Resolve to temporary texture when doing readpixels

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 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 "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 201 matching lines @@
   ScopedFrameBufferBinder(GLES2DecoderImpl* decoder, GLuint id);
   ~ScopedFrameBufferBinder();
 
  private:
   GLES2DecoderImpl* decoder_;
   DISALLOW_COPY_AND_ASSIGN(ScopedFrameBufferBinder);
 };
 
 // Temporarily changes a decoder's bound frame buffer to a resolved version of
 // the multisampled offscreen render buffer if that buffer is multisampled, and,
-// if it is bound or enforce_internal_framebuffer is true.
+// if it is bound or enforce_internal_framebuffer is true. If internal is
+// true, the resolved framebuffer is not visible to the parent.
 class ScopedResolvedFrameBufferBinder {
  public:
   ScopedResolvedFrameBufferBinder(GLES2DecoderImpl* decoder,
-                                  bool enforce_internal_framebuffer);
+                                  bool enforce_internal_framebuffer,
+                                  bool internal);
   ~ScopedResolvedFrameBufferBinder();
 
  private:
   GLES2DecoderImpl* decoder_;
   bool resolve_and_bind_;
   DISALLOW_COPY_AND_ASSIGN(ScopedResolvedFrameBufferBinder);
 };
 
 // Encapsulates an OpenGL texture.
 class Texture {
@@ skipping 1041 matching lines @@
   scoped_ptr<RenderBuffer> offscreen_target_color_render_buffer_;
   scoped_ptr<RenderBuffer> offscreen_target_depth_render_buffer_;
   scoped_ptr<RenderBuffer> offscreen_target_stencil_render_buffer_;
   GLenum offscreen_target_color_format_;
   GLenum offscreen_target_depth_format_;
   GLenum offscreen_target_stencil_format_;
   GLsizei offscreen_target_samples_;
 
   GLuint copy_texture_to_parent_texture_fb_;
 
-  // The copy that is saved when SwapBuffers is called.  It is also
-  // used as the destination for multi-sample resolves.
+  // The copy that is saved when SwapBuffers is called.
   scoped_ptr<FrameBuffer> offscreen_saved_frame_buffer_;
   scoped_ptr<Texture> offscreen_saved_color_texture_;
+
+  // The copy that is used as the destination for multi-sample resolves.
+  scoped_ptr<FrameBuffer> offscreen_resolved_frame_buffer_;
+  scoped_ptr<Texture> offscreen_resolved_color_texture_;
   GLenum offscreen_saved_color_format_;
 
   scoped_ptr<Callback1<gfx::Size>::Type> resize_callback_;
   scoped_ptr<Callback0::Type> swap_buffers_callback_;
 
   // The format of the back buffer_
   GLenum back_buffer_color_format_;
   bool back_buffer_has_depth_;
   bool back_buffer_has_stencil_;
 
@@ skipping 71 matching lines @@
   ScopedGLErrorSuppressor suppressor(decoder_);
   glBindFramebufferEXT(GL_FRAMEBUFFER, id);
 }
 
 ScopedFrameBufferBinder::~ScopedFrameBufferBinder() {
   ScopedGLErrorSuppressor suppressor(decoder_);
   decoder_->RestoreCurrentFramebufferBindings();
 }
 
 ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
-    GLES2DecoderImpl* decoder, bool enforce_internal_framebuffer)
+    GLES2DecoderImpl* decoder, bool enforce_internal_framebuffer, bool internal)
     : decoder_(decoder) {
   resolve_and_bind_ = (decoder_->offscreen_target_frame_buffer_.get() &&
                        decoder_->IsOffscreenBufferMultisampled() &&
                        (!decoder_->bound_read_framebuffer_.get() ||
                         enforce_internal_framebuffer));
   if (!resolve_and_bind_)
     return;
 
