cc: Adding ETC1 support to UIResourceBitmap and ResourceProvider

cc/scheduler/texture_uploader.cc

Index: cc/scheduler/texture_uploader.cc
diff --git a/cc/scheduler/texture_uploader.cc b/cc/scheduler/texture_uploader.cc
index cebc98689118949bb9081a33b215552133db0aa4..3bafa194d31c558f35c72688496c0855ec4c97a9 100644
--- a/cc/scheduler/texture_uploader.cc
+++ b/cc/scheduler/texture_uploader.cc
@@ -76,13 +76,15 @@ unsigned TextureUploader::Query::Value() {
 
 TextureUploader::TextureUploader(WebKit::WebGraphicsContext3D* context,
                                  bool use_map_tex_sub_image,
-                                 bool use_shallow_flush)
+                                 bool use_shallow_flush,
+                                 bool use_compressed_texture_etc1)
     : context_(context),
       num_blocking_texture_uploads_(0),
       use_map_tex_sub_image_(use_map_tex_sub_image),
       sub_image_size_(0),
       use_shallow_flush_(use_shallow_flush),
-      num_texture_uploads_since_last_flush_(0) {
+      num_texture_uploads_since_last_flush_(0),
+      use_compressed_texture_etc1_(use_compressed_texture_etc1) {

[no sievers, 2013/10/23 20:33:15]

nit: I'd rename this to 'have_compressed_texture_etc1_' since it's not really
used to chose an alternate codepath like the flags above. You might also just
remove it from this class since you are only using it for a DCHECK(). The the
decoder would already generate a GL error if you tried to use the format where
the extension is not available and the function call is explicit enough
(UploadWithTexSubImageETC1).

[powei, 2013/10/23 22:20:07]

Done.  Removed.

   for (size_t i = kUploadHistorySizeInitial; i > 0; i--)
     textures_per_second_history_.insert(kDefaultEstimatedTexturesPerSecond);
 }
@@ -186,11 +188,17 @@ void TextureUploader::UploadWithTexSubImage(const uint8* image,
     return;
   DCHECK(image);
 
+  if (format == ETC1) {
+    UploadWithTexSubImageETC1(
+        image, image_rect, source_rect, dest_offset, format);
+    return;
+  }
+
   // Offset from image-rect to source-rect.
   gfx::Vector2d offset(source_rect.origin() - image_rect.origin());
 
   const uint8* pixel_source;
-  unsigned bytes_per_pixel = BytesPerPixel(format);
+  unsigned bytes_per_pixel = BitsPerPixel(format) / 8;

[kaanb, 2013/10/23 20:30:09]

could you keep a BytesPerPixel method in resource_provider.h that simply returns
BitsPerPixel(format) / 8 

[powei, 2013/10/23 22:20:07]

Done.

   // Use 4-byte row alignment (OpenGL default) for upload performance.
   // Assuming that GL_UNPACK_ALIGNMENT has not changed from default.
   unsigned upload_image_stride =
@@ -239,11 +247,13 @@ void TextureUploader::UploadWithMapTexSubImage(const uint8* image,
   if (source_rect.IsEmpty())
     return;
   DCHECK(image);
+  // Compressed textures have no implementation of mapTexSubImage.
+  DCHECK_NE(ETC1, format);
 
   // Offset from image-rect to source-rect.
   gfx::Vector2d offset(source_rect.origin() - image_rect.origin());
 
-  unsigned bytes_per_pixel = BytesPerPixel(format);
+  unsigned bytes_per_pixel = BitsPerPixel(format) / 8;
   // Use 4-byte row alignment (OpenGL default) for upload performance.
   // Assuming that GL_UNPACK_ALIGNMENT has not changed from default.
   unsigned upload_image_stride =
@@ -285,6 +295,34 @@ void TextureUploader::UploadWithMapTexSubImage(const uint8* image,
   context_->unmapTexSubImage2DCHROMIUM(pixel_dest);
 }
 
+void TextureUploader::UploadWithTexSubImageETC1(const uint8* image,
+                                                gfx::Rect image_rect,
+                                                gfx::Rect source_rect,
+                                                gfx::Vector2d dest_offset,
+                                                ResourceFormat format) {
+  TRACE_EVENT0("cc", "TextureUploader::UploadWithTexSubImageETC1");
+  DCHECK(use_compressed_texture_etc1_);
+  // ETC1 does not support subimage uploads yet.
+  DCHECK(image_rect == source_rect);
+  DCHECK_EQ(0, dest_offset.x());
+  DCHECK_EQ(0, dest_offset.y());
+
+  gfx::Size size = source_rect.size();
+  DCHECK_EQ(0, size.width() % 4);
+  DCHECK_EQ(0, size.height() % 4);
+
+  context_->compressedTexSubImage2D(

[no sievers, 2013/10/23 20:33:15]

Wait, I'm confused. Like your comment says above, texSubImage does not work with
ETC1.
The spec does not support it, and there is even a unit test
(GLES2DecoderManualInitTest.CompressedTexImage2DETC1, see 'Test
CompressedTexSubImage not allowed'). 

[powei, 2013/10/23 22:20:07]

Done.  My comment above was to discourage users from using subimage uploads on
an etc1 resource, but I did not know that this is not even supported.  I've
changed it to just compressedTexImage2D.

+      GL_TEXTURE_2D,
+      0, /* level */
+      0, /* x */
+      0, /* y */
+      size.width(),
+      size.height(),
+      GLDataFormat(format),
+      Resource::MemorySizeBytes(size, format),
+      image);
+}
+
 void TextureUploader::ProcessQueries() {
   while (!pending_queries_.empty()) {
     if (pending_queries_.front()->IsPending())