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/render/BitmapTextRenderStep.h"
9
10 #include "include/core/SkM44.h"
11 #include "include/gpu/graphite/Recorder.h"
12 #include "src/gpu/graphite/AtlasProvider.h"
13 #include "src/gpu/graphite/ContextUtils.h"
14 #include "src/gpu/graphite/DrawParams.h"
15 #include "src/gpu/graphite/DrawWriter.h"
16 #include "src/gpu/graphite/PipelineData.h"
17 #include "src/gpu/graphite/RecorderPriv.h"
18 #include "src/gpu/graphite/render/CommonDepthStencilSettings.h"
19 #include "src/gpu/graphite/text/TextAtlasManager.h"
20 #include "src/sksl/SkSLString.h"
21 #include "src/text/gpu/SubRunContainer.h"
22 #include "src/text/gpu/VertexFiller.h"
23
24 using AtlasSubRun = sktext::gpu::AtlasSubRun;
25
26 namespace skgpu::graphite {
27
28 namespace {
29
30 // We are expecting to sample from up to 4 textures
31 constexpr int kNumTextAtlasTextures = 4;
32
33 } // namespace
34
BitmapTextRenderStep(bool isLCD)35 BitmapTextRenderStep::BitmapTextRenderStep(bool isLCD)
36 : RenderStep("BitmapTextRenderStep",
37 "",
38 isLCD ? Flags::kPerformsShading | Flags::kHasTextures | Flags::kEmitsCoverage |
39 Flags::kLCDCoverage
40 : Flags::kPerformsShading | Flags::kHasTextures | Flags::kEmitsCoverage,
41 /*uniforms=*/{{"subRunDeviceMatrix", SkSLType::kFloat4x4},
42 {"deviceToLocal" , SkSLType::kFloat4x4},
43 {"atlasSizeInv" , SkSLType::kFloat2}},
44 PrimitiveType::kTriangleStrip,
45 kDirectDepthGEqualPass,
46 /*vertexAttrs=*/ {},
47 /*instanceAttrs=*/
48 {{"size", VertexAttribType::kUShort2, SkSLType::kUShort2},
49 {"uvPos", VertexAttribType::kUShort2, SkSLType::kUShort2},
50 {"xyPos", VertexAttribType::kFloat2, SkSLType::kFloat2},
51 {"indexAndFlags", VertexAttribType::kUShort2, SkSLType::kUShort2},
52 {"strikeToSourceScale", VertexAttribType::kFloat, SkSLType::kFloat},
53 {"depth", VertexAttribType::kFloat, SkSLType::kFloat},
54 {"ssboIndices", VertexAttribType::kUShort2, SkSLType::kUShort2}},
55 /*varyings=*/
56 {{"textureCoords", SkSLType::kFloat2},
57 {"texIndex", SkSLType::kHalf},
58 {"maskFormat", SkSLType::kHalf}}) {}
59
~BitmapTextRenderStep()60 BitmapTextRenderStep::~BitmapTextRenderStep() {}
61
vertexSkSL() const62 std::string BitmapTextRenderStep::vertexSkSL() const {
63 // Returns the body of a vertex function, which must define a float4 devPosition variable and
64 // must write to an already-defined float2 stepLocalCoords variable.
65 return "texIndex = half(indexAndFlags.x);"
66 "maskFormat = half(indexAndFlags.y);"
67 "float2 unormTexCoords;"
68 "float4 devPosition = text_vertex_fn(float2(sk_VertexID >> 1, sk_VertexID & 1), "
69 "subRunDeviceMatrix, "
70 "deviceToLocal, "
71 "atlasSizeInv, "
72 "float2(size), "
73 "float2(uvPos), "
74 "xyPos, "
75 "strikeToSourceScale, "
76 "depth, "
77 "textureCoords, "
78 "unormTexCoords, "
79 "stepLocalCoords);";
80 }
81
texturesAndSamplersSkSL(const ResourceBindingRequirements & bindingReqs,int * nextBindingIndex) const82 std::string BitmapTextRenderStep::texturesAndSamplersSkSL(
83 const ResourceBindingRequirements& bindingReqs, int* nextBindingIndex) const {
84 std::string result;
85
86 for (unsigned int i = 0; i < kNumTextAtlasTextures; ++i) {
87 result += EmitSamplerLayout(bindingReqs, nextBindingIndex);
88 SkSL::String::appendf(&result, " sampler2D text_atlas_%u;\n", i);
89 }
90
91 return result;
92 }
93
fragmentCoverageSkSL() const94 const char* BitmapTextRenderStep::fragmentCoverageSkSL() const {
95 // The returned SkSL must write its coverage into a 'half4 outputCoverage' variable (defined in
96 // the calling code) with the actual coverage splatted out into all four channels.
97 static_assert(kNumTextAtlasTextures == 4);
98 return "outputCoverage = bitmap_text_coverage_fn(sample_indexed_atlas(textureCoords, "
99 "int(texIndex), "
100 "text_atlas_0, "
101 "text_atlas_1, "
102 "text_atlas_2, "
103 "text_atlas_3), "
104 "int(maskFormat));";
105 }
106
writeVertices(DrawWriter * dw,const DrawParams & params,skvx::ushort2 ssboIndices) const107 void BitmapTextRenderStep::writeVertices(DrawWriter* dw,
108 const DrawParams& params,
109 skvx::ushort2 ssboIndices) const {
110 const SubRunData& subRunData = params.geometry().subRunData();
111
112 subRunData.subRun()->vertexFiller().fillInstanceData(dw,
113 subRunData.startGlyphIndex(),
114 subRunData.glyphCount(),
115 subRunData.subRun()->instanceFlags(),
116 ssboIndices,
117 subRunData.subRun()->glyphs(),
118 params.order().depthAsFloat());
119 }
120
writeUniformsAndTextures(const DrawParams & params,PipelineDataGatherer * gatherer) const121 void BitmapTextRenderStep::writeUniformsAndTextures(const DrawParams& params,
122 PipelineDataGatherer* gatherer) const {
123 SkDEBUGCODE(UniformExpectationsValidator uev(gatherer, this->uniforms());)
124
125 const SubRunData& subRunData = params.geometry().subRunData();
126 unsigned int numProxies;
127 Recorder* recorder = subRunData.recorder();
128 const sk_sp<TextureProxy>* proxies =
129 recorder->priv().atlasProvider()->textAtlasManager()->getProxies(
130 subRunData.subRun()->maskFormat(), &numProxies);
131 SkASSERT(proxies && numProxies > 0);
132
133 // write uniforms
134 gatherer->write(params.transform().matrix()); // subRunDeviceMatrix
135 gatherer->write(subRunData.deviceToLocal());
136 SkV2 atlasDimensionsInverse = {1.f/proxies[0]->dimensions().width(),
137 1.f/proxies[0]->dimensions().height()};
138 gatherer->write(atlasDimensionsInverse);
139
140 // write textures and samplers
141 const SkSamplingOptions kSamplingOptions(SkFilterMode::kNearest);
142 constexpr SkTileMode kTileModes[2] = { SkTileMode::kClamp, SkTileMode::kClamp };
143 for (unsigned int i = 0; i < numProxies; ++i) {
144 gatherer->add(kSamplingOptions, kTileModes, proxies[i]);
145 }
146 // If the atlas has less than 4 active proxies we still need to set up samplers for the shader.
147 for (unsigned int i = numProxies; i < kNumTextAtlasTextures; ++i) {
148 gatherer->add(kSamplingOptions, kTileModes, proxies[0]);
149 }
150 }
151
152 } // namespace skgpu::graphite
153