color: Towards ColorTransform optimizations and code generation

ui/gfx/color_transform_unittest.cc

Index: ui/gfx/color_transform_unittest.cc
diff --git a/ui/gfx/color_transform_unittest.cc b/ui/gfx/color_transform_unittest.cc
index 3fc43c2b239b45462fd91eb46f56ca2959bb8427..46fa0e5913b13845cf8733573c9abc4fa37229ff 100644
--- a/ui/gfx/color_transform_unittest.cc
+++ b/ui/gfx/color_transform_unittest.cc
@@ -84,6 +84,53 @@ TEST(SimpleColorSpace, BT709toSRGB) {
   EXPECT_GT(tmp.z(), tmp.y());
 }
 
+TEST(SimpleColorSpace, SRGBFromICCAndNotICC) {
+  float kEpsilon = 0.001f;
+  ColorTransform::TriStim value_fromicc;
+  ColorTransform::TriStim value_default;
+
+  ICCProfile srgb_icc_profile = ICCProfileForTestingSRGB();
+  ColorSpace srgb_fromicc = srgb_icc_profile.GetColorSpace();
+  ColorSpace srgb_default = gfx::ColorSpace::CreateSRGB();
+  ColorSpace xyzd50 = gfx::ColorSpace::CreateXYZD50();
+
+  value_fromicc = value_default = ColorTransform::TriStim(0.1, 0.5, 0.9);
+
+  std::unique_ptr<ColorTransform> toxyzd50_fromicc(
+      ColorTransform::NewColorTransform(
+          srgb_fromicc, xyzd50, ColorTransform::Intent::INTENT_ABSOLUTE));
+  // This will have 1 step, namely, the QCMS transform.
+  EXPECT_EQ(toxyzd50_fromicc->NumberOfStepsForTesting(), 1u);
+  toxyzd50_fromicc->transform(&value_fromicc, 1);
+
+  std::unique_ptr<ColorTransform> toxyzd50_default(
+      ColorTransform::NewColorTransform(
+          srgb_default, xyzd50, ColorTransform::Intent::INTENT_ABSOLUTE));
+  // This will have a transfer function and then linear transform.
+  EXPECT_EQ(toxyzd50_default->NumberOfStepsForTesting(), 2u);
+  toxyzd50_default->transform(&value_default, 1);
+
+  EXPECT_NEAR(value_fromicc.x(), value_default.x(), kEpsilon);
+  EXPECT_NEAR(value_fromicc.y(), value_default.y(), kEpsilon);
+  EXPECT_NEAR(value_fromicc.z(), value_default.z(), kEpsilon);
+
+  value_fromicc = value_default = ColorTransform::TriStim(0.1, 0.5, 0.9);
+
+  std::unique_ptr<ColorTransform> fromxyzd50_fromicc(
+      ColorTransform::NewColorTransform(
+          xyzd50, srgb_fromicc, ColorTransform::Intent::INTENT_ABSOLUTE));
+  fromxyzd50_fromicc->transform(&value_fromicc, 1);
+
+  std::unique_ptr<ColorTransform> fromxyzd50_default(
+      ColorTransform::NewColorTransform(
+          xyzd50, srgb_default, ColorTransform::Intent::INTENT_ABSOLUTE));
+  fromxyzd50_default->transform(&value_default, 1);
+
+  EXPECT_NEAR(value_fromicc.x(), value_default.x(), kEpsilon);
+  EXPECT_NEAR(value_fromicc.y(), value_default.y(), kEpsilon);
+  EXPECT_NEAR(value_fromicc.z(), value_default.z(), kEpsilon);
+}
+
 TEST(SimpleColorSpace, BT709toSRGBICC) {
   ICCProfile srgb_icc = ICCProfileForTestingSRGB();
   ColorSpace bt709 = ColorSpace::CreateREC709();
@@ -175,10 +222,33 @@ TEST(SimpleColorSpace, UnknownToSRGB) {
 class TransferTest : public testing::TestWithParam<ColorSpace::TransferID> {};
 
 TEST_P(TransferTest, basicTest) {
+  gfx::ColorSpace space_with_transfer(ColorSpace::PrimaryID::BT709, GetParam(),
+                                      ColorSpace::MatrixID::RGB,
+                                      ColorSpace::RangeID::FULL);
+  gfx::ColorSpace space_linear(
+      ColorSpace::PrimaryID::BT709, ColorSpace::TransferID::LINEAR,
+      ColorSpace::MatrixID::RGB, ColorSpace::RangeID::FULL);
+
+  std::unique_ptr<ColorTransform> to_linear(ColorTransform::NewColorTransform(
+      space_with_transfer, space_linear,
+      ColorTransform::Intent::INTENT_ABSOLUTE));
+
+  std::unique_ptr<ColorTransform> from_linear(ColorTransform::NewColorTransform(
+      space_linear, space_with_transfer,
+      ColorTransform::Intent::INTENT_ABSOLUTE));
+
+  // The transforms will ahve 1 or 0 steps (0 for linear).
+  size_t expected_steps = 1u;
+  if (GetParam() == ColorSpace::TransferID::LINEAR)
+    expected_steps = 0u;
+  EXPECT_EQ(to_linear->NumberOfStepsForTesting(), expected_steps);
+  EXPECT_EQ(from_linear->NumberOfStepsForTesting(), expected_steps);
+
   for (float x = 0.0f; x <= 1.0f; x += 1.0f / 128.0f) {
-    float linear = ColorTransform::ToLinearForTesting(GetParam(), x);
-    float x2 = ColorTransform::FromLinearForTesting(GetParam(), linear);
-    EXPECT_NEAR(x, x2, 0.001f);
+    ColorTransform::TriStim tristim(x, x, x);
+    to_linear->transform(&tristim, 1);
+    from_linear->transform(&tristim, 1);
+    EXPECT_NEAR(x, tristim.x(), 0.001f);
   }
 }