| /* |
| * Copyright 2021 Google LLC. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrVertexChunkArray_DEFINED |
| #define GrVertexChunkArray_DEFINED |
| |
| #include "include/core/SkRefCnt.h" |
| #include "include/private/base/SkNoncopyable.h" |
| #include "include/private/base/SkTArray.h" |
| #include "include/private/base/SkTypeTraits.h" |
| #include "src/gpu/BufferWriter.h" |
| #include "src/gpu/ganesh/GrBuffer.h" |
| |
| class GrMeshDrawTarget; |
| |
| // Represents a chunk of vertex data. Use with GrVertexChunkArray and GrVertexChunkBuilder. We write |
| // the data out in chunks when we don't start out knowing exactly how many vertices (or instances) |
| // we will end up writing. |
| struct GrVertexChunk { |
| sk_sp<const GrBuffer> fBuffer; |
| int fCount = 0; |
| int fBase; // baseVertex or baseInstance, depending on the use case. |
| |
| static_assert(::sk_is_trivially_relocatable<decltype(fBuffer)>::value); |
| |
| using sk_is_trivially_relocatable = std::true_type; |
| }; |
| |
| // Represents an array of GrVertexChunks. |
| // |
| // We only preallocate 1 chunk because if the array needs to grow, then we're also allocating a |
| // brand new GPU buffer anyway. |
| using GrVertexChunkArray = SkSTArray<1, GrVertexChunk>; |
| |
| // Builds a GrVertexChunkArray. The provided Target must not be used externally throughout the |
| // entire lifetime of this object. |
| class GrVertexChunkBuilder : SkNoncopyable { |
| public: |
| GrVertexChunkBuilder(GrMeshDrawTarget* target, GrVertexChunkArray* chunks, |
| size_t stride, int minVerticesPerChunk) |
| : fTarget(target) |
| , fChunks(chunks) |
| , fStride(stride) |
| , fMinVerticesPerChunk(minVerticesPerChunk) { |
| SkASSERT(fMinVerticesPerChunk > 0); |
| } |
| |
| ~GrVertexChunkBuilder(); |
| |
| size_t stride() const { return fStride; } |
| |
| // Appends 'count' contiguous vertices. These vertices are not guaranteed to be contiguous with |
| // previous or future calls to appendVertices. |
| SK_ALWAYS_INLINE skgpu::VertexWriter appendVertices(int count) { |
| SkASSERT(count > 0); |
| if (fCurrChunkVertexCount + count > fCurrChunkVertexCapacity && !this->allocChunk(count)) { |
| SkDEBUGCODE(fLastAppendAmount = 0;) |
| return {}; |
| } |
| SkASSERT(fCurrChunkVertexCount + count <= fCurrChunkVertexCapacity); |
| fCurrChunkVertexCount += count; |
| SkDEBUGCODE(fLastAppendAmount = count;) |
| return std::exchange(fCurrChunkVertexWriter, |
| fCurrChunkVertexWriter.makeOffset(fStride * count)); |
| } |
| |
| // Pops the most recent 'count' contiguous vertices. Since there is no guarantee of contiguity |
| // between appends, 'count' may be no larger than the most recent call to appendVertices(). |
| void popVertices(int count) { |
| SkASSERT(count <= fLastAppendAmount); |
| SkASSERT(fLastAppendAmount <= fCurrChunkVertexCount); |
| SkASSERT(count >= 0); |
| fCurrChunkVertexCount -= count; |
| fCurrChunkVertexWriter = fCurrChunkVertexWriter.makeOffset(fStride * -count); |
| SkDEBUGCODE(fLastAppendAmount -= count;) |
| } |
| |
| private: |
| bool allocChunk(int minCount); |
| |
| GrMeshDrawTarget* const fTarget; |
| GrVertexChunkArray* const fChunks; |
| const size_t fStride; |
| int fMinVerticesPerChunk; |
| |
| skgpu::VertexWriter fCurrChunkVertexWriter; |
| int fCurrChunkVertexCount = 0; |
| int fCurrChunkVertexCapacity = 0; |
| |
| SkDEBUGCODE(int fLastAppendAmount = 0;) |
| }; |
| |
| #endif |