "Zoom to fit when you add a new entity",
        type: "toggle",
        default: true,
        get value() {
            return config.autoFitAdd;
        },
        set value(param) {
            config.autoFitAdd = param;
        }
    },
    "zoom-when-sizing": {
        name: "Zoom On Size",
        desc: "Zoom to fit when you select an entity's size",
        type: "toggle",
        default: false,
        get value() {
            return config.autoFitSize;
        },
        set value(param) {
            config.autoFitSize = param;
        }
    },
    "show-ratios": {
        name: "Show Ratios",
        desc: "Show the proportions between the current selection and the most recent selection.",
        type: "toggle",
        default: false,
        get value() {
            return config.showRatios;
        },
        set value(param) {
            config.showRatios = param;
            updateInfo();
        }
    },
    "show-horizon": {
        name: "Show Horizon",
        desc: "Show how far the horizon would be for the selected character",
        type: "toggle",
        default: false,
        get value() {
            return config.showHorizon;
        },
        set value(param) {
            config.showHorizon = param;
            updateInfo();
        }
    },
    "attach-rulers": {
        name: "Attach Rulers",
        desc: "Rulers will attach to the currently-selected entity, moving around with it.",
        type: "toggle",
        default: true,
        get value() {
            return config.rulersStick;
        },
        set value(param) {
            config.rulersStick = param;
        }
    },
    "units": {
        name: "Default Units",
        desc: "Which kind of unit to use by default",
        type: "select",
        default: "metric",
        options: [
            "metric",
            "customary",
            "relative",
            "quirky"
        ],
        get value() {
            return config.units;
        },
        set value(param) {
            config.units = param;
            updateSizes();
        }
    },
    "names": {
        name: "Show Names",
        desc: "Display names over entities",
        type: "toggle",
        default: true,
        get value() {
            return checkBodyClass("toggle-entity-name");
        },
        set value(param) {
            toggleBodyClass("toggle-entity-name", param);
        }
    },
    "bottom-names": {
        name: "Bottom Names",
        desc: "Display names at the bottom",
        type: "toggle",
        default: false,
        get value() {
            return checkBodyClass("toggle-bottom-name");
        },
        set value(param) {
            toggleBodyClass("toggle-bottom-name", param);
        }
    },
    "top-names": {
        name: "Show Arrows",
        desc: "Point to entities that are much larger than the current view",
        type: "toggle",
        default: false,
        get value() {
            return checkBodyClass("toggle-top-name");
        },
        set value(param) {
            toggleBodyClass("toggle-top-name", param);
        }
    },
    "height-bars": {
        name: "Height Bars",
        desc: "Draw dashed lines to the top of each entity",
        type: "toggle",
        default: false,
        get value() {
            return checkBodyClass("toggle-height-bars");
        },
        set value(param) {
            toggleBodyClass("toggle-height-bars", param);
        }
    },
    "flag-nsfw": {
        name: "Flag NSFW",
        desc: "Highlight NSFW things in red",
        type: "toggle",
        default: false,
        get value() {
            return checkBodyClass("flag-nsfw");
        },
        set value(param) {
            toggleBodyClass("flag-nsfw", param);
        }
    },
    "glowing-entities": {
        name: "Glowing Edges",
        desc: "Makes all entities glow",
        type: "toggle",
        default: false,
        get value() {
            return checkBodyClass("toggle-entity-glow");
        },
        set value(param) {
            toggleBodyClass("toggle-entity-glow", param);
        }
    },
    "smoothing": {
        name: "Smoothing",
        desc: "Smooth out movements and size changes. Disable for better performance.",
        type: "toggle",
        default: true,
        get value() {
            return checkBodyClass("smoothing");
        },
        set value(param) {
            toggleBodyClass("smoothing", param);
        }
    },
    "auto-mass": {
        name: "Estimate Mass",
        desc: "Guess the mass of things that don't have one specified using the selected body type",
        type: "select",
        default: "off",
        disabled: "off",
        options: [
            "off",
            "human",
            "quadruped at shoulder",
        ],
        get value() {
            return config.autoMass
        },
        set value(param) {
            config.autoMass = param
        }
    },
    "auto-food-intake": {
        name: "Estimate Food Intake",
        desc: "Guess how much food creatures need, based on their mass -- 2000kcal per 150lbs",
        type: "toggle",
        default: false,
        get value() {
            return config.autoFoodIntake
        },
        set value(param) {
            config.autoFoodIntake = param
        }
    },
    "auto-caloric-value": {
        name: "Estimate Caloric Value",
        desc: "Guess how much food a creature is worth -- 860kcal per pound",
        type: "toggle",
        default: false,
        get value() {
            return config.autoCaloricValue
        },
        set value(param) {
            config.autoCaloricValue = param
        }
    },
    "auto-prey-capacity": {
        name: "Estimate Prey Capacity",
        desc: "Guess how much prey creatures can hold, based on their mass",
        type: "select",
        default: "none",
        options: [
            "none",
            "realistic",
            "same-size"
        ],
        get value() {
            return config.autoPreyCapacity;
        },
        set value(param) {
            config.autoPreyCapacity = param;
        }
    },
}

function prepareSettings(userSettings) {
    const menubar = document.querySelector("#settings-menu");

    Object.entries(settingsData).forEach(([id, entry]) => {
        const holder = document.createElement("label");
        holder.classList.add("settings-holder");
        
        const input = document.createElement("input");
        input.id = "setting-" + id;
        
        const vertical = document.createElement("div");
        vertical.classList.add("settings-vertical");
        
        const name = document.createElement("label");
        name.innerText = entry.name;
        name.classList.add("settings-name");
        name.setAttribute("for", input.id);

        const desc = document.createElement("label");
        desc.innerText = entry.desc;
        desc.classList.add("settings-desc");
        desc.setAttribute("for", input.id);

        if (entry.type == "toggle") {
            input.type = "checkbox";

            input.checked = userSettings[id] === undefined ? entry.default : userSettings[id];
            
            holder.setAttribute("for", input.id);

            vertical.appendChild(name);
            vertical.appendChild(desc);
            holder.appendChild(vertical);
            holder.appendChild(input);
            menubar.appendChild(holder);

            const update = () => {
                if (input.checked) {
                    holder.classList.add("enabled");
                    holder.classList.remove("disabled");
                } else {
                    holder.classList.remove("enabled");
                    holder.classList.add("disabled");
                }
                
                entry.value = input.checked;
            }
            
            update();

            input.addEventListener("change", update);
        } else if (entry.type == "select") {
            // we don't use the input element we made!

            const select = document.createElement("select");
            select.id = "setting-" + id;

            entry.options.forEach(choice => {
                const option = document.createElement("option");
                option.innerText = choice;
                select.appendChild(option);
            })

            select.value = userSettings[id] === undefined ? entry.default : userSettings[id];

            vertical.appendChild(name);
            vertical.appendChild(desc);
            holder.appendChild(vertical);
            holder.appendChild(select);
            menubar.appendChild(holder);

            const update = () => {
                entry.value = select.value;

                if (entry.disabled !== undefined && entry.value !== entry.disabled) {
                    holder.classList.add("enabled");
                    holder.classList.remove("disabled");
                } else {
                    holder.classList.remove("enabled");
                    holder.classList.add("disabled");
                }
            }

            update();

            select.addEventListener("change", update);
        }
    })
}

function prepareMenu() {
    prepareSidebar();
    updateSaveInfo();

    if (checkHelpDate()) {
        document.querySelector("#open-help").classList.add("highlighted");
    }
}

function updateSaveInfo() {
    const saves = getSaves();
    const load = document.querySelector("#menu-load ~ select");
    load.innerHTML = "";
    saves.forEach(save => {
        const option = document.createElement("option");
        option.innerText = save;
        option.value = save;
        load.appendChild(option);
    });
    
    const del = document.querySelector("#menu-delete ~ select");
    del.innerHTML = "";
    saves.forEach(save => {
        const option = document.createElement("option");
        option.innerText = save;
        option.value = save;
        del.appendChild(option);
    });
}

function getSaves() {
    try {
        const results = [];
        Object.keys(localStorage).forEach(key => {
            if (key.startsWith("macrovision-save-")) {
                results.push(key.replace("macrovision-save-", ""));
            }
        })
        return results;
    } catch (err) {
        alert("Something went wrong while loading (maybe you didn't have anything saved. Check the F12 console for the error.")
        console.error(err);
        return false;
    }
}
function getUserSettings() {
    try {
        const settings = JSON.parse(localStorage.getItem("settings"));
        return settings === null ? {} : settings;
    } catch {
        return {};
    }
}

