Mailbox support for texture layers.

cc/texture_layer_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/texture_layer_impl.h"
 
 #include "base/stringprintf.h"
+#include "cc/layer_tree_impl.h"
 #include "cc/quad_sink.h"
 #include "cc/renderer.h"
 #include "cc/texture_draw_quad.h"
 
 namespace cc {
 
-TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* treeImpl, int id)
+TextureLayerImpl::TextureLayerImpl(LayerTreeImpl* treeImpl, int id, bool usesMailbox)
     : LayerImpl(treeImpl, id)
     , m_textureId(0)
     , m_externalTextureResource(0)
     , m_premultipliedAlpha(true)
     , m_flipped(true)
     , m_uvRect(0, 0, 1, 1)
+    , m_hasPendingMailbox(false)
+    , m_usesMailbox(usesMailbox)
 {
   m_vertexOpacity[0] = 1.0f;
   m_vertexOpacity[1] = 1.0f;
   m_vertexOpacity[2] = 1.0f;
   m_vertexOpacity[3] = 1.0f;
 }
 
 TextureLayerImpl::~TextureLayerImpl()
 {
+    if (m_externalTextureResource) {
+        DCHECK(m_usesMailbox);
+        ResourceProvider* provider = layerTreeImpl()->resource_provider();
+        provider->deleteResource(m_externalTextureResource);
+    }
+    if (m_hasPendingMailbox && !m_pendingMailboxName.empty())
+        m_pendingMailboxReleaseCallback.Run(0);
+}
+
+void TextureLayerImpl::setTextureMailbox(const std::string& mailboxName, const base::Callback<void(unsigned)>& releaseCallback)
+{
+    DCHECK(m_usesMailbox);
+    // Same mailbox name was commited, nothing to do.
+    if (m_pendingMailboxName.compare(mailboxName) == 0)
+        return;
+    // Two commits without a draw, ack the previous mailbox.
+    if (m_hasPendingMailbox && !m_pendingMailboxReleaseCallback.is_null())
+        m_pendingMailboxReleaseCallback.Run(0);
+
+    m_pendingMailboxName = mailboxName;
+    m_hasPendingMailbox = true;
+    m_pendingMailboxReleaseCallback = releaseCallback;
 }
 
 void TextureLayerImpl::willDraw(ResourceProvider* resourceProvider)
 {
-    if (!m_textureId)
+    if (!m_usesMailbox) {
+        if (!m_textureId)
+            return;
+        DCHECK(!m_externalTextureResource);
+        m_externalTextureResource = resourceProvider->createResourceFromExternalTexture(m_textureId);
         return;
-    DCHECK(!m_externalTextureResource);
-    m_externalTextureResource = resourceProvider->createResourceFromExternalTexture(m_textureId);
+    }
+
+    if (!m_hasPendingMailbox)
+        return;
+
+    if (m_externalTextureResource) {
+        DCHECK(!resourceProvider->inUseByConsumer(m_externalTextureResource));

[piman, 2013/01/08 02:01:52]

This check may not be true with ubercomp (because the resource may not be back
from the parent yet), however it's also not needed, since if the resource is
still in use, it'll just be marked for deletion, the deletion itself (and the
callback) will happen once the texture comes back from the parent.

[alexst (slow to review), 2013/01/08 02:46:27]

Done.

+        resourceProvider->deleteResource(m_externalTextureResource);
+        m_externalTextureResource = 0;
+    }
+    if (!m_pendingMailboxName.empty())
+        m_externalTextureResource = resourceProvider->createResourceFromTextureMailbox(m_pendingMailboxName, m_pendingMailboxReleaseCallback);
+    m_hasPendingMailbox = false;
 }
 
 void TextureLayerImpl::appendQuads(QuadSink& quadSink, AppendQuadsData& appendQuadsData)
 {
     if (!m_externalTextureResource)
         return;
 
     SharedQuadState* sharedQuadState = quadSink.useSharedQuadState(createSharedQuadState());
     appendDebugBorderQuad(quadSink, sharedQuadState, appendQuadsData);
 
     gfx::Rect quadRect(gfx::Point(), contentBounds());
     gfx::Rect opaqueRect(contentsOpaque() ? quadRect : gfx::Rect());
     scoped_ptr<TextureDrawQuad> quad = TextureDrawQuad::Create();
     quad->SetNew(sharedQuadState, quadRect, opaqueRect, m_externalTextureResource, m_premultipliedAlpha, m_uvRect, m_vertexOpacity, m_flipped);
 
     // Perform explicit clipping on a quad to avoid setting a scissor later.
     if (sharedQuadState->is_clipped && quad->PerformClipping())
         sharedQuadState->is_clipped = false;
     if (!quad->rect.IsEmpty())
         quadSink.append(quad.PassAs<DrawQuad>(), appendQuadsData);
 }
 
 void TextureLayerImpl::didDraw(ResourceProvider* resourceProvider)
 {
+    if (m_usesMailbox)
+        return;
     if (!m_externalTextureResource)
         return;
     // FIXME: the following assert will not be true when sending resources to a
     // parent compositor. A synchronization scheme (double-buffering or
     // pipelining of updates) for the client will need to exist to solve this.
     DCHECK(!resourceProvider->inUseByConsumer(m_externalTextureResource));
     resourceProvider->deleteResource(m_externalTextureResource);
     m_externalTextureResource = 0;
 }
 
@@ skipping 16 matching lines @@
     m_textureId = 0;
     m_externalTextureResource = 0;
 }
 
 const char* TextureLayerImpl::layerTypeAsString() const
 {
     return "TextureLayer";
 }
 
 }  // namespace cc