color_utils_unittest.cc

// Copyright (c) 2006-2008 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 <stdlib.h>

#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "third_party/skia/include/core/SkColorPriv.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/color_utils.h"
#include "ui/gfx/geometry/rect.h"

namespace color_utils {

TEST(ColorUtils, SkColorToHSLRed) {
  HSL hsl = {0, 0, 0};
  SkColorToHSL(SK_ColorRED, &hsl);
  EXPECT_DOUBLE_EQ(hsl.h, 0);
  EXPECT_DOUBLE_EQ(hsl.s, 1);
  EXPECT_DOUBLE_EQ(hsl.l, 0.5);
}

TEST(ColorUtils, SkColorToHSLGrey) {
  HSL hsl = {0, 0, 0};
  SkColorToHSL(SkColorSetARGB(255, 128, 128, 128), &hsl);
  EXPECT_DOUBLE_EQ(hsl.h, 0);
  EXPECT_DOUBLE_EQ(hsl.s, 0);
  EXPECT_EQ(static_cast<int>(hsl.l * 100),
            static_cast<int>(0.5 * 100));  // Accurate to two decimal places.
}

TEST(ColorUtils, HSLToSkColorWithAlpha) {
  SkColor red = SkColorSetARGB(128, 255, 0, 0);
  HSL hsl = {0, 1, 0.5};
  SkColor result = HSLToSkColor(hsl, 128);
  EXPECT_EQ(SkColorGetA(red), SkColorGetA(result));
  EXPECT_EQ(SkColorGetR(red), SkColorGetR(result));
  EXPECT_EQ(SkColorGetG(red), SkColorGetG(result));
  EXPECT_EQ(SkColorGetB(red), SkColorGetB(result));
}

TEST(ColorUtils, RGBtoHSLRoundTrip) {
  // Just spot check values near the edges.
  for (int r = 0; r < 10; ++r) {
    for (int g = 0; g < 10; ++g) {
      for (int b = 0; b < 10; ++b) {
        SkColor rgb = SkColorSetARGB(255, r, g, b);
        HSL hsl = {0, 0, 0};
        SkColorToHSL(rgb, &hsl);
        SkColor out = HSLToSkColor(hsl, 255);
        EXPECT_EQ(SkColorGetR(out), SkColorGetR(rgb));
        EXPECT_EQ(SkColorGetG(out), SkColorGetG(rgb));
        EXPECT_EQ(SkColorGetB(out), SkColorGetB(rgb));
      }
    }
  }
  for (int r = 240; r < 256; ++r) {
    for (int g = 240; g < 256; ++g) {
      for (int b = 240; b < 256; ++b) {
        SkColor rgb = SkColorSetARGB(255, r, g, b);
        HSL hsl = {0, 0, 0};
        SkColorToHSL(rgb, &hsl);
        SkColor out = HSLToSkColor(hsl, 255);
        EXPECT_EQ(SkColorGetR(out), SkColorGetR(rgb));
        EXPECT_EQ(SkColorGetG(out), SkColorGetG(rgb));
        EXPECT_EQ(SkColorGetB(out), SkColorGetB(rgb));
      }
    }
  }
}

TEST(ColorUtils, IsWithinHSLRange) {
  HSL hsl = {0.3, 0.4, 0.5};
  HSL lower = {0.2, 0.3, 0.4};
  HSL upper = {0.4, 0.5, 0.6};
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  // Bounds are inclusive.
  hsl.h = 0.2;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.h = 0.4;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.s = 0.3;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.s = 0.5;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.l = 0.4;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.l = 0.6;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
}

TEST(ColorUtils, IsWithinHSLRangeHueWrapAround) {
  HSL hsl = {0.3, 0.4, 0.5};
  HSL lower = {0.8, -1, -1};
  HSL upper = {1.2, -1, -1};
  hsl.h = 0.1;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.h = 0.9;
  EXPECT_TRUE(IsWithinHSLRange(hsl, lower, upper));
  hsl.h = 0.3;
  EXPECT_FALSE(IsWithinHSLRange(hsl, lower, upper));
}

TEST(ColorUtils, ColorToHSLRegisterSpill) {
  // In a opt build on Linux, this was causing a register spill on my laptop
  // (Pentium M) when converting from SkColor to HSL.
  SkColor input = SkColorSetARGB(255, 206, 154, 89);
  HSL hsl = {-1, -1, -1};
  SkColor result = HSLShift(input, hsl);
  // |result| should be the same as |input| since we passed in a value meaning
  // no color shift.
  EXPECT_EQ(SkColorGetA(input), SkColorGetA(result));
  EXPECT_EQ(SkColorGetR(input), SkColorGetR(result));
  EXPECT_EQ(SkColorGetG(input), SkColorGetG(result));
  EXPECT_EQ(SkColorGetB(input), SkColorGetB(result));
}

TEST(ColorUtils, CalculateBoringScore_Empty) {
  SkBitmap bitmap;
  EXPECT_DOUBLE_EQ(1.0, CalculateBoringScore(bitmap));
}

TEST(ColorUtils, CalculateBoringScore_SingleColor) {
  const gfx::Size kSize(20, 10);
  gfx::Canvas canvas(kSize, 1.0f, true);
  // Fill all pixels in black.
  canvas.FillRect(gfx::Rect(kSize), SK_ColorBLACK);

  SkBitmap bitmap =
      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
  // The thumbnail should deserve the highest boring score.
  EXPECT_DOUBLE_EQ(1.0, CalculateBoringScore(bitmap));
}

TEST(ColorUtils, CalculateBoringScore_TwoColors) {
  const gfx::Size kSize(20, 10);

  gfx::Canvas canvas(kSize, 1.0f, true);
  // Fill all pixels in black.
  canvas.FillRect(gfx::Rect(kSize), SK_ColorBLACK);
  // Fill the left half pixels in white.
  canvas.FillRect(gfx::Rect(0, 0, kSize.width() / 2, kSize.height()),
                  SK_ColorWHITE);

  SkBitmap bitmap =
      skia::GetTopDevice(*canvas.sk_canvas())->accessBitmap(false);
  ASSERT_EQ(kSize.width(), bitmap.width());
  ASSERT_EQ(kSize.height(), bitmap.height());
  // The thumbnail should be less boring because two colors are used.
  EXPECT_DOUBLE_EQ(0.5, CalculateBoringScore(bitmap));
}

TEST(ColorUtils, AlphaBlend) {
  SkColor fore = SkColorSetARGB(255, 200, 200, 200);
  SkColor back = SkColorSetARGB(255, 100, 100, 100);

  EXPECT_TRUE(AlphaBlend(fore, back, 255) == fore);
  EXPECT_TRUE(AlphaBlend(fore, back, 0) == back);

  // One is fully transparent, result is partially transparent.
  back = SkColorSetA(back, 0);
  EXPECT_EQ(136U, SkColorGetA(AlphaBlend(fore, back, 136)));

  // Both are fully transparent, result is fully transparent.
  fore = SkColorSetA(fore, 0);
  EXPECT_EQ(0U, SkColorGetA(AlphaBlend(fore, back, 255)));
}

}  // namespace color_utils