   ScopedGLErrorSuppressor suppressor(decoder_);
   glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT,
                        decoder_->offscreen_target_frame_buffer_->id());
-  glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT,
-                       decoder_->offscreen_saved_frame_buffer_->id());
+  GLuint targetid;
+  if (internal) {
+    if (!decoder_->offscreen_resolved_frame_buffer_.get()) {
+      decoder_->offscreen_resolved_frame_buffer_.reset(
+          new FrameBuffer(decoder_));
+      decoder_->offscreen_resolved_frame_buffer_->Create();
+      decoder_->offscreen_resolved_color_texture_.reset(new Texture(decoder_));
+      decoder_->offscreen_resolved_color_texture_->Create();
+
+      DCHECK(decoder_->offscreen_saved_color_format_);
+      decoder_->offscreen_resolved_color_texture_->AllocateStorage(
+          decoder_->offscreen_size_, decoder_->offscreen_saved_color_format_);
+
+      decoder_->offscreen_resolved_frame_buffer_->AttachRenderTexture(
+          decoder_->offscreen_resolved_color_texture_.get());
+      if (decoder_->offscreen_resolved_frame_buffer_->CheckStatus() !=
+          GL_FRAMEBUFFER_COMPLETE) {
+        LOG(ERROR) << "ScopedResolvedFrameBufferBinder failed "
+                   << "because offscreen resolved FBO was incomplete.";
+        return;
+      }
+    }
+    targetid = decoder_->offscreen_resolved_frame_buffer_->id();
+  } else {
+    targetid = decoder_->offscreen_saved_frame_buffer_->id();
+  }
+  glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, targetid);
   const int width = decoder_->offscreen_size_.width();
   const int height = decoder_->offscreen_size_.height();
   glDisable(GL_SCISSOR_TEST);
   if (IsAngle()) {
     glBlitFramebufferANGLE(0, 0, width, height, 0, 0, width, height,
                            GL_COLOR_BUFFER_BIT, GL_NEAREST);
   } else {
     glBlitFramebufferEXT(0, 0, width, height, 0, 0, width, height,
                          GL_COLOR_BUFFER_BIT, GL_NEAREST);
   }
-  glBindFramebufferEXT(GL_FRAMEBUFFER,
-                       decoder_->offscreen_saved_frame_buffer_->id());
+  glBindFramebufferEXT(GL_FRAMEBUFFER, targetid);
 }
 
 ScopedResolvedFrameBufferBinder::~ScopedResolvedFrameBufferBinder() {
   if (!resolve_and_bind_)
     return;
 
   ScopedGLErrorSuppressor suppressor(decoder_);
   decoder_->RestoreCurrentFramebufferBindings();
   if (decoder_->enable_scissor_test_) {
     glEnable(GL_SCISSOR_TEST);
@@ skipping 889 matching lines @@
 
   offscreen_saved_frame_buffer_->AttachRenderTexture(
       offscreen_saved_color_texture_.get());
   if (offscreen_saved_frame_buffer_->CheckStatus() !=
       GL_FRAMEBUFFER_COMPLETE) {
     LOG(ERROR) << "GLES2DecoderImpl::UpdateOffscreenFrameBufferSize failed "
                << "because offscreen saved FBO was incomplete.";
     return false;
   }
 
+  // Destroy the offscreen resolved framebuffers.
+  if (offscreen_resolved_frame_buffer_.get())
+    offscreen_resolved_frame_buffer_->Destroy();
+  if (offscreen_resolved_color_texture_.get())
+    offscreen_resolved_color_texture_->Destroy();
+  offscreen_resolved_color_texture_.reset();
+  offscreen_resolved_frame_buffer_.reset();
+
   // Clear the offscreen color texture.
   {
     ScopedFrameBufferBinder binder(this, offscreen_saved_frame_buffer_->id());
     glClearColor(0, 0, 0, 0);
     glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
     glDisable(GL_SCISSOR_TEST);
     glClear(GL_COLOR_BUFFER_BIT);
     RestoreClearState();
   }
 
@@ skipping 99 matching lines @@
     if (offscreen_target_color_render_buffer_.get())
       offscreen_target_color_render_buffer_->Destroy();
     if (offscreen_target_depth_render_buffer_.get())
       offscreen_target_depth_render_buffer_->Destroy();
     if (offscreen_target_stencil_render_buffer_.get())
       offscreen_target_stencil_render_buffer_->Destroy();
     if (offscreen_saved_frame_buffer_.get())
       offscreen_saved_frame_buffer_->Destroy();
     if (offscreen_saved_color_texture_.get())
       offscreen_saved_color_texture_->Destroy();
+    if (offscreen_resolved_frame_buffer_.get())
+      offscreen_resolved_frame_buffer_->Destroy();
+    if (offscreen_resolved_color_texture_.get())
+      offscreen_resolved_color_texture_->Destroy();
 
     // must release the ContextGroup before destroying the context as its
     // destructor uses GL.
     group_ = NULL;
   } else {
     if (offscreen_target_frame_buffer_.get())
       offscreen_target_frame_buffer_->Invalidate();
     if (offscreen_target_color_texture_.get())
       offscreen_target_color_texture_->Invalidate();
     if (offscreen_target_color_render_buffer_.get())
       offscreen_target_color_render_buffer_->Invalidate();
     if (offscreen_target_depth_render_buffer_.get())
       offscreen_target_depth_render_buffer_->Invalidate();
     if (offscreen_target_stencil_render_buffer_.get())
       offscreen_target_stencil_render_buffer_->Invalidate();
     if (offscreen_saved_frame_buffer_.get())
       offscreen_saved_frame_buffer_->Invalidate();
     if (offscreen_saved_color_texture_.get())
       offscreen_saved_color_texture_->Invalidate();
+    if (offscreen_resolved_frame_buffer_.get())
+      offscreen_resolved_frame_buffer_->Invalidate();
+    if (offscreen_resolved_color_texture_.get())
+      offscreen_resolved_color_texture_->Invalidate();
   }
 
