add drawing methods to Ox.Image, allow for asynchronous image manipulation

source/Ox.Image/Ox.Image.js

@@ -180,6 +180,16 @@ Ox.load.Image = function(options, callback) {
             });
         };
 
+        /*@
+        drawCircle <f> Draws a circle
+            (point, radius, options) -> <o> The image object
+            point <[n]> Center (<code>[x, y]</code>)
+            radius <n> Radius in px
+            options <o> Options
+                color <s|'rgb(0, 0, 0)'> CSS color
+                fill <s|'rgba(0, 0, 0, 0)'> CSS color
+                width <n|1> Line width in px
+        @*/
         that.drawCircle = function(point, radius, options) {
             options = options || {};
             that.context.strokeStyle = options.color || 'rgb(0, 0, 0)';
@@ -192,6 +202,14 @@ Ox.load.Image = function(options, callback) {
             return that;
         };
 
+        /*@
+        drawLine <f> Draws a line
+            (points, options) -> <o> The image object
+            points <[a]> End points (<code>[[x1, y1], [x2, y2]]</code>)
+            options <o> Options
+                color <s|'rgb(0, 0, 0)'> CSS color
+                width <n|1> Line width in px
+        @*/
         that.drawLine = function(points, options, isPath) {
             options = options || {};
             that.context.strokeStyle = options.color || 'rgb(0, 0, 0)';
@@ -203,6 +221,15 @@ Ox.load.Image = function(options, callback) {
             return that;
         };
 
+        /*@
+        drawPath <f> Draws a path
+            (points, options) -> <o> The image object
+            points <[a]> Points (<code>[[x1, y2], [x2, y2], ...]</code>)
+            options <o> Options
+                color <s|'rgb(0, 0, 0)'> CSS color
+                fill <s|'rgba(0, 0, 0, 0)'> CSS color
+                width <n|1> Line width in px
+        @*/
         that.drawPath = function(points, options) {
             var n = points.length;
             options = options || {};
@@ -217,6 +244,16 @@ Ox.load.Image = function(options, callback) {
             return that;
         };
 
+        /*@
+        drawRectangle <f> Draws a rectangle
+            (point, size, options) -> <o> The image object
+            point <[n]> Top left corner (<code>[x, y]</code>)
+            size <[n]> Width and height in px (<code>[w, h]</code>)
+            options <o> Options
+                color <s|'rgb(0, 0, 0)'> CSS color
+                fill <s|'rgba(0, 0, 0, 0)'> CSS color
+                width <n|1> Line width in px
+        @*/
         that.drawRectangle = function(point, size, options) {
             options = options || {};
             that.context.strokeStyle = options.color || 'rgb(0, 0, 0)';
@@ -227,6 +264,17 @@ Ox.load.Image = function(options, callback) {
             return that;
         };
 
+        /*@
+        drawText <f> Draws text
+            (text, point, options) -> <o> The image object
+            text <s> Text
+            point <[n]> Top left corner (<code>[x, y]</code>)
+            options <o> Options
+                color <s|'rgb(0, 0, 0)'> CSS color
+                font <s|'10px sans-serif'> CSS font
+                outline <s|'0px rgba(0, 0, 0, 0)'> CSS border
+                textAlign <n|'start'> CSS text-align
+        @*/
         that.drawText = function(text, point, options) {
             options = options || {};
             var match = (
@@ -322,10 +370,9 @@ Ox.load.Image = function(options, callback) {
                 });
             }));
             b = 0;
-            that.forEach(function(rgba, xy) {
+            that.forEach(function(rgba, xy, index) {
                 // If alpha is not 255, the RGB values may not be preserved
                 if (rgba[3] == 255) {
-                    var index = getIndex(xy);
                     Ox.loop(3, function(c) {
                         // fixme: use: var data = that.context.imageData.data[i + c]
                         var i = index + c;
@@ -346,9 +393,10 @@ Ox.load.Image = function(options, callback) {
                         });
                     });
                 }
+            }, function() {
+                that.context.putImageData(self.imageData, 0, 0);
+                callback(that);
             });
-            that.context.putImageData(self.imageData, 0, 0);
-            callback(that);
             return that;
         };
 
