cc: Adding ETC1 support to UIResourceBitmap and ResourceProvider

cc/resources/resource_provider.cc

Index: cc/resources/resource_provider.cc
diff --git a/cc/resources/resource_provider.cc b/cc/resources/resource_provider.cc
index 0a214a44fa283de5a3224682520448ae47397430..82ca73b800947114673d8687a1e3fb247d9f6c37 100644
--- a/cc/resources/resource_provider.cc
+++ b/cc/resources/resource_provider.cc
@@ -47,6 +47,7 @@ GLenum TextureToStorageFormat(ResourceFormat format) {
     case RGBA_4444:
     case LUMINANCE_8:
     case RGB_565:
+    case ETC1:
       NOTREACHED();
       break;
   }
@@ -62,6 +63,7 @@ bool IsFormatSupportedForStorage(ResourceFormat format) {
     case RGBA_4444:
     case LUMINANCE_8:
     case RGB_565:
+    case ETC1:
       return false;
   }
   return false;
@@ -838,6 +840,7 @@ bool ResourceProvider::InitializeGL() {
   use_texture_storage_ext_ = caps.texture_storage;
   use_shallow_flush_ = caps.shallow_flush;
   use_texture_usage_hint_ = caps.texture_usage;
+  use_compressed_texture_etc1_ = caps.texture_format_etc1;
 
   texture_uploader_ =
       TextureUploader::Create(context3d, use_map_sub, use_shallow_flush_);
@@ -1264,6 +1267,7 @@ void ResourceProvider::AcquirePixelBuffer(ResourceId id) {
   DCHECK(!resource->external);
   DCHECK_EQ(resource->exported_count, 0);
   DCHECK(!resource->image_id);
+  DCHECK_NE(ETC1, resource->format);
 
   if (resource->type == GLTexture) {
     WebGraphicsContext3D* context3d = Context3d();
@@ -1596,15 +1600,32 @@ void ResourceProvider::LazyAllocate(Resource* resource) {
                                               size.width(),
                                               size.height()));
   } else {
-    GLC(context3d, context3d->texImage2D(GL_TEXTURE_2D,
-                                         0,
-                                         GLInternalFormat(format),
-                                         size.width(),
-                                         size.height(),
-                                         0,
-                                         GLDataFormat(format),
-                                         GLDataType(format),
-                                         NULL));
+    if (format == ETC1) {
+      DCHECK(use_compressed_texture_etc1_);
+      DCHECK_EQ(0, size.width() % 4);
+      DCHECK_EQ(0, size.height() % 4);
+      GLC(context3d,
+          context3d->compressedTexImage2D(
+              GL_TEXTURE_2D,
+              0,
+              GLInternalFormat(format),
+              size.width(),
+              size.height(),
+              0,
+              cc::Resource::MemorySizeBytes(size, format),
+              NULL));

[no sievers, 2013/10/23 22:49:59]

I don't think glCompressedTexImage2D() supports passing NULL here to preallocate
the storage per the spec. 
The service side seems to handle null pointers (but I did not look at the
cmdbuffer code in the middle). It allocates a buffer set to 0. But even then, if
that doesn't decode properly, this call could still fail (spec: 'If the
compressed image is not encoded according to the defined image format, the
results of the call are
undefined.').

Maybe should just do nothing herefor ETC1?

[powei, 2013/10/23 23:25:58]

Done.  Thanks for catching that.

+    } else {
+      GLC(context3d,
+          context3d->texImage2D(GL_TEXTURE_2D,
+                                0,
+                                GLInternalFormat(format),
+                                size.width(),
+                                size.height(),
+                                0,
+                                GLDataFormat(format),
+                                GLDataType(format),
+                                NULL));
+    }
   }
 }