1 /*
2  * Copyright 2015 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 GrSamplerState_DEFINED
9 #define GrSamplerState_DEFINED
10 
11 #include "include/gpu/GrTypes.h"
12 
13 /**
14  * Represents the filtering and tile modes used to access a texture.
15  */
16 class GrSamplerState {
17 public:
18     enum class Filter : uint8_t { kNearest, kBilerp, kMipMap };
19     enum class WrapMode : uint8_t { kClamp, kRepeat, kMirrorRepeat, kClampToBorder };
20 
ClampNearest()21     static constexpr GrSamplerState ClampNearest() { return GrSamplerState(); }
ClampBilerp()22     static constexpr GrSamplerState ClampBilerp() {
23         return GrSamplerState(WrapMode::kClamp, Filter::kBilerp);
24     }
25 
GrSamplerState()26     constexpr GrSamplerState() : GrSamplerState(WrapMode::kClamp, Filter::kNearest) {}
27 
GrSamplerState(WrapMode wrapXAndY,Filter filter)28     constexpr GrSamplerState(WrapMode wrapXAndY, Filter filter)
29             : fWrapModes{wrapXAndY, wrapXAndY}, fFilter(filter) {}
30 
GrSamplerState(const WrapMode wrapModes[2],Filter filter)31     constexpr GrSamplerState(const WrapMode wrapModes[2], Filter filter)
32             : fWrapModes{wrapModes[0], wrapModes[1]}, fFilter(filter) {}
33 
34     constexpr GrSamplerState(const GrSamplerState&) = default;
35 
36     GrSamplerState& operator=(const GrSamplerState& that) {
37         fWrapModes[0] = that.fWrapModes[0];
38         fWrapModes[1] = that.fWrapModes[1];
39         fFilter = that.fFilter;
40         return *this;
41     }
42 
filter()43     Filter filter() const { return fFilter; }
44 
setFilterMode(Filter filterMode)45     void setFilterMode(Filter filterMode) { fFilter = filterMode; }
46 
setWrapModeX(const WrapMode wrap)47     void setWrapModeX(const WrapMode wrap) { fWrapModes[0] = wrap; }
setWrapModeY(const WrapMode wrap)48     void setWrapModeY(const WrapMode wrap) { fWrapModes[1] = wrap; }
49 
wrapModeX()50     WrapMode wrapModeX() const { return fWrapModes[0]; }
wrapModeY()51     WrapMode wrapModeY() const { return fWrapModes[1]; }
52 
isRepeated()53     bool isRepeated() const {
54         return (WrapMode::kClamp != fWrapModes[0] && WrapMode::kClampToBorder != fWrapModes[0]) ||
55                (WrapMode::kClamp != fWrapModes[1] && WrapMode::kClampToBorder != fWrapModes[1]);
56     }
57 
58     bool operator==(const GrSamplerState& that) const {
59         return fWrapModes[0] == that.fWrapModes[0] && fWrapModes[1] == that.fWrapModes[1] &&
60                fFilter == that.fFilter;
61     }
62 
63     bool operator!=(const GrSamplerState& that) const { return !(*this == that); }
64 
GenerateKey(const GrSamplerState & samplerState)65     static uint8_t GenerateKey(const GrSamplerState& samplerState) {
66         const int kTileModeXShift = 2;
67         const int kTileModeYShift = 4;
68 
69         SkASSERT(static_cast<int>(samplerState.filter()) <= 3);
70         uint8_t key = static_cast<uint8_t>(samplerState.filter());
71 
72         SkASSERT(static_cast<int>(samplerState.wrapModeX()) <= 3);
73         key |= (static_cast<uint8_t>(samplerState.wrapModeX()) << kTileModeXShift);
74 
75         SkASSERT(static_cast<int>(samplerState.wrapModeY()) <= 3);
76         key |= (static_cast<uint8_t>(samplerState.wrapModeY()) << kTileModeYShift);
77 
78         return key;
79     }
80 
81 private:
82     WrapMode fWrapModes[2];
83     Filter fFilter;
84 };
85 
86 #endif
87