cc/raster/texture_compressor_etc1_unittest.cc

// Copyright 2015 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/raster/texture_compressor.h"

#include "testing/gtest/include/gtest/gtest.h"

namespace cc {
namespace {

const int kImageWidth = 256;
const int kImageHeight = 256;
const int kImageChannels = 4;
const int kImageSizeInBytes = kImageWidth * kImageHeight * kImageChannels;

TEST(TextureCompressorETC1Test, Compress256x256Ratio) {
  scoped_ptr<TextureCompressor> compressor =
      TextureCompressor::Create(TextureCompressor::kFormatETC1);
  uint8_t src[kImageSizeInBytes];
  uint8_t dst[kImageSizeInBytes];
  const unsigned int kImagePoison = 0xDEADBEEF;

  // Poison destination bytes so we can see how much has been
  // overwritten by compression algorithm.
  uint32_t* dst_32 = reinterpret_cast<uint32_t*>(dst);
  for (int i = 0; i < kImageWidth * kImageHeight; i++) {
    dst_32[i] = kImagePoison;
  }

  // Generate test texture.
  for (int i = 0; i < kImageSizeInBytes; i++) {
    src[i] = i % 256;
  }

  compressor->Compress(src, dst, kImageWidth, kImageHeight,
                       TextureCompressor::kQualityLow);

  int compressed_size = 0;
  for (compressed_size = 0; compressed_size < kImageWidth * kImageHeight;
       compressed_size++) {
    if (dst_32[compressed_size] == kImagePoison) {
      // Represents size in bytes of the compressed block.
      compressed_size = compressed_size * 4;
      break;
    }
  }

  // Check if compression ratio is 8:1 for RGBA or BGRA images, after discarding
  // alpha channel.
  EXPECT_EQ(kImageSizeInBytes, compressed_size * 8);
}

}  // namespace
}  // namespace cc