/*
 * Copyright 2020 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "bench/Benchmark.h"
#include "include/gpu/GrContext.h"
#include "src/gpu/GrContextPriv.h"
#include "src/gpu/GrOpFlushState.h"
#include "src/gpu/tessellate/GrTessellatePathOp.h"
#include "tools/ToolUtils.h"

// This is the number of cubics in desk_chalkboard.skp. (There are no quadratics in the chalkboard.)
constexpr static int kNumCubicsInChalkboard = 47182;

static SkPath make_cubic_path() {
    SkRandom rand;
    SkPath path;
    for (int i = 0; i < kNumCubicsInChalkboard/2; ++i) {
                float x = std::ldexp(rand.nextF(), (i % 18)) / 1e3f;
        path.cubicTo(111.625f*x, 308.188f*x, 764.62f*x, -435.688f*x, 742.63f*x, 85.187f*x);
        path.cubicTo(764.62f*x, -435.688f*x, 111.625f*x, 308.188f*x, 0, 0);
    }
    return path;
}

static sk_sp<GrContext> make_tessellation_mock_context() {
    GrMockOptions mockOptions;
    mockOptions.fDrawInstancedSupport = true;
    mockOptions.fTessellationSupport = true;
    mockOptions.fMapBufferFlags = GrCaps::kCanMap_MapFlag;
    return GrContext::MakeMock(&mockOptions);
}

// This serves as a base class for benchmarking individual methods on GrTessellatePathOp.
class GrTessellatePathOp::TestingOnly_Benchmark : public Benchmark {
public:
    TestingOnly_Benchmark(const char* subName, SkPath path, const SkMatrix& m)
            : fCtx(make_tessellation_mock_context())
            , fOp(m, path, GrPaint(), GrAAType::kMSAA)
            , fFlushState(fCtx->priv().getGpu(), fCtx->priv().resourceProvider(), nullptr,
                          GrBufferAllocPool::CpuBufferCache::Make(6)) {
        fName.printf("tessellate_%s", subName);
    }

    const char* onGetName() override { return fName.c_str(); }
    bool isSuitableFor(Backend backend) final { return backend == kNonRendering_Backend; }

    class MiddleOutInnerTrianglesBench;
    class OuterCubicsBench;
    class CubicWedgesBench;

private:
    void onDraw(int loops, SkCanvas*) final {
        for (int i = 0; i < loops; ++i) {
            fOp.fTriangleBuffer.reset();
            fOp.fDoStencilTriangleBuffer = false;
            fOp.fDoFillTriangleBuffer = false;
            fOp.fCubicBuffer.reset();
            fOp.fStencilCubicsShader = nullptr;
            this->runBench(&fFlushState, &fOp);
        }
    }

    virtual void runBench(GrOpFlushState*, GrTessellatePathOp*) = 0;

    sk_sp<GrContext> fCtx;
    GrTessellatePathOp fOp;
    GrOpFlushState fFlushState;
    SkString fName;
};

class GrTessellatePathOp::TestingOnly_Benchmark::MiddleOutInnerTrianglesBench
        : public GrTessellatePathOp::TestingOnly_Benchmark {
public:
    MiddleOutInnerTrianglesBench()
            : TestingOnly_Benchmark("prepareMiddleOutInnerTriangles",
                                    ToolUtils::make_star(SkRect::MakeWH(100, 100),
                                                         kNumCubicsInChalkboard),
                                    SkMatrix::I()) {
    }
    void runBench(GrOpFlushState* flushState, GrTessellatePathOp* op) override {
        int numBeziers;
        op->prepareMiddleOutInnerTriangles(flushState, &numBeziers);
    }
};

DEF_BENCH( return new GrTessellatePathOp::TestingOnly_Benchmark::MiddleOutInnerTrianglesBench(););

class GrTessellatePathOp::TestingOnly_Benchmark::OuterCubicsBench
        : public GrTessellatePathOp::TestingOnly_Benchmark {
public:
    OuterCubicsBench()
            : TestingOnly_Benchmark("prepareOuterCubics", make_cubic_path(), SkMatrix::I()) {
    }
    void runBench(GrOpFlushState* flushState, GrTessellatePathOp* op) override {
        op->prepareOuterCubics(flushState, kNumCubicsInChalkboard,
                               CubicDataAlignment::kVertexBoundary);
    }
};

DEF_BENCH( return new GrTessellatePathOp::TestingOnly_Benchmark::OuterCubicsBench(););

class GrTessellatePathOp::TestingOnly_Benchmark::CubicWedgesBench
        : public GrTessellatePathOp::TestingOnly_Benchmark {
public:
    CubicWedgesBench()
            : TestingOnly_Benchmark("prepareCubicWedges", make_cubic_path(), SkMatrix::I()) {
    }
    void runBench(GrOpFlushState* flushState, GrTessellatePathOp* op) override {
        op->prepareCubicWedges(flushState);
    }
};

DEF_BENCH( return new GrTessellatePathOp::TestingOnly_Benchmark::CubicWedgesBench(););