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#include <limits>
13
14/**
15 * Represents the filtering and tile modes used to access a texture.
16 */
17class GrSamplerState {
18public:
19 enum class Filter : uint8_t { kNearest, kLinear, kLast = kLinear };
20 enum class MipmapMode : uint8_t { kNone, kNearest, kLinear, kLast = kLinear };
21
22 enum class WrapMode : uint8_t {
23 kClamp,
24 kRepeat,
25 kMirrorRepeat,
26 kClampToBorder,
27 kLast = kClampToBorder
28 };
29
30 static constexpr int kFilterCount = static_cast<int>(Filter::kLast) + 1;
31 static constexpr int kWrapModeCount = static_cast<int>(WrapMode::kLast) + 1;
32
33 constexpr GrSamplerState() = default;
34
35 constexpr GrSamplerState(WrapMode wrapXAndY, Filter filter, MipmapMode mm = MipmapMode::kNone)
36 : fWrapModes{wrapXAndY, wrapXAndY}, fFilter(filter), fMipmapMode(mm) {}
37
38 constexpr GrSamplerState(WrapMode wrapX,
39 WrapMode wrapY,
40 Filter filter,
41 MipmapMode mm = MipmapMode::kNone)
42 : fWrapModes{wrapX, wrapY}, fFilter(filter), fMipmapMode(mm) {}
43
44 constexpr GrSamplerState(const WrapMode wrapModes[2],
45 Filter filter,
46 MipmapMode mm = MipmapMode::kNone)
47 : fWrapModes{wrapModes[0], wrapModes[1]}, fFilter(filter), fMipmapMode(mm) {}
48
49 constexpr /*explicit*/ GrSamplerState(Filter filter) : fFilter(filter) {}
50 constexpr GrSamplerState(Filter filter, MipmapMode mm) : fFilter(filter), fMipmapMode(mm) {}
51
52 constexpr GrSamplerState(const GrSamplerState&) = default;
53
54 constexpr GrSamplerState& operator=(const GrSamplerState&) = default;
55
56 constexpr WrapMode wrapModeX() const { return fWrapModes[0]; }
57
58 constexpr WrapMode wrapModeY() const { return fWrapModes[1]; }
59
60 constexpr bool isRepeated() const {
61 return fWrapModes[0] == WrapMode::kRepeat || fWrapModes[0] == WrapMode::kMirrorRepeat ||
62 fWrapModes[1] == WrapMode::kRepeat || fWrapModes[1] == WrapMode::kMirrorRepeat;
63 }
64
65 constexpr Filter filter() const { return fFilter; }
66
67 constexpr MipmapMode mipmapMode() const { return fMipmapMode; }
68
69 constexpr GrMipmapped mipmapped() const {
70 return GrMipmapped(fMipmapMode != MipmapMode::kNone);
71 }
72
73 constexpr void setFilterMode(Filter filterMode) { fFilter = filterMode; }
74
75 constexpr void setMipmapMode(MipmapMode mm) { fMipmapMode = mm; }
76
77 constexpr void setWrapModeX(const WrapMode wrap) { fWrapModes[0] = wrap; }
78
79 constexpr void setWrapModeY(const WrapMode wrap) { fWrapModes[1] = wrap; }
80
81 constexpr bool operator==(GrSamplerState that) const {
82 return fWrapModes[0] == that.fWrapModes[0] && fWrapModes[1] == that.fWrapModes[1] &&
83 fFilter == that.fFilter && fMipmapMode == that.fMipmapMode;
84 }
85
86 constexpr bool operator!=(const GrSamplerState& that) const { return !(*this == that); }
87
88 /**
89 * Turn the sampler state into an integer from a tightly packed range for use as an index
90 * (or key)
91 */
92 constexpr uint8_t asIndex() const {
93 constexpr int kNumWraps = static_cast<int>(WrapMode::kLast) + 1;
94 constexpr int kNumFilters = static_cast<int>(Filter::kLast ) + 1;
95 int result = static_cast<int>(fWrapModes[0])*1
96 + static_cast<int>(fWrapModes[1])*kNumWraps
97 + static_cast<int>(fFilter) *kNumWraps*kNumWraps
98 + static_cast<int>(fMipmapMode) *kNumWraps*kNumWraps*kNumFilters;
99 SkASSERT(result <= kNumUniqueSamplers);
100 return static_cast<uint8_t>(result);
101 }
102
103 static constexpr int kNumUniqueSamplers = (static_cast<int>(WrapMode::kLast ) + 1)
104 * (static_cast<int>(WrapMode::kLast ) + 1)
105 * (static_cast<int>(Filter::kLast ) + 1)
106 * (static_cast<int>(MipmapMode::kLast) + 1);
107private:
108 WrapMode fWrapModes[2] = {WrapMode::kClamp, WrapMode::kClamp};
109 Filter fFilter = GrSamplerState::Filter::kNearest;
110 MipmapMode fMipmapMode = GrSamplerState::MipmapMode::kNone;
111};
112
113static_assert(GrSamplerState::kNumUniqueSamplers <=
114 std::numeric_limits<decltype(GrSamplerState{}.asIndex())>::max());
115
116#endif
117