function exportUserSettings() {
    const settings = {};
    Object.entries(settingsData).forEach(([id, entry]) => {
        settings[id] = entry.value;
    });

    return settings;
}

function setUserSettings(settings) {
    try {
        localStorage.setItem("settings", JSON.stringify(settings));
    } catch {
        // :(
    }
}
const lastHelpChange = 1601955834693;

function checkHelpDate() {
    // disabling this for now
    return false;
    try {
        const old = localStorage.getItem("help-viewed");

        if (old === null || old < lastHelpChange) {
            return true;
        }

        return false;
    } catch {
        console.warn("Could not set the help-viewed date");
        return false;
    }
}

function setHelpDate() {
    try {
        localStorage.setItem("help-viewed", Date.now());
    } catch {
        console.warn("Could not set the help-viewed date");
    }
}

function doYScroll() {
    const worldHeight = config.height.toNumber("meters");
    config.y += scrollDirection * worldHeight / 180;
    updateSizes();
    scrollDirection *= 1.05;
}
function doXScroll() {
    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    config.x += scrollDirection * worldWidth / 180 ;
    updateSizes();
    scrollDirection *= 1.05;
}

function doZoom() {
    const oldHeight = config.height;

    setWorldHeight(oldHeight, math.multiply(oldHeight, 1 + zoomDirection / 10));
    zoomDirection *= 1.05;
}

function doSize() {
    if (selected) {
        const entity = entities[selected.dataset.key];
        const oldHeight = entity.views[entity.view].height;
        entity.views[entity.view].height = math.multiply(oldHeight, sizeDirection < 0 ? -1/sizeDirection : sizeDirection);
        entity.dirty = true;
        updateEntityOptions(entity, entity.view);
        updateViewOptions(entity, entity.view);
        updateSizes(true);
        sizeDirection *= 1.01;

        const ownHeight = entity.views[entity.view].height.toNumber("meters");
        let extra = entity.views[entity.view].image.extra;
        extra = extra === undefined ? 1 : extra;
        const worldHeight = config.height.toNumber("meters");

        if (ownHeight * extra > worldHeight) {
            setWorldHeight(config.height, math.multiply(entity.views[entity.view].height, extra));
        } else if (ownHeight * extra * 10 < worldHeight) {
            setWorldHeight(config.height, math.multiply(entity.views[entity.view].height, extra * 10));
        }
    }
}

function selectNewUnit() {
    const unitSelector = document.querySelector("#options-height-unit");
    checkFitWorld();
    const scaleInput = document.querySelector("#options-height-value");
    const newVal = math.unit(scaleInput.value, unitSelector.dataset.oldUnit).toNumber(unitSelector.value);
    setNumericInput(scaleInput, newVal);
    updateWorldHeight();
    unitSelector.dataset.oldUnit = unitSelector.value;
}

// given a world position, return the position relative to the entity at normal scale
function entityRelativePosition(pos, entityElement) {
    const entity = entities[entityElement.dataset.key]
    const x = parseFloat(entityElement.dataset.x)
    const y = parseFloat(entityElement.dataset.y)

    pos.x -= x
    pos.y -= y

    pos.x /= entity.scale
    pos.y /= entity.scale

    return pos
}

document.addEventListener("DOMContentLoaded", () => {
    prepareMenu();
    prepareEntities();

    document.querySelector("#open-help").addEventListener("click", e => {
        setHelpDate();
        document.querySelector("#open-help").classList.remove("highlighted");
        window.open("https://www.notion.so/Macrovision-5c7f9377424743358ddf6db5671f439e", "_blank");
    });

    document.querySelector("#copy-screenshot").addEventListener("click", e => {
        copyScreenshot();
    });

    document.querySelector("#save-screenshot").addEventListener("click", e => {
        saveScreenshot();
    });

    document.querySelector("#open-screenshot").addEventListener("click", e => {
        openScreenshot();
    });
    
    document.querySelector("#toggle-menu").addEventListener("click", e => {
        const popoutMenu = document.querySelector("#sidebar-menu");
        if (popoutMenu.classList.contains("visible")) {
            popoutMenu.classList.remove("visible");
        } else {
            document.querySelectorAll(".popout-menu").forEach(menu => menu.classList.remove("visible"));
            const rect = e.target.getBoundingClientRect();
            popoutMenu.classList.add("visible");

            popoutMenu.style.left = rect.x + rect.width + 10 + "px";
            popoutMenu.style.top = rect.y + rect.height + 10 + "px";

            let menuWidth = popoutMenu.getBoundingClientRect().width;
            let screenWidth = window.innerWidth;

            if (menuWidth * 1.5 > screenWidth) {
                popoutMenu.style.left = 25 + "px";
            }
        }
        e.stopPropagation();
    });

    document.querySelector("#sidebar-menu").addEventListener("click", e => {
        e.stopPropagation();
    });

    document.addEventListener("click", e => {
        document.querySelector("#sidebar-menu").classList.remove("visible");
    });


    document.querySelector("#toggle-settings").addEventListener("click", e => {
        const popoutMenu = document.querySelector("#settings-menu");
        if (popoutMenu.classList.contains("visible")) {
            popoutMenu.classList.remove("visible");
        } else {
            document.querySelectorAll(".popout-menu").forEach(menu => menu.classList.remove("visible"));
            const rect = e.target.getBoundingClientRect();
            popoutMenu.classList.add("visible");
            popoutMenu.style.left = rect.x + rect.width + 10 + "px";
            popoutMenu.style.top = rect.y + rect.height + 10 + "px";
            
            let menuWidth = popoutMenu.getBoundingClientRect().width;
            let screenWidth = window.innerWidth;

            if (menuWidth * 1.5 > screenWidth) {
                popoutMenu.style.left = 25 + "px";
            }
        }
        e.stopPropagation();
    });

    document.querySelector("#settings-menu").addEventListener("click", e => {
        e.stopPropagation();
    });

    document.addEventListener("click", e => {
        document.querySelector("#settings-menu").classList.remove("visible");
    });



    window.addEventListener("unload", () => {
        saveScene("autosave");
        setUserSettings(exportUserSettings());
    });

    document.querySelector("#options-selected-entity").addEventListener("input", e => {
        if (e.target.value == "None") {
            deselect()
        } else {
            select(document.querySelector("#entity-" + e.target.value));
        }

    });

    document.querySelector("#menu-toggle-sidebar").addEventListener("click", e => {
        const sidebar = document.querySelector("#options");
        if (sidebar.classList.contains("hidden")) {
            sidebar.classList.remove("hidden");
            e.target.classList.remove("rotate-forward");
            e.target.classList.add("rotate-backward");
        } else {
            sidebar.classList.add("hidden");
            e.target.classList.add("rotate-forward");
            e.target.classList.remove("rotate-backward");
        }
        handleResize();
    });

    document.querySelector("#menu-fullscreen").addEventListener("click", toggleFullScreen);

    document.querySelector("#options-order-forward").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].priority += 1;
        }
        document.querySelector("#options-order-display").innerText = entities[selected.dataset.key].priority;
        updateSizes();
    });

    document.querySelector("#options-order-back").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].priority -= 1;
        }
        document.querySelector("#options-order-display").innerText = entities[selected.dataset.key].priority;
        updateSizes();
    });

    document.querySelector("#options-brightness-up").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].brightness += 1;
        }
        document.querySelector("#options-brightness-display").innerText = entities[selected.dataset.key].brightness;
        updateSizes();
    });

    document.querySelector("#options-brightness-down").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].brightness -= 1;
        }
        document.querySelector("#options-brightness-display").innerText = entities[selected.dataset.key].brightness;
        updateSizes();
    });

    document.querySelector("#options-rotate-left").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].rotation -= Math.PI/4;
        }
        selected.querySelector("img").style.setProperty("--rotation",  (entities[selected.dataset.key].rotation * 180 / Math.PI) + "deg")
        updateSizes();
    });

    document.querySelector("#options-rotate-right").addEventListener("click", e => {
        if (selected) {
            entities[selected.dataset.key].rotation += Math.PI/4;
        }
        selected.querySelector("img").style.setProperty("--rotation",  (entities[selected.dataset.key].rotation * 180 / Math.PI) + "deg")
        updateSizes();
    });

    document.querySelector("#options-flip").addEventListener("click", e => {
        if (selected) {
            selected.querySelector(".entity-image").classList.toggle("flipped");
        }
        document.querySelector("#options-brightness-display").innerText = entities[selected.dataset.key].brightness;
        updateSizes();
    });

    const sceneChoices = document.querySelector("#menu-preset ~ select");

