xref: /aosp_15_r20/external/skia/src/gpu/ganesh/ops/QuadPerEdgeAA.h (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2018 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 QuadPerEdgeAA_DEFINED
9 #define QuadPerEdgeAA_DEFINED
10 
11 #include "include/core/SkRefCnt.h"
12 #include "include/private/SkColorData.h"
13 #include "include/private/base/SkAssert.h"
14 #include "include/private/base/SkDebug.h"
15 #include "include/private/gpu/ganesh/GrTypesPriv.h"
16 #include "src/gpu/BufferWriter.h"
17 #include "src/gpu/ganesh/GrSamplerState.h"
18 #include "src/gpu/ganesh/geometry/GrQuad.h"
19 #include "src/gpu/ganesh/geometry/GrQuadUtils.h"
20 #include "src/gpu/ganesh/ops/TextureOp.h"
21 
22 #include <cstddef>
23 
24 class GrBackendFormat;
25 class GrBuffer;
26 class GrCaps;
27 class GrColorSpaceXform;
28 class GrGeometryProcessor;
29 class GrMeshDrawTarget;
30 class GrOpsRenderPass;
31 class SkArenaAlloc;
32 struct GrShaderCaps;
33 struct SkRect;
34 
35 namespace skgpu {
36 class Swizzle;
37 }
38 
39 namespace skgpu::ganesh::QuadPerEdgeAA {
40 using Saturate = skgpu::ganesh::TextureOp::Saturate;
41 
42 enum class CoverageMode { kNone, kWithPosition, kWithColor };
43 enum class Subset : bool { kNo = false, kYes = true };
44 enum class ColorType { kNone, kByte, kFloat, kLast = kFloat };
45 static const int kColorTypeCount = static_cast<int>(ColorType::kLast) + 1;
46 
47 enum class IndexBufferOption {
48     kPictureFramed,  // geometrically AA'd   -> 8 verts/quad + an index buffer
49     kIndexedRects,   // non-AA'd but indexed -> 4 verts/quad + an index buffer
50     kTriStrips,      // non-AA'd             -> 4 verts/quad but no index buffer
51     kLast = kTriStrips
52 };
53 static const int kIndexBufferOptionCount = static_cast<int>(IndexBufferOption::kLast) + 1;
54 
55 IndexBufferOption CalcIndexBufferOption(GrAAType aa, int numQuads);
56 
57 // Gets the minimum ColorType that can represent a color.
58 ColorType MinColorType(SkPMColor4f);
59 
60 // Specifies the vertex configuration for an op that renders per-edge AA quads. The vertex
61 // order (when enabled) is device position, color, local position, subset, aa edge equations.
62 // This order matches the constructor argument order of VertexSpec and is the order that
63 // GPAttributes maintains. If hasLocalCoords is false, then the local quad type can be ignored.
