void DrawingBuffer::initialize(const IntSize& size)
{
ASSERT(m_context);
m_attributes = m_context->getContextAttributes();
if (m_attributes.alpha) {
m_internalColorFormat = GraphicsContext3D::RGBA;
m_colorFormat = GraphicsContext3D::RGBA;
m_internalRenderbufferFormat = Extensions3D::RGBA8_OES;
} else {
m_internalColorFormat = GraphicsContext3D::RGB;
m_colorFormat = GraphicsContext3D::RGB;
m_internalRenderbufferFormat = Extensions3D::RGB8_OES;
}
m_context->getIntegerv(GraphicsContext3D::MAX_TEXTURE_SIZE, &m_maxTextureSize);
m_fbo = m_context->createFramebuffer();
if (m_separateFrontTexture)
m_frontColorBuffer = createColorTexture();
m_context->bindFramebuffer(GraphicsContext3D::FRAMEBUFFER, m_fbo);
m_colorBuffer = createColorTexture();
m_context->framebufferTexture2D(GraphicsContext3D::FRAMEBUFFER, GraphicsContext3D::COLOR_ATTACHMENT0, GraphicsContext3D::TEXTURE_2D, m_colorBuffer, 0);
createSecondaryBuffers();
reset(size);
#if ENABLE(CANVAS_USES_MAILBOX)
m_lastColorBuffer = createNewMailbox(m_colorBuffer);
#endif // ENABLE(CANVAS_USES_MAILBOX)
}
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;
}
bool DrawingBuffer::prepareMailbox(blink::WebExternalTextureMailbox* outMailbox, blink::WebExternalBitmap* bitmap)
{
if (!m_context || !m_contentsChanged)
return false;
m_context->makeContextCurrent();
// Resolve the multisampled buffer into m_colorBuffer texture.
if (m_multisampleMode != None)
commit();
if (bitmap) {
bitmap->setSize(size());
unsigned char* pixels = bitmap->pixels();
bool needPremultiply = m_attributes.alpha && !m_attributes.premultipliedAlpha;
WebGLImageConversion::AlphaOp op = needPremultiply ? WebGLImageConversion::AlphaDoPremultiply : WebGLImageConversion::AlphaDoNothing;
if (pixels)
readBackFramebuffer(pixels, size().width(), size().height(), ReadbackSkia, op);
}
// We must restore the texture binding since creating new textures,
// consuming and producing mailboxes changes it.
ScopedTextureUnit0BindingRestorer restorer(m_context, m_activeTextureUnit, m_texture2DBinding);
// First try to recycle an old buffer.
RefPtr<MailboxInfo> frontColorBufferMailbox = recycledMailbox();
// No buffer available to recycle, create a new one.
if (!frontColorBufferMailbox) {
unsigned newColorBuffer = createColorTexture(m_size);
// Bad things happened, abandon ship.
if (!newColorBuffer)
return false;
frontColorBufferMailbox = createNewMailbox(newColorBuffer);
}
if (m_preserveDrawingBuffer == Discard) {
swap(frontColorBufferMailbox->textureId, m_colorBuffer);
// 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(GL_FRAMEBUFFER, m_fbo);
if (m_multisampleMode == ImplicitResolve)
m_context->framebufferTexture2DMultisampleEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_colorBuffer, 0, m_sampleCount);
else
m_context->framebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_colorBuffer, 0);
} else {
m_context->copyTextureCHROMIUM(GL_TEXTURE_2D, m_colorBuffer, frontColorBufferMailbox->textureId, 0, GL_RGBA, GL_UNSIGNED_BYTE);
}
if (m_multisampleMode != None && !m_framebufferBinding)
bind();
else
restoreFramebufferBinding();
m_contentsChanged = false;
m_context->bindTexture(GL_TEXTURE_2D, frontColorBufferMailbox->textureId);
m_context->produceTextureCHROMIUM(GL_TEXTURE_2D, frontColorBufferMailbox->mailbox.name);
m_context->flush();
frontColorBufferMailbox->mailbox.syncPoint = m_context->insertSyncPoint();
markLayerComposited();
*outMailbox = frontColorBufferMailbox->mailbox;
m_frontColorBuffer = frontColorBufferMailbox->textureId;
return true;
}
bool DrawingBuffer::prepareMailbox(WebExternalTextureMailbox* outMailbox, WebExternalBitmap* bitmap)
{
if (m_destructionInProgress) {
// It can be hit in the following sequence.
