意义不明

拿到mv后写的第一个插件……导出地图为png图片，需要修改chrome打开参数以支持读取本地文件。

/*:
 * @plugindesc 不是很优雅的导出实际地图png，请用chrome增加参数--disable-web-security --allow-file-access-from-files后打开index.html
 * @author SureBrz
 *
 * @param mapId
 * @desc 要转换的地图id
 * @default 1
*/

(function() {

    var parameters = PluginManager.parameters('SaveMapImg');
    var mapId = parameters['mapId'] || 1;

    // = =||
    Graphics.isFontLoaded = function(name) {
        return true;
    };

    // 新增 绘制所有tile到bitmap
    Tilemap.prototype._paintAllMapTiles = function(bitmap, startX, startY) {
        var tileCols = this._mapWidth;
        var tileRows = this._mapHeight;
        for (var y = 0; y < tileRows; y++) {
            for (var x = 0; x < tileCols; x++) {
                this._paintActualTiles(bitmap, x, y);
            }
        }
    };
    // 新增 绘制一个tile到bitmap
    Tilemap.prototype._paintActualTiles = function(bitmap, x, y) {
        var tableEdgeVirtualId = 10000;
        var mx = x;
        var my = y;
        var dx = mx * this._tileWidth;
        var dy = my * this._tileHeight;
        var tileId0 = this._readMapData(mx, my, 0);
        var tileId1 = this._readMapData(mx, my, 1);
        var tileId2 = this._readMapData(mx, my, 2);
        var tileId3 = this._readMapData(mx, my, 3);
        var shadowBits = this._readMapData(mx, my, 4);
        var upperTileId1 = this._readMapData(mx, my - 1, 1);
        var lowerTiles = [];
        var upperTiles = [];

        if (this._isHigherTile(tileId0)) {
            upperTiles.push(tileId0);
        } else {
            lowerTiles.push(tileId0);
        }
        if (this._isHigherTile(tileId1)) {
            upperTiles.push(tileId1);
        } else {
            lowerTiles.push(tileId1);
        }

        lowerTiles.push(-shadowBits);

        if (this._isTableTile(upperTileId1) && !this._isTableTile(tileId1)) {
            if (!Tilemap.isShadowingTile(tileId0)) {
                lowerTiles.push(tableEdgeVirtualId + upperTileId1);
            }
        }

        if (this._isOverpassPosition(mx, my)) {
            upperTiles.push(tileId2);
            upperTiles.push(tileId3);
        } else {
            if (this._isHigherTile(tileId2)) {
                upperTiles.push(tileId2);
            } else {
                lowerTiles.push(tileId2);
            }
            if (this._isHigherTile(tileId3)) {
                upperTiles.push(tileId3);
            } else {
                lowerTiles.push(tileId3);
            }
        }


        for (var i = 0; i < lowerTiles.length; i++) {
            var lowerTileId = lowerTiles[i];
            if (lowerTileId < 0) {
                this._drawShadow(bitmap, shadowBits, dx, dy);
            } else if (lowerTileId >= tableEdgeVirtualId) {
                this._drawTableEdge(bitmap, upperTileId1, dx, dy);
            } else {
                this._drawTile(bitmap, lowerTileId, dx, dy);
            }
        }

        for (var j = 0; j < upperTiles.length; j++) {
            this._drawTile(bitmap, upperTiles[j], dx, dy);
        }
    };
    // 追加
    var _Scene_Boot_prototype_create = Scene_Boot.prototype.create;
    Scene_Boot.prototype.create = function() {
        DataManager.loadMapData(mapId);
        this.mapBitmapsLoaded = false;
        _Scene_Boot_prototype_create.call(this);
    };

    // 重写
    Scene_Boot.prototype.isReady = function() {
        if (Scene_Base.prototype.isReady.call(this)) {
            return DataManager.isDatabaseLoaded() && DataManager.isMapLoaded() && this.isGameFontLoaded();
        } else {
            return false;
        }
    };

    // 重写
    Scene_Boot.prototype.start = function() {
        DataManager.setupNewGame();
        $gameMap.setup(mapId);
        this.spriteset = new Spriteset_Map();
    };

    // 新增
    Scene_Boot.prototype.update = function() {
        console.log("Scene_Boot.update");
        if (!this.mapBitmapsLoaded && ImageManager.isReady()) {
            // 保存图片
            var tilemap = this.spriteset._tilemap;
            var width = tilemap._tileWidth * tilemap._mapWidth; //this._width;
            var height = tilemap._tileHeight * tilemap._mapHeight; //this._height;
            var bitmap = new Bitmap(width, height);
            tilemap._paintAllMapTiles(bitmap, 0, 0);
            window.location.href = bitmap.context.canvas.toDataURL("image/png").replace("image/png", "image/octet-stream");
            this.mapBitmapsLoaded = true
        }
        Scene_Base.prototype.update.call(this);
    };

}());

放进plugins里，用法参注释。