OffscreenCanvas.cpp [plain text]
#include "config.h"
#include "OffscreenCanvas.h"
#if ENABLE(OFFSCREEN_CANVAS)
#include "CSSValuePool.h"
#include "CanvasRenderingContext.h"
#include "Document.h"
#include "HTMLCanvasElement.h"
#include "ImageBitmap.h"
#include "ImageData.h"
#include "JSBlob.h"
#include "JSDOMPromiseDeferred.h"
#include "MIMETypeRegistry.h"
#include "OffscreenCanvasRenderingContext2D.h"
#include "PlaceholderRenderingContext.h"
#include "WebGLRenderingContext.h"
#include "WorkerGlobalScope.h"
#include <wtf/IsoMallocInlines.h>
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(OffscreenCanvas);
DetachedOffscreenCanvas::DetachedOffscreenCanvas(std::unique_ptr<ImageBuffer>&& buffer, const IntSize& size, bool originClean)
: m_buffer(WTFMove(buffer))
, m_size(size)
, m_originClean(originClean)
{
}
std::unique_ptr<ImageBuffer> DetachedOffscreenCanvas::takeImageBuffer()
{
return WTFMove(m_buffer);
}
WeakPtr<HTMLCanvasElement> DetachedOffscreenCanvas::takePlaceholderCanvas()
{
ASSERT(isMainThread());
return std::exchange(m_placeholderCanvas, nullptr);
}
Ref<OffscreenCanvas> OffscreenCanvas::create(ScriptExecutionContext& context, unsigned width, unsigned height)
{
return adoptRef(*new OffscreenCanvas(context, width, height));
}
Ref<OffscreenCanvas> OffscreenCanvas::create(ScriptExecutionContext& context, std::unique_ptr<DetachedOffscreenCanvas>&& detachedCanvas)
{
Ref<OffscreenCanvas> clone = adoptRef(*new OffscreenCanvas(context, detachedCanvas->size().width(), detachedCanvas->size().height()));
clone->setImageBuffer(detachedCanvas->takeImageBuffer());
if (!detachedCanvas->originClean())
clone->setOriginTainted();
callOnMainThread([detachedCanvas = WTFMove(detachedCanvas), offscreenCanvas = makeRef(clone.get())] () mutable {
offscreenCanvas->m_placeholderCanvas = detachedCanvas->takePlaceholderCanvas();
offscreenCanvas->scriptExecutionContext()->postTask({ ScriptExecutionContext::Task::CleanupTask,
[releaseOffscreenCanvas = WTFMove(offscreenCanvas)] (ScriptExecutionContext&) { } });
});
return clone;
}
Ref<OffscreenCanvas> OffscreenCanvas::create(ScriptExecutionContext& context, HTMLCanvasElement& canvas)
{
auto offscreen = adoptRef(*new OffscreenCanvas(context, canvas.width(), canvas.height()));
offscreen->setPlaceholderCanvas(canvas);
return offscreen;
}
OffscreenCanvas::OffscreenCanvas(ScriptExecutionContext& context, unsigned width, unsigned height)
: CanvasBase(IntSize(width, height))
, ContextDestructionObserver(&context)
{
}
OffscreenCanvas::~OffscreenCanvas()
{
notifyObserversCanvasDestroyed();
m_context = nullptr; setImageBuffer(nullptr);
}
unsigned OffscreenCanvas::width() const
{
if (m_detached)
return 0;
return CanvasBase::width();
}
unsigned OffscreenCanvas::height() const
{
if (m_detached)
return 0;
return CanvasBase::height();
}
void OffscreenCanvas::setWidth(unsigned newWidth)
{
if (m_detached)
return;
setSize(IntSize(newWidth, height()));
}
void OffscreenCanvas::setHeight(unsigned newHeight)
{
if (m_detached)
return;
setSize(IntSize(width(), newHeight));
}
void OffscreenCanvas::setSize(const IntSize& newSize)
{
CanvasBase::setSize(newSize);
reset();
}
ExceptionOr<Optional<OffscreenRenderingContext>> OffscreenCanvas::getContext(JSC::JSGlobalObject& state, RenderingContextType contextType, Vector<JSC::Strong<JSC::Unknown>>&& arguments)
{
if (m_detached)
return Exception { InvalidStateError };
if (contextType == RenderingContextType::_2d) {
if (m_context) {
if (!is<OffscreenCanvasRenderingContext2D>(*m_context))
return { { WTF::nullopt } };
return { { RefPtr<OffscreenCanvasRenderingContext2D> { &downcast<OffscreenCanvasRenderingContext2D>(*m_context) } } };
}
m_context = makeUnique<OffscreenCanvasRenderingContext2D>(*this);
if (!m_context)
return { { WTF::nullopt } };
