cc: Adding ETC1 support to UIResourceBitmap and ResourceProvider

cc/scheduler/texture_uploader.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/scheduler/texture_uploader.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/debug/trace_event.h"
@@ skipping 168 matching lines @@
                                             gfx::Vector2d dest_offset,
                                             ResourceFormat format) {
   TRACE_EVENT0("cc", "TextureUploader::UploadWithTexSubImage");
 
   // Early-out if this is a no-op, and assert that |image| be valid if this is
   // not a no-op.
   if (source_rect.IsEmpty())
     return;
   DCHECK(image);
 
+  // ETC1 textures take a separate path

[kaanb, 2013/10/18 16:54:49]

I don't think you need this comment, the code is self-explanatory.

[powei, 2013/10/23 05:36:15]

Done.

+  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);
   // Use 4-byte row alignment (OpenGL default) for upload performance.
   // Assuming that GL_UNPACK_ALIGNMENT has not changed from default.
   unsigned upload_image_stride =
       RoundUp(bytes_per_pixel * source_rect.width(), 4u);
 
@@ skipping 33 matching lines @@
                                                gfx::Rect source_rect,
                                                gfx::Vector2d dest_offset,
                                                ResourceFormat format) {
   TRACE_EVENT0("cc", "TextureUploader::UploadWithMapTexSubImage");
 
   // Early-out if this is a no-op, and assert that |image| be valid if this is
   // not a no-op.
   if (source_rect.IsEmpty())
     return;
   DCHECK(image);
+  // Compressed textures have no implementation of mapTexSubImage.
+  DCHECK_NE(format, ETC1);

[kaanb, 2013/10/18 16:54:49]

nit: DCHECK_NE(ETC1, format);

[powei, 2013/10/23 05:36:15]

Done.

 
   // Offset from image-rect to source-rect.
   gfx::Vector2d offset(source_rect.origin() - image_rect.origin());
 
   unsigned bytes_per_pixel = BytesPerPixel(format);
   // Use 4-byte row alignment (OpenGL default) for upload performance.
   // Assuming that GL_UNPACK_ALIGNMENT has not changed from default.
   unsigned upload_image_stride =
       RoundUp(bytes_per_pixel * source_rect.width(), 4u);
 
@@ skipping 26 matching lines @@
       memcpy(&pixel_dest[upload_image_stride * row],
              &image[bytes_per_pixel *
                  (offset.x() + (offset.y() + row) * image_rect.width())],
              source_rect.width() * bytes_per_pixel);
     }
   }
 
   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");
+
+  // ETC1 does not support subimage uploads yet.
+  DCHECK(image_rect == source_rect);
+  DCHECK_EQ(dest_offset.x(), 0);

[kaanb, 2013/10/18 16:54:49]

nit: the first parameter to DCHECK is the expected value, hence
DCHECK_EQ(0, des_offset.x())

[powei, 2013/10/23 05:36:15]

Done.

+  DCHECK_EQ(dest_offset.y(), 0);
+
+  context_->compressedTexSubImage2D(
+      GL_TEXTURE_2D,
+      0, /* level */
+      0, /* x */
+      0, /* y */
+      source_rect.width(),
+      source_rect.height(),
+      GLDataFormat(format),
+      Resource::ETC1SizeInBytes(source_rect.size()),
+      image);
+}
+
 void TextureUploader::ProcessQueries() {
   while (!pending_queries_.empty()) {
     if (pending_queries_.front()->IsPending())
       break;
 
     unsigned us_elapsed = pending_queries_.front()->Value();
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Renderer4.TextureGpuUploadTimeUS", us_elapsed, 0, 100000, 50);
 
     // Clamp the queries to saner values in case the queries fail.
     us_elapsed = std::max(1u, us_elapsed);
     us_elapsed = std::min(15000u, us_elapsed);
 
     if (!pending_queries_.front()->is_non_blocking())
       num_blocking_texture_uploads_--;
 
     // Remove the min and max value from our history and insert the new one.
     double textures_per_second = 1.0 / (us_elapsed * 1e-6);
     if (textures_per_second_history_.size() >= kUploadHistorySizeMax) {
       textures_per_second_history_.erase(textures_per_second_history_.begin());
       textures_per_second_history_.erase(--textures_per_second_history_.end());
     }
     textures_per_second_history_.insert(textures_per_second);
 
     available_queries_.push_back(pending_queries_.take_front());
   }
 }
 
 }  // namespace cc