   if (context_.get()) {
     context_->ReleaseCurrent(NULL);
     context_->Destroy();
   }
   context_ = NULL;
 
   offscreen_target_frame_buffer_.reset();
   offscreen_target_color_texture_.reset();
   offscreen_target_color_render_buffer_.reset();
   offscreen_target_depth_render_buffer_.reset();
   offscreen_target_stencil_render_buffer_.reset();
   offscreen_saved_frame_buffer_.reset();
   offscreen_saved_color_texture_.reset();
+  offscreen_resolved_frame_buffer_.reset();
+  offscreen_resolved_color_texture_.reset();
 }
 
 bool GLES2DecoderImpl::SetParent(GLES2Decoder* new_parent,
                                  uint32 new_parent_texture_id) {
   if (!offscreen_saved_color_texture_.get())
     return false;
 
   // Remove the saved frame buffer mapping from the parent decoder. The
   // parent pointer is a weak pointer so it will be null if the parent has
   // already been destroyed.
@@ skipping 2627 matching lines @@
   if (!validators_->pixel_type.IsValid(type)) {
     SetGLError(GL_INVALID_ENUM, "glReadPixels: type GL_INVALID_ENUM");
     return error::kNoError;
   }
   if (width == 0 || height == 0) {
     return error::kNoError;
   }
 
   CopyRealGLErrorsToWrapper();
 
-  ScopedResolvedFrameBufferBinder binder(this, false);
+  ScopedResolvedFrameBufferBinder binder(this, false, true);
 
   // Get the size of the current fbo or backbuffer.
   gfx::Size max_size = GetBoundReadFrameBufferSize();
 
   GLint max_x;
   GLint max_y;
   if (!SafeAdd(x, width, &max_x) || !SafeAdd(y, height, &max_y)) {
     SetGLError(GL_INVALID_VALUE, "glReadPixels: dimensions out of range");
     return error::kNoError;
   }
@@ skipping 766 matching lines @@
   GLenum read_format = GetBoundReadFrameBufferInternalFormat();
   uint32 channels_exist = GLES2Util::GetChannelsForFormat(read_format);
   uint32 channels_needed = GLES2Util::GetChannelsForFormat(internal_format);
 
   if ((channels_needed & channels_exist) != channels_needed) {
     SetGLError(GL_INVALID_OPERATION, "glCopyTexImage2D: incompatible format");
     return;
   }
 
   CopyRealGLErrorsToWrapper();
-  ScopedResolvedFrameBufferBinder binder(this, false);
+  ScopedResolvedFrameBufferBinder binder(this, false, true);
   gfx::Size size = GetBoundReadFrameBufferSize();
 
   if (info->IsAttachedToFramebuffer()) {
     state_dirty_ = true;
   }
 
   // Clip to size to source dimensions
   GLint copyX = 0;
   GLint copyY = 0;
   GLint copyWidth = 0;
@@ skipping 67 matching lines @@
   GLenum read_format = GetBoundReadFrameBufferInternalFormat();
   uint32 channels_exist = GLES2Util::GetChannelsForFormat(read_format);
   uint32 channels_needed = GLES2Util::GetChannelsForFormat(format);
 
   if ((channels_needed & channels_exist) != channels_needed) {
     SetGLError(
         GL_INVALID_OPERATION, "glCopyTexSubImage2D: incompatible format");
     return;
   }
 
-  ScopedResolvedFrameBufferBinder binder(this, false);
+  ScopedResolvedFrameBufferBinder binder(this, false, true);
   gfx::Size size = GetBoundReadFrameBufferSize();
   GLint copyX = 0;
   GLint copyY = 0;
   GLint copyWidth = 0;
   GLint copyHeight = 0;
   Clip(x, width, size.width(), &copyX, &copyWidth);
   Clip(y, height, size.height(), &copyY, &copyHeight);
   if (copyX != x ||
       copyY != y ||
       copyWidth != width ||
@@ skipping 522 matching lines @@
     // pending.
     if (!UpdateOffscreenFrameBufferSize()) {
       LOG(ERROR) << "Context lost because reallocation of offscreen FBO "
                  << "failed.";
       return error::kLostContext;
     }
 
     if (IsOffscreenBufferMultisampled()) {
       // For multisampled buffers, bind the resolved frame buffer so that
       // callbacks can call ReadPixels or CopyTexImage2D.
-      ScopedResolvedFrameBufferBinder binder(this, true);
+      ScopedResolvedFrameBufferBinder binder(this, true, false);
       if (swap_buffers_callback_.get()) {
         swap_buffers_callback_->Run();
       }
       return error::kNoError;
     } else {
       ScopedFrameBufferBinder binder(this,
                                      offscreen_target_frame_buffer_->id());
 
       if (surface_->IsOffscreen()) {
         // Copy the target frame buffer to the saved offscreen texture.
@@ skipping 245 matching lines @@
   return false;
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu