xref: /aosp_15_r20/external/skia/modules/skottie/src/effects/InvertEffect.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2019 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 "include/core/SkColorFilter.h"
9 #include "include/core/SkRefCnt.h"
10 #include "include/effects/SkColorMatrix.h"
11 #include "include/private/base/SkAssert.h"
12 #include "modules/skottie/src/SkottiePriv.h"
13 #include "modules/skottie/src/animator/Animator.h"
14 #include "modules/skottie/src/effects/Effects.h"
15 #include "modules/sksg/include/SkSGColorFilter.h"
16 #include "modules/sksg/include/SkSGRenderNode.h"
17 
18 #include <array>
19 #include <cstddef>
20 #include <cstdint>
21 #include <utility>
22 
23 namespace skjson {
24 class ArrayValue;
25 }
26 
27 namespace skottie {
28 namespace internal {
29 
30 namespace {
31 
32 class InvertEffectAdapter final : public AnimatablePropertyContainer {
33 public:
Make(const skjson::ArrayValue & jprops,sk_sp<sksg::RenderNode> layer,const AnimationBuilder * abuilder)34     static sk_sp<InvertEffectAdapter> Make(const skjson::ArrayValue& jprops,
35                                            sk_sp<sksg::RenderNode> layer,
36                                            const AnimationBuilder* abuilder) {
37         return sk_sp<InvertEffectAdapter>(
38                     new InvertEffectAdapter(jprops, std::move(layer), abuilder));
39     }
40 
node() const41     const sk_sp<sksg::ExternalColorFilter>& node() const { return fColorFilter; }
42 
43 private:
InvertEffectAdapter(const skjson::ArrayValue & jprops,sk_sp<sksg::RenderNode> layer,const AnimationBuilder * abuilder)44     InvertEffectAdapter(const skjson::ArrayValue& jprops,
45                         sk_sp<sksg::RenderNode> layer,
46                         const AnimationBuilder* abuilder)
47         : fColorFilter(sksg::ExternalColorFilter::Make(std::move(layer))) {
48         enum : size_t {
49             kChannel_Index = 0,
50         };
51 
52         EffectBinder(jprops, *abuilder, this).bind(kChannel_Index, fChannel);
53     }
54 
onSync()55     void onSync() override {
56         enum class CS { kRGB, kHSL, kYIQ };
57 
58         struct STColorMatrix {
59             std::array<float,4> scale,
60                                 trans;
61             CS                  cs;
62         };
63 
64         const auto stcm = [this]() -> STColorMatrix {
65             // https://helpx.adobe.com/after-effects/using/channel-effects.html#invert_effect
66             enum : uint8_t {
67                 kRGB_Channel =  1,
68                   kR_Channel =  2,
69                   kG_Channel =  3,
70                   kB_Channel =  4,
71 
72                 // NB: HLS vs. HSL
73                 kHLS_Channel =  6,
74                   kH_Channel =  7,
75                   kL_Channel =  8,
76                   kS_Channel =  9,
77 
78                 kYIQ_Channel = 11,
79                   kY_Channel = 12,
80                   kI_Channel = 13,
81                   kQ_Channel = 14,
82 
83                   kA_Channel = 16,
84             };
85 
86             switch (static_cast<uint8_t>(fChannel)) {
87             case   kR_Channel: return { {-1, 1, 1, 1}, {  1,0,0,0}, CS::kRGB }; // r' = 1 - r
88             case   kG_Channel: return { { 1,-1, 1, 1}, {  0,1,0,0}, CS::kRGB }; // g' = 1 - g
89             case   kB_Channel: return { { 1, 1,-1, 1}, {  0,0,1,0}, CS::kRGB }; // b' = 1 - b
90             case   kA_Channel: return { { 1, 1, 1,-1}, {  0,0,0,1}, CS::kRGB }; // a' = 1 - a
91             case kRGB_Channel: return { {-1,-1,-1, 1}, {  1,1,1,0}, CS::kRGB };
92 
93             case   kH_Channel: return { {-1, 1, 1, 1}, {.5f,0,0,0}, CS::kHSL }; // h' = .5 - h
94             case   kS_Channel: return { { 1,-1, 1, 1}, {  0,1,0,0}, CS::kHSL }; // s' = 1 - s
95             case   kL_Channel: return { { 1, 1,-1, 1}, {  0,0,1,0}, CS::kHSL }; // l' = 1 - l
96             case kHLS_Channel: return { {-1,-1,-1, 1}, {.5f,1,1,0}, CS::kHSL };
97 
98             case   kY_Channel: return { {-1, 1, 1, 1}, {  1,0,0,0}, CS::kYIQ }; // y' = 1 - y
99             case   kI_Channel: return { { 1,-1, 1, 1}, {  0,0,0,0}, CS::kYIQ }; // i' = -i
100             case   kQ_Channel: return { { 1, 1,-1, 1}, {  0,0,0,0}, CS::kYIQ }; // q' = -q
101             case kYIQ_Channel: return { {-1,-1,-1, 1}, {  1,0,0,0}, CS::kYIQ };
102 
103                       default: return { { 1, 1, 1, 1}, {  0,0,0,0}, CS::kRGB };
104             }
105 
106             SkUNREACHABLE;
107         }();
108 
109         SkColorMatrix m(
110             stcm.scale[0],             0,             0,             0, stcm.trans[0],
111                         0, stcm.scale[1],             0,             0, stcm.trans[1],
112                         0,             0, stcm.scale[2],             0, stcm.trans[2],
113                         0,             0,             0, stcm.scale[3], stcm.trans[3]
114 
115         );
116 
117         if (stcm.cs == CS::kYIQ) {
118             // https://en.wikipedia.org/wiki/YIQ
119             static constexpr SkColorMatrix RGB2YIQ(
120                 0.2990f,  0.5870f,  0.1140f, 0, 0,
121                 0.5959f, -0.2746f, -0.3213f, 0, 0,
122                 0.2115f, -0.5227f,  0.3112f, 0, 0,
123                       0,        0,        0, 1, 0
124             );
125             static constexpr SkColorMatrix YIQ2RGB(
126                       1,  0.9560f,  0.6190f, 0, 0,
127                       1, -0.2720f, -0.6470f, 0, 0,
128                       1, -1.1060f,  1.7030f, 0, 0,
129                       0,        0,        0, 1, 0
130             );
131 
132             m.preConcat (RGB2YIQ);
133             m.postConcat(YIQ2RGB);
134         }
135 
136         fColorFilter->setColorFilter(stcm.cs == CS::kHSL ? SkColorFilters::HSLAMatrix(m)
137                                                          : SkColorFilters::Matrix(m));
138     }
139 
140     const sk_sp<sksg::ExternalColorFilter> fColorFilter;
141 
142     float fChannel = 0;
143 };
144 
145 } // namespace
146 
attachInvertEffect(const skjson::ArrayValue & jprops,sk_sp<sksg::RenderNode> layer) const147 sk_sp<sksg::RenderNode> EffectBuilder::attachInvertEffect(const skjson::ArrayValue& jprops,
148                                                           sk_sp<sksg::RenderNode> layer) const {
149     return fBuilder->attachDiscardableAdapter<InvertEffectAdapter>(jprops,
150                                                                    std::move(layer),
151                                                                    fBuilder);
152 }
153 
154 } // namespace internal
155 } // namespace skottie
156