cc: Adding support for RGBA_4444 tile textures

cc/resources/resource_provider.cc

 // Copyright 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 "cc/resources/resource_provider.h"
 
 #include <algorithm>
 #include <limits>
 
+#if defined(OS_ANDROID)
+#include "base/android/sys_utils.h"
+#endif
+
 #include "base/containers/hash_tables.h"
 #include "base/debug/alias.h"
 #include "base/stl_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "cc/output/gl_renderer.h"  // For the GLC() macro.
 #include "cc/resources/platform_color.h"
 #include "cc/resources/transferable_resource.h"
 #include "cc/scheduler/texture_uploader.h"
 #include "gpu/GLES2/gl2extchromium.h"
@@ skipping 658 matching lines @@
     : output_surface_(output_surface),
       lost_output_surface_(false),
       highp_threshold_min_(highp_threshold_min),
       next_id_(1),
       next_child_(1),
       default_resource_type_(InvalidType),
       use_texture_storage_ext_(false),
       use_texture_usage_hint_(false),
       use_shallow_flush_(false),
       max_texture_size_(0),
-      best_texture_format_(0) {}
+      best_texture_format_(0),
+      use_16bit_textures_(false) {
+#if defined(OS_ANDROID)
+    if (base::android::SysUtils::IsLowEndDevice())
+      use_16bit_textures_ = true;
+#endif
+}
 
 void ResourceProvider::InitializeSoftware() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_NE(Bitmap, default_resource_type_);
 
   CleanUpGLIfNeeded();
 
   default_resource_type_ = Bitmap;
   max_texture_size_ = INT_MAX / 2;
   best_texture_format_ = GL_RGBA;
@@ skipping 469 matching lines @@
     DCHECK(resource->gl_pixel_buffer_id);
     context3d->bindTexture(GL_TEXTURE_2D, resource->gl_id);
     context3d->bindBuffer(
         GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM,
         resource->gl_pixel_buffer_id);
     if (!resource->gl_upload_query_id)
       resource->gl_upload_query_id = context3d->createQueryEXT();
     context3d->beginQueryEXT(
         GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM,
         resource->gl_upload_query_id);
+    GLenum texture_data_type = use_16bit_textures_
+        ? GL_UNSIGNED_SHORT_4_4_4_4 : GL_UNSIGNED_BYTE;
     if (allocate) {
       context3d->asyncTexImage2DCHROMIUM(GL_TEXTURE_2D,
                                          0, /* level */
                                          resource->format,
                                          resource->size.width(),
                                          resource->size.height(),
                                          0, /* border */
                                          resource->format,
-                                         GL_UNSIGNED_BYTE,
+                                         texture_data_type,
                                          NULL);
     } else {
       context3d->asyncTexSubImage2DCHROMIUM(GL_TEXTURE_2D,
                                             0, /* level */
                                             0, /* x */
                                             0, /* y */
                                             resource->size.width(),
                                             resource->size.height(),
                                             resource->format,
-                                            GL_UNSIGNED_BYTE,
+                                            texture_data_type,
                                             NULL);
     }
     context3d->endQueryEXT(GL_ASYNC_PIXEL_TRANSFERS_COMPLETED_CHROMIUM);
     context3d->bindBuffer(GL_PIXEL_UNPACK_TRANSFER_BUFFER_CHROMIUM, 0);
   }
 
   if (resource->pixels) {
     DCHECK(!resource->mailbox.IsValid());
     DCHECK(resource->pixel_buffer);
     DCHECK(resource->format == GL_RGBA);
@@ skipping 94 matching lines @@
   LazyCreate(resource);
 
   DCHECK(resource->gl_id || resource->allocated);
   if (resource->allocated || !resource->gl_id)
     return;
   resource->allocated = true;
   WebGraphicsContext3D* context3d = output_surface_->context3d();
   gfx::Size& size = resource->size;
   GLenum format = resource->format;
   GLC(context3d, context3d->bindTexture(GL_TEXTURE_2D, resource->gl_id));
   if (use_texture_storage_ext_ && IsTextureFormatSupportedForStorage(format)) {

[Sami, 2013/08/08 10:11:01]

glTexStorage2D should also work with RGBA4_OES so try adding that to the list in
IsTextureFormatSupportedForStorage().

[kaanb, 2013/08/08 17:25:05]

I'm getting black tiles when I change the internalformat parameter of
glTexImage2D to RGBA4_OES and dtrainor@ noticed the same when he changed it for
the browser compositor. Could it be possible that we're not supporting the
extension that adds RGBA4_OES?

     GLenum storage_format = TextureToStorageFormat(format);
     GLC(context3d, context3d->texStorage2DEXT(GL_TEXTURE_2D,
                                               1,
                                               storage_format,
                                               size.width(),
                                               size.height()));
   } else {
+    GLenum texture_data_type = use_16bit_textures_
+        ? GL_UNSIGNED_SHORT_4_4_4_4 : GL_UNSIGNED_BYTE;
     GLC(context3d, context3d->texImage2D(GL_TEXTURE_2D,
                                          0,
                                          format,
                                          size.width(),
                                          size.height(),
                                          0,
                                          format,
-                                         GL_UNSIGNED_BYTE,
+                                         texture_data_type,

[Sami, 2013/08/08 10:11:01]

This parameter only sets the format of the data that is passed into
glTexImage2D. To set the format of the texture itself, we need to set |format|
to RGBA4_OES. Probably the best way to do that is to initialize
best_texture_format_ to RGBA4_OES.

There are also a bunch of assumptions in ResourceProvider that sizeof(pixel) ==
4 which we'd need to fix.

[kaanb, 2013/08/08 17:25:05]

See the comment on RGBA4_OES above.

                                          NULL));
   }
 }
 
 void ResourceProvider::EnableReadLockFences(ResourceProvider::ResourceId id,
                                             bool enable) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ResourceMap::iterator it = resources_.find(id);
   CHECK(it != resources_.end());
   Resource* resource = &it->second;
@@ skipping 102 matching lines @@
   return stride;
 }
 
 GLint ResourceProvider::GetActiveTextureUnit(WebGraphicsContext3D* context) {
   GLint active_unit = 0;
   context->getIntegerv(GL_ACTIVE_TEXTURE, &active_unit);
   return active_unit;
 }
 
 }  // namespace cc