@@ -376,9 +424,8 @@ Ox.load.Image = function(options, callback) {
                     return mode & 1 << b ? b : null;
                 }),
                 done = 0, len = 4, str = '';
-            that.forEach(function(rgba, xy) {
+            that.forEach(function(rgba, xy, index) {
                 if (rgba[3] == 255) {
-                    var index = getIndex(xy);
                     Ox.loop(3, function(c) {
                         var i = index + c;
                         Ox.forEach(bits, function(bit) {
@@ -415,16 +462,18 @@ Ox.load.Image = function(options, callback) {
                     });
                     return done != 2;
                 }
-            });
+            }, function() {
-            try {
+                try {
-                if (deflate) {
+                    if (deflate) {
-                    Ox.decodeDeflate(str, callback);
+                        Ox.decodeDeflate(str, callback);
-                } else {
+                    } else {
-                    callback(Ox.decodeUTF8(str));
+                        callback(Ox.decodeUTF8(str));
+                    }
+                } catch (e) {
+                    error('decode');
                 }
-            } catch (e) {
+            });
-                error('decode');
+            return that;
-            }
         }
 
         /*@
@@ -473,26 +522,40 @@ Ox.load.Image = function(options, callback) {
         };
 
         /*@
-        forEach <f> Pixel-wise forEach function
+        forEach <f> Pixel-wise forEach loop
         (fn) -> <o> The image object
+        (fn, callback) -> <o> The image object
         fn <f> Iterator function
             rgba <[n]> RGBA values
             xy <[n]> XY coordinates
+            i <n> Pixel index
+        callback <f> Callback function (if present, forEach is async)
         @*/
-        that.forEach = function(fn) {
+        that.forEach = function(fn, callback) {
-            Ox.loop(0, self.data.length, 4, function(i) {
+            var data = self.data;
+            Ox._loop(0, data.length, 4, function(i) {
                 return fn([
-                    self.data[i], self.data[i + 1],
+                    data[i], data[i + 1], data[i + 2], data[i + 3]
-                    self.data[i + 2], self.data[i + 3]
+                ], getXY(i), i);
-                ], getXY(i));
+            }, 10000, callback);
-            })
             return that;
         };
 
+        /*@
+        getSize <f> Returns width and height
+            () -> <o> Image size
+                width <n> Width in px
+                height <n> Height in px
+        @*/
         that.getSize = function() {
             return {width: self.width, height: self.height};
         };
 
+        /*@
+        hue <f> Change the hue of the image
+            (val) -> <o> The image object
+            val <n> Hue, in degrees
+        @*/
         that.hue = function(val) {
             return that.map(function(rgba) {
                 var hsl = Ox.hsl([rgba[0], rgba[1], rgba[2]]), rgb;
@@ -511,7 +574,6 @@ Ox.load.Image = function(options, callback) {
             (imageData) -> <o> Image object with new image data
             imageData <o> ImageData object
         @*/
-
         that.imageData = function() {
             if (arguments.length == 0) {
                 return self.imageData;
@@ -545,18 +607,16 @@ Ox.load.Image = function(options, callback) {
         fn <f> Iterator function
             rgba <[n]> RGBA values
             xy <[n]> XY coordinates
+            i <n> Pixel index
         @*/
-        that.map = function(fn) {
+        that.map = function(fn, callback) {
             self.imageData = that.context.getImageData(0, 0, self.width, self.height);
             self.data = self.imageData.data;
-            Ox.loop(0, self.data.length, 4, function(i) {
+            that.forEach(function(rgba, xy, i) {
-                fn([
+                fn(rgba, xy, i).forEach(function(val, c) {
-                    self.data[i], self.data[i + 1],
-                    self.data[i + 2], self.data[i + 3]
-                ], getXY(i)).forEach(function(val, c) {
                     self.data[i + c] = val;
                 });
-            })
+            });
             that.context.putImageData(self.imageData, 0, 0);
             return that;
         };
@@ -650,7 +710,7 @@ Ox.load.Image = function(options, callback) {
         };
 
         that.resize = function(width, height) {
-            // fixme: may not work this way
+            // fixme: doesn't work this way
             that.canvas.attr({
                 width: width,
                 height: height