third_party/skia_next/third_party/skia/src/gpu/tessellate/PathWedgeTessellator.h

/*
 * 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 tessellate_PathWedgeTessellator_DEFINED
#define tessellate_PathWedgeTessellator_DEFINED

#include "src/gpu/GrVertexChunkArray.h"
#include "src/gpu/tessellate/PathTessellator.h"

class GrCaps;
class GrGpuBuffer;
class GrPipeline;

namespace skgpu {

// Prepares an array of "wedge" patches for GrWedgeTessellateShader. A wedge is an independent,
// 5-point closed contour consisting of 4 control points plus an anchor point fanning from the
// center of the curve's resident contour. A wedge can be either a cubic or a conic. Quadratics and
// lines are converted to cubics. Once stencilled, these wedges alone define the complete path.
class PathWedgeTessellator : public PathTessellator {
public:
    // Creates a wedge tessellator with the shader type best suited for the given path description.
    static PathTessellator* Make(SkArenaAlloc*,
                                 const SkMatrix& viewMatrix,
                                 const SkPMColor4f&,
                                 int numPathVerbs,
                                 const GrPipeline&,
                                 const GrCaps&);

    void prepare(GrMeshDrawTarget*, const PathDrawList&, int totalCombinedPathVerbCnt) override;


#if SK_GPU_V1
    void draw(GrOpFlushState*) const override;
#endif

private:
    PathWedgeTessellator(GrPathTessellationShader* shader) : PathTessellator(shader) {}

    GrVertexChunkArray fVertexChunkArray;

    // If using fixed count, this is the number of vertices we need to emit per instance.
    int fFixedIndexCount;
    sk_sp<const GrGpuBuffer> fFixedCountVertexBuffer;
    sk_sp<const GrGpuBuffer> fFixedCountIndexBuffer;
};

}  // namespace skgpu

#endif  // tessellate_PathWedgeTessellator_DEFINED