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/MiddleOutFanRenderStep.h"
9
10 #include "include/core/SkPath.h"
11 #include "include/private/base/SkDebug.h"
12 #include "src/base/SkEnumBitMask.h"
13 #include "src/core/SkSLTypeShared.h"
14 #include "src/gpu/BufferWriter.h"
15 #include "src/gpu/graphite/Attribute.h"
16 #include "src/gpu/graphite/DrawOrder.h"
17 #include "src/gpu/graphite/DrawParams.h"
18 #include "src/gpu/graphite/DrawTypes.h"
19 #include "src/gpu/graphite/DrawWriter.h"
20 #include "src/gpu/graphite/PipelineData.h"
21 #include "src/gpu/graphite/geom/Geometry.h"
22 #include "src/gpu/graphite/geom/Shape.h"
23 #include "src/gpu/graphite/geom/Transform_graphite.h"
24 #include "src/gpu/graphite/render/CommonDepthStencilSettings.h"
25 #include "src/gpu/tessellate/MiddleOutPolygonTriangulator.h"
26
27 #include <algorithm>
28 #include <string_view>
29
30 namespace skgpu::graphite {
31
MiddleOutFanRenderStep(bool evenOdd)32 MiddleOutFanRenderStep::MiddleOutFanRenderStep(bool evenOdd)
33 : RenderStep("MiddleOutFanRenderStep",
34 evenOdd ? "even-odd" : "winding",
35 Flags::kRequiresMSAA,
36 /*uniforms=*/{{"localToDevice", SkSLType::kFloat4x4}},
37 PrimitiveType::kTriangles,
38 evenOdd ? kEvenOddStencilPass : kWindingStencilPass,
39 /*vertexAttrs=*/
40 {{"position", VertexAttribType::kFloat2, SkSLType::kFloat2},
41 {"depth", VertexAttribType::kFloat, SkSLType::kFloat},
42 {"ssboIndices", VertexAttribType::kUInt2, SkSLType::kUInt2}},
43 /*instanceAttrs=*/{}) {}
44
~MiddleOutFanRenderStep()45 MiddleOutFanRenderStep::~MiddleOutFanRenderStep() {}
46
vertexSkSL() const47 std::string MiddleOutFanRenderStep::vertexSkSL() const {
48 return R"(
49 float4 devPosition = localToDevice * float4(position, 0.0, 1.0);
50 devPosition.z = depth;
51 stepLocalCoords = position;
52 )";
53 }
54
writeVertices(DrawWriter * writer,const DrawParams & params,skvx::uint2 ssboIndices) const55 void MiddleOutFanRenderStep::writeVertices(DrawWriter* writer,
56 const DrawParams& params,
57 skvx::uint2 ssboIndices) const {
58 // TODO: Have Shape provide a path-like iterator so we don't actually have to convert non
59 // paths to SkPath just to iterate their pts/verbs
60 SkPath path = params.geometry().shape().asPath();
61
62 const int maxTrianglesInFans = std::max(path.countVerbs() - 2, 0);
63
64 float depth = params.order().depthAsFloat();
65
66 DrawWriter::Vertices verts{*writer};
67 verts.reserve(maxTrianglesInFans * 3);
68 for (tess::PathMiddleOutFanIter it(path); !it.done();) {
69 for (auto [p0, p1, p2] : it.nextStack()) {
70 verts.append(3) << p0 << depth << ssboIndices
71 << p1 << depth << ssboIndices
72 << p2 << depth << ssboIndices;
73 }
74 }
75 }
76
writeUniformsAndTextures(const DrawParams & params,PipelineDataGatherer * gatherer) const77 void MiddleOutFanRenderStep::writeUniformsAndTextures(const DrawParams& params,
78 PipelineDataGatherer* gatherer) const {
79 SkDEBUGCODE(UniformExpectationsValidator uev(gatherer, this->uniforms());)
80
81 gatherer->write(params.transform().matrix());
82 }
83
84 } // namespace skgpu::graphite
85