    Object.entries(scenes).forEach(([id, scene]) => {
        const option = document.createElement("option");
        option.innerText = id;
        option.value = id;
        sceneChoices.appendChild(option);
    });

    document.querySelector("#menu-preset").addEventListener("click", e => {
        const chosen = sceneChoices.value;
        removeAllEntities();
        scenes[chosen]();
    });

    entityX = document.querySelector("#entities").getBoundingClientRect().x;
    canvasWidth = document.querySelector("#display").clientWidth - 100;
    canvasHeight = document.querySelector("#display").clientHeight - 50;

    document.querySelector("#options-height-value").addEventListener("change", e => {
        updateWorldHeight();
    })

    document.querySelector("#options-height-value").addEventListener("keydown", e => {
        e.stopPropagation();
    })

    const unitSelector = document.querySelector("#options-height-unit");

    Object.entries(unitChoices.length).forEach(([group, entries]) => {
        const optGroup = document.createElement("optgroup");
        optGroup.label = group;
        unitSelector.appendChild(optGroup);

        entries.forEach(entry => {
            const option = document.createElement("option");
            option.innerText = entry;

            // we haven't loaded user settings yet, so we can't choose the unit just yet

            unitSelector.appendChild(option);
        })

    });

    unitSelector.addEventListener("input", selectNewUnit);

    param = window.location.hash;

    // we now use the fragment for links, but we should still support old stuff:

    if (param.length > 0) {
        param = param.substring(1);
    } else {
        param = new URL(window.location.href).searchParams.get("scene");
    }

    document.querySelector("#world").addEventListener("mousedown", e => {
        // only middle mouse clicks
        if (e.which == 2) {
            panning = true;
            panOffsetX = e.clientX;
            panOffsetY = e.clientY;

            Object.keys(entities).forEach(key => {
                document.querySelector("#entity-" + key).classList.add("no-transition");
            });
        }
    });

    document.addEventListener("mouseup", e => {
        if (e.which == 2) {
            panning = false;
            Object.keys(entities).forEach(key => {
                document.querySelector("#entity-" + key).classList.remove("no-transition");
            });
        }
    });

    document.querySelector("#world").addEventListener("touchstart", e => {
        if (!rulerMode) {
            panning = true;
            panOffsetX = e.touches[0].clientX;
            panOffsetY = e.touches[0].clientY;
            e.preventDefault();
            Object.keys(entities).forEach(key => {
                document.querySelector("#entity-" + key).classList.add("no-transition");
            });
        }
    });

    document.querySelector("#world").addEventListener("touchend", e => {
        panning = false;
        Object.keys(entities).forEach(key => {
            document.querySelector("#entity-" + key).classList.remove("no-transition");
        });
    });
    document.querySelector("#world").addEventListener("mousedown", e => {
        // only left mouse clicks
        if (e.which == 1 && rulerMode) {
            let entX = document.querySelector("#entities").getBoundingClientRect().x;
            let entY = document.querySelector("#entities").getBoundingClientRect().y;
            let pos = pix2pos({ x: e.clientX - entX, y: e.clientY - entY });

            if (config.rulersStick && selected) {
                pos = entityRelativePosition(pos, selected)
            }
            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y, entityKey: null };

            if (config.rulersStick && selected) {
                currentRuler.entityKey = selected.dataset.key
            }
        }
    });
    document.querySelector("#world").addEventListener("mouseup", e => {
        // only left mouse clicks
        if (e.which == 1 && currentRuler) {
            rulers.push(currentRuler);
            currentRuler = null;
            rulerMode = false;
        }
    });

    document.querySelector("#world").addEventListener("touchstart", e => {
        if (rulerMode) {
            let entX = document.querySelector("#entities").getBoundingClientRect().x;
            let entY = document.querySelector("#entities").getBoundingClientRect().y;
            let pos = pix2pos({ x: e.touches[0].clientX - entX, y: e.touches[0].clientY - entY });

            if (config.rulersStick && selected) {
                pos = entityRelativePosition(pos, selected)
            }
            currentRuler = { x0: pos.x, y0: pos.y, x1: pos.y, y1: pos.y, entityKey: null };
            if (config.rulersStick && selected) {
                currentRuler.entityKey = selected.dataset.key
            }
        }
    });
    document.querySelector("#world").addEventListener("touchend", e => {
        if (currentRuler) {
            rulers.push(currentRuler);
            currentRuler = null;
            rulerMode = false;
        }
    });

    document.querySelector("body").appendChild(testCtx.canvas);

    world.addEventListener("mousedown", e => deselect(e));
    world.addEventListener("touchstart", e => deselect({
        which: 1,
    }));
    document.querySelector("#entities").addEventListener("mousedown", deselect);
    document.querySelector("#display").addEventListener("mousedown", deselect);
    document.addEventListener("mouseup", e => clickUp(e));
    document.addEventListener("touchend", e => {
        const fakeEvent = {
            target: e.target,
            clientX: e.changedTouches[0].clientX,
            clientY: e.changedTouches[0].clientY,
            which: 1
        };
        clickUp(fakeEvent);
    });

    const formList = document.querySelector("#entity-form");

    formList.addEventListener("input", e => {
        const entity = entities[selected.dataset.key];
        entity.form = e.target.value;
        entity.view = entity.formViews[entity.form];
        if (Object.keys(entity.forms).length > 0)
            entity.views[entity.view].height = entity.formSizes[entity.form].height;
        
        preloadViews(entity);

        configViewList(entity, entity.view);

        const image = entity.views[entity.view].image;
        selected.querySelector(".entity-image").src = image.source;

        configViewOptions(entity, entity.view);

        displayAttribution(image.source);

        if (image.bottom !== undefined) {
            selected.querySelector(".entity-image").style.setProperty("--offset", ((-1 + image.bottom) * 100) + "%")
        } else {
            selected.querySelector(".entity-image").style.setProperty("--offset", ((-1) * 100) + "%")
        }

        if (config.autoFitSize) {
            let targets = {};
            targets[selected.dataset.key] = entities[selected.dataset.key];
            fitEntities(targets);
        }

        configSizeList(entity);
        updateSizes();
        updateEntityOptions(entities[selected.dataset.key], e.target.value);
        updateViewOptions(entities[selected.dataset.key], entity.view);
    });

    const viewList = document.querySelector("#entity-view");

    document.querySelector("#entity-view").addEventListener("input", e => {
        const entity = entities[selected.dataset.key];
        entity.view = e.target.value;
        preloadViews(entity);

        const image = entities[selected.dataset.key].views[e.target.value].image;
        selected.querySelector(".entity-image").src = image.source;

        configViewOptions(entity, entity.view);

        displayAttribution(image.source);

        if (image.bottom !== undefined) {
            selected.querySelector(".entity-image").style.setProperty("--offset", ((-1 + image.bottom) * 100) + "%")
        } else {
            selected.querySelector(".entity-image").style.setProperty("--offset", ((-1) * 100) + "%")
        }
        updateSizes();
        updateEntityOptions(entities[selected.dataset.key], e.target.value);
        updateViewOptions(entities[selected.dataset.key], e.target.value);
    });

    document.querySelector("#entity-view").addEventListener("input", e => {
        if (viewList.options[viewList.selectedIndex].classList.contains("nsfw")) {
            viewList.classList.add("nsfw");
        } else {
            viewList.classList.remove("nsfw");
        }
    })

    clearViewList();

    document.querySelector("#menu-clear").addEventListener("click", e => {
        removeAllEntities();
    });

    document.querySelector("#delete-entity").disabled = true;
    document.querySelector("#delete-entity").addEventListener("click", e => {
        if (selected) {
            removeEntity(selected);
            selected = null;
        }
    });

    document.querySelector("#menu-order-height").addEventListener("click", e => {
        const order = Object.keys(entities).sort((a, b) => {
            const entA = entities[a];
            const entB = entities[b];
            const viewA = entA.view;
            const viewB = entB.view;
            const heightA = entA.views[viewA].height.to("meter").value;
            const heightB = entB.views[viewB].height.to("meter").value;
            return heightA - heightB;
        });

        arrangeEntities(order);
    });

