Add raw image support

package.json

@@ -28,8 +28,7 @@
     "pretest": "standard examples/*.js test/server.js test/public/*.js benchmarks/run.js lib/context2d.js util/has_lib.js browser.js index.js && node-gyp build",
     "test": "mocha test/*.test.js",
     "pretest-server": "node-gyp build",
-    "test-server": "node test/server.js",
-    "install": "node-pre-gyp install --fallback-to-build"
+    "test-server": "node test/server.js"
   },
   "binary": {
     "module_name": "canvas",

src/Image.cc

@@ -61,6 +61,7 @@ Image::Initialize(Nan::ADDON_REGISTER_FUNCTION_ARGS_TYPE target) {
   SetProtoAccessor(proto, Nan::New("naturalWidth").ToLocalChecked(), GetNaturalWidth, NULL, ctor);
   SetProtoAccessor(proto, Nan::New("naturalHeight").ToLocalChecked(), GetNaturalHeight, NULL, ctor);
   SetProtoAccessor(proto, Nan::New("dataMode").ToLocalChecked(), GetDataMode, SetDataMode, ctor);
+  SetProtoAccessor(proto, Nan::New("rawData").ToLocalChecked(), GetRawData, NULL, ctor);
 
   ctor->Set(Nan::New("MODE_IMAGE").ToLocalChecked(), Nan::New<Number>(DATA_IMAGE));
   ctor->Set(Nan::New("MODE_MIME").ToLocalChecked(), Nan::New<Number>(DATA_MIME));
@@ -185,6 +186,25 @@ NAN_METHOD(Image::GetSource){
   info.GetReturnValue().Set(Nan::New<String>(img->filename ? img->filename : "").ToLocalChecked());
 }
 
+/*
+ * Get raw data.
+ */
+NAN_GETTER(Image::GetRawData) {
+  Image *img = Nan::ObjectWrap::Unwrap<Image>(info.This());
+  if (img->_surface) {
+    // Return raw ARGB data -- just a memcpy()
+    cairo_surface_t *surface = img->_surface;
+    cairo_surface_flush(surface);
+    const unsigned char *data = cairo_image_surface_get_data(surface);
+    unsigned int nBytes = cairo_image_surface_get_stride(surface) * img->height;
+    Local<Object> buf = Nan::CopyBuffer(reinterpret_cast<const char*>(data), nBytes).ToLocalChecked();
+    info.GetReturnValue().Set(buf);
+  } else {
+    info.GetReturnValue().Set(Nan::Undefined());
+  }
+  return;
+}
+
 /*
  * Clean up assets and variables.
  */

src/Image.h

@@ -53,6 +53,7 @@ class Image: public Nan::ObjectWrap {
     static NAN_SETTER(SetHeight);
     static NAN_METHOD(GetSource);
     static NAN_METHOD(SetSource);
+    static NAN_GETTER(GetRawData);
     inline uint8_t *data(){ return cairo_image_surface_get_data(_surface); }
     inline int stride(){ return cairo_image_surface_get_stride(_surface); }
     static int isPNG(uint8_t *data);

test/image.test.js

@@ -114,6 +114,14 @@ describe('Image', function () {
     })
   })
 
+  it('returns raw image data', function() {
+    const img = new Image();
+    img.src = png_clock;
+    const buf = img.rawData;
+    assert.ok(buf instanceof Buffer);
+    assert.strictEqual(buf.length, 409600);
+  })
+
   it('calls Image#onload multiple times', function () {
     return loadImage(png_clock).then((img) => {
       let onloadCalled = 0