Attaching an image to many color attachment points is unsupported

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 <stddef.h>
 #include <stdint.h>
 
 #include "base/logging.h"
@@ skipping 71 matching lines @@
 
   bool IsTextureAttachment() const override { return false; }
   bool IsRenderbufferAttachment() const override { return true; }
 
   bool IsTexture(TextureRef* /* texture */) const override { return false; }
 
   bool IsRenderbuffer(Renderbuffer* renderbuffer) const override {
     return renderbuffer_.get() == renderbuffer;
   }
 
+  bool IsSameAttachment(const Attachment* attachment) const override {
+    if (attachment->IsRenderbufferAttachment()) {
+      const RenderbufferAttachment* other =
+          reinterpret_cast<const RenderbufferAttachment*>(attachment);
+      return IsRenderbuffer(other->renderbuffer());
+    }
+    return false;
+  }
+
   bool Is3D() const override { return false; }
 
   bool CanRenderTo(const FeatureInfo*) const override { return true; }
 
   void DetachFromFramebuffer(Framebuffer* framebuffer) const override {
     // Nothing to do for renderbuffers.
   }
 
   bool IsLayerValid() const override { return true; }
 
@@ skipping 111 matching lines @@
     return texture_ref_->texture()->IsLevelPartiallyCleared(target_, level_);
   }
 
   bool IsTextureAttachment() const override { return true; }
   bool IsRenderbufferAttachment() const override { return false; }
 
   bool IsTexture(TextureRef* texture) const override {
     return texture == texture_ref_.get();
   }
 
+  bool IsSameAttachment(const Attachment* attachment) const override {
+    if (attachment->IsTextureAttachment()) {
+      const TextureAttachment* other =
+          reinterpret_cast<const TextureAttachment*>(attachment);
+      return IsTexture(other->texture()) &&
+          layer_ == other->layer() &&
+          target_ == other->target() &&
+          level_ == other->level();
+    }
+    return false;
+  }
+
   bool IsRenderbuffer(Renderbuffer* /* renderbuffer */) const override {
     return false;
   }
 
   bool Is3D() const override {
     return (target_ == GL_TEXTURE_3D || target_ == GL_TEXTURE_2D_ARRAY);
   }
 
   TextureRef* texture() const {
     return texture_ref_.get();
@@ skipping 471 matching lines @@
       } else if (attachment->samples() != samples) {
         // It's possible that the specified samples isn't the actual samples a
         // GL implementation uses, but we always return INCOMPLETE_MULTISAMPLE
         // here to ensure consistent behaviors across platforms.
         return GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE;
       }
     }
     if (!attachment->CanRenderTo(feature_info)) {
       return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
     }
+
+    // Attaching an image to more than one color attachment point should return
+    // FRAMEBUFFER_UNSUPPORTED.
+    if (it->first >= GL_COLOR_ATTACHMENT0 &&
+        it->first < GL_COLOR_ATTACHMENT0 + manager_->max_color_attachments_) {
+      for (GLenum i = it->first + 1;
+           i < GL_COLOR_ATTACHMENT0 + manager_->max_color_attachments_; i++) {
+        const Attachment* other = GetAttachment(i);
+        if (other && attachment->IsSameAttachment(other)) {
+          return GL_FRAMEBUFFER_UNSUPPORTED;
+        }
+      }
+    }
   }
 
   // This does not mean the framebuffer is actually complete. It just means our
   // checks passed.
   return GL_FRAMEBUFFER_COMPLETE;
 }
 
 GLenum Framebuffer::GetStatus(
     TextureManager* texture_manager, GLenum target) const {
   if (!manager_->GetFramebufferComboCompleteCache()) {
@@ skipping 280 matching lines @@
 
 bool FramebufferManager::IsComplete(
     Framebuffer* framebuffer) {
   DCHECK(framebuffer);
   return framebuffer->framebuffer_complete_state_count_id() ==
       framebuffer_state_change_count_;
 }
 
 }  // namespace gles2
 }  // namespace gpu