    // TODO: write some generic logic for this lol

    document.querySelector("#scroll-left").addEventListener("mousedown", e => {
        scrollDirection = -1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doXScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-right").addEventListener("mousedown", e => {
        scrollDirection = 1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doXScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-left").addEventListener("touchstart", e => {
        scrollDirection = -1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doXScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-right").addEventListener("touchstart", e => {
        scrollDirection = 1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doXScroll, 1000 / 20);
        e.stopPropagation();
    });


    document.querySelector("#scroll-up").addEventListener("mousedown", e => {
        scrollDirection = 1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doYScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-down").addEventListener("mousedown", e => {
        scrollDirection = -1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doYScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-up").addEventListener("touchstart", e => {
        scrollDirection = 1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doYScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#scroll-down").addEventListener("touchstart", e => {
        scrollDirection = -1;
        clearInterval(scrollHandle);
        scrollHandle = setInterval(doYScroll, 1000 / 20);
        e.stopPropagation();
    });

    document.addEventListener("mouseup", e => {
        clearInterval(scrollHandle);
        scrollHandle = null;
    });

    document.addEventListener("touchend", e => {
        clearInterval(scrollHandle);
        scrollHandle = null;
    });

    document.querySelector("#zoom-in").addEventListener("mousedown", e => {
        zoomDirection = -1;
        clearInterval(zoomHandle);
        zoomHandle = setInterval(doZoom, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#zoom-out").addEventListener("mousedown", e => {
        zoomDirection = 1;
        clearInterval(zoomHandle);
        zoomHandle = setInterval(doZoom, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#zoom-in").addEventListener("touchstart", e => {
        zoomDirection = -1;
        clearInterval(zoomHandle);
        zoomHandle = setInterval(doZoom, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#zoom-out").addEventListener("touchstart", e => {
        zoomDirection = 1;
        clearInterval(zoomHandle);
        zoomHandle = setInterval(doZoom, 1000 / 20);
        e.stopPropagation();
    });

    document.addEventListener("mouseup", e => {
        clearInterval(zoomHandle);
        zoomHandle = null;
    });

    document.addEventListener("touchend", e => {
        clearInterval(zoomHandle);
        zoomHandle = null;
    });

    document.querySelector("#shrink").addEventListener("mousedown", e => {
        sizeDirection = -1;
        clearInterval(sizeHandle);
        sizeHandle = setInterval(doSize, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#grow").addEventListener("mousedown", e => {
        sizeDirection = 1;
        clearInterval(sizeHandle);
        sizeHandle = setInterval(doSize, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#shrink").addEventListener("touchstart", e => {
        sizeDirection = -1;
        clearInterval(sizeHandle);
        sizeHandle = setInterval(doSize, 1000 / 20);
        e.stopPropagation();
    });

    document.querySelector("#grow").addEventListener("touchstart", e => {
        sizeDirection = 1;
        clearInterval(sizeHandle);
        sizeHandle = setInterval(doSize, 1000 / 20);
        e.stopPropagation();
    });

    document.addEventListener("mouseup", e => {
        clearInterval(sizeHandle);
        sizeHandle = null;
    });

    document.addEventListener("touchend", e => {
        clearInterval(sizeHandle);
        sizeHandle = null;
    });

    document.querySelector("#ruler").addEventListener("click", e => {
        rulerMode = !rulerMode;
        if (rulerMode) {
            toast("Ready to draw a ruler mark");
        } else {
            toast("Cancelled ruler mode");
        }
    });

    document.querySelector("#ruler").addEventListener("mousedown", e => {
        e.stopPropagation();
    });

    document.querySelector("#ruler").addEventListener("touchstart", e => {
        e.stopPropagation();
    });

    document.querySelector("#fit").addEventListener("click", e => {
        if (selected) {
            let targets = {};
            targets[selected.dataset.key] = entities[selected.dataset.key];
            fitEntities(targets);
        }
    });

    document.querySelector("#fit").addEventListener("mousedown", e => {
        e.stopPropagation();
    });

    document.querySelector("#fit").addEventListener("touchstart", e => {
        e.stopPropagation();
    });

    document.querySelector("#options-world-fit").addEventListener("click", () => fitWorld(true));

    document.querySelector("#options-reset-pos-x").addEventListener("click", () => { config.x = 0; updateSizes(); });
    document.querySelector("#options-reset-pos-y").addEventListener("click", () => { config.y = 0; updateSizes(); });

    document.addEventListener("keydown", e => {
        if (e.key == "Delete") {
            if (selected) {
                removeEntity(selected);
                selected = null;
            }
        }
    })

    document.addEventListener("keydown", e => {
        if (e.key == "Shift") {
            shiftHeld = true;
            e.preventDefault();
        } else if (e.key == "Alt") {
            altHeld = true;
            movingInBounds = false; // don't snap the object back in bounds when we let go
            e.preventDefault();
        }
    });

    document.addEventListener("keyup", e => {
        if (e.key == "Shift") {
            shiftHeld = false;
            e.preventDefault();
        } else if (e.key == "Alt") {
            altHeld = false;
            e.preventDefault();
        }

    });

    window.addEventListener("resize", handleResize);

    // TODO: further investigate why the tool initially starts out with wrong
    // values under certain circumstances (seems to be narrow aspect ratios -
    // maybe the menu bar is animating when it shouldn't)

    setTimeout(handleResize, 250);
    setTimeout(handleResize, 500);
    setTimeout(handleResize, 750);
    setTimeout(handleResize, 1000);


    document.querySelector("#menu-permalink").addEventListener("click", e => {
        linkScene();
    });

    document.querySelector("#menu-export").addEventListener("click", e => {
        copyScene();
    });

    document.querySelector("#menu-import").addEventListener("click", e => {
        pasteScene();
    });

    document.querySelector("#menu-save").addEventListener("click", e => {
        const name = document.querySelector("#menu-save ~ input").value;
        if (/\S/.test(name)) {
            saveScene(name);
        }
        updateSaveInfo();
    });

    document.querySelector("#menu-load").addEventListener("click", e => {
        const name = document.querySelector("#menu-load ~ select").value;
        if (/\S/.test(name)) {
            loadScene(name);
        }
        
    });

    document.querySelector("#menu-delete").addEventListener("click", e => {
        const name = document.querySelector("#menu-delete ~ select").value;
        if (/\S/.test(name)) {
            deleteScene(name);
        }
    });

    document.querySelector("#menu-load-autosave").addEventListener("click", e => {
        loadScene("autosave");
    });

    document.querySelector("#menu-add-image").addEventListener("click", e => {
        document.querySelector("#file-upload-picker").click();
    });

    document.querySelector("#file-upload-picker").addEventListener("change", e => {
        if (e.target.files.length > 0) {
            for (let i=0; i<e.target.files.length; i++) {
                customEntityFromFile(e.target.files[i]);
            }
        }
            
    })

    document.querySelector("#menu-clear-rulers").addEventListener("click", e => {
        rulers = [];
        drawRulers();
    });

    document.addEventListener("paste", e => {

        let index = 0;
        let item = null;
        let found = false;

        for (; index < e.clipboardData.items.length; index++) {
            item = e.clipboardData.items[index];
            if (item.type == "image/png") {
                found = true;
                break;
            }
        }

        if (!found) {
            return;
        }
        
        let url = null;

        const file = item.getAsFile();

        customEntityFromFile(file);
    });

    document.querySelector("#world").addEventListener("dragover", e => {
        e.preventDefault();
    })

    document.querySelector("#world").addEventListener("drop", e => {
        e.preventDefault();
        if (e.dataTransfer.files.length > 0) {
            let entX = document.querySelector("#entities").getBoundingClientRect().x;
            let entY = document.querySelector("#entities").getBoundingClientRect().y;
            let coords = pix2pos({x: e.clientX-entX, y: e.clientY-entY});
            customEntityFromFile(e.dataTransfer.files[0], coords.x, coords.y);
        }
    })
    clearEntityOptions();
    clearViewOptions();
    clearAttribution();

    // we do this last because configuring settings can cause things
    // to happen (e.g. auto-fit)
    prepareSettings(getUserSettings());

    // now that we have this loaded, we can set it

    unitSelector.dataset.oldUnit = defaultUnits.length[config.units];

    document.querySelector("#options-height-unit").value = defaultUnits.length[config.units];

    // ...and then update the world height by setting off an input event

    document.querySelector("#options-height-unit").dispatchEvent(new Event('input', {

    }));

    

    if (param === null) {
        scenes["Empty"]();
    }

    else {
        try {
            const data = JSON.parse(b64DecodeUnicode(param));
            if (data.entities === undefined) {
                return;
            }
            if (data.world === undefined) {
                return;
            }

            importScene(data);
        } catch (err) {
            console.error(err);
            scenes["Empty"]();

            // probably wasn't valid data 
        }
    }
    document.querySelector("#world").addEventListener("wheel", e => {


        if (shiftHeld) {
            if (selected) {
                const dir = e.deltaY > 0 ? 10 / 11 : 11 / 10;
                const entity = entities[selected.dataset.key];
                entity.views[entity.view].height = math.multiply(entity.views[entity.view].height, dir);
                entity.dirty = true;
                updateEntityOptions(entity, entity.view);
                updateViewOptions(entity, entity.view);
                updateSizes(true);
            } else {
                const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
                config.x += (e.deltaY > 0 ? 1 : -1) * worldWidth / 20 ;
                updateSizes();
                updateSizes();
            }

