skia2/tests/ColorSpaceXformTest.cpp

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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> CreateDefaultXform(const sk_sp<SkGammas>& srcGamma,
const SkMatrix44& srcToDst, const sk_sp<SkGammas>& dstGamma) {
sk_sp<SkColorSpace> srcSpace(
new SkColorSpace_Base(nullptr, srcGamma, SkMatrix::I(), nullptr));
sk_sp<SkColorSpace> dstSpace(
new SkColorSpace_Base(nullptr, dstGamma, SkMatrix::I(), nullptr));
return SkColorSpaceXform::New(srcSpace, dstSpace);
}
};
static bool almost_equal(int x, int y) {
return SkTAbs(x - y) <= 1;
}
static void test_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];
// Identity matrix
SkMatrix44 srcToDst = SkMatrix44::I();
// Create and perform xform
std::unique_ptr<SkColorSpaceXform> xform =
ColorSpaceXformTest::CreateDefaultXform(gammas, srcToDst, gammas);
xform->xform_RGB1_8888(dstPixels, srcPixels, width);
// Since the 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
SkGammaCurve red, green, blue;
constexpr size_t tableSize = 10;
red.fTable = std::unique_ptr<float[]>(new float[tableSize]);
green.fTable = std::unique_ptr<float[]>(new float[tableSize]);
blue.fTable = std::unique_ptr<float[]>(new float[tableSize]);
red.fTableSize = green.fTableSize = blue.fTableSize = 10;
red.fTable[0] = green.fTable[0] = blue.fTable[0] = 0.00f;
red.fTable[1] = green.fTable[1] = blue.fTable[1] = 0.05f;
red.fTable[2] = green.fTable[2] = blue.fTable[2] = 0.10f;
red.fTable[3] = green.fTable[3] = blue.fTable[3] = 0.15f;
red.fTable[4] = green.fTable[4] = blue.fTable[4] = 0.25f;
red.fTable[5] = green.fTable[5] = blue.fTable[5] = 0.35f;
red.fTable[6] = green.fTable[6] = blue.fTable[6] = 0.45f;
red.fTable[7] = green.fTable[7] = blue.fTable[7] = 0.60f;
red.fTable[8] = green.fTable[8] = blue.fTable[8] = 0.75f;
red.fTable[9] = green.fTable[9] = blue.fTable[9] = 1.00f;
sk_sp<SkGammas> gammas =
sk_make_sp<SkGammas>(std::move(red), std::move(green), std::move(blue));
test_xform(r, gammas);
}
DEF_TEST(ColorSpaceXform_ParametricGamma, r) {
// Parametric gamma curves
SkGammaCurve red, green, blue;
// Interval, switch xforms at 0.0031308f
red.fD = green.fD = blue.fD = 0.04045f;
// First equation:
red.fE = green.fE = blue.fE = 1.0f / 12.92f;
// Second equation:
// Note that the function is continuous (it's actually sRGB).
red.fA = green.fA = blue.fA = 1.0f / 1.055f;
red.fB = green.fB = blue.fB = 0.055f / 1.055f;
red.fC = green.fC = blue.fC = 0.0f;
red.fG = green.fG = blue.fG = 2.4f;
sk_sp<SkGammas> gammas =
sk_make_sp<SkGammas>(std::move(red), std::move(green), std::move(blue));
test_xform(r, gammas);
}
DEF_TEST(ColorSpaceXform_ExponentialGamma, r) {
// Exponential gamma curves
SkGammaCurve red, green, blue;
red.fValue = green.fValue = blue.fValue = 1.4f;
sk_sp<SkGammas> gammas =
sk_make_sp<SkGammas>(std::move(red), std::move(green), std::move(blue));
test_xform(r, gammas);
}