1 /*
2 * Copyright 2021 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "modules/skottie/src/effects/Effects.h"
9
10 #include "include/effects/SkRuntimeEffect.h"
11 #include "modules/skottie/src/Adapter.h"
12 #include "modules/skottie/src/SkottieJson.h"
13 #include "modules/skottie/src/SkottieValue.h"
14 #include "modules/sksg/include/SkSGColorFilter.h"
15
16 namespace skottie::internal {
17
18 #ifdef SK_ENABLE_SKSL
19
20 namespace {
21
22 // Convert to black & white, based on input luminance and a threshold uniform.
23 static constexpr char gThresholdSkSL[] =
24 "uniform half t;"
25
26 "half4 main(half4 color) {"
27 "half4 c = unpremul(color);"
28
29 "half lum = dot(c.rgb, half3(0.2126, 0.7152, 0.0722)),"
30 "bw = step(t, lum);"
31
32 "return bw.xxx1 * c.a;"
33 "}"
34 ;
35
threshold_effect()36 static sk_sp<SkRuntimeEffect> threshold_effect() {
37 static const SkRuntimeEffect* effect =
38 SkRuntimeEffect::MakeForColorFilter(SkString(gThresholdSkSL), {}).effect.release();
39 SkASSERT(effect);
40
41 return sk_ref_sp(effect);
42 }
43
44 class ThresholdAdapter final : public DiscardableAdapterBase<ThresholdAdapter,
45 sksg::ExternalColorFilter> {
46 public:
ThresholdAdapter(const skjson::ArrayValue & jprops,sk_sp<sksg::RenderNode> layer,const AnimationBuilder & abuilder)47 ThresholdAdapter(const skjson::ArrayValue& jprops,
48 sk_sp<sksg::RenderNode> layer,
49 const AnimationBuilder& abuilder)
50 : INHERITED(sksg::ExternalColorFilter::Make(std::move(layer)))
51 {
52 enum : size_t {
53 kLevel_Index = 0,
54 };
55
56 EffectBinder(jprops, abuilder, this).bind(kLevel_Index, fLevel);
57 }
58
59 private:
onSync()60 void onSync() override {
61 auto cf =
62 threshold_effect()->makeColorFilter(SkData::MakeWithCopy(&fLevel, sizeof(fLevel)));
63
64 this->node()->setColorFilter(std::move(cf));
65 }
66
67 ScalarValue fLevel = 0;
68
69 using INHERITED = DiscardableAdapterBase<ThresholdAdapter, sksg::ExternalColorFilter>;
70 };
71
72 } // namespace
73
74 #endif // SK_ENABLE_SKSL
75
attachThresholdEffect(const skjson::ArrayValue & jprops,sk_sp<sksg::RenderNode> layer) const76 sk_sp<sksg::RenderNode> EffectBuilder::attachThresholdEffect(const skjson::ArrayValue& jprops,
77 sk_sp<sksg::RenderNode> layer) const {
78 #ifdef SK_ENABLE_SKSL
79 return fBuilder->attachDiscardableAdapter<ThresholdAdapter>(jprops,
80 std::move(layer),
81 *fBuilder);
82 #else
83 // TODO(skia:12197)
84 return layer;
85 #endif
86 }
87
88 } // namespace skottie::internal
89