Started getImageData()

lib/context2d.js

@@ -12,6 +12,8 @@
 var canvas = require('../build/default/canvas')
   , Context2d = canvas.CanvasRenderingContext2d
   , CanvasGradient = canvas.CanvasGradient
+  , ImageData = canvas.ImageData
+  , PixelArray = canvas.CanvasPixelArray
   , colors = require('./colors');
 
 /**
@@ -448,4 +450,20 @@ Context2d.prototype.__defineSetter__('textAlign', function(val){
 
 Context2d.prototype.__defineGetter__('textAlign', function(){
   return this.lastTextAlignment || 'start';
-});
+});
+
+/**
+ * Get `ImageData` with the given rect.
+ *
+ * @param {Number} x
+ * @param {Number} y
+ * @param {Number} width
+ * @param {Number} height
+ * @return {ImageData}
+ * @api public
+ */
+
+Context2d.prototype.getImageData = function(x, y, width, height){
+  var arr = new PixelArray(this.canvas, x, y, width, height);
+  return new ImageData(arr);
+};

src/ImageData.cc

@@ -33,8 +33,9 @@ Handle<Value>
 ImageData::New(const Arguments &args) {
   HandleScope scope;
   // TODO: arg assertions
-  PixelArray *data = ObjectWrap::Unwrap<PixelArray>(args[0]->ToObject());
-  ImageData *imageData = new ImageData(data);
+  PixelArray *arr = ObjectWrap::Unwrap<PixelArray>(args[0]->ToObject());
+  ImageData *imageData = new ImageData(arr);
+  args.This()->Set(String::NewSymbol("data"), args[0]);
   imageData->Wrap(args.This());
   return args.This();
 }
@@ -57,4 +58,4 @@ Handle<Value>
 ImageData::GetHeight(Local<String> prop, const AccessorInfo &info) {
   ImageData *imageData = ObjectWrap::Unwrap<ImageData>(info.This());
   return Number::New(imageData->pixelArray()->height());
-}
+}

src/ImageData.h

@@ -20,9 +20,8 @@ class ImageData: public node::ObjectWrap {
     static Handle<Value> GetHeight(Local<String> prop, const AccessorInfo &info);
     inline PixelArray *pixelArray(){ return _arr; }
     ImageData(PixelArray *arr): _arr(arr) {}
-    ~ImageData() { delete _arr; };
   private:
     PixelArray *_arr;
 };
 
-#endif
+#endif

src/PixelArray.cc

@@ -56,7 +56,6 @@ PixelArray::New(const Arguments &args) {
     default:
       return ThrowException(Exception::TypeError(String::New("invalid arguments")));
   }
-
   // Let v8 handle accessors (and clamping)
   args.This()->SetIndexedPropertiesToPixelData(
       arr->data()
@@ -81,6 +80,8 @@ PixelArray::GetLength(Local<String> prop, const AccessorInfo &info) {
 
 PixelArray::PixelArray(Canvas *canvas, int src_x, int src_y, int width, int height):
   _width(width), _height(height) {
+  _data = (uint8_t *) malloc(length());
+  memset(_data, 0, length());
 }
 
 PixelArray::PixelArray(int width, int height):
@@ -90,5 +91,5 @@ PixelArray::PixelArray(int width, int height):
 }
 
 PixelArray::~PixelArray() {
-
-}
+  free(_data);
+}

src/PixelArray.h

@@ -29,4 +29,4 @@ class PixelArray: public node::ObjectWrap {
     int _width, _height;
 };
 
-#endif
+#endif