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

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 48e503cb45b3d1e64986d369edfe70d7f3557c16..455390147328629a23b4856f514e66db8b548f97 100644
--- a/gpu/command_buffer/service/framebuffer_manager.cc
+++ b/gpu/command_buffer/service/framebuffer_manager.cc
@@ -6,6 +6,7 @@
 #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"
@@ -102,7 +103,8 @@ class RenderbufferAttachment
   }
 
   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());
@@ -216,7 +218,8 @@ class TextureAttachment
   }
 
   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(
@@ -233,6 +236,18 @@ class TextureAttachment
         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;
   }
 
@@ -406,7 +421,7 @@ GLenum Framebuffer::GetColorAttachmentTextureType() const {
   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;
   }
@@ -418,7 +433,8 @@ GLenum Framebuffer::IsPossiblyComplete() const {
     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) {