gpu: Allow framebuffers with mixed samples if the hw supports it

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 561 matching lines @@
 }
 
 GLenum Framebuffer::IsPossiblyComplete(const FeatureInfo* feature_info) const {
   if (attachments_.empty()) {
     return GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT;
   }
 
   GLsizei width = -1;
   GLsizei height = -1;
   GLsizei samples = -1;
+  const bool kSamplesMustMatch =
+      feature_info->context_type() == CONTEXT_TYPE_WEBGL1 ||
+      feature_info->context_type() == CONTEXT_TYPE_WEBGL2 ||
+      !feature_info->feature_flags().chromium_framebuffer_mixed_samples;
+
   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,
                                             feature_info->context_type(),
                                             manager_->max_color_attachments_)) {
       return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
     }
     if (!attachment->IsLayerValid()) {
       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) {
       // Since DirectX doesn't allow attachments to be of different sizes,
       // even though ES3 allows it, it is still forbidden to ensure consistent
       // behaviors across platforms.
       return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT;
     }
-    if (samples < 0) {
-      samples = attachment->samples();
-    } 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 (kSamplesMustMatch) {
+      if (samples < 0) {
+        samples = attachment->samples();
+      } 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;
     }
   }
 
   // This does not mean the framebuffer is actually complete. It just means our
   // checks passed.
   return GL_FRAMEBUFFER_COMPLETE;
 }
@@ skipping 250 matching lines @@
 
 bool FramebufferManager::IsComplete(
     Framebuffer* framebuffer) {
   DCHECK(framebuffer);
   return framebuffer->framebuffer_complete_state_count_id() ==
       framebuffer_state_change_count_;
 }
 
 }  // namespace gles2
 }  // namespace gpu