return { { RefPtr<OffscreenCanvasRenderingContext2D> { &downcast<OffscreenCanvasRenderingContext2D>(*m_context) } } };
}
#if ENABLE(WEBGL)
if (contextType == RenderingContextType::Webgl) {
if (m_context) {
if (is<WebGLRenderingContext>(*m_context))
return { { RefPtr<WebGLRenderingContext> { &downcast<WebGLRenderingContext>(*m_context) } } };
return { { WTF::nullopt } };
}
auto scope = DECLARE_THROW_SCOPE(state.vm());
auto attributes = convert<IDLDictionary<WebGLContextAttributes>>(state, !arguments.isEmpty() ? arguments[0].get() : JSC::jsUndefined());
RETURN_IF_EXCEPTION(scope, Exception { ExistingExceptionError });
m_context = WebGLRenderingContextBase::create(*this, attributes, "webgl");
if (!m_context)
return { { WTF::nullopt } };
return { { RefPtr<WebGLRenderingContext> { &downcast<WebGLRenderingContext>(*m_context) } } };
}
#endif
return Exception { TypeError };
}
ExceptionOr<RefPtr<ImageBitmap>> OffscreenCanvas::transferToImageBitmap()
{
if (m_detached || !m_context)
return Exception { InvalidStateError };
if (is<OffscreenCanvasRenderingContext2D>(*m_context)) {
if (!width() || !height())
return { RefPtr<ImageBitmap> { nullptr } };
if (!m_hasCreatedImageBuffer)
return { ImageBitmap::create({ ImageBuffer::create(size(), RenderingMode::Unaccelerated), ImageBuffer::SerializationState { true, false, false }}) };
auto buffer = takeImageBuffer();
if (!buffer)
return { RefPtr<ImageBitmap> { nullptr } };
return { ImageBitmap::create({ WTFMove(buffer), ImageBuffer::SerializationState { originClean(), false, false }}) };
}
#if ENABLE(WEBGL)
if (is<WebGLRenderingContext>(*m_context)) {
auto webGLContext = &downcast<WebGLRenderingContext>(*m_context);
auto imageBitmap = ImageBitmap::create(size());
if (!imageBitmap->buffer())
return { RefPtr<ImageBitmap> { nullptr } };
auto* gc3d = webGLContext->graphicsContextGL();
gc3d->paintRenderingResultsToCanvas(imageBitmap->buffer());
GCGLfloat clearColor[4];
gc3d->getFloatv(GraphicsContextGL::COLOR_CLEAR_VALUE, clearColor);
gc3d->clearColor(0, 0, 0, 0);
gc3d->clear(GraphicsContextGL::COLOR_BUFFER_BIT | GraphicsContextGL::DEPTH_BUFFER_BIT | GraphicsContextGL::STENCIL_BUFFER_BIT);
gc3d->clearColor(clearColor[0], clearColor[1], clearColor[2], clearColor[3]);
return { WTFMove(imageBitmap) };
}
#endif
return Exception { NotSupportedError };
}
static String toEncodingMimeType(const String& mimeType)
{
if (!MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType))
return "image/png"_s;
return mimeType.convertToASCIILowercase();
}
static Optional<double> qualityFromDouble(double qualityNumber)
{
if (!(qualityNumber >= 0 && qualityNumber <= 1))
return WTF::nullopt;
return qualityNumber;
}
void OffscreenCanvas::convertToBlob(ImageEncodeOptions&& options, Ref<DeferredPromise>&& promise)
{
if (!originClean()) {
promise->reject(SecurityError);
return;
}
if (size().isEmpty()) {
promise->reject(IndexSizeError);
return;
}
if (m_detached || !buffer()) {
promise->reject(InvalidStateError);
return;
}
makeRenderingResultsAvailable();
auto encodingMIMEType = toEncodingMimeType(options.type);
auto quality = qualityFromDouble(options.quality);
Vector<uint8_t> blobData = buffer()->toData(encodingMIMEType, quality);
if (blobData.isEmpty()) {
promise->reject(EncodingError);
return;
}
Ref<Blob> blob = Blob::create(canvasBaseScriptExecutionContext(), WTFMove(blobData), encodingMIMEType);
promise->resolveWithNewlyCreated<IDLInterface<Blob>>(WTFMove(blob));
}
void OffscreenCanvas::didDraw(const FloatRect& rect)
{
clearCopiedImage();
scheduleCommitToPlaceholderCanvas();
notifyObserversCanvasChanged(rect);
}
Image* OffscreenCanvas::copiedImage() const
{
if (m_detached)
return nullptr;
if (!m_copiedImage && buffer()) {
if (m_context)
m_context->paintRenderingResultsToCanvas();
m_copiedImage = buffer()->copyImage(CopyBackingStore, PreserveResolution::Yes);
}
return m_copiedImage.get();
