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/*
* 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 "SkColorPriv.h"
#include "SkColorSpace.h"
#include "SkColorSpace_Base.h"
#include "SkColorSpaceXform.h"
#include "Test.h"
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_Base(
nullptr, kNonStandard_SkGammaNamed, gammas, SkMatrix::I(), nullptr));
// Use special testing entry point, so we don't skip the xform, even though src == dst.
return SlowIdentityXform(space);
}
};
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) {
// 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);
xform->apply(dstPixels, srcPixels, width, kN32_SkColorType, kOpaque_SkAlphaType);
// 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),
SkGetPackedR32(dstPixels[i])));
REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 8) & 0xFF),
SkGetPackedG32(dstPixels[i])));
REPORTER_ASSERT(r, almost_equal(((srcPixels[i] >> 16) & 0xFF),
SkGetPackedB32(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());
gammas->fRedType = gammas->fGreenType = gammas->fBlueType = SkGammas::Type::kTable_Type;
gammas->fRedData.fTable.fSize = gammas->fGreenData.fTable.fSize =
gammas->fBlueData.fTable.fSize = tableSize;
gammas->fRedData.fTable.fOffset = gammas->fGreenData.fTable.fOffset =
gammas->fBlueData.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);
}
DEF_TEST(ColorSpaceXform_ParametricGamma, r) {
// Parametric gamma curves
void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(SkGammas::Params));
sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas());
gammas->fRedType = gammas->fGreenType = gammas->fBlueType = SkGammas::Type::kParam_Type;
gammas->fRedData.fParamOffset = gammas->fGreenData.fParamOffset =
gammas->fBlueData.fParamOffset = 0;
SkGammas::Params* params = SkTAddOffset<SkGammas::Params>(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);
}
DEF_TEST(ColorSpaceXform_ExponentialGamma, r) {
// Exponential gamma curves
sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new SkGammas());
gammas->fRedType = gammas->fGreenType = gammas->fBlueType = SkGammas::Type::kValue_Type;
gammas->fRedData.fValue = gammas->fGreenData.fValue = gammas->fBlueData.fValue = 1.4f;
test_identity_xform(r, gammas);
}
DEF_TEST(ColorSpaceXform_NonMatchingGamma, r) {
constexpr size_t tableSize = 10;
void* memory = sk_malloc_throw(sizeof(SkGammas) + sizeof(float) * tableSize +
sizeof(SkGammas::Params));
sk_sp<SkGammas> gammas = sk_sp<SkGammas>(new (memory) SkGammas());
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;
SkGammas::Params* params = SkTAddOffset<SkGammas::Params>(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->fRedType = SkGammas::Type::kValue_Type;
gammas->fRedData.fValue = 1.2f;
gammas->fGreenType = SkGammas::Type::kTable_Type;
gammas->fGreenData.fTable.fSize = tableSize;
gammas->fGreenData.fTable.fOffset = 0;
gammas->fBlueType = SkGammas::Type::kParam_Type;
gammas->fBlueData.fParamOffset = sizeof(float) * tableSize;
test_identity_xform(r, gammas);
}
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