xref: /aosp_15_r20/external/skia/src/gpu/graphite/mtl/MtlSampler.mm (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1/*
2 * Copyright 2022 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 "src/gpu/graphite/mtl/MtlSampler.h"
9
10#include "include/core/SkSamplingOptions.h"
11#include "src/gpu/graphite/mtl/MtlCaps.h"
12#include "src/gpu/graphite/mtl/MtlSharedContext.h"
13
14namespace skgpu::graphite {
15
16MtlSampler::MtlSampler(const MtlSharedContext* sharedContext,
17                       sk_cfp<id<MTLSamplerState>> samplerState)
18        : Sampler(sharedContext)
19        , fSamplerState(std::move(samplerState)) {}
20
21static inline MTLSamplerAddressMode tile_mode_to_mtl_sampler_address(SkTileMode tileMode,
22                                                                     const Caps& caps) {
23    switch (tileMode) {
24        case SkTileMode::kClamp:
25            return MTLSamplerAddressModeClampToEdge;
26        case SkTileMode::kRepeat:
27            return MTLSamplerAddressModeRepeat;
28        case SkTileMode::kMirror:
29            return MTLSamplerAddressModeMirrorRepeat;
30        case SkTileMode::kDecal:
31            // For this tilemode, we should have checked that clamp-to-border support exists.
32            // If it doesn't we should have fallen back to a shader instead.
33            // TODO: for textures with alpha, we could use ClampToZero if there's no
34            // ClampToBorderColor as they'll clamp to (0,0,0,0).
35            // Unfortunately textures without alpha end up clamping to (0,0,0,1).
36            if (@available(macOS 10.12, iOS 14.0, tvOS 14.0, *)) {
37                SkASSERT(caps.clampToBorderSupport());
38                return MTLSamplerAddressModeClampToBorderColor;
39            } else {
40                SkASSERT(false);
41                return MTLSamplerAddressModeClampToZero;
42            }
43    }
44    SkUNREACHABLE;
45}
46
47sk_sp<MtlSampler> MtlSampler::Make(const MtlSharedContext* sharedContext,
48                                   const SkSamplingOptions& samplingOptions,
49                                   SkTileMode xTileMode,
50                                   SkTileMode yTileMode) {
51    sk_cfp<MTLSamplerDescriptor*> desc([[MTLSamplerDescriptor alloc] init]);
52
53    MTLSamplerMinMagFilter minMagFilter = [&] {
54        switch (samplingOptions.filter) {
55            case SkFilterMode::kNearest: return MTLSamplerMinMagFilterNearest;
56            case SkFilterMode::kLinear:  return MTLSamplerMinMagFilterLinear;
57        }
58        SkUNREACHABLE;
59    }();
60
61    MTLSamplerMipFilter mipFilter = [&] {
62      switch (samplingOptions.mipmap) {
63          case SkMipmapMode::kNone:    return MTLSamplerMipFilterNotMipmapped;
64          case SkMipmapMode::kNearest: return MTLSamplerMipFilterNearest;
65          case SkMipmapMode::kLinear:  return MTLSamplerMipFilterLinear;
66      }
67      SkUNREACHABLE;
68    }();
69
70    (*desc).rAddressMode = MTLSamplerAddressModeClampToEdge;
71    (*desc).sAddressMode = tile_mode_to_mtl_sampler_address(xTileMode, sharedContext->mtlCaps());
72    (*desc).tAddressMode = tile_mode_to_mtl_sampler_address(yTileMode, sharedContext->mtlCaps());
73    (*desc).magFilter = minMagFilter;
74    (*desc).minFilter = minMagFilter;
75    (*desc).mipFilter = mipFilter;
76    (*desc).lodMinClamp = 0.0f;
77    (*desc).lodMaxClamp = FLT_MAX;  // default value according to docs.
78    (*desc).maxAnisotropy = 1;      // TODO: if we start using aniso, need to add to key
79    (*desc).normalizedCoordinates = true;
80    if (@available(macOS 10.11, iOS 9.0, tvOS 9.0, *)) {
81        (*desc).compareFunction = MTLCompareFunctionNever;
82    }
83#ifdef SK_ENABLE_MTL_DEBUG_INFO
84    NSString* tileModeLabels[] = {
85        @"Clamp",
86        @"Repeat",
87        @"Mirror",
88        @"Decal"
89    };
90    NSString* minMagFilterLabels[] = {
91        @"Nearest",
92        @"Linear"
93    };
94    NSString* mipFilterLabels[] = {
95        @"MipNone",
96        @"MipNearest",
97        @"MipLinear"
98    };
99
100    (*desc).label = [NSString stringWithFormat:@"X%@Y%@%@%@",
101                                               tileModeLabels[(int)xTileMode],
102                                               tileModeLabels[(int)yTileMode],
103                                               minMagFilterLabels[(int)samplingOptions.filter],
104                                               mipFilterLabels[(int)samplingOptions.mipmap]];
105#endif
106
107    sk_cfp<id<MTLSamplerState>> sampler(
108            [sharedContext->device() newSamplerStateWithDescriptor:desc.get()]);
109    if (!sampler) {
110        return nullptr;
111    }
112    return sk_sp<MtlSampler>(new MtlSampler(sharedContext, std::move(sampler)));
113}
114
115void MtlSampler::freeGpuData() {
116    fSamplerState.reset();
117}
118
119} // namespace skgpu::graphite
120
121