/*
 * Copyright 2022 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "src/gpu/graphite/RendererProvider.h"

#include "include/core/SkPathTypes.h"
#include "include/core/SkVertices.h"
#include "src/gpu/AtlasTypes.h"
#include "src/gpu/graphite/Caps.h"
#include "src/gpu/graphite/InternalDrawTypeFlags.h"
#include "src/gpu/graphite/render/AnalyticBlurRenderStep.h"
#include "src/gpu/graphite/render/AnalyticRRectRenderStep.h"
#include "src/gpu/graphite/render/BitmapTextRenderStep.h"
#include "src/gpu/graphite/render/CircularArcRenderStep.h"
#include "src/gpu/graphite/render/CommonDepthStencilSettings.h"
#include "src/gpu/graphite/render/CoverBoundsRenderStep.h"
#include "src/gpu/graphite/render/CoverageMaskRenderStep.h"
#include "src/gpu/graphite/render/MiddleOutFanRenderStep.h"
#include "src/gpu/graphite/render/PerEdgeAAQuadRenderStep.h"
#include "src/gpu/graphite/render/SDFTextLCDRenderStep.h"
#include "src/gpu/graphite/render/SDFTextRenderStep.h"
#include "src/gpu/graphite/render/TessellateCurvesRenderStep.h"
#include "src/gpu/graphite/render/TessellateStrokesRenderStep.h"
#include "src/gpu/graphite/render/TessellateWedgesRenderStep.h"
#include "src/gpu/graphite/render/VerticesRenderStep.h"
#include "src/sksl/SkSLUtil.h"

#ifdef SK_ENABLE_VELLO_SHADERS
#include "src/gpu/graphite/compute/VelloRenderer.h"
#endif

namespace skgpu::graphite {

bool RendererProvider::IsVelloRendererSupported(const Caps* caps) {
#ifdef SK_ENABLE_VELLO_SHADERS
    return caps->computeSupport();
#else
    return false;
#endif
}

// The destructor is intentionally defined here and not in the header file to allow forward
// declared types (such as `VelloRenderer`) to be defined as a `std::unique_ptr` parameter type
// in members.
RendererProvider::~RendererProvider() = default;

RendererProvider::RendererProvider(const Caps* caps, StaticBufferManager* bufferManager) {
    const bool infinitySupport = caps->shaderCaps()->fInfinitySupport;

    // Single-step renderers don't share RenderSteps
    auto initFromStep = [&](Renderer* renderer,
                            std::unique_ptr<RenderStep> singleStep,
                            DrawTypeFlags drawTypes) {
        std::string name = "SingleStep[";
        name += singleStep->name();
        name += "]";
        this->initRenderer(renderer, name, drawTypes, this->assumeOwnership(std::move(singleStep)));
    };

    initFromStep(&fConvexTessellatedWedges,
                 std::make_unique<TessellateWedgesRenderStep>(
                        RenderStep::RenderStepID::kTessellateWedges_Convex,
                        infinitySupport, kDirectDepthLessPass, bufferManager),
                 DrawTypeFlags::kNonSimpleShape);
    initFromStep(&fTessellatedStrokes,
                 std::make_unique<TessellateStrokesRenderStep>(infinitySupport),
                 DrawTypeFlags::kNonSimpleShape);
    initFromStep(&fCoverageMask,
                 std::make_unique<CoverageMaskRenderStep>(),
                 static_cast<DrawTypeFlags>((int) DrawTypeFlags::kNonSimpleShape |
                                            (int) InternalDrawTypeFlags::kCoverageMask));

    static constexpr struct {
        skgpu::MaskFormat fFormat;
        DrawTypeFlags     fDrawType;
    } kBitmapTextVariants [] = {
        // We are using 565 here to represent LCD text, regardless of texture format
        { skgpu::MaskFormat::kA8,   DrawTypeFlags::kBitmapText_Mask  },
        { skgpu::MaskFormat::kA565, DrawTypeFlags::kBitmapText_LCD   },
        { skgpu::MaskFormat::kARGB, DrawTypeFlags::kBitmapText_Color }
    };

    for (auto textVariant : kBitmapTextVariants) {
        initFromStep(&fBitmapText[int(textVariant.fFormat)],
                     std::make_unique<BitmapTextRenderStep>(textVariant.fFormat),
                     textVariant.fDrawType);
    }

