text: /*
   * Copyright 2016 Google Inc.
   *
   * Use of this source code is governed by a BSD-style license that can be
   * found in the LICENSE file.
   */
  
  #include "Resources.h"
  #include "SkCodec.h"
  #include "SkCodecPriv.h"
  #include "SkColorPriv.h"
  #include "SkColorSpace.h"
  #include "SkColorSpace_A2B.h"
  #include "SkColorSpace_Base.h"
  #include "SkColorSpace_XYZ.h"
  #include "SkColorSpaceXform_Base.h"
  #include "Test.h"
  
  static constexpr int kChannels = 3;
  
  class ColorSpaceXformTest {
  public:
      static std::unique_ptr<SkColorSpaceXform> CreateIdentityXform(const sk_sp<SkGammas>& gammas) {
          // Logically we can pass any matrix here.  For simplicty, pass I(), i.e. D50 XYZ gamut.
          sk_sp<SkColorSpace> space(new SkColorSpace_XYZ(
                  kNonStandard_SkGammaNamed, gammas, SkMatrix::I(), nullptr));
  
          // Use special testing entry point, so we don't skip the xform, even though src == dst.
          return SlowIdentityXform(static_cast<SkColorSpace_XYZ*>(space.get()));
      }
  
      static std::unique_ptr<SkColorSpaceXform> CreateIdentityXform_A2B(
              SkGammaNamed gammaNamed, const sk_sp<SkGammas>& gammas) {
          std::vector<SkColorSpace_A2B::Element> srcElements;
          // sRGB
          const float values[16] = {
              0.4358f, 0.3853f, 0.1430f, 0.0f,
              0.2224f, 0.7170f, 0.0606f, 0.0f,
              0.0139f, 0.0971f, 0.7139f, 0.0f,
              0.0000f, 0.0000f, 0.0000f, 1.0f
          };
          SkMatrix44 arbitraryMatrix{SkMatrix44::kUninitialized_Constructor};
          arbitraryMatrix.setRowMajorf(values);
          if (kNonStandard_SkGammaNamed == gammaNamed) {
              SkASSERT(gammas);
              srcElements.push_back(SkColorSpace_A2B::Element(gammas));
          } else {
              srcElements.push_back(SkColorSpace_A2B::Element(gammaNamed, kChannels));
          }
          srcElements.push_back(SkColorSpace_A2B::Element(arbitraryMatrix));
          auto srcSpace =
                  ColorSpaceXformTest::CreateA2BSpace(SkColorSpace_A2B::PCS::kXYZ,
                                                      SkColorSpace_Base::InputColorFormat::kRGB,
                                                      std::move(srcElements));
          sk_sp<SkColorSpace> dstSpace(new SkColorSpace_XYZ(gammaNamed, gammas, arbitraryMatrix,
                                                            nullptr));
  
          return SkColorSpaceXform::New(static_cast<SkColorSpace_A2B*>(srcSpace.get()),
                                        static_cast<SkColorSpace_XYZ*>(dstSpace.get()));
      }
  
      static sk_sp<SkColorSpace> CreateA2BSpace(SkColorSpace_A2B::PCS pcs,
                                                SkColorSpace_Base::InputColorFormat inputColorFormat,
                                                std::vector<SkColorSpace_A2B::Element> elements) {
          return sk_sp<SkColorSpace>(new SkColorSpace_A2B(inputColorFormat, std::move(elements),
                                                          pcs, nullptr));
      }
  };
  
  static bool almost_equal(int x, int y) {
      return SkTAbs(x - y) <= 1;
  }
  
  static void test_identity_xform(skiatest::Reporter* r, const sk_sp<SkGammas>& gammas,
                                  bool repeat) {
      // Arbitrary set of 10 pixels
      constexpr int width = 10;
      constexpr uint32_t srcPixels[width] = {
              0xFFABCDEF, 0xFF146829, 0xFF382759, 0xFF184968, 0xFFDE8271,
              0xFF32AB52, 0xFF0383BC, 0xFF000102, 0xFFFFFFFF, 0xFFDDEEFF, };
      uint32_t dstPixels[width];
  