        } else {
            if (config.autoFit) {
                toastRateLimit("Zoom is locked! Check Settings to disable.", "zoom-lock", 1000);
            } else {
                const dir = e.deltaY < 0 ? 10 / 11 : 11 / 10;
                const change = config.height.toNumber("meters") - math.multiply(config.height, dir).toNumber("meters");
                if (!config.lockYAxis) {
                    config.y += change / 2;
                }
                setWorldHeight(config.height, math.multiply(config.height, dir));
                updateWorldOptions();

            }
            
        }
        checkFitWorld();
    })

    updateWorldHeight();

    document.querySelector("#search-box").addEventListener("change", e => doSearch(e.target.value));

});

let searchText = "";

function doSearch(value) {
    searchText = value;
    updateFilter();
}

function customEntityFromFile(file, x=0.5, y=0.5) {
    file.arrayBuffer().then(buf => {
        arr = new Uint8Array(buf);
        blob = new Blob([arr], {type: file.type });
        url = window.URL.createObjectURL(blob)
        makeCustomEntity(url, x, y);
    });
}

function makeCustomEntity(url, x=0.5, y=0.5) {
    const maker = createEntityMaker(
        {
            name: "Custom Entity"
        },
        {
            custom: {
                attributes: {
                    height: {
                        name: "Height",
                        power: 1,
                        type: "length",
                        base: math.unit(6, "feet")
                    }
                },
                image: {
                    source: url
                },
                name: "Image",
                info: {},
                rename: false
            }
        },
        []
    );

    const entity = maker.constructor();

    entity.scale = config.height.toNumber("feet") / 20;

    entity.ephemeral = true;
    displayEntity(entity, "custom", x, y, true, true);
}

const filterDefs = {
    none: {
        id: "none",
        name: "No Filter",
        extract: maker => [],
        render: name => name,
        sort: (tag1, tag2) => tag1[1].localeCompare(tag2[1])
    },
    author: {
        id: "author",
        name: "Authors",
        extract: maker => maker.authors ? maker.authors : [],
        render: author => attributionData.people[author].name,
        sort: (tag1, tag2) => tag1[1].localeCompare(tag2[1])
    },
    owner: {
        id: "owner",
        name: "Owners",
        extract: maker => maker.owners ? maker.owners : [],
        render: owner => attributionData.people[owner].name,
        sort: (tag1, tag2) => tag1[1].localeCompare(tag2[1])
    },
    species: {
        id: "species",
        name: "Species",
        extract: maker => maker.info && maker.info.species ? getSpeciesInfo(maker.info.species) : [],
        render: species => speciesData[species].name,
        sort: (tag1, tag2) => tag1[1].localeCompare(tag2[1])
    },
    tags: {
        id: "tags",
        name: "Tags",
        extract: maker => maker.info && maker.info.tags ? maker.info.tags : [],
        render: tag => tagDefs[tag],
        sort: (tag1, tag2) => tag1[1].localeCompare(tag2[1])
    },
    size: {
        id: "size",
        name: "Normal Size",
        extract: maker => maker.sizes && maker.sizes.length > 0 ? Array.from(maker.sizes.reduce((result, size) => {
            if (result && !size.default) {
                return result;
            }
            let meters = size.height.toNumber("meters");
            if (meters < 1e-1) {
                return ["micro"];
            } else if (meters < 1e1) {
                return ["moderate"];
            } else {
                return ["macro"];
            }
        }, null)) : [],
        render: tag => { return {
            "micro": "Micro",
            "moderate": "Moderate",
            "macro": "Macro"
        }[tag]},
        sort: (tag1, tag2) => {
            const order = {
                "micro": 0,
                "moderate": 1,
                "macro": 2
            };

            return order[tag1[0]] - order[tag2[0]];
        }
    },
    allSizes: {
        id: "allSizes",
        name: "Possible Size",
        extract: maker => maker.sizes ? Array.from(maker.sizes.reduce((set, size) => {
            
            const height = size.height;

            let result = Object.entries(sizeCategories).reduce((result, [name, value]) => {
                if (result) {
                    return result;
                } else {
                    if (math.compare(height, value) <= 0) {
                        return name;
                    }
                }
            }, null);

            set.add(result ? result : "infinite");

            return set;
        }, new Set())) : [],
        render: tag => tag[0].toUpperCase() + tag.slice(1),
        sort: (tag1, tag2) => {
            const order = [
                "atomic", "microscopic", "tiny", "small", "moderate", "large", "macro", "megamacro", "planetary", "stellar",
                "galactic", "universal", "omniversal", "infinite"
            ]

            return order.indexOf(tag1[0]) - order.indexOf(tag2[0]);
        }
    }
}

const sizeCategories = {
    "atomic": math.unit(100, "angstroms"),
    "microscopic": math.unit(100, "micrometers"),
    "tiny": math.unit(100, "millimeters"),
    "small": math.unit(1, "meter"),
    "moderate": math.unit(3, "meters"),
    "large": math.unit(10, "meters"),
    "macro": math.unit(300, "meters"),
    "megamacro": math.unit(1000, "kilometers"),
    "planetary": math.unit(10, "earths"),
    "stellar": math.unit(10, "solarradii"),
    "galactic": math.unit(10, "galaxies"),
    "universal": math.unit(10, "universes"),
    "omniversal": math.unit(10, "multiverses")
};

function prepareEntities() {
    availableEntities["buildings"] = makeBuildings();
    availableEntities["characters"] = makeCharacters();
    availableEntities["clothing"] = makeClothing();
    availableEntities["creatures"] = makeCreatures();
    availableEntities["fiction"] = makeFiction();
    availableEntities["food"] = makeFood();
    availableEntities["furniture"] = makeFurniture();
    availableEntities["landmarks"] = makeLandmarks();
    availableEntities["naturals"] = makeNaturals();
    availableEntities["objects"] = makeObjects();
    availableEntities["pokemon"] = makePokemon();
    availableEntities["real-buildings"] = makeRealBuildings();
    availableEntities["real-terrain"] = makeRealTerrains();
    availableEntities["species"] = makeSpecies();
    availableEntities["vehicles"] = makeVehicles();

    availableEntities["species"].forEach(x => {
        if (x.name == "Human") {
            availableEntities["food"].push(x);
        }
    })

    availableEntities["characters"].sort((x, y) => {
        return x.name.localeCompare(y.name)
    });
    availableEntities["species"].sort((x, y) => {
        return x.name.localeCompare(y.name)
    });
    availableEntities["objects"].sort((x, y) => {
        return x.name.localeCompare(y.name)
    });
    const holder = document.querySelector("#spawners");
    const filterHolder = document.querySelector("#filters");

    const categorySelect = document.createElement("select");
    categorySelect.id = "category-picker";
    const filterSelect = document.createElement("select");
    filterSelect.id = "filter-picker";

    holder.appendChild(categorySelect);
    filterHolder.appendChild(filterSelect);

    const filterSets = {};

    Object.values(filterDefs).forEach(filter => {
        filterSets[filter.id] = new Set();
    })

    Object.entries(availableEntities).forEach(([category, entityList]) => {
        const select = document.createElement("select");
        select.id = "create-entity-" + category;
        select.classList.add("entity-select");
        for (let i = 0; i < entityList.length; i++) {
            const entity = entityList[i];
            const option = document.createElement("option");
            option.value = i;
            option.innerText = entity.name;
            select.appendChild(option);

            if (entity.nsfw) {
                option.classList.add("nsfw");
            }

            Object.values(filterDefs).forEach(filter => {
                filter.extract(entity).forEach(result => {
                    filterSets[filter.id].add(result);
                });
            });            

            availableEntitiesByName[entity.name] = entity;
        };

        select.addEventListener("change", e => {
            if (select.options[select.selectedIndex]?.classList.contains("nsfw")) {
                select.classList.add("nsfw");
            } else {
                select.classList.remove("nsfw");
            }

            // preload the entity's first image

            const entity = entityList[select.selectedIndex]?.constructor();

            if (entity)
            {
                let img = new Image();
                img.src = entity.currentView.image.source;
            }
            