// 1. WebGL draws something.
// 2. The compositor begins the frame.
// 3. Javascript makes a context lost using WEBGL_lose_context extension.
// 4. Here.
return false;
}
ASSERT(!m_isHidden);
if (!m_contentsChanged)
return false;
if (m_newMailboxCallback)
(*m_newMailboxCallback)();
// Resolve the multisampled buffer into m_colorBuffer texture.
if (m_antiAliasingMode != None)
commit();
if (bitmap) {
bitmap->setSize(size());
unsigned char* pixels = bitmap->pixels();
bool needPremultiply = m_wantAlphaChannel && !m_premultipliedAlpha;
WebGLImageConversion::AlphaOp op = needPremultiply ? WebGLImageConversion::AlphaDoPremultiply : WebGLImageConversion::AlphaDoNothing;
if (pixels)
readBackFramebuffer(pixels, size().width(), size().height(), ReadbackSkia, op);
}
// We must restore the texture binding since creating new textures,
// consuming and producing mailboxes changes it.
ScopedTextureUnit0BindingRestorer restorer(m_gl, m_activeTextureUnit, m_texture2DBinding);
// First try to recycle an old buffer.
RefPtr<MailboxInfo> frontColorBufferMailbox = recycledMailbox();
// No buffer available to recycle, create a new one.
if (!frontColorBufferMailbox)
frontColorBufferMailbox = createNewMailbox(createTextureAndAllocateMemory(m_size));
if (m_preserveDrawingBuffer == Discard) {
std::swap(frontColorBufferMailbox->textureInfo, m_colorBuffer);
attachColorBufferToReadFramebuffer();
if (m_discardFramebufferSupported) {
// Explicitly discard framebuffer to save GPU memory bandwidth for tile-based GPU arch.
const GLenum attachments[3] = { GL_COLOR_ATTACHMENT0, GL_DEPTH_ATTACHMENT, GL_STENCIL_ATTACHMENT };
m_gl->DiscardFramebufferEXT(GL_FRAMEBUFFER, 3, attachments);
}
} else {
m_gl->CopyTextureCHROMIUM(m_colorBuffer.textureId, frontColorBufferMailbox->textureInfo.textureId, frontColorBufferMailbox->textureInfo.parameters.internalColorFormat, GL_UNSIGNED_BYTE, GL_FALSE, GL_FALSE, GL_FALSE);
}
restoreFramebufferBindings();
m_contentsChanged = false;
m_gl->ProduceTextureDirectCHROMIUM(frontColorBufferMailbox->textureInfo.textureId, frontColorBufferMailbox->textureInfo.parameters.target, frontColorBufferMailbox->mailbox.name);
const GLuint64 fenceSync = m_gl->InsertFenceSyncCHROMIUM();
m_gl->Flush();
m_gl->GenSyncTokenCHROMIUM(fenceSync, frontColorBufferMailbox->mailbox.syncToken);
frontColorBufferMailbox->mailbox.validSyncToken = true;
frontColorBufferMailbox->mailbox.allowOverlay = frontColorBufferMailbox->textureInfo.imageId != 0;
frontColorBufferMailbox->mailbox.textureTarget = frontColorBufferMailbox->textureInfo.parameters.target;
frontColorBufferMailbox->mailbox.textureSize = WebSize(m_size.width(), m_size.height());
setBufferClearNeeded(true);
// set m_parentDrawingBuffer to make sure 'this' stays alive as long as it has live mailboxes
ASSERT(!frontColorBufferMailbox->m_parentDrawingBuffer);
frontColorBufferMailbox->m_parentDrawingBuffer = this;
*outMailbox = frontColorBufferMailbox->mailbox;
m_frontColorBuffer = { frontColorBufferMailbox->textureInfo, frontColorBufferMailbox->mailbox };
return true;
}