      // Create and perform an identity xform.
      std::unique_ptr<SkColorSpaceXform> xform = ColorSpaceXformTest::CreateIdentityXform(gammas);
      bool result = xform->apply(select_xform_format(kN32_SkColorType), dstPixels,
                                 SkColorSpaceXform::kBGRA_8888_ColorFormat, srcPixels, width,
                                 kOpaque_SkAlphaType);
      REPORTER_ASSERT(r, result);
  
      // Since the src->dst matrix is the identity, and the gamma curves match,
      // the pixels should be unchanged.
      for (int i = 0; i < width; i++) {
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >>  0) & 0xFF),
                                          SkGetPackedB32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >>  8) & 0xFF),
                                          SkGetPackedG32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 16) & 0xFF),
                                          SkGetPackedR32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 24) & 0xFF),
                                          SkGetPackedA32(dstPixels[i])));
      }
  
      if (repeat) {
          // We should cache part of the transform after the run.  So it is interesting
          // to make sure it still runs correctly the second time.
          test_identity_xform(r, gammas, false);
      }
  }
  
  static void test_identity_xform_A2B(skiatest::Reporter* r, SkGammaNamed gammaNamed,
                                      const sk_sp<SkGammas>& gammas) {
      // Arbitrary set of 10 pixels
      constexpr int width = 10;
      constexpr uint32_t srcPixels[width] = {
              0xFFABCDEF, 0xFF146829, 0xFF382759, 0xFF184968, 0xFFDE8271,
              0xFF32AB52, 0xFF0383BC, 0xFF000102, 0xFFFFFFFF, 0xFFDDEEFF, };
      uint32_t dstPixels[width];
  
      // Create and perform an identity xform.
      auto xform = ColorSpaceXformTest::CreateIdentityXform_A2B(gammaNamed, gammas);
      bool result = xform->apply(select_xform_format(kN32_SkColorType), dstPixels,
                                 SkColorSpaceXform::kBGRA_8888_ColorFormat, srcPixels, width,
                                 kOpaque_SkAlphaType);
      REPORTER_ASSERT(r, result);
  
      // Since the src->dst matrix is the identity, and the gamma curves match,
      // the pixels should be unchanged.
      for (int i = 0; i < width; i++) {
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >>  0) & 0xFF),
                                          SkGetPackedB32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >>  8) & 0xFF),
                                          SkGetPackedG32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 16) & 0xFF),
                                          SkGetPackedR32(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 24) & 0xFF),
                                          SkGetPackedA32(dstPixels[i])));
      }
  }
  
  DEF_TEST(ColorSpaceXform_TableGamma, r) {
      // Lookup-table based gamma curves
      constexpr size_t tableSize = 10;
      void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(float) * tableSize);
      sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas(kChannels));
      for (int i = 0; i < kChannels; ++i) {
          gammas->fType[i] = SkGammas::Type::kTable_Type;
          gammas->fData[i].fTable.fSize = tableSize;
          gammas->fData[i].fTable.fOffset = 0;
      }
  
      float* table = SkTAddOffset<float>(memory, sizeof(SkGammas));
  
      table[0] = 0.00f;
      table[1] = 0.05f;
      table[2] = 0.10f;
      table[3] = 0.15f;
      table[4] = 0.25f;
      table[5] = 0.35f;
      table[6] = 0.45f;
      table[7] = 0.60f;
      table[8] = 0.75f;
      table[9] = 1.00f;
      test_identity_xform(r, gammas, true);
      test_identity_xform_A2B(r, kNonStandard_SkGammaNamed, gammas);
  }
  