        })

        const button = document.createElement("button");
        button.id = "create-entity-" + category + "-button";
        button.classList.add("entity-button");

        button.innerHTML = "<i class=\"far fa-plus-square\"></i>";

        button.addEventListener("click", e => {
            if (entityList[select.value] == null)
                return;

            const newEntity = entityList[select.value].constructor()
            let yOffset = 0;

            if (config.lockYAxis) {
                if (config.groundPos === "very-high") {
                    yOffset = config.height.toNumber("meters") / 12 * 5;
                }
                else if (config.groundPos === "high") {
                    yOffset = config.height.toNumber("meters") / 12 * 4;
                }
                else if (config.groundPos === "medium") {
                    yOffset = config.height.toNumber("meters") / 12 * 3;
                }
                else if (config.groundPos === "low") {
                    yOffset = config.height.toNumber("meters") / 12 * 2;
                }
                else if (config.groundPos === "very-low") {
                    yOffset = config.height.toNumber("meters") / 12 * 1;
                }
                else if (config.groundPos === "bottom") {
                    yOffset = 0;
                }
            } else {
                yOffset = (config.lockYAxis ? 0 : config.height.toNumber("meters")/2);
            }
            displayEntity(newEntity, newEntity.defaultView, config.x, config.y + yOffset, true, true);
        });

        const categoryOption = document.createElement("option");
        categoryOption.value = category
        categoryOption.innerText = category;

        if (category == "characters") {
            categoryOption.selected = true;
            select.classList.add("category-visible");
            button.classList.add("category-visible");
        }

        categorySelect.appendChild(categoryOption);
        holder.appendChild(select);
        holder.appendChild(button);
    });

    Object.values(filterDefs).forEach(filter => {
        const option = document.createElement("option");
        option.innerText = filter.name;
        option.value = filter.id;
        filterSelect.appendChild(option);

        const filterNameSelect = document.createElement("select");
        filterNameSelect.classList.add("filter-select");
        filterNameSelect.id = "filter-" + filter.id;
        filterHolder.appendChild(filterNameSelect);

        const button = document.createElement("button");
        button.classList.add("filter-button");
        button.id = "create-filtered-" + filter.id + "-button";
        filterHolder.appendChild(button);

        const counter = document.createElement("div");
        counter.classList.add("button-counter");
        counter.innerText = "10";
        button.appendChild(counter);
        const i = document.createElement("i");
        i.classList.add("fas");
        i.classList.add("fa-plus");
        button.appendChild(i);

        button.addEventListener("click", e => {
            const makers = Array.from(document.querySelector(".entity-select.category-visible")).filter(element => !element.classList.contains("filtered"));
            const count = makers.length + 2;
            let index = 1;

            if (makers.length > 50) {
                if (!confirm("Really spawn " + makers.length + " things at once?")) {
                    return;
                }
            }

            const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;

            const spawned = makers.map(element => {
                const category = document.querySelector("#category-picker").value;
                const maker = availableEntities[category][element.value];
                const entity = maker.constructor()
                displayEntity(entity, entity.view, -worldWidth * 0.45 + config.x + worldWidth * 0.9 * index / (count - 1), config.y);
                index += 1;
                return entityIndex - 1;
            });
            updateSizes(true);

            if (config.autoFitAdd) {
                let targets = {};
                spawned.forEach(key => {
                    targets[key] = entities[key];
                })
                fitEntities(targets);
            }
        });

        Array.from(filterSets[filter.id]).map(name => [name, filter.render(name)]).sort(filterDefs[filter.id].sort).forEach(name => {
            const option = document.createElement("option");
            option.innerText = name[1];
            option.value = name[0];
            filterNameSelect.appendChild(option);
        });
        
        filterNameSelect.addEventListener("change", e => {
            updateFilter();
        });
    });

    console.log("Loaded " + Object.keys(availableEntitiesByName).length + " entities");

    categorySelect.addEventListener("input", e => {
        const oldSelect = document.querySelector(".entity-select.category-visible");
        oldSelect.classList.remove("category-visible");
        const oldButton = document.querySelector(".entity-button.category-visible");
        oldButton.classList.remove("category-visible");

        const newSelect = document.querySelector("#create-entity-" + e.target.value);
        newSelect.classList.add("category-visible");
        const newButton = document.querySelector("#create-entity-" + e.target.value + "-button");
        newButton.classList.add("category-visible");

        recomputeFilters();
        updateFilter();
    });

    recomputeFilters();

    filterSelect.addEventListener("input", e => {
        const oldSelect = document.querySelector(".filter-select.category-visible");
        if (oldSelect)
            oldSelect.classList.remove("category-visible");

        const newSelect = document.querySelector("#filter-" + e.target.value);
        if (newSelect && e.target.value != "none")
            newSelect.classList.add("category-visible");

        updateFilter();
    });

    ratioInfo = document.body.querySelector(".extra-info")

}

// Only display authors and owners if they appear
// somewhere in the current entity list
function recomputeFilters() {
    const category = document.querySelector("#category-picker").value;

    const filterSets = {};

    Object.values(filterDefs).forEach(filter => {
        filterSets[filter.id] = new Set();
    });
    
    document.querySelectorAll(".entity-select.category-visible > option").forEach(element => {
        const entity = availableEntities[category][element.value];
        
        Object.values(filterDefs).forEach(filter => {
            filter.extract(entity).forEach(result => {
                filterSets[filter.id].add(result);
            });
        });
    });

    Object.values(filterDefs).forEach(filter => {
        // always show the "none" option
        let found = filter.id == "none";

        document.querySelectorAll("#filter-" + filter.id + " > option").forEach(element => {
            if (filterSets[filter.id].has(element.value) || filter.id == "none") {
                element.classList.remove("filtered");
                element.disabled = false;
                found = true;
            } else {
                element.classList.add("filtered");
                element.disabled = true;
            }
        });


        const filterOption = document.querySelector("#filter-picker > option[value='" + filter.id + "']");
        if (found) {
            filterOption.classList.remove("filtered");
            filterOption.disabled = false;
        } else {
            filterOption.classList.add("filtered");
            filterOption.disabled = true;
        }
    });

    document.querySelector("#filter-picker").value = "none";
    document.querySelector("#filter-picker").dispatchEvent(new Event("input"));
}

function updateFilter() {
    const category = document.querySelector("#category-picker").value;
    const type = document.querySelector("#filter-picker").value;
    const filterKeySelect = document.querySelector(".filter-select.category-visible");

    clearFilter();

    const noFilter = !filterKeySelect;

    let key;
    let current = document.querySelector(".entity-select.category-visible").value;

    if (!noFilter)
    {
        key = filterKeySelect.value;
        current
    }
    
    let replace = current == "";
    let first = null;

    let count = 0;

    const lowerSearchText = searchText !== "" ? searchText.toLowerCase() : null;
    document.querySelectorAll(".entity-select.category-visible > option").forEach(element => {
        let keep = noFilter;

        if (!noFilter && filterDefs[type].extract(availableEntities[category][element.value]).indexOf(key) >= 0) {
            keep = true;
        }

        if (searchText != "" && !availableEntities[category][element.value].name.toLowerCase().includes(lowerSearchText))
        {
            keep = false;
        }

        if (!keep) {
            element.classList.add("filtered");
            element.disabled = true;

            if (current == element.value) {
                replace = true;
            }
        } else {
            count += 1;
            if (!first) {
                first = element.value;
            }
        } 
    });

    const button = document.querySelector(".filter-select.category-visible + button");

    if (button) {
        button.querySelector(".button-counter").innerText = count;
    }

    if (replace) {
        document.querySelector(".entity-select.category-visible").value = first;
        document.querySelector("#create-entity-" + category).dispatchEvent(new Event("change"));
    }
}

function clearFilter() {
    document.querySelectorAll(".entity-select.category-visible > option").forEach(element => {
        element.classList.remove("filtered");
        element.disabled = false;
    });
}

document.addEventListener("mousemove", (e) => {
    if (currentRuler) {
        let entX = document.querySelector("#entities").getBoundingClientRect().x;
        let entY = document.querySelector("#entities").getBoundingClientRect().y;
        let position = pix2pos({ x: e.clientX - entX, y: e.clientY - entY });

        if (config.rulersStick && selected) {
            position = entityRelativePosition(position, selected)
        }
        currentRuler.x1 = position.x;
        currentRuler.y1 = position.y;
    }
    drawRulers();
});

document.addEventListener("touchmove", (e) => {
    if (currentRuler) {
        let entX = document.querySelector("#entities").getBoundingClientRect().x;
        let entY = document.querySelector("#entities").getBoundingClientRect().y;
        let position = pix2pos({ x: e.touches[0].clientX - entX, y: e.touches[0].clientY - entY });
        if (config.rulersStick && selected) {
            position = entityRelativePosition(position, selected)
        }
        currentRuler.x1 = position.x;
        currentRuler.y1 = position.y;
    }
    drawRulers();
});