64 struct VertexSpec {
65 public:
VertexSpecVertexSpec66     VertexSpec()
67             : fDeviceQuadType(0)     // kAxisAligned
68             , fLocalQuadType(0)      // kAxisAligned
69             , fIndexBufferOption(0)  // kPictureFramed
70             , fHasLocalCoords(false)
71             , fColorType(0)  // kNone
72             , fHasSubset(false)
73             , fUsesCoverageAA(false)
74             , fCompatibleWithCoverageAsAlpha(false)
75             , fRequiresGeometrySubset(false) {}
76 
VertexSpecVertexSpec77     VertexSpec(GrQuad::Type deviceQuadType,
78                ColorType colorType,
79                GrQuad::Type localQuadType,
80                bool hasLocalCoords,
81                Subset subset,
82                GrAAType aa,
83                bool coverageAsAlpha,
84                IndexBufferOption indexBufferOption)
85             : fDeviceQuadType(static_cast<unsigned>(deviceQuadType))
86             , fLocalQuadType(static_cast<unsigned>(localQuadType))
87             , fIndexBufferOption(static_cast<unsigned>(indexBufferOption))
88             , fHasLocalCoords(hasLocalCoords)
89             , fColorType(static_cast<unsigned>(colorType))
90             , fHasSubset(static_cast<unsigned>(subset))
91             , fUsesCoverageAA(aa == GrAAType::kCoverage)
92             , fCompatibleWithCoverageAsAlpha(coverageAsAlpha)
93             , fRequiresGeometrySubset(aa == GrAAType::kCoverage &&
94                                       deviceQuadType > GrQuad::Type::kRectilinear) {}
95 
deviceQuadTypeVertexSpec96     GrQuad::Type deviceQuadType() const { return static_cast<GrQuad::Type>(fDeviceQuadType); }
localQuadTypeVertexSpec97     GrQuad::Type localQuadType() const { return static_cast<GrQuad::Type>(fLocalQuadType); }
indexBufferOptionVertexSpec98     IndexBufferOption indexBufferOption() const {
99         return static_cast<IndexBufferOption>(fIndexBufferOption);
100     }
hasLocalCoordsVertexSpec101     bool hasLocalCoords() const { return fHasLocalCoords; }
colorTypeVertexSpec102     ColorType colorType() const { return static_cast<ColorType>(fColorType); }
hasVertexColorsVertexSpec103     bool hasVertexColors() const { return ColorType::kNone != this->colorType(); }
hasSubsetVertexSpec104     bool hasSubset() const { return fHasSubset; }
usesCoverageAAVertexSpec105     bool usesCoverageAA() const { return fUsesCoverageAA; }
compatibleWithCoverageAsAlphaVertexSpec106     bool compatibleWithCoverageAsAlpha() const { return fCompatibleWithCoverageAsAlpha; }
requiresGeometrySubsetVertexSpec107     bool requiresGeometrySubset() const { return fRequiresGeometrySubset; }
108     // Will always be 2 or 3
109     int deviceDimensionality() const;
110     // Will always be 0 if hasLocalCoords is false, otherwise will be 2 or 3
111     int localDimensionality() const;
112 
verticesPerQuadVertexSpec113     int verticesPerQuad() const { return fUsesCoverageAA ? 8 : 4; }
114 
115     CoverageMode coverageMode() const;
116     size_t vertexSize() const;
117 
needsIndexBufferVertexSpec118     bool needsIndexBuffer() const {
119         return this->indexBufferOption() != IndexBufferOption::kTriStrips;
120     }
121 
primitiveTypeVertexSpec122     GrPrimitiveType primitiveType() const {
123         switch (this->indexBufferOption()) {
124             case IndexBufferOption::kPictureFramed:
125                 return GrPrimitiveType::kTriangles;
126             case IndexBufferOption::kIndexedRects:
127                 return GrPrimitiveType::kTriangles;
128             case IndexBufferOption::kTriStrips:
129                 return GrPrimitiveType::kTriangleStrip;
130         }
131 
132         SkUNREACHABLE;
133     }
134 
135 private:
136     static_assert(GrQuad::kTypeCount <= 4, "GrQuad::Type doesn't fit in 2 bits");
137     static_assert(kColorTypeCount <= 4, "Color doesn't fit in 2 bits");
138     static_assert(kIndexBufferOptionCount <= 4, "IndexBufferOption doesn't fit in 2 bits");
139 
140     unsigned fDeviceQuadType : 2;
141     unsigned fLocalQuadType : 2;
142     unsigned fIndexBufferOption : 2;
143     unsigned fHasLocalCoords : 1;
144     unsigned fColorType : 2;
145     unsigned fHasSubset : 1;
146     unsigned fUsesCoverageAA : 1;
147     unsigned fCompatibleWithCoverageAsAlpha : 1;
148     // The geometry subset serves to clip off pixels touched by quads with sharp corners that
149     // would otherwise exceed the miter limit for the AA-outset geometry.
