ui/gfx/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/color_utils.h"

TEST(ColorUtils, SkColorToHSLRed) {
  color_utils::HSL hsl = { 0, 0, 0 };
  color_utils::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) {
  color_utils::HSL hsl = { 0, 0, 0 };
  color_utils::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);
  color_utils::HSL hsl = { 0, 1, 0.5 };
  SkColor result = color_utils::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);
        color_utils::HSL hsl = { 0, 0, 0 };
        color_utils::SkColorToHSL(rgb, &hsl);
        SkColor out = color_utils::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);
        color_utils::HSL hsl = { 0, 0, 0 };
        color_utils::SkColorToHSL(rgb, &hsl);
        SkColor out = color_utils::HSLToSkColor(hsl, 255);
        EXPECT_EQ(SkColorGetR(out), SkColorGetR(rgb));
        EXPECT_EQ(SkColorGetG(out), SkColorGetG(rgb));
        EXPECT_EQ(SkColorGetB(out), SkColorGetB(rgb));
      }
    }
  }
}

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);
  color_utils::HSL hsl = { -1, -1, -1 };
  SkColor result = color_utils::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, AlphaBlend) {
  SkColor fore = SkColorSetARGB(255, 200, 200, 200);
  SkColor back = SkColorSetARGB(255, 100, 100, 100);

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

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

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