document.addEventListener("mousemove", (e) => {
    if (clicked) {
        let position = pix2pos({ x: e.clientX - dragOffsetX, y: e.clientY - dragOffsetY });

        if (movingInBounds) {
            position = snapPos(position);
        } else {
            let x = e.clientX - dragOffsetX;
            let y = e.clientY - dragOffsetY;
            if (x >= 0 && x <= canvasWidth && y >= 0 && y <= canvasHeight) {
                movingInBounds = true;
            }
        }
        clicked.dataset.x = position.x;
        clicked.dataset.y = position.y;
        updateEntityElement(entities[clicked.dataset.key], clicked);

        if (hoveringInDeleteArea(e)) {
            document.querySelector("#menubar").classList.add("hover-delete");
        } else {
            document.querySelector("#menubar").classList.remove("hover-delete");
        }
    }
    if (panning && panReady) {
        
        const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
        const worldHeight = config.height.toNumber("meters");

        config.x -= (e.clientX - panOffsetX) / canvasWidth * worldWidth;
        config.y += (e.clientY - panOffsetY) / canvasHeight * worldHeight;
        panOffsetX = e.clientX;
        panOffsetY = e.clientY;
        updateSizes();
        panReady = false;
        setTimeout(() => panReady=true, 1000/120);
    }
});

document.addEventListener("touchmove", (e) => {
    if (clicked) {
        e.preventDefault();
        let x = e.touches[0].clientX;
        let y = e.touches[0].clientY;

        const position = snapPos(pix2pos({ x: x - dragOffsetX, y: y - dragOffsetY }));
        clicked.dataset.x = position.x;
        clicked.dataset.y = position.y;
        updateEntityElement(entities[clicked.dataset.key], clicked);

        // what a hack
        // I should centralize this 'fake event' creation...
        if (hoveringInDeleteArea({ clientY: y })) {
            document.querySelector("#menubar").classList.add("hover-delete");
        } else {
            document.querySelector("#menubar").classList.remove("hover-delete");
        }
    }
    if (panning && panReady) {
        
        const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
        const worldHeight = config.height.toNumber("meters");

        config.x -= (e.touches[0].clientX - panOffsetX) / canvasWidth * worldWidth;
        config.y += (e.touches[0].clientY - panOffsetY) / canvasHeight * worldHeight;
        panOffsetX = e.touches[0].clientX;
        panOffsetY = e.touches[0].clientY;
        updateSizes();
        panReady = false;
        setTimeout(() => panReady=true, 1000/60);
    }
}, { passive: false });

function checkFitWorld() {
    if (config.autoFit) {
        fitWorld();
        return true;
    }
    return false;
}

function fitWorld(manual = false, factor = 1.1) {
    if (Object.keys(entities).length > 0) {
        fitEntities(entities, factor);
    }
    
}

function fitEntities(targetEntities, manual = false, factor = 1.1) {
    let minX = Infinity;
    let maxX = -Infinity;
    let minY = Infinity;
    let maxY = -Infinity;

    let count = 0;

    const worldWidth = config.height.toNumber("meters") / canvasHeight * canvasWidth;
    const worldHeight = config.height.toNumber("meters");


    Object.entries(targetEntities).forEach(([key, entity]) => {
        const view = entity.view;

        let extra = entity.views[view].image.extra;
        extra = extra === undefined ? 1 : extra;

        const image = document.querySelector("#entity-" + key + " > .entity-image");
        const x = parseFloat(document.querySelector("#entity-" + key).dataset.x);

        let width = image.width;
        let height = image.height;

        // only really relevant if the images haven't loaded in yet
        if (height == 0) {
            height = 100;
        }
        if (width == 0) {
            width = height;
        }

        const xBottom = x - entity.views[view].height.toNumber("meters") * width / height / 2;
        const xTop = x + entity.views[view].height.toNumber("meters") * width / height / 2;

        const y = parseFloat(document.querySelector("#entity-" + key).dataset.y);
        const yBottom = y;
        const yTop = entity.views[view].height.toNumber("meters") + yBottom;

        minX = Math.min(minX, xBottom);
        maxX = Math.max(maxX, xTop);
        minY = Math.min(minY, yBottom);
        maxY = Math.max(maxY, yTop);

        count += 1;
    });

    if (config.lockYAxis) {
        minY = 0;
    }
    let ySize = (maxY - minY) * factor;
    let xSize = (maxX - minX) * factor;

    if (xSize / ySize > worldWidth / worldHeight) {
        ySize *= ((xSize / ySize) / (worldWidth / worldHeight));
    }

    config.x = (maxX + minX) / 2;
    config.y = minY;

    height = math.unit(ySize, "meter")

    setWorldHeight(config.height, math.multiply(height, factor));
}

function updateWorldHeight() {
    const unit = document.querySelector("#options-height-unit").value;
    const rawValue = document.querySelector("#options-height-value").value;

    var value
    try {
        value = math.evaluate(rawValue)
        if (typeof(value) !== "number") {
            try {
                value = value.toNumber(unit)
            } catch {
                toast("Invalid input: " + rawValue + " can't be converted to " + unit)
            }
        }
    } catch {
        toast("Invalid input: could not parse " + rawValue)
        return;
    }

    const newHeight = Math.max(0.000000001, value);
    const oldHeight = config.height;

    setWorldHeight(oldHeight, math.unit(newHeight, unit), true);
}

function setWorldHeight(oldHeight, newHeight, keepUnit=false) {
    worldSizeDirty = true;
    config.height = newHeight.to(document.querySelector("#options-height-unit").value)

    const unit = document.querySelector("#options-height-unit").value;
    setNumericInput(document.querySelector("#options-height-value"), config.height.toNumber(unit));
    Object.entries(entities).forEach(([key, entity]) => {
        const element = document.querySelector("#entity-" + key);
        let newPosition;

        if (altHeld) {
            newPosition = adjustAbs({ x: element.dataset.x, y: element.dataset.y }, oldHeight, config.height);
        } else {
            newPosition = { x: element.dataset.x, y: element.dataset.y };
        }

        element.dataset.x = newPosition.x;
        element.dataset.y = newPosition.y;
    });

    if (!keepUnit) {
        pickUnit()
    }

    updateSizes();
}

function loadScene(name = "default") {
    if (name === "") {
        name = "default"
    }
    try {
        const data = JSON.parse(localStorage.getItem("macrovision-save-" + name));
        if (data === null) {
            console.error("Couldn't load " + name)
            return false;
        }
        importScene(data);
        toast("Loaded " + name);
        return true;
    } catch (err) {
        alert("Something went wrong while loading (maybe you didn't have anything saved. Check the F12 console for the error.")
        console.error(err);
        return false;
    }
}

function saveScene(name = "default") {
    try {
        const string = JSON.stringify(exportScene());
        localStorage.setItem("macrovision-save-" + name, string);
        toast("Saved as " + name);
    } catch (err) {
        alert("Something went wrong while saving (maybe I don't have localStorage permissions, or exporting failed). Check the F12 console for the error.")
        console.error(err);
    }
}

function deleteScene(name = "default") {
    if (confirm("Really delete the " + name + " scene?")) {
        try {
            localStorage.removeItem("macrovision-save-" + name)
            toast("Deleted " + name);
        } catch (err) {
            console.error(err);
        }
    }
    updateSaveInfo();
}

function exportScene() {
    const results = {};

    results.entities = [];

    Object.entries(entities).filter(([key, entity]) => entity.ephemeral !== true).forEach(([key, entity]) => {
        const element = document.querySelector("#entity-" + key);
        results.entities.push({
            name: entity.identifier,
            customName: entity.name,
            scale: entity.scale,
            rotation: entity.rotation,
            view: entity.view,
            form: entity.form,
            x: element.dataset.x,
            y: element.dataset.y,
            priority: entity.priority,
            brightness: entity.brightness
        });
    });

    const unit = document.querySelector("#options-height-unit").value;
    results.world = {
        height: config.height.toNumber(unit),
        unit: unit,
        x: config.x,
        y: config.y
    }

    results.version = migrationDefs.length;

    return results;
}

// btoa doesn't like anything that isn't ASCII
// great

// thanks to https://stackoverflow.com/questions/30106476/using-javascripts-atob-to-decode-base64-doesnt-properly-decode-utf-8-strings
// for providing an alternative

function b64EncodeUnicode(str) {
    // first we use encodeURIComponent to get percent-encoded UTF-8,
    // then we convert the percent encodings into raw bytes which
    // can be fed into btoa.
    return btoa(encodeURIComponent(str).replace(/%([0-9A-F]{2})/g,
        function toSolidBytes(match, p1) {
            return String.fromCharCode('0x' + p1);
        }));
}

function b64DecodeUnicode(str) {
    // Going backwards: from bytestream, to percent-encoding, to original string.
    return decodeURIComponent(atob(str).split('').map(function (c) {
        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
    }).join(''));
}

function linkScene() {
    loc = new URL(window.location);
    const link = loc.protocol + "//" + loc.host + loc.pathname + "#" + b64EncodeUnicode(JSON.stringify(exportScene()));
    window.history.replaceState(null, "Macrovision", link);
    try {
        navigator.clipboard.writeText(link);
        toast("Copied permalink to clipboard");
    } catch {
        toast("Couldn't copy permalink");
    }
    
