Initial add SkMixers
Just using with composeshader for now, plan to try that sort of generalization
for colorfilters and imagefilters in follow-on cls.
Bug: skia:
Change-Id: Ic9650b8ea6f6278e6bfd657e90befbf9e71f383c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/198823
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/tests/MixerTest.cpp b/tests/MixerTest.cpp
new file mode 100644
index 0000000..5a25eb4
--- /dev/null
+++ b/tests/MixerTest.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2019 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkMixer.h"
+#include "Test.h"
+#include "SkColorData.h"
+#include "SkMixerBase.h"
+
+static void check_color(skiatest::Reporter* reporter,
+ const SkPMColor4f& result, const SkPMColor4f& expected) {
+ const float tol = 1/510.f; // made up
+ for (int i = 0; i < 4; ++i) {
+ REPORTER_ASSERT(reporter, SkScalarNearlyEqual(result[i], expected[i], tol));
+ }
+}
+
+static void check_mixer(skiatest::Reporter* reporter, sk_sp<SkMixer> mixer,
+ const SkPMColor4f& a, const SkPMColor4f& b, const SkPMColor4f& expected) {
+ SkPMColor4f result = as_MB(mixer)->test_mix(a, b);
+ check_color(reporter, result, expected);
+
+ auto data = mixer->serialize();
+ auto m2 = SkMixerBase::Deserialize(data->data(), data->size());
+ SkPMColor4f r2 = as_MB(m2)->test_mix(a, b);
+ REPORTER_ASSERT(reporter, result == r2);
+}
+
+DEF_TEST(Mixer, r) {
+ const SkPMColor4f transparent = {0, 0, 0, 0};
+ const SkPMColor4f red = {1, 0, 0, 1};
+ const SkPMColor4f magenta = {1, 0, 1, 1};
+ const SkPMColor4f blue = {0, 0, 1, 1};
+
+ auto first = SkMixer::MakeFirst();
+ auto second = SkMixer::MakeSecond();
+ check_mixer(r, first, red, blue, red);
+ check_mixer(r, second, red, blue, blue);
+
+ check_mixer(r, first->makeReverse(), red, blue, blue);
+ check_mixer(r, second->makeReverse(), red, blue, red);
+
+ check_mixer(r, SkMixer::MakeLerp(0), red, blue, red);
+ check_mixer(r, SkMixer::MakeLerp(0.0001f), red, blue, red);
+ check_mixer(r, SkMixer::MakeLerp(0.5f), red, blue, {0.5f, 0, 0.5f, 1});
+ check_mixer(r, SkMixer::MakeLerp(0.9999f), red, blue, blue);
+ check_mixer(r, SkMixer::MakeLerp(1), red, blue, blue);
+
+ check_mixer(r, SkMixer::MakeBlend(SkBlendMode::kClear), red, blue, transparent);
+ check_mixer(r, SkMixer::MakeBlend(SkBlendMode::kSrc), red, blue, red);
+ check_mixer(r, SkMixer::MakeBlend(SkBlendMode::kDst), red, blue, blue);
+ check_mixer(r, SkMixer::MakeBlend(SkBlendMode::kPlus), red, blue, magenta);
+
+ // mx should average the results of Plus and Clear
+ auto mx = SkMixer::MakeLerp(0.5f)->makeMerge(SkMixer::MakeBlend(SkBlendMode::kPlus),
+ SkMixer::MakeConst(0));
+ check_mixer(r, mx, red, blue, {0.5f, 0, 0.5f, 0.5f});
+}