Added coffee version of bkcore.ImageData and added missing doc

bkcore.coffee/ImageData.js

@@ -0,0 +1,156 @@
+// Generated by CoffeeScript 1.4.0
+
+/*
+  Loads an image and gives access to pixel data.
+  
+  @class bkcore.ImageData
+  @author Thibaut 'BKcore' Despoulain <http://bkcore.com>
+*/
+
+
+(function() {
+  var ImageData, exports;
+
+  ImageData = (function() {
+    /*
+        Creates a new ImageData object
+        
+        @param path string The path of the image
+        @param callback function A callback function to be called
+          once th eimage is loaded
+    */
+
+    function ImageData(path, callback) {
+      var _this = this;
+      this.image = new Image;
+      this.pixels = null;
+      this.canvas = null;
+      this.loaded = false;
+      this.image.onload = function() {
+        var context;
+        _this.canvas = document.createElement('canvas');
+        _this.canvas.width = _this.image.width;
+        _this.canvas.height = _this.image.height;
+        context = _this.canvas.getContext('2d');
+        context.drawImage(_this.image, 0, 0);
+        _this.pixels = context.getImageData(0, 0, _this.canvas.width, _this.canvas.height);
+        _this.loaded = true;
+        context = null;
+        _this.canvas = null;
+        _this.image = null;
+        return callback != null ? callback.call(_this) : void 0;
+      };
+      this.image.crossOrigin = "anonymous";
+      this.image.src = path;
+    }
+
+    /*
+        Gets pixel RGBA data at given index
+        
+        @param x int In pixels
+        @param y int In pixels
+        @return Object{r,g,b,a}
+    */
+
+
+    ImageData.prototype.getPixel = function(x, y) {
+      var i;
+      if (!(this.pixels != null) || x < 0 || y < 0 || x >= this.pixels.width || y >= this.pixels.height) {
+        return {
+          r: 0,
+          g: 0,
+          b: 0,
+          a: 0
+        };
+      }
+      i = (y * this.pixels.width + x) * 4;
+      return {
+        r: this.pixels.data[i],
+        g: this.pixels.data[i + 1],
+        b: this.pixels.data[i + 2],
+        a: this.pixels.data[i + 3]
+      };
+    };
+
+    /*
+        Gets pixel RGBA data at given float index using bilinear interpolation
+        
+        @param x float In subpixels
+        @param y float In subpixels
+        @return Object{r,g,b,a}
+    */
+
+
+    ImageData.prototype.getPixelBilinear = function(fx, fy) {
+      var ax, ay, c, cf1, cf2, cx, cxy, cy, dx, dy, rx, ry, x, y;
+      x = Math.floor(fx);
+      y = Math.floor(fy);
+      rx = fx - x - .5;
+      ry = fy - y - .5;
+      ax = Math.abs(rx);
+      ay = Math.abs(ry);
+      dx = rx < 0 ? -1 : 1;
+      dy = ry < 0 ? -1 : 1;
+      c = this.getPixel(x, y);
+      cx = this.getPixel(x + dx, y);
+      cy = this.getPixel(x, y + dy);
+      cxy = this.getPixel(x + dx, y + dy);
+      cf1 = [(1 - ax) * c.r + ax * cx.r, (1 - ax) * c.g + ax * cx.g, (1 - ax) * c.b + ax * cx.b, (1 - ax) * c.a + ax * cx.a];
+      cf2 = [(1 - ax) * cy.r + ax * cxy.r, (1 - ax) * cy.g + ax * cxy.g, (1 - ax) * cy.b + ax * cxy.b, (1 - ax) * cy.a + ax * cxy.a];
+      return {
+        r: (1 - ay) * cf1[0] + ay * cf2[0],
+        g: (1 - ay) * cf1[1] + ay * cf2[1],
+        b: (1 - ay) * cf1[2] + ay * cf2[2],
+        a: (1 - ay) * cf1[3] + ay * cf2[3]
+      };
+    };
+
+    /*
+        Gets pixel data at given index
+        as 3-bytes integer (for floating-point textures erzats, from RGB values)
+        
+        @param x int In pixels
+        @param y int In pixels
+        @return int (R + G*255 + B*255*255)
+    */
+
+
+    ImageData.prototype.getPixelF = function(x, y) {
+      var c;
+      c = this.getPixel(x, y);
+      return c.r + c.g * 255 + c.b * 255 * 255;
+    };
+
+    /*
+        Gets pixel data at given float index using bilinear interpolationas
+        as 3-bytes integer (for floating-point textures erzats, from RGB values)
+        
+        @param x float In subpixels
+        @param y float In subpixels
+        @return Object{r,g,b,a}
+    */
+
+
+    ImageData.prototype.getPixelFBilinear = function(fx, fy) {
+      var c;
+      c = this.getPixelBilinear(fx, fy);
+      return c.r + c.g * 255 + c.b * 255 * 255;
+    };
+
+    return ImageData;
+
+  })();
+
+  /*
+    Exports
+    @package bkcore
+  */
+
+
+  exports = exports != null ? exports : this;
+
+  exports.bkcore || (exports.bkcore = {});
+
+  exports.bkcore.ImageData = ImageData;
+
+}).call(this);