Tileset: tile lookup features

Author: mikewesthad

v3/src/gameobjects/tilemap/Tileset.js

@@ -0,0 +1,88 @@
+var Class = require('../../utils/Class');
+
+var Tileset = new Class({
+
+    initialize:
+
+    function Tileset (name, firstgid, tileWidth, tileHeight, tileMargin, tileSpacing, properties)
+    {
+        if (tileWidth === undefined || tileWidth <= 0) { tileWidth = 32; }
+        if (tileHeight === undefined || tileHeight <= 0) { tileHeight = 32; }
+        if (tileMargin === undefined) { tileMargin = 0; }
+        if (tileSpacing === undefined) { tileSpacing = 0; }
+
+        this.name = name;
+        this.firstgid = firstgid;
+        this.tileWidth = tileWidth;
+        this.tileHeight = tileHeight;
+        this.tileMargin = tileMargin;
+        this.tileSpacing = tileSpacing;
+        this.properties = properties;
+        this.image = null;
+        this.rows = 0;
+        this.columns = 0;
+        this.total = 0;
+        this.texCoordinates = [];
+    },
+
+    setImage: function (texture)
+    {
+        this.image = texture;
+        this.updateTileData(this.image.source[0].width, this.image.source[0].height);
+    },
+
+    containsTileIndex: function (tileIndex)
+    {
+        return (
+            tileIndex >= this.firstgid &&
+            tileIndex < (this.firstgid + this.total)
+        );
+    },
+
+    getTileTextureCoordinates: function (tileIndex)
+    {
+        if (!this.containsTileIndex(tileIndex)) { return null; }
+        return this.texCoordinates[tileIndex - this.firstgid];
+    },
+
+    updateTileData: function (imageWidth, imageHeight)
+    {
+        var rowCount = (imageHeight - this.tileMargin * 2 + this.tileSpacing) / (this.tileHeight + this.tileSpacing);
+        var colCount = (imageWidth - this.tileMargin * 2 + this.tileSpacing) / (this.tileWidth + this.tileSpacing);
+
+        if (rowCount % 1 !== 0 || colCount % 1 !== 0)
+        {
+            console.warn('Tileset ' + this.name + ' image tile area is not an even multiple of tile size');
+        }
+
+        // In Tiled a tileset image that is not an even multiple of the tile dimensions
+        // is truncated - hence the floor when calculating the rows/columns.
+        rowCount = Math.floor(rowCount);
+        colCount = Math.floor(colCount);
+
+        this.rows = rowCount;
+        this.columns = colCount;
+
+        // In Tiled, "empty" spaces in a tileset count as tiles and hence count towards the gid
+        this.total = rowCount * colCount;
+
+        this.texCoordinates.length = 0;
+
+        var tx = this.tileMargin;
+        var ty = this.tileMargin;
+
+        for (var y = 0; y < this.rows; y++)
+        {
+            for (var x = 0; x < this.columns; x++)
+            {
+                this.texCoordinates.push({ x: tx, y: ty });
+                tx += this.tileWidth + this.tileSpacing;
+            }
+
+            tx = this.tileMargin;
+            ty += this.tileHeight + this.tileSpacing;
+        }
+    }
+});
+
+module.exports = Tileset;