150     unsigned fRequiresGeometrySubset : 1;
151     };
152 
153     // A Tessellator is responsible for processing a series of device+local GrQuads into a VBO,
154     // as specified by a VertexSpec. This vertex data can then be processed by a GP created with
155     // MakeProcessor and/or MakeTexturedProcessor.
156     class Tessellator {
157     public:
158         explicit Tessellator(const VertexSpec& spec, char* vertices);
159 
160         // Calculates (as needed) inset and outset geometry for anti-aliasing, and appends all
161         // necessary position and vertex attributes required by this Tessellator's VertexSpec into
162         // the 'vertices' the Tessellator was called with. The insetting and outsetting may
163         // damage the provided GrQuads (as this is intended to work with GrQuadBuffer::Iter).
164         // 'localQuad' can be null if the VertexSpec does not use local coords.
165         void append(GrQuad* deviceQuad, GrQuad* localQuad,
166                     const SkPMColor4f& color, const SkRect& uvSubset, GrQuadAAFlags aaFlags);
167 
168         SkDEBUGCODE(skgpu::BufferWriter::Mark vertexMark() const { return fVertexWriter.mark(); })
169 
170     private:
171         // VertexSpec defines many unique ways to write vertex attributes, which can be handled
172         // generically by branching per-quad based on the VertexSpec. However, there are several
173         // specs that appear in the wild far more frequently, so they use explicit WriteQuadProcs
174         // that have no branches.
175         typedef void (*WriteQuadProc)(VertexWriter* vertices, const VertexSpec& spec,
176                                       const GrQuad* deviceQuad, const GrQuad* localQuad,
177                                       const float coverage[4], const SkPMColor4f& color,
178                                       const SkRect& geomSubset, const SkRect& texSubset);
179         static WriteQuadProc GetWriteQuadProc(const VertexSpec& spec);
180 
181         GrQuadUtils::TessellationHelper fAAHelper;
182         VertexSpec                      fVertexSpec;
183         VertexWriter                    fVertexWriter;
184         WriteQuadProc                   fWriteProc;
185     };
186 
187     GrGeometryProcessor* MakeProcessor(SkArenaAlloc*, const VertexSpec&);
188 
189     GrGeometryProcessor* MakeTexturedProcessor(SkArenaAlloc*,
190                                                const VertexSpec&,
191                                                const GrShaderCaps&,
192                                                const GrBackendFormat&,
193                                                GrSamplerState,
194                                                const skgpu::Swizzle&,
195                                                sk_sp<GrColorSpaceXform> textureColorSpaceXform,
196                                                Saturate);
197 
198     // This method will return the correct index buffer for the specified indexBufferOption.
199     // It will, correctly, return nullptr if the indexBufferOption is kTriStrips.
200     sk_sp<const GrBuffer> GetIndexBuffer(GrMeshDrawTarget*, IndexBufferOption);
201 
202     // What is the maximum number of quads allowed for the specified indexBuffer option?
203     int QuadLimit(IndexBufferOption);
204 
205     // This method will issue the draw call on the provided GrOpsRenderPass, as specified by the
206     // indexing method in vertexSpec. It is up to the calling code to allocate, fill in, and bind a
207     // vertex buffer, and to acquire and bind the correct index buffer (if needed) with
208     // GrPrimitiveRestart::kNo.
209     //
210     // @param runningQuadCount  the number of quads already stored in 'vertexBuffer' and
211     //                          'indexBuffer' e.g., different GrMeshes have already been placed in
212     //                          the buffers to allow dynamic state changes.
213     // @param quadCount         the number of quads that will be drawn by the provided 'mesh'.
214     //                          A subsequent ConfigureMesh call would the use
215     //                          'runningQuadCount' + 'quadCount' for its new 'runningQuadCount'.
216     void IssueDraw(const GrCaps&, GrOpsRenderPass*, const VertexSpec&, int runningQuadCount,
217                    int quadCount, int maxVerts, int absVertBufferOffset);
218 
219     }  // namespace skgpu::ganesh::QuadPerEdgeAA
220 
221 #endif // QuadPerEdgeAA_DEFINED
222