    // SDF text (lcd and single channel)
    initFromStep(&fSDFText[/*lcd=*/true],
                 std::make_unique<SDFTextLCDRenderStep>(),
                 DrawTypeFlags::kSDFText_LCD);
    initFromStep(&fSDFText[/*lcd=*/false],
                 std::make_unique<SDFTextRenderStep>(),
                 DrawTypeFlags::kSDFText);

    initFromStep(&fAnalyticRRect,
                 std::make_unique<AnalyticRRectRenderStep>(bufferManager),
                 DrawTypeFlags::kAnalyticRRect);
    initFromStep(&fPerEdgeAAQuad,
                 std::make_unique<PerEdgeAAQuadRenderStep>(bufferManager),
                 DrawTypeFlags::kPerEdgeAAQuad);
    initFromStep(&fNonAABoundsFill,
                 std::make_unique<CoverBoundsRenderStep>(
                        RenderStep::RenderStepID::kCoverBounds_NonAAFill,
                        kDirectDepthLessPass),
                 DrawTypeFlags::kNonAAFillRect);
    initFromStep(&fCircularArc,
                 std::make_unique<CircularArcRenderStep>(bufferManager),
                 DrawTypeFlags::kCircularArc);
    initFromStep(&fAnalyticBlur,
                 std::make_unique<AnalyticBlurRenderStep>(),
                 DrawTypeFlags::kDropShadows);

    // vertices
    for (PrimitiveType primType : {PrimitiveType::kTriangles, PrimitiveType::kTriangleStrip}) {
        for (bool color : {false, true}) {
            for (bool texCoords : {false, true}) {
                DrawTypeFlags dtFlags = DrawTypeFlags::kDrawVertices;
                if (primType == PrimitiveType::kTriangles && color && !texCoords) {
                    // Android uses this drawVertices combination for drop shadows
                    dtFlags = static_cast<DrawTypeFlags>(dtFlags | DrawTypeFlags::kDropShadows);
                }

                int index = 4*(primType == PrimitiveType::kTriangleStrip) + 2*color + texCoords;
                initFromStep(&fVertices[index],
                             std::make_unique<VerticesRenderStep>(primType, color, texCoords),
                             dtFlags);
            }
        }
    }

    // The tessellating path renderers that use stencil can share the cover steps.
    auto coverFill = std::make_unique<CoverBoundsRenderStep>(
            RenderStep::RenderStepID::kCoverBounds_RegularCover, kRegularCoverPass);
    auto coverInverse = std::make_unique<CoverBoundsRenderStep>(
            RenderStep::RenderStepID::kCoverBounds_InverseCover, kInverseCoverPass);

    for (bool evenOdd : {false, true}) {
        // These steps can be shared by regular and inverse fills
        auto stencilFan = std::make_unique<MiddleOutFanRenderStep>(evenOdd);
        auto stencilCurve = std::make_unique<TessellateCurvesRenderStep>(
                evenOdd, infinitySupport, bufferManager);
        auto stencilWedge =
                evenOdd ? std::make_unique<TessellateWedgesRenderStep>(
                                RenderStep::RenderStepID::kTessellateWedges_EvenOdd,
                                infinitySupport, kEvenOddStencilPass, bufferManager)
                        : std::make_unique<TessellateWedgesRenderStep>(
                                RenderStep::RenderStepID::kTessellateWedges_Winding,
                                infinitySupport, kWindingStencilPass, bufferManager);

        for (bool inverse : {false, true}) {
            static const char* kTessVariants[4] =
                    {"[winding]", "[evenodd]", "[inverse-winding]", "[inverse-evenodd]"};

            int index = 2*inverse + evenOdd; // matches SkPathFillType
            std::string variant = kTessVariants[index];

            const RenderStep* coverStep = inverse ? coverInverse.get() : coverFill.get();
            this->initRenderer(&