  DEF_TEST(ColorSpaceXform_ParametricGamma, r) {
      // Parametric gamma curves
      void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(SkColorSpaceTransferFn));
      sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas(kChannels));
      for (int i = 0; i < kChannels; ++i) {
          gammas->fType[i] = SkGammas::Type::kParam_Type;
          gammas->fData[i].fParamOffset = 0;
      }
  
      SkColorSpaceTransferFn* params = SkTAddOffset<SkColorSpaceTransferFn>
              (memory, sizeof(SkGammas));
  
      // Interval, switch xforms at 0.0031308f
      params->fD = 0.04045f;
  
      // First equation:
      params->fE = 1.0f / 12.92f;
      params->fF = 0.0f;
  
      // Second equation:
      // Note that the function is continuous (it's actually sRGB).
      params->fA = 1.0f / 1.055f;
      params->fB = 0.055f / 1.055f;
      params->fC = 0.0f;
      params->fG = 2.4f;
      test_identity_xform(r, gammas, true);
      test_identity_xform_A2B(r, kNonStandard_SkGammaNamed, gammas);
  }
  
  DEF_TEST(ColorSpaceXform_ExponentialGamma, r) {
      // Exponential gamma curves
      sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new SkGammas(kChannels));
      for (int i = 0; i < kChannels; ++i) {
          gammas->fType[i] = SkGammas::Type::kValue_Type;
          gammas->fData[i].fValue = 1.4f;
      }
      test_identity_xform(r, gammas, true);
      test_identity_xform_A2B(r, kNonStandard_SkGammaNamed, gammas);
  }
  
  DEF_TEST(ColorSpaceXform_NamedGamma, r) {
      sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new SkGammas(kChannels));
      gammas->fType[0] = gammas->fType[1] = gammas->fType[2] = SkGammas::Type::kNamed_Type;
      gammas->fData[0].fNamed = kSRGB_SkGammaNamed;
      gammas->fData[1].fNamed = k2Dot2Curve_SkGammaNamed;
      gammas->fData[2].fNamed = kLinear_SkGammaNamed;
      test_identity_xform(r, gammas, true);
      test_identity_xform_A2B(r, kNonStandard_SkGammaNamed, gammas);
      test_identity_xform_A2B(r, kSRGB_SkGammaNamed, nullptr);
      test_identity_xform_A2B(r, k2Dot2Curve_SkGammaNamed, nullptr);
      test_identity_xform_A2B(r, kLinear_SkGammaNamed, nullptr);
  }
  
  DEF_TEST(ColorSpaceXform_NonMatchingGamma, r) {
      constexpr size_t tableSize = 10;
      void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(float) * tableSize +
                                     sizeof(SkColorSpaceTransferFn));
      sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas(kChannels));
  
      float* table = SkTAddOffset<float>(memory, sizeof(SkGammas));
      table[0] = 0.00f;
      table[1] = 0.15f;
      table[2] = 0.20f;
      table[3] = 0.25f;
      table[4] = 0.35f;
      table[5] = 0.45f;
      table[6] = 0.55f;
      table[7] = 0.70f;
      table[8] = 0.85f;
      table[9] = 1.00f;
  
      SkColorSpaceTransferFn* params = SkTAddOffset<SkColorSpaceTransferFn>(memory,
              sizeof(SkGammas) + sizeof(float) * tableSize);
      params->fA = 1.0f / 1.055f;
      params->fB = 0.055f / 1.055f;
      params->fC = 0.0f;
      params->fD = 0.04045f;
      params->fE = 1.0f / 12.92f;
      params->fF = 0.0f;
      params->fG = 2.4f;
  
      gammas->fType[0] = SkGammas::Type::kValue_Type;
      gammas->fData[0].fValue = 1.2f;
  
      gammas->fType[1] = SkGammas::Type::kTable_Type;
      gammas->fData[1].fTable.fSize = tableSize;
      gammas->fData[1].fTable.fOffset = 0;
  
      gammas->fType[2] = SkGammas::Type::kParam_Type;
      gammas->fData[2].fParamOffset = sizeof(float) * tableSize;
  
      test_identity_xform(r, gammas, true);
      test_identity_xform_A2B(r, kNonStandard_SkGammaNamed, gammas);
  }
  
