void DrawingBuffer::paintCompositedResultsToCanvas(ImageBuffer* imageBuffer)
{
if (!m_context || !m_context->makeContextCurrent() || m_context->getExtensions()->getGraphicsResetStatusARB() != GraphicsContext3D::NO_ERROR)
return;
Extensions3D* extensions = m_context->getExtensions();
#if ENABLE(CANVAS_USES_MAILBOX)
// Since the m_frontColorBuffer was produced and sent to the compositor, it cannot be bound to an fbo.
// We have to make a copy of it here and bind that copy instead.
unsigned sourceTexture = createColorTexture(m_size);
extensions->copyTextureCHROMIUM(GraphicsContext3D::TEXTURE_2D, m_frontColorBuffer, sourceTexture, 0, GraphicsContext3D::RGBA, GraphicsContext3D::UNSIGNED_BYTE);
#else
// FIXME: Re-examine general correctness of this code beacause m_colorBuffer may contain a stale copy of the data
// that was sent to the compositor at some point in the past.
unsigned sourceTexture = frontColorBuffer();
#endif // ENABLE(CANVAS_USES_MAILBOX)
// Since we're using the same context as WebGL, we have to restore any state we change (in this case, just the framebuffer binding).
// FIXME: The WebGLRenderingContext tracks the current framebuffer binding, it would be slightly more efficient to use this value
// rather than querying it off of the context.
GC3Dint previousFramebuffer = 0;
m_context->getIntegerv(GraphicsContext3D::FRAMEBUFFER_BINDING, &previousFramebuffer);
Platform3DObject framebuffer = m_context->createFramebuffer();
m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, framebuffer);
m_context->framebufferTexture2D(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::COLOR_ATTACHMENT0, GraphicsContext3D::TEXTURE_2D, sourceTexture, 0);
extensions->paintFramebufferToCanvas(framebuffer, size().width(), size().height(), !m_attributes.premultipliedAlpha, imageBuffer);
m_context->deleteFramebuffer(framebuffer);
#if ENABLE(CANVAS_USES_MAILBOX)
m_context->deleteTexture(sourceTexture);
#endif // ENABLE(CANVAS_USES_MAILBOX)
m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, previousFramebuffer);
}
bool ImageBuffer::copyToPlatformTexture(GraphicsContext3D& context, Platform3DObject texture, GC3Denum internalFormat, bool premultiplyAlpha, bool flipY)
{
if (!m_data.m_layerBridge || !platformLayer())
return false;
Platform3DObject sourceTexture = m_data.m_layerBridge->backBufferTexture();
if (!context.makeContextCurrent())
return false;
Extensions3D* extensions = context.getExtensions();
if (!extensions->supports("GL_CHROMIUM_copy_texture") || !extensions->supports("GL_CHROMIUM_flipy"))
return false;
// The canvas is stored in a premultiplied format, so unpremultiply if necessary.
context.pixelStorei(Extensions3D::UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM, !premultiplyAlpha);
// The canvas is stored in an inverted position, so the flip semantics are reversed.
context.pixelStorei(Extensions3D::UNPACK_FLIP_Y_CHROMIUM, !flipY);
extensions->copyTextureCHROMIUM(GraphicsContext3D::TEXTURE_2D, sourceTexture, texture, 0, internalFormat);
context.pixelStorei(Extensions3D::UNPACK_FLIP_Y_CHROMIUM, false);
context.pixelStorei(Extensions3D::UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM, false);
context.flush();
return true;
}
bool DrawingBuffer::prepareMailbox(WebKit::WebExternalTextureMailbox* outMailbox)
{
if (!m_context || !m_contentsChanged || !m_lastColorBuffer)
return false;
m_context->makeContextCurrent();
// Resolve the multisampled buffer into the texture referenced by m_lastColorBuffer mailbox.
if (multisample())
commit();
// We must restore the texture binding since creating new textures,
// consuming and producing mailboxes changes it.
ScopedTextureUnit0BindingRestorer restorer(m_context.get(), m_activeTextureUnit, m_texture2DBinding);
// First try to recycle an old buffer.
RefPtr<MailboxInfo> nextFrontColorBuffer = getRecycledMailbox();
// No buffer available to recycle, create a new one.
if (!nextFrontColorBuffer) {
unsigned newColorBuffer = createColorTexture(m_size);
// Bad things happened, abandon ship.
if (!newColorBuffer)
return false;
nextFrontColorBuffer = createNewMailbox(newColorBuffer);
}
if (m_preserveDrawingBuffer == Discard) {
m_colorBuffer = nextFrontColorBuffer->textureId;
swap(nextFrontColorBuffer, m_lastColorBuffer);
// It appears safe to overwrite the context's framebuffer binding in the Discard case since there will always be a
// WebGLRenderingContext::clearIfComposited() call made before the next draw call which restores the framebuffer binding.
// If this stops being true at some point, we should track the current framebuffer binding in the DrawingBuffer and restore
// it after attaching the new back buffer here.
m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_fbo);
m_context->framebufferTexture2D(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::COLOR_ATTACHMENT0, GraphicsContext3D::TEXTURE_2D, m_colorBuffer, 0);
} else {
Extensions3D* extensions = m_context->getExtensions();
extensions->copyTextureCHROMIUM(GraphicsContext3D::TEXTURE_2D, m_colorBuffer, nextFrontColorBuffer->textureId, 0, GraphicsContext3D::RGBA, GraphicsContext3D::UNSIGNED_BYTE);
}
if (multisample() && !m_framebufferBinding)
bind();
else
restoreFramebufferBinding();
m_contentsChanged = false;
context()->bindTexture(GraphicsContext3D::TEXTURE_2D, nextFrontColorBuffer->textureId);
context()->produceTextureCHROMIUM(GraphicsContext3D::TEXTURE_2D, nextFrontColorBuffer->mailbox.name);
context()->flush();
m_context->markLayerComposited();
*outMailbox = nextFrontColorBuffer->mailbox;
m_frontColorBuffer = nextFrontColorBuffer->textureId;
return true;
}