}
void OffscreenCanvas::clearCopiedImage() const
{
m_copiedImage = nullptr;
}
SecurityOrigin* OffscreenCanvas::securityOrigin() const
{
auto& context = *canvasBaseScriptExecutionContext();
if (is<WorkerGlobalScope>(context))
return &downcast<WorkerGlobalScope>(context).topOrigin();
return &downcast<Document>(context).securityOrigin();
}
bool OffscreenCanvas::canDetach() const
{
return !m_detached && !m_context;
}
std::unique_ptr<DetachedOffscreenCanvas> OffscreenCanvas::detach()
{
if (!canDetach())
return nullptr;
m_detached = true;
auto detached = makeUnique<DetachedOffscreenCanvas>(takeImageBuffer(), size(), originClean());
detached->m_placeholderCanvas = std::exchange(m_placeholderCanvas, nullptr);
return detached;
}
void OffscreenCanvas::setPlaceholderCanvas(HTMLCanvasElement& canvas)
{
ASSERT(!m_context);
ASSERT(isMainThread());
m_placeholderCanvas = makeWeakPtr(canvas);
}
void OffscreenCanvas::pushBufferToPlaceholder()
{
callOnMainThread([protectedThis = makeRef(*this), this] () mutable {
auto locker = holdLock(m_commitLock);
if (m_placeholderCanvas && m_hasPendingCommitData) {
std::unique_ptr<ImageBuffer> buffer = ImageBuffer::create(FloatSize(m_pendingCommitData->size()), RenderingMode::Unaccelerated);
buffer->putImageData(AlphaPremultiplication::Premultiplied, *m_pendingCommitData, IntRect(IntPoint(), m_pendingCommitData->size()));
m_placeholderCanvas->setImageBufferAndMarkDirty(WTFMove(buffer));
m_hasPendingCommitData = false;
}
scriptExecutionContext()->postTask([releaseThis = WTFMove(protectedThis)] (ScriptExecutionContext&) { });
});
}
void OffscreenCanvas::commitToPlaceholderCanvas()
{
auto* imageBuffer = buffer();
if (!imageBuffer)
return;
if (m_context && (m_context->isWebGL() || m_context->isAccelerated()))
m_context->paintRenderingResultsToCanvas();
if (isMainThread()) {
if (m_placeholderCanvas) {
if (auto bufferCopy = imageBuffer->copyRectToBuffer(FloatRect(FloatPoint(), imageBuffer->logicalSize()), ColorSpace::SRGB, imageBuffer->context()))
m_placeholderCanvas->setImageBufferAndMarkDirty(WTFMove(bufferCopy));
}
return;
}
auto locker = holdLock(m_commitLock);
bool shouldPushBuffer = !m_hasPendingCommitData;
m_pendingCommitData = imageBuffer->getImageData(AlphaPremultiplication::Premultiplied, IntRect(IntPoint(), imageBuffer->logicalSize()));
m_hasPendingCommitData = true;
if (shouldPushBuffer)
pushBufferToPlaceholder();
}
void OffscreenCanvas::scheduleCommitToPlaceholderCanvas()
{
if (!m_hasScheduledCommit) {
auto& scriptContext = *scriptExecutionContext();
m_hasScheduledCommit = true;
scriptContext.postTask([protectedThis = makeRef(*this), this] (ScriptExecutionContext&) {
m_hasScheduledCommit = false;
commitToPlaceholderCanvas();
});
}
}
CSSValuePool& OffscreenCanvas::cssValuePool()
{
auto* context = canvasBaseScriptExecutionContext();
if (context->isWorkerGlobalScope())
return downcast<WorkerGlobalScope>(*context).cssValuePool();
ASSERT(context->isDocument());
return CSSValuePool::singleton();
}
void OffscreenCanvas::createImageBuffer() const
{
m_hasCreatedImageBuffer = true;
if (!width() || !height())
return;
setImageBuffer(ImageBuffer::create(size(), RenderingMode::Unaccelerated));
}
std::unique_ptr<ImageBuffer> OffscreenCanvas::takeImageBuffer() const
{
if (!m_detached)
m_hasCreatedImageBuffer = true;
if (size().isEmpty())
return nullptr;
clearCopiedImage();
return setImageBuffer(m_detached ? nullptr : ImageBuffer::create(size(), RenderingMode::Unaccelerated));
}
void OffscreenCanvas::reset()
{
resetGraphicsContextState();
if (is<OffscreenCanvasRenderingContext2D>(m_context.get()))
downcast<OffscreenCanvasRenderingContext2D>(*m_context).reset();
m_hasCreatedImageBuffer = false;
setImageBuffer(nullptr);
clearCopiedImage();
notifyObserversCanvasResized();
scheduleCommitToPlaceholderCanvas();
}
}
#endif