  DEF_TEST(ColorSpaceXform_A2BCLUT, r) {
      constexpr int inputChannels = 3;
      constexpr int gp            = 4; // # grid points
  
      constexpr int numEntries    = gp*gp*gp*3;
      const uint8_t gridPoints[3] = {gp, gp, gp};
      void* memory = sk_malloc_throw(sizeof(SkColorLookUpTable) + sizeof(float) * numEntries);
      sk_sp<SkColorLookUpTable> colorLUT(new (memory) SkColorLookUpTable(inputChannels, gridPoints));
      // make a CLUT that rotates R, G, and B ie R->G, G->B, B->R
      float* table = SkTAddOffset<float>(memory, sizeof(SkColorLookUpTable));
      for (int r = 0; r < gp; ++r) {
          for (int g = 0; g < gp; ++g) {
              for (int b = 0; b < gp; ++b) {
                  table[3*(gp*gp*r + gp*g + b) + 0] = g * (1.f / (gp - 1.f));
                  table[3*(gp*gp*r + gp*g + b) + 1] = b * (1.f / (gp - 1.f));
                  table[3*(gp*gp*r + gp*g + b) + 2] = r * (1.f / (gp - 1.f));
              }
          }
      }
  
      // build an even distribution of pixels every (7 / 255) steps
      // to test the xform on
      constexpr int pixelgp   = 7;
      constexpr int numPixels = pixelgp*pixelgp*pixelgp;
      SkAutoTMalloc<uint32_t> srcPixels(numPixels);
      int srcIndex = 0;
      for (int r = 0; r < pixelgp; ++r) {
          for (int g = 0; g < pixelgp; ++g) {
              for (int b = 0; b < pixelgp; ++b) {
                  const int red   = (int) (r * (255.f / (pixelgp - 1.f)));
                  const int green = (int) (g * (255.f / (pixelgp - 1.f)));
                  const int blue  = (int) (b * (255.f / (pixelgp - 1.f)));
                  srcPixels[srcIndex] = SkColorSetRGB(red, green, blue);
                  ++srcIndex;
              }
          }
      }
      SkAutoTMalloc<uint32_t> dstPixels(numPixels);
  
      // src space is identity besides CLUT
      std::vector<SkColorSpace_A2B::Element> srcElements;
      srcElements.push_back(SkColorSpace_A2B::Element(std::move(colorLUT)));
      auto srcSpace = ColorSpaceXformTest::CreateA2BSpace(SkColorSpace_A2B::PCS::kXYZ,
                                                          SkColorSpace_Base::InputColorFormat::kRGB,
                                                          std::move(srcElements));
      // dst space is entirely identity
      auto dstSpace = SkColorSpace::MakeRGB(SkColorSpace::kLinear_RenderTargetGamma, SkMatrix44::I());
      auto xform = SkColorSpaceXform::New(srcSpace.get(), dstSpace.get());
      bool result = xform->apply(SkColorSpaceXform::kRGBA_8888_ColorFormat, dstPixels.get(),
                                 SkColorSpaceXform::kRGBA_8888_ColorFormat, srcPixels.get(),
                                 numPixels, kOpaque_SkAlphaType);
      REPORTER_ASSERT(r, result);
  
      for (int i = 0; i < numPixels; ++i) {
          REPORTER_ASSERT(r, almost_equal(SkColorGetR(srcPixels[i]),
                                          SkColorGetG(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(SkColorGetG(srcPixels[i]),
                                          SkColorGetB(dstPixels[i])));
          REPORTER_ASSERT(r, almost_equal(SkColorGetB(srcPixels[i]),
                                          SkColorGetR(dstPixels[i])));
      }
  }
  
  