initial crack at potluck with pixi, because someone asked

potluck.js

window.Potluck = {};

let _index_to_coords = function(index, columns) {
    return [index % columns, Math.floor(index / columns)];
};

Potluck.begin = function() {
    let renderer = PIXI.autoDetectRenderer(800, 600);
    document.body.appendChild(renderer.view);

    // FIXME custom xhr loader for this?
    PIXI.loader.add('maps/test.json');
    PIXI.loader.load(on_map_load);
    let mapdata;

    function on_map_load() {
        console.log(arguments);

        mapdata = PIXI.loader.resources['maps/test.json'].data;
        // FIXME can i get the tileset constructor to do this or something
        PIXI.loader.add('sheet', 'maps/' + mapdata.tilesets[0].image);
        PIXI.loader.load(on_pixi_load);
    }

    function on_pixi_load() {
        let stage = new PIXI.Container;

        // FIXME can i put the tileset in resources?
        let tileset = new Potluck.TiledTileset(mapdata.tilesets[0], PIXI.loader.resources['sheet'].texture);
        for (let i = 0; i < mapdata.layers[0].data.length; i++) {
            let t = mapdata.layers[0].data[i];
            if (t == 0)
                continue;

            let sprite = new PIXI.Sprite(tileset.get_subtex(t));
            let [x, y] = _index_to_coords(i, mapdata.layers[0].width);
            sprite.x = x * tileset.rawdata.tilewidth;
            sprite.y = y * tileset.rawdata.tileheight;
            console.log(sprite);
            stage.addChild(sprite);
        }
        renderer.render(stage);
    }
};


Potluck.TiledTileset = function(rawdata, texture) {
    this.rawdata = rawdata;
    this.texture = texture;
    
    this.rectangles = [];
    this.subtextures = [];
};

Potluck.TiledTileset.prototype.get_rectangle = function(gt) {
    let t = gt - this.rawdata.firstgid;
    if (! this.rectangles[t]) {
        let [x, y] = _index_to_coords(t, this.rawdata.columns);
        let tw = this.rawdata.tilewidth;
        let th = this.rawdata.tileheight;
        this.rectangles[t] = new PIXI.Rectangle(x * tw, y * th, tw, th);
    }

    return this.rectangles[t];
};

Potluck.TiledTileset.prototype.get_subtex = function(gt) {
    let t = gt - this.rawdata.firstgid;
    if (! this.subtextures[t]) {
        this.subtextures[t] = new PIXI.Texture(this.texture, this.get_rectangle(gt));
    }

    return this.subtextures[t];
};