GraphicsContext* HTMLCanvasElement::existingDrawingContext() const
{
if (!hasImageBuffer())
return 0;
return drawingContext();
}
void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r)
{
if (m_context) {
if (!paintsIntoCanvasBuffer())
return;
m_context->paintRenderingResultsToCanvas();
}
if (hasImageBuffer()) {
ImageBuffer* imageBuffer = buffer();
if (imageBuffer) {
CompositeOperator compositeOperator = !m_context || m_context->hasAlpha() ? CompositeSourceOver : CompositeCopy;
if (m_presentedImage)
context->drawImage(m_presentedImage.get(), pixelSnappedIntRect(r), compositeOperator, DoNotRespectImageOrientation);
else
context->drawImageBuffer(imageBuffer, pixelSnappedIntRect(r), 0, compositeOperator);
}
} else {
// When alpha is false, we should draw to opaque black.
if (m_context && !m_context->hasAlpha())
context->fillRect(FloatRect(r), Color(0, 0, 0));
}
if (is3D())
toWebGLRenderingContext(m_context.get())->markLayerComposited();
}
PassRefPtr<Image> blink::CanvasRenderingContext2D::getImage(
AccelerationHint hint,
SnapshotReason reason) const {
if (!hasImageBuffer())
return nullptr;
return canvas()->buffer()->newImageSnapshot(hint, reason);
}
void HTMLCanvasElement::reset()
{
if (m_ignoreReset)
return;
resetDirtyRect();
bool ok;
bool hadImageBuffer = hasImageBuffer();
int w = getAttribute(widthAttr).toInt(&ok);
if (!ok || w < 0)
w = DefaultWidth;
int h = getAttribute(heightAttr).toInt(&ok);
if (!ok || h < 0)
h = DefaultHeight;
if (m_contextStateSaver) {
// Reset to the initial graphics context state.
m_contextStateSaver->restore();
m_contextStateSaver->save();
}
if (m_context && m_context->is2d())
toCanvasRenderingContext2D(m_context.get())->reset();
IntSize oldSize = size();
IntSize newSize(w, h);
// If the size of an existing buffer matches, we can just clear it instead of reallocating.
// This optimization is only done for 2D canvases for now.
if (hadImageBuffer && oldSize == newSize && m_context && m_context->is2d()) {
if (!m_didClearImageBuffer)
clearImageBuffer();
return;
}
setSurfaceSize(newSize);
if (m_context && m_context->is3d() && oldSize != size())
toWebGLRenderingContext(m_context.get())->reshape(width(), height());
if (RenderObject* renderer = this->renderer()) {
if (renderer->isCanvas()) {
if (oldSize != size()) {
toRenderHTMLCanvas(renderer)->canvasSizeChanged();
if (renderBox() && renderBox()->hasAcceleratedCompositing())
renderBox()->contentChanged(CanvasChanged);
}
if (hadImageBuffer)
renderer->setShouldDoFullPaintInvalidation(true);
}
}
WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator end = m_observers.end();
for (WillBeHeapHashSet<RawPtrWillBeWeakMember<CanvasObserver> >::iterator it = m_observers.begin(); it != end; ++it)
(*it)->canvasResized(this);
}
void HTMLCanvasElement::ensureUnacceleratedImageBuffer()
{
if ((hasImageBuffer() && !m_imageBuffer->isAccelerated()) || m_didFailToCreateImageBuffer)
return;
discardImageBuffer();
OpacityMode opacityMode = !m_context || m_context->hasAlpha() ? NonOpaque : Opaque;
m_imageBuffer = ImageBuffer::create(size(), opacityMode);
m_didFailToCreateImageBuffer = !m_imageBuffer;
}
void HTMLCanvasElement::didProcessTask()
{
// This method gets invoked if didDraw was called earlier in the current task.
ASSERT(!m_dirtyRect.isEmpty());
if (is3D()) {
didFinalizeFrame();
} else {
ASSERT(hasImageBuffer());
m_imageBuffer->finalizeFrame(m_dirtyRect);
}
ASSERT(m_dirtyRect.isEmpty());
}
void HTMLCanvasElement::clearImageBuffer()
{
ASSERT(hasImageBuffer() && !m_didFailToCreateImageBuffer);
ASSERT(!m_didClearImageBuffer);
ASSERT(m_context);
m_didClearImageBuffer = true;
if (m_context->is2d()) {
// No need to undo transforms/clip/etc. because we are called right
// after the context is reset.
toCanvasRenderingContext2D(m_context.get())->clearRect(0, 0, width(), height());
}
}
AffineTransform HTMLCanvasElement::baseTransform() const
{
ASSERT(hasImageBuffer() && !m_didFailToCreateImageBuffer);
return m_imageBuffer->baseTransform();
}
ImageBuffer* HTMLCanvasElement::buffer() const
{
if (!hasImageBuffer() && !m_didFailToCreateImageBuffer)
const_cast<HTMLCanvasElement*>(this)->createImageBuffer();
return m_imageBuffer.get();
}