Reland: Add ETC1 powered SSE encoder for tile texture compression

cc/resources/texture_compressor_unittest.cc

Index: cc/resources/texture_compressor_unittest.cc
diff --git a/cc/resources/texture_compressor_unittest.cc b/cc/resources/texture_compressor_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..cfbfa2146ed3533f93e7dbb6161446f1198c5aa1
--- /dev/null
+++ b/cc/resources/texture_compressor_unittest.cc
@@ -0,0 +1,64 @@
+// 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/resources/texture_compressor.h"
+
+#include "cc/base/util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+#define TEST_IMAGE_WIDTH 256
+#define TEST_IMAGE_HEIGHT 256
+#define TEST_IMAGE_CHANNELS 4
+#define TEST_IMAGE_SIZE \
+  (TEST_IMAGE_WIDTH * TEST_IMAGE_HEIGHT * TEST_IMAGE_CHANNELS)
+
+#define TEST_IMAGE_POISON 0xDEADBEEF
+#define TEST_PIXEL_LIMIT 256
+
+TEST(TextureCompressorTest, CreateETC1) {
+  scoped_ptr<TextureCompressor> compressor =
+      TextureCompressor::Create(TextureCompressor::kFormatETC1);
+  EXPECT_NE(nullptr, compressor);
+}
+
+TEST(TextureCompressorTest, CompressRatioETC1) {
+  scoped_ptr<TextureCompressor> compressor =
+      TextureCompressor::Create(TextureCompressor::kFormatETC1);
+  uint8_t src[TEST_IMAGE_SIZE];
+  uint8_t dst[TEST_IMAGE_SIZE];
+  int compressed_size = 0;
+
+  /* Poison destination bytes */
+  uint32_t* dst_32 = reinterpret_cast<uint32_t*>(dst);
+  for (int i = 0; i < TEST_IMAGE_WIDTH * TEST_IMAGE_HEIGHT; i++) {
+    dst_32[i] = TEST_IMAGE_POISON;
+  }
+
+  /* Generate test texture */
+  for (int i = 0; i < TEST_IMAGE_SIZE; i++) {
+    src[i] = i % TEST_PIXEL_LIMIT;
+  }
+
+  compressor->Compress(src, dst, TEST_IMAGE_WIDTH, TEST_IMAGE_HEIGHT,
+                       (TextureCompressor::Quality)0);
+  for (compressed_size = 0;
+       compressed_size < TEST_IMAGE_WIDTH * TEST_IMAGE_HEIGHT;
+       compressed_size++) {
+    if (dst_32[compressed_size] == TEST_IMAGE_POISON) {
+      compressed_size =
+          compressed_size * 4; /* size in bytes of the compressed block */
+      break;
+    }
+  }
+
+  /* Check if compression ratio is 8:1 for RGBA or BGRA images, after discarding
+   * alpha channel */
+  EXPECT_EQ(compressed_size * 8, TEST_IMAGE_SIZE);
+}
+
+}  // namespace
+}  // namespace cc