xref: /aosp_15_r20/external/skia/src/core/SkBlendModePriv.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2016 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 #ifndef SkBlendModePriv_DEFINED
9 #define SkBlendModePriv_DEFINED
10 
11 #include "include/core/SkBlendMode.h"
12 #include "include/core/SkColor.h"
13 #include "include/private/SkColorData.h"
14 
15 class SkRasterPipeline;
16 class SkPaint;
17 
18 /**
19  *  Sentinel value for SkBlendMode enum.
20  *
21  *  Will never be a valid enum value, but will be storable in a byte.
22  */
23 constexpr uint8_t kCustom_SkBlendMode = 0xFF;
24 
25 bool SkBlendMode_SupportsCoverageAsAlpha(SkBlendMode);
26 
SkBlendMode_CaresAboutRBOrder(SkBlendMode mode)27 static inline bool SkBlendMode_CaresAboutRBOrder(SkBlendMode mode) {
28     return (mode > SkBlendMode::kLastSeparableMode);
29 }
30 
31 bool SkBlendMode_ShouldPreScaleCoverage(SkBlendMode, bool rgb_coverage);
32 void SkBlendMode_AppendStages(SkBlendMode, SkRasterPipeline*);
33 
34 SkPMColor4f SkBlendMode_Apply(SkBlendMode, const SkPMColor4f& src, const SkPMColor4f& dst);
35 
36 enum class SkBlendFastPath {
37     kNormal,      // draw normally
38     kSrcOver,     //< draw as if in srcover mode
39     kSkipDrawing  //< draw nothing
40 };
41 
42 /**
43  *  Given a paint, determine whether the paint's blend mode can be
44  *  replaced with kSrcOver or not drawn at all. This can inform drawing optimizations.
45  */
46 SkBlendFastPath CheckFastPath(const SkPaint&, bool dstIsOpaque);
47 
48 #endif
49