}

function copyScene() {
    const results = exportScene();

    navigator.clipboard.writeText(JSON.stringify(results));
}

function pasteScene() {
    try {
        navigator.clipboard.readText().then(text => {
            const data = JSON.parse(text);
            if (data.entities === undefined) {
                return;
            }
            if (data.world === undefined) {
                return;
            }

            importScene(data);
        }).catch(err => alert(err));
    } catch (err) {
        console.error(err);

        // probably wasn't valid data 
    }
}
// TODO - don't just search through every single entity 
// probably just have a way to do lookups directly

function findEntity(name) {
    return availableEntitiesByName[name];
}

const migrationDefs = [
    /*
    Migration: 0 -> 1
    
    Adds x and y coordinates for the camera
    */

    data => {
        data.world.x = 0;
        data.world.y = 0;
    },
    /*
    Migration: 1 -> 2

    Adds priority and brightness to each entity
    */

    data => {
        data.entities.forEach(entity => {
            entity.priority = 0;
            entity.brightness = 1;
        });
    },
    /*
    Migration: 2 -> 3

    Custom names are exported
    */

    data => {
        data.entities.forEach(entity => {
            entity.customName = entity.name
        });
    },
    /*
    Migration: 3 -> 4

    Rotation is now stored
    */

    data => {
        data.entities.forEach(entity => {
            entity.rotation = 0
        });
    }
]


function migrateScene(data) {
    if (data.version === undefined) {
        alert("This save was created before save versions were tracked. The scene may import incorrectly.");
        console.trace()
        data.version = 0;
    } else if (data.version < migrationDefs.length) {
        migrationDefs[data.version](data);
        data.version += 1;
        migrateScene(data);
    }
}

function importScene(data) {
    removeAllEntities();

    migrateScene(data);

    data.entities.forEach(entityInfo => {
        const entity = findEntity(entityInfo.name).constructor();
        entity.name = entityInfo.customName;
        entity.scale = entityInfo.scale;
        entity.rotation = entityInfo.rotation;
        entity.priority = entityInfo.priority;
        entity.brightness = entityInfo.brightness;
        entity.form = entityInfo.form;
        displayEntity(entity, entityInfo.view, entityInfo.x, entityInfo.y);
    });

    config.height = math.unit(data.world.height, data.world.unit);
    config.x = data.world.x;
    config.y = data.world.y;

    const height = math.unit(data.world.height, data.world.unit).toNumber(defaultUnits.length[config.units]);

    document.querySelector("#options-height-value").value = height;
    document.querySelector("#options-height-unit").dataset.oldUnit = defaultUnits.length[config.units];
    document.querySelector("#options-height-unit").value = defaultUnits.length[config.units];

    if (data.canvasWidth) {
        doHorizReposition(data.canvasWidth / canvasWidth);
    }

    updateSizes();
}

function renderToCanvas() {
    const ctx = document.querySelector("#display").getContext("2d");

    Object.entries(entities).sort((ent1, ent2) => {
        z1 = document.querySelector("#entity-" + ent1[0]).style.zIndex;
        z2 = document.querySelector("#entity-" + ent2[0]).style.zIndex;
        return z1 - z2;
    }).forEach(([id, entity]) => {
        element = document.querySelector("#entity-" + id);
        img = element.querySelector("img");

        let x = parseFloat(element.dataset.x);
        let y = parseFloat(element.dataset.y);

        let coords = pos2pix({x: x, y: y});

        let offset = img.style.getPropertyValue("--offset");
        offset = parseFloat(offset.substring(0, offset.length-1))

        let xSize = img.width;
        let ySize = img.height;
        x = coords.x
        y = coords.y + ySize/2 + ySize * offset / 100;
        const oldFilter = ctx.filter
        const brightness = getComputedStyle(element).getPropertyValue("--brightness")
        ctx.filter = `brightness(${brightness})`;
        
        ctx.save();
        ctx.resetTransform();
        ctx.scale(window.devicePixelRatio, window.devicePixelRatio)
        ctx.translate(x, y);
        ctx.rotate(entity.rotation);
        ctx.drawImage(img, -xSize/2, -ySize/2, xSize, ySize);
        ctx.restore();

        ctx.filter = oldFilter
    });
    ctx.drawImage(document.querySelector("#rulers"), 0, 0);
}

function exportCanvas(callback) {
    /** @type {CanvasRenderingContext2D} */
    const ctx = document.querySelector("#display").getContext("2d");
    const blob = ctx.canvas.toBlob(callback);
}

function generateScreenshot(callback) {
    /** @type {CanvasRenderingContext2D} */
    const ctx = document.querySelector("#display").getContext("2d");

    if (config.groundKind !== "none") {
        ctx.fillStyle = backgroundColors[config.groundKind];
        ctx.fillRect(0, pos2pix({x: 0, y: 0}).y, canvasWidth + 100, canvasHeight);
    }
    
    renderToCanvas();

    ctx.resetTransform();

    ctx.fillStyle = "#999";
    ctx.font = "normal normal lighter 16pt coda";
    ctx.fillText("macrovision.crux.sexy", 10, 25);

    
    exportCanvas(blob => {
        callback(blob);
    });   
}

function copyScreenshot() {
    if (window.ClipboardItem === undefined) {
        alert("Sorry, this browser doesn't yet support writing images to the clipboard.");
        return;
    }
    generateScreenshot(blob => {
        navigator.clipboard.write([
            new ClipboardItem({
                "image/png": blob
            })
        ]).then(e => 
            toast("Copied to clipboard!"))
            .catch(e => {
            toast("Couldn't write to the clipboard. Make sure the screenshot completes before switching tabs.")
        })
    });   
    drawScales(false);
}

function saveScreenshot() {
    generateScreenshot(blob => {
        const a = document.createElement("a");
        a.href = URL.createObjectURL(blob);
        a.setAttribute("download", "macrovision.png");
        a.click();
    });   
    drawScales(false);
}

function openScreenshot() {
    generateScreenshot(blob => {
        const a = document.createElement("a");
        a.href = URL.createObjectURL(blob);
        a.setAttribute("target", "_blank");
        a.click();
    });   
    drawScales(false);
}

const rateLimits = {};

function toast(msg) {
    let div = document.createElement("div");
    div.innerHTML = msg;
    div.classList.add("toast");

    document.body.appendChild(div);

    setTimeout(() => {
        document.body.removeChild(div);
    }, 5000)
}

function toastRateLimit(msg, key, delay) {
    if (!rateLimits[key]) {
        toast(msg);
        rateLimits[key] = setTimeout(() => {
            delete rateLimits[key]
        }, delay);
    }
}
let lastTime = undefined;

function pan(fromX, fromY, fromHeight, toX, toY, toHeight, duration) {

    Object.keys(entities).forEach(key => {
        document.querySelector("#entity-" + key).classList.add("no-transition");
    });

    config.x = fromX;
    config.y = fromY;
    config.height = math.unit(fromHeight, "meters")
    updateSizes();

    lastTime = undefined;

    requestAnimationFrame((timestamp) => panTo(toX, toY, toHeight, (toX - fromX) / duration, (toY - fromY) / duration, (toHeight - fromHeight) / duration, timestamp, duration));
}

function panTo(x, y, height, xSpeed, ySpeed, heightSpeed, timestamp, remaining) {
    if (lastTime === undefined) {
        lastTime = timestamp;
    }
    dt = timestamp - lastTime;
    remaining -= dt;
    if (remaining < 0) {
        dt += remaining
    }
    let newX = config.x + xSpeed * dt;
    let newY = config.y + ySpeed * dt;
    let newHeight = config.height.toNumber("meters") + heightSpeed * dt;
    if (remaining > 0) {
        requestAnimationFrame((timestamp) => panTo(x, y, height, xSpeed, ySpeed, heightSpeed, timestamp, remaining))
    } else {
        Object.keys(entities).forEach(key => {
            document.querySelector("#entity-" + key).classList.remove("no-transition");
        });
    }
    config.x = newX;
    config.y = newY;
    config.height = math.unit(newHeight, "meters");
    updateSizes();
}