cc/test/pixel_test_utils.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/test/pixel_test_utils.h"
   6
   7 #include <string>
   8 #include <vector>
   9
  10 #include "base/file_util.h"
  11 #include "base/logging.h"
  12 #include "third_party/skia/include/core/SkBitmap.h"
  13 #include "ui/gfx/codec/png_codec.h"
  14
  15 namespace cc {
  16
  17 bool WritePNGFile(const SkBitmap& bitmap, const base::FilePath& file_path,
  18     bool discard_transparency) {
  19   std::vector<unsigned char> png_data;
  20   if (gfx::PNGCodec::EncodeBGRASkBitmap(bitmap,
  21                                         discard_transparency,
  22                                         &png_data) &&
  23       base::CreateDirectory(file_path.DirName())) {
  24     char* data = reinterpret_cast<char*>(&png_data[0]);
  25     int size = static_cast<int>(png_data.size());
  26     return base::WriteFile(file_path, data, size) == size;
  27   }
  28   return false;
  29 }
  30
  31 bool ReadPNGFile(const base::FilePath& file_path, SkBitmap* bitmap) {
  32   DCHECK(bitmap);
  33   std::string png_data;
  34   return base::ReadFileToString(file_path, &png_data) &&
  35          gfx::PNGCodec::Decode(reinterpret_cast<unsigned char*>(&png_data[0]),
  36                                png_data.length(),
  37                                bitmap);
  38 }
  39
  40 bool MatchesPNGFile(const SkBitmap& gen_bmp, base::FilePath ref_img_path,
  41                     const PixelComparator& comparator) {
  42   SkBitmap ref_bmp;
  43   if (!ReadPNGFile(ref_img_path, &ref_bmp)) {
  44     LOG(ERROR) << "Cannot read reference image: " << ref_img_path.value();
  45     return false;
  46   }
  47
  48   // Check if images size matches
  49   if (gen_bmp.width() != ref_bmp.width() ||
  50       gen_bmp.height() != ref_bmp.height()) {
  51     LOG(ERROR)
  52         << "Dimensions do not match! "
  53         << "Actual: " << gen_bmp.width() << "x" << gen_bmp.height()
  54         << "; "
  55         << "Expected: " << ref_bmp.width() << "x" << ref_bmp.height();
  56     return false;
  57   }
  58
  59   // Shortcut for empty images. They are always equal.
  60   if (gen_bmp.width() == 0 || gen_bmp.height() == 0)
  61     return true;
  62
  63   return comparator.Compare(gen_bmp, ref_bmp);
  64 }
  65
  66 }  // namespace cc