58 lines
2.0 KiB
C++
58 lines
2.0 KiB
C++
/*
|
|
* Copyright 2020 Google LLC
|
|
*
|
|
* Use of this source code is governed by a BSD-style license that can be
|
|
* found in the LICENSE file.
|
|
*/
|
|
|
|
#include "include/core/SkCanvas.h"
|
|
#include "include/core/SkSurface.h"
|
|
#include "include/utils/SkRandom.h"
|
|
#include "src/core/SkSamplingPriv.h"
|
|
#include "tests/Test.h"
|
|
#include "tools/Resources.h"
|
|
#include "tools/ToolUtils.h"
|
|
|
|
// In general, sampling under identity matrix should not affect the pixels. However,
|
|
// cubic resampling when B != 0 is expected to change pixels.
|
|
//
|
|
DEF_TEST(sampling_with_identity_matrix, r) {
|
|
const char* names[] = {
|
|
"images/mandrill_128.png", "images/color_wheel.jpg",
|
|
};
|
|
|
|
SkRandom rand;
|
|
for (auto name : names) {
|
|
auto src = GetResourceAsImage(name);
|
|
auto surf = SkSurface::MakeRasterN32Premul(src->width(), src->height());
|
|
auto canvas = surf->getCanvas();
|
|
|
|
auto dotest = [&](const SkSamplingOptions& sampling, bool expect_same) {
|
|
canvas->clear(0);
|
|
canvas->drawImage(src.get(), 0, 0, sampling, nullptr);
|
|
auto dst = surf->makeImageSnapshot();
|
|
|
|
REPORTER_ASSERT(r, SkSamplingPriv::NoChangeWithIdentityMatrix(sampling) == expect_same);
|
|
REPORTER_ASSERT(r, ToolUtils::equal_pixels(src.get(), dst.get()) == expect_same);
|
|
};
|
|
|
|
// Exercise all non-cubics -- expecting no changes
|
|
for (auto m : {SkMipmapMode::kNone, SkMipmapMode::kNearest, SkMipmapMode::kLinear}) {
|
|
for (auto f : {SkFilterMode::kNearest, SkFilterMode::kLinear}) {
|
|
dotest(SkSamplingOptions(f, m), true);
|
|
}
|
|
}
|
|
|
|
// Exercise cubic variants with B zero and non-zero
|
|
constexpr int N = 30; // try a bunch of random values
|
|
for (int i = 0; i < N; ++i) {
|
|
float C = rand.nextF();
|
|
dotest(SkSamplingOptions({0, C}), true);
|
|
|
|
float B = rand.nextF() * 0.9f + 0.05f; // non-zero but still within (0,,,1]
|
|
SkASSERT(B != 0);
|
|
dotest(SkSamplingOptions({B, C}), false);
|
|
}
|
|
}
|
|
}
|