Implement support for rendering to 32-bit float textures on ES3

gpu/command_buffer/service/framebuffer_manager.cc

 // Copyright (c) 2012 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/framebuffer_manager.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
+#include "gpu/command_buffer/service/feature_info.h"
 #include "gpu/command_buffer/service/renderbuffer_manager.h"
 #include "gpu/command_buffer/service/texture_manager.h"
 #include "ui/gl/gl_bindings.h"
 
 namespace gpu {
 namespace gles2 {
 
 DecoderFramebufferState::DecoderFramebufferState()
     : clear_state_dirty(false),
       bound_read_framebuffer(NULL),
@@ skipping 76 matching lines @@
 
   virtual bool CanRenderTo() const OVERRIDE {
     return true;
   }
 
   virtual void DetachFromFramebuffer(Framebuffer* framebuffer) const OVERRIDE {
     // Nothing to do for renderbuffers.
   }
 
   virtual bool ValidForAttachmentType(
-      GLenum attachment_type, uint32 max_color_attachments) OVERRIDE {
+      GLenum attachment_type, uint32 max_color_attachments,
+      const FeatureInfo*) OVERRIDE {
     uint32 need = GLES2Util::GetChannelsNeededForAttachmentType(
         attachment_type, max_color_attachments);
     uint32 have = GLES2Util::GetChannelsForFormat(internal_format());
     return (need & have) != 0;
   }
 
   Renderbuffer* renderbuffer() const {
     return renderbuffer_.get();
   }
 
@@ skipping 93 matching lines @@
     return texture_ref_->texture()->CanRenderTo();
   }
 
   virtual void DetachFromFramebuffer(Framebuffer* framebuffer)
       const OVERRIDE {
     texture_ref_->texture()->DetachFromFramebuffer();
     framebuffer->OnTextureRefDetached(texture_ref_.get());
   }
 
   virtual bool ValidForAttachmentType(
-      GLenum attachment_type, uint32 max_color_attachments) OVERRIDE {
+      GLenum attachment_type, uint32 max_color_attachments,
+      const FeatureInfo* feature_info) OVERRIDE {
     GLenum type = 0;
     GLenum internal_format = 0;
     if (!texture_ref_->texture()->GetLevelType(
         target_, level_, &type, &internal_format)) {
       return false;
     }
     uint32 need = GLES2Util::GetChannelsNeededForAttachmentType(
         attachment_type, max_color_attachments);
     uint32 have = GLES2Util::GetChannelsForFormat(internal_format);
 
     // Workaround for NVIDIA drivers that incorrectly expose these formats as
     // renderable:
     if (internal_format == GL_LUMINANCE || internal_format == GL_ALPHA ||
         internal_format == GL_LUMINANCE_ALPHA) {
       return false;
     }
+    // As a workaround for ANGLE implementing rendering to float textures in
+    // an unspecified way, accept all internalformats for float textures when
+    // using ANGLE. Otherwise only allow rendering to float textures as exposed
+    // by CHROMIUM_color_buffer_float_rgb(a).

[piman, 2014/02/11 21:28:38]

I don't think this is right.
When using ANGLE, we'd still get GL_RGBA32F from the client, and we need to
translate that into GL_RGBA on the service side.

[Ken Russell (switch to Gerrit), 2014/02/12 00:11:01]

When running on ANGLE, the command buffer won't expose the
GL_CHROMIUM_color_buffer_float_rgb{a} extension, so the client side won't send
down the sized internal format.

+    if ((internal_format == GL_RGBA32F &&
+         !feature_info->feature_flags().chromium_color_buffer_float_rgba) ||
+        (internal_format == GL_RGB32F &&
+         !feature_info->feature_flags().chromium_color_buffer_float_rgb) ||
+        (type == GL_FLOAT && !feature_info->feature_flags().is_angle &&
+         internal_format != GL_RGBA32F && internal_format != GL_RGB32F)) {
+      return false;
+    }
     return (need & have) != 0;
   }
 
   virtual void AddToSignature(
       TextureManager* texture_manager, std::string* signature) const OVERRIDE {
     DCHECK(signature);
     texture_manager->AddToSignature(
         texture_ref_.get(), target_, level_, signature);
   }
 
@@ skipping 153 matching lines @@
 
 GLenum Framebuffer::GetColorAttachmentTextureType() const {
   AttachmentMap::const_iterator it = attachments_.find(GL_COLOR_ATTACHMENT0);
   if (it == attachments_.end()) {
     return 0;
   }
   const Attachment* attachment = it->second.get();
   return attachment->texture_type();
 }
 
-GLenum Framebuffer::IsPossiblyComplete() const {
+GLenum Framebuffer::IsPossiblyComplete(const FeatureInfo* feature_info) 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.get();
     if (!attachment->ValidForAttachmentType(attachment_type,
-                                            manager_->max_color_attachments_)) {
+                                            manager_->max_color_attachments_,
+                                            feature_info)) {
       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) {
@@ skipping 227 matching lines @@
        ++it) {
     TextureDetachObserver* observer = *it;
     observer->OnTextureRefDetachedFromFramebuffer(texture);
   }
 }
 
 }  // namespace gles2
 }  // namespace gpu