Defer clearing textures and renderbuffers

gpu/command_buffer/service/framebuffer_manager.cc

Index: gpu/command_buffer/service/framebuffer_manager.cc
diff --git a/gpu/command_buffer/service/framebuffer_manager.cc b/gpu/command_buffer/service/framebuffer_manager.cc
index 909a45182b9cec65da344468745fde47538f18e2..0ce9df075ec63e8553f2281c55cfccc673a153f9 100644
--- a/gpu/command_buffer/service/framebuffer_manager.cc
+++ b/gpu/command_buffer/service/framebuffer_manager.cc
@@ -13,34 +13,36 @@ class RenderbufferAttachment
     : public FramebufferManager::FramebufferInfo::Attachment {
  public:
   explicit RenderbufferAttachment(
-      RenderbufferManager::RenderbufferInfo* render_buffer)
-      : render_buffer_(render_buffer) {
+      RenderbufferManager::RenderbufferInfo* renderbuffer)
+      : renderbuffer_(renderbuffer) {
   }
 
   virtual ~RenderbufferAttachment() { }
 
   virtual GLsizei width() const {
-    return render_buffer_->width();
+    return renderbuffer_->width();
   }
 
   virtual GLsizei height() const {
-    return render_buffer_->height();
+    return renderbuffer_->height();
   }
 
   virtual GLenum internal_format() const {
-    return render_buffer_->internal_format();
+    return renderbuffer_->internal_format();
   }
 
   virtual GLsizei samples() const {
-    return render_buffer_->samples();
+    return renderbuffer_->samples();
   }
 
   virtual bool cleared() const {
-    return render_buffer_->cleared();
+    return renderbuffer_->cleared();
   }
 
-  virtual void set_cleared() {
-    render_buffer_->set_cleared();
+  virtual void SetCleared(
+      RenderbufferManager* renderbuffer_manager,
+      TextureManager* /* texture_manager */) {
+    renderbuffer_manager->SetCleared(renderbuffer_);
   }
 
   virtual bool IsTexture(TextureManager::TextureInfo* /* texture */) const {
@@ -51,12 +53,21 @@ class RenderbufferAttachment
     return true;
   }
 
-  RenderbufferManager::RenderbufferInfo* render_buffer() const {
-    return render_buffer_.get();
+  virtual void DetachFromFramebuffer() {
+    // Nothing to do for renderbuffers.
+  }
+
+  virtual bool ValidForAttachmentType(GLenum attachment_type) {
+    // TODO(gman): Fill this out.
+    return true;
+  }
+
+  RenderbufferManager::RenderbufferInfo* renderbuffer() const {
+    return renderbuffer_.get();
   }
 
  private:
-  RenderbufferManager::RenderbufferInfo::Ref render_buffer_;
+  RenderbufferManager::RenderbufferInfo::Ref renderbuffer_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderbufferAttachment);
 };
@@ -99,12 +110,13 @@ class TextureAttachment
   }
 
   virtual bool cleared() const {
-    // Textures are cleared on creation.
-    return true;
+    return texture_->IsLevelCleared(target_, level_);
   }
 
-  virtual void set_cleared() {
-    NOTREACHED();
+  virtual void SetCleared(
+      RenderbufferManager* /* renderbuffer_manager */,
+      TextureManager* texture_manager) {
+    texture_manager->SetLevelCleared(texture_, target_, level_);
   }
 
   virtual bool IsTexture(TextureManager::TextureInfo* texture) const {
@@ -119,6 +131,15 @@ class TextureAttachment
     return texture_->CanRenderTo();
   }
 
+  virtual void DetachFromFramebuffer() {
+    texture_->DetachFromFramebuffer();
+  }
+
+  virtual bool ValidForAttachmentType(GLenum attachment_type) {
+    // TODO(gman): Fill this out.
+    return true;
+  }
+
  private:
   TextureManager::TextureInfo::Ref texture_;
   GLenum target_;
@@ -133,15 +154,24 @@ FramebufferManager::~FramebufferManager() {
   DCHECK(framebuffer_infos_.empty());
 }
 
