1 // Copyright (c) 2013 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 #ifndef CC_TEST_PIXEL_COMPARATOR_H_ 6 #define CC_TEST_PIXEL_COMPARATOR_H_ 7 8 #include "base/compiler_specific.h" 9 #include "third_party/skia/include/core/SkBitmap.h" 10 11 namespace cc { 12 13 // Interface for pixel comparators. 14 class PixelComparator { 15 public: ~PixelComparator()16 virtual ~PixelComparator() {} 17 18 virtual bool Compare(const SkBitmap& actual_bmp, 19 const SkBitmap& expected_bmp) const = 0; 20 }; 21 22 // Exact pixel comparator. Counts the number of pixel with an error. 23 class ExactPixelComparator : public PixelComparator { 24 public: 25 explicit ExactPixelComparator(const bool discard_alpha); ~ExactPixelComparator()26 virtual ~ExactPixelComparator() {} 27 28 // Returns true if the two bitmaps are identical. Otherwise, returns false 29 // and report the number of pixels with an error on LOG(ERROR). Differences 30 // in the alpha channel are ignored. 31 virtual bool Compare(const SkBitmap& actual_bmp, 32 const SkBitmap& expected_bmp) const OVERRIDE; 33 34 private: 35 // Exclude alpha channel from comparison? 36 bool discard_alpha_; 37 }; 38 39 // Fuzzy pixel comparator. Counts small and arbitrary errors separately and 40 // computes average and maximum absolute errors per color channel. 41 class FuzzyPixelComparator : public PixelComparator { 42 public: 43 FuzzyPixelComparator(const bool discard_alpha, 44 const float error_pixels_percentage_limit, 45 const float small_error_pixels_percentage_limit, 46 const float avg_abs_error_limit, 47 const int max_abs_error_limit, 48 const int small_error_threshold); ~FuzzyPixelComparator()49 virtual ~FuzzyPixelComparator() {} 50 51 // Computes error metrics and returns true if the errors don't exceed the 52 // specified limits. Otherwise, returns false and reports the error metrics on 53 // LOG(ERROR). Differences in the alpha channel are ignored. 54 virtual bool Compare(const SkBitmap& actual_bmp, 55 const SkBitmap& expected_bmp) const OVERRIDE; 56 57 private: 58 // Exclude alpha channel from comparison? 59 bool discard_alpha_; 60 // Limit for percentage of pixels with an error. 61 float error_pixels_percentage_limit_; 62 // Limit for percentage of pixels with a small error. 63 float small_error_pixels_percentage_limit_; 64 // Limit for average absolute error (excluding identical pixels). 65 float avg_abs_error_limit_; 66 // Limit for largest absolute error. 67 int max_abs_error_limit_; 68 // Threshold for small errors. 69 int small_error_threshold_; 70 }; 71 72 } // namespace cc 73 74 #endif // CC_TEST_PIXEL_COMPARATOR_H_ 75