| /* |
| * 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/SkImage.h" |
| #include "include/core/SkRefCnt.h" |
| #include "include/core/SkSamplingOptions.h" |
| #include "include/core/SkSurface.h" |
| #include "include/core/SkTypes.h" |
| #include "src/base/SkRandom.h" |
| #include "src/core/SkSamplingPriv.h" |
| #include "tests/Test.h" |
| #include "tools/Resources.h" |
| #include "tools/ToolUtils.h" |
| |
| #include <initializer_list> |
| |
| // 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); |
| } |
| } |
| } |