+void FramebufferManager::FramebufferInfo::MarkAsDeleted() {
+  service_id_ = 0;
+  while (!attachments_.empty()) {
+    Attachment* attachment = attachments_.begin()->second.get();
+    attachment->DetachFromFramebuffer();
+    attachments_.erase(attachments_.begin());
+  }
+}
+
 void FramebufferManager::Destroy(bool have_context) {
   while (!framebuffer_infos_.empty()) {
-    if (have_context) {
-      FramebufferInfo* info = framebuffer_infos_.begin()->second;
-      if (!info->IsDeleted()) {
+    FramebufferInfo* info = framebuffer_infos_.begin()->second;
+    if (!info->IsDeleted()) {
+      if (have_context) {
         GLuint service_id = info->service_id();
         glDeleteFramebuffersEXT(1, &service_id);
-        info->MarkAsDeleted();
       }
+      info->MarkAsDeleted();
     }
     framebuffer_infos_.erase(framebuffer_infos_.begin());
   }
@@ -158,8 +188,8 @@ void FramebufferManager::CreateFramebufferInfo(
 }
 
 FramebufferManager::FramebufferInfo::FramebufferInfo(GLuint service_id)
-    : service_id_(service_id)
-    , has_been_bound_(false) {
+    : service_id_(service_id),
+      has_been_bound_(false) {
 }
 
 FramebufferManager::FramebufferInfo::~FramebufferInfo() {}
@@ -175,12 +205,14 @@ bool FramebufferManager::FramebufferInfo::HasUnclearedAttachment(
   return false;
 }
 
-void FramebufferManager::FramebufferInfo::MarkAttachedRenderbuffersAsCleared() {
+void FramebufferManager::FramebufferInfo::MarkAttachmentsAsCleared(
+      RenderbufferManager* renderbuffer_manager,
+      TextureManager* texture_manager) {
   for (AttachmentMap::iterator it = attachments_.begin();
        it != attachments_.end(); ++it) {
     Attachment* attachment = it->second;
     if (!attachment->cleared()) {
-      attachment->set_cleared();
+      attachment->SetCleared(renderbuffer_manager, texture_manager);
     }
   }
 }
@@ -204,18 +236,52 @@ GLenum FramebufferManager::FramebufferInfo::GetColorAttachmentFormat() const {
   return attachment->internal_format();
 }
 
-bool FramebufferManager::FramebufferInfo::IsNotComplete() const {
+GLenum FramebufferManager::FramebufferInfo::IsPossiblyComplete() const {
+  if (attachments_.empty()) {
+    return GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT;
+  }
+
+  GLsizei width = -1;
+  GLsizei height = -1;
   for (AttachmentMap::const_iterator it = attachments_.begin();
        it != attachments_.end(); ++it) {
+    GLenum attachment_type = it->first;
     Attachment* attachment = it->second;
-    if (attachment->width() == 0 || attachment->height() == 0) {
-      return true;
+    if (!attachment->ValidForAttachmentType(attachment_type)) {
+      return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
+    }
+    if (width < 0) {
+      width = attachment->width();
+      height = attachment->height();
+      if (width == 0 || height == 0) {
+        return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
+      }
+    } else {
+      if (attachment->width() != width || attachment->height() != height) {
+        return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT;
+      }
     }
+
     if (!attachment->CanRenderTo()) {
-      return true;
+      return GL_FRAMEBUFFER_UNSUPPORTED;
     }
   }
-  return false;
+
+  // This does not mean the framebuffer is actually complete. It just means our
+  // checks passed.
+  return GL_FRAMEBUFFER_COMPLETE;
+}
+
+bool FramebufferManager::FramebufferInfo::IsCleared() const {
+  // are all the attachments cleaared?
+  for (AttachmentMap::const_iterator it = attachments_.begin();
+       it != attachments_.end(); ++it) {
+    Attachment* attachment = it->second;
+    if (!attachment->cleared()) {
+      return false;
+    }
+  }
+  return true;
 }
 
 FramebufferManager::FramebufferInfo* FramebufferManager::GetFramebufferInfo(