Issue 2972: Canvas toDataURL isn't supported
http://code.google.com/p/chromium/issues/detail?id=2972
Comment #6 by [EMAIL PROTECTED]:
When implementing this be sure and pick up the tests identified in 2972,
they are all related.
Here's an implementation of getImageData I started on:
PassRefPtr<ImageData> ImageBuffer::getImageData(const IntRect& rect) const
{
PassRefPtr<ImageData> result = ImageData::create(rect.width(),
rect.height());
unsigned char* data = result->data()->data().data();
if (rect.x() < 0 || rect.y() < 0 || (rect.x() + rect.width()) >
m_size.width() || (rect.y() +
rect.height()) > m_size.height())
memset(data, 0, result->data()->length());
int originx = rect.x();
int destx = 0;
if (originx < 0) {
destx = -originx;
originx = 0;
}
int endx = rect.x() + rect.width();
if (endx > m_size.width())
endx = m_size.width();
int numColumns = endx - originx;
int originy = rect.y();
int desty = 0;
if (originy < 0) {
desty = -originy;
originy = 0;
}
int endy = rect.y() + rect.height();
if (endy > m_size.height())
endy = m_size.height();
int numRows = endy - originy;
unsigned srcBytesPerRow = 4 * m_size.width();
unsigned destBytesPerRow = 4 * numColumns;
unsigned char* srcRows = reinterpret_cast<unsigned
char*>(context()->platformContext()->bitmap()-
>getAddr32(0, 0)) + originy * srcBytesPerRow + originx * 4;
unsigned char* destRows = data + desty * destBytesPerRow + destx * 4;
for (int y = 0; y < numRows; ++y) {
memcpy(destRows, srcRows, destBytesPerRow);
srcRows += srcBytesPerRow;
destRows += destBytesPerRow;
}
return result;
}
Additionally you'll need to define a custom indexed getters in the v8
binding code. Here's a start at
that (in v8_proxy.cc):
static v8::Handle<v8::Value> GetIndexedPropertyOfCanvasPixelArray(
uint32_t index, v8::Local<v8::Object> object, v8::Local<v8::Value>
data) {
// TODO, assert that object must be a collection type
ASSERT(V8Proxy::MaybeDOMWrapper(object));
V8ClassIndex::V8WrapperType t = V8Proxy::GetDOMWrapperType(object);
ASSERT(t != V8ClassIndex::NODE);
CanvasPixelArray* pixel_array =
V8Proxy::ToNativeObject<CanvasPixelArray>(t, object);
unsigned char result;
if (!pixel_array->get(index, result))
return return v8::Handle<v8::Value>();
// Need to return value here.
}
And add the following switch to V8Proxy::GetTemplate:
case V8ClassIndex::CANVASPIXELARRAY:
desc->InstanceTemplate()->SetIndexedPropertyHandler(
GetIndexedPropertyOfCanvasPixelArray());
break;
The IDL also defines a custom index setter. That'll have to be wired up in
the binding code as well
with a custom function.
Issue attribute updates:
Cc: [EMAIL PROTECTED]
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