xref: /aosp_15_r20/external/skia/src/gpu/graphite/precompile/PrecompileBlender.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2024 Google LLC
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/gpu/graphite/precompile/PrecompileBlender.h"
9 
10 #include "include/effects/SkRuntimeEffect.h"
11 #include "include/gpu/graphite/precompile/PrecompileRuntimeEffect.h"
12 #include "src/core/SkKnownRuntimeEffects.h"
13 #include "src/gpu/Blend.h"
14 #include "src/gpu/graphite/PaintParams.h"
15 #include "src/gpu/graphite/precompile/PrecompileBaseComplete.h"
16 #include "src/gpu/graphite/precompile/PrecompileBlenderPriv.h"
17 
18 namespace skgpu::graphite {
19 
20 PrecompileBlender::~PrecompileBlender() = default;
21 
22 //--------------------------------------------------------------------------------------------------
23 class PrecompileBlendModeBlender final : public PrecompileBlender {
24 public:
PrecompileBlendModeBlender(SkBlendMode blendMode)25     PrecompileBlendModeBlender(SkBlendMode blendMode) : fBlendMode(blendMode) {}
26 
27 protected:
asBlendMode() const28     std::optional<SkBlendMode> asBlendMode() const final { return fBlendMode; }
29 
addToKey(const KeyContext & keyContext,PaintParamsKeyBuilder * builder,PipelineDataGatherer * gatherer,int desiredCombination) const30     void addToKey(const KeyContext& keyContext,
31                   PaintParamsKeyBuilder* builder,
32                   PipelineDataGatherer* gatherer,
33                   int desiredCombination) const final {
34         SkASSERT(desiredCombination == 0); // The blend mode blender only ever has one combination
35 
36         AddBlendMode(keyContext, builder, gatherer, fBlendMode);
37     }
38 
39 private:
40     SkBlendMode fBlendMode;
41 };
42 
Mode(SkBlendMode blendMode)43 sk_sp<PrecompileBlender> PrecompileBlenders::Mode(SkBlendMode blendMode) {
44     return sk_make_sp<PrecompileBlendModeBlender>(blendMode);
45 }
46 
47 //--------------------------------------------------------------------------------------------------
Arithmetic()48 sk_sp<PrecompileBlender> PrecompileBlenders::Arithmetic() {
49     const SkRuntimeEffect* arithmeticEffect =
50             GetKnownRuntimeEffect(SkKnownRuntimeEffects::StableKey::kArithmetic);
51 
52     return PrecompileRuntimeEffects::MakePrecompileBlender(sk_ref_sp(arithmeticEffect));
53 }
54 
55 //--------------------------------------------------------------------------------------------------
PrecompileBlenderList(SkSpan<const sk_sp<PrecompileBlender>> blenders)56 PrecompileBlenderList::PrecompileBlenderList(SkSpan<const sk_sp<PrecompileBlender>> blenders) {
57     for (const auto& b : blenders) {
58         if (!b) {
59             // A null SkBlender is equivalent to kSrcOver
60             fHasPorterDuffBlender = true;
61         } else if (b->priv().asBlendMode().has_value()) {
62             SkBlendMode bm = b->priv().asBlendMode().value();
63 
64             SkSpan<const float> coeffs = skgpu::GetPorterDuffBlendConstants(bm);
65             if (!coeffs.empty()) {
66                 fHasPorterDuffBlender = true;
67             } else if (bm >= SkBlendMode::kHue) {
68                 fHasHSLCBlender = true;
69             } else {
70                 SkASSERT(b->priv().numCombinations() == 1);
71                 fFixedBlenderEffects.push_back(b); // No reduced shader snippet for this blend mode
72                 fNumCombos++;
73             }
74         } else {
75             // Runtime blenders are always fixed
76             fFixedBlenderEffects.push_back(b);
77             fNumCombos += b->priv().numCombinations();
78         }
79     }
80 
81     if (!fHasPorterDuffBlender && !fHasHSLCBlender && fFixedBlenderEffects.empty()) {
82         fHasPorterDuffBlender = true; // Fallback to kSrcOver
83     }
84 
85     if (fHasPorterDuffBlender) {
86         fNumCombos++;
87     }
88     if (fHasHSLCBlender) {
89         fNumCombos++;
90     }
91 }
92 
PrecompileBlenderList(SkSpan<const SkBlendMode> blendModes)93 PrecompileBlenderList::PrecompileBlenderList(SkSpan<const SkBlendMode> blendModes) {
94     for (SkBlendMode bm : blendModes) {
95         SkSpan<const float> coeffs = skgpu::GetPorterDuffBlendConstants(bm);
96         if (!coeffs.empty()) {
97             fHasPorterDuffBlender = true;
98         } else if (bm >= SkBlendMode::kHue) {
99             fHasHSLCBlender = true;
100         } else {
101             fFixedBlenderEffects.push_back(PrecompileBlenders::Mode(bm));
102         }
103     }
104 
105     if (!fHasPorterDuffBlender && !fHasHSLCBlender && fFixedBlenderEffects.empty()) {
106         fHasPorterDuffBlender = true; // Fallback to kSrcOver
107     }
108 
109     fNumCombos = fHasPorterDuffBlender + fHasHSLCBlender + SkTo<int>(fFixedBlenderEffects.size());
110 }
111 
selectOption(int desiredCombination) const112 std::pair<sk_sp<PrecompileBlender>, int> PrecompileBlenderList::selectOption(
113         int desiredCombination) const {
114     SkASSERT(desiredCombination >= 0 && desiredCombination < this->numCombinations());
115 
116     if (fHasPorterDuffBlender) {
117         if (desiredCombination == 0) {
118             // Porter-Duff constant consolidated blend option, pick kSrcOver as a stand-in
119             return {PrecompileBlenders::Mode(SkBlendMode::kSrcOver), 0};
120         } else {
121             desiredCombination--;
122         }
123     }
124 
125     if (fHasHSLCBlender) {
126         if (desiredCombination == 0) {
127             // HSLC blend option, pick kHue arbitrarily
128             return {PrecompileBlenders::Mode(SkBlendMode::kHue), 0};
129         } else {
130             desiredCombination--;
131         }
132     }
133 
134     if (!fFixedBlenderEffects.empty()) {
135         auto [option, childCombination] =
136                 PrecompileBase::SelectOption<PrecompileBlender>(fFixedBlenderEffects,
137                                                                 desiredCombination);
138 
139         // Double-check that we aren't returning a blend mode that should have been consolidated.
140         SkDEBUGCODE(auto bm = option->priv().asBlendMode();)
141         SkASSERT(!bm || (*bm > SkBlendMode::kXor && *bm < SkBlendMode::kHue));
142         return {option, childCombination};
143     }
144 
145     SkUNREACHABLE;
146 }
147 
148 
149 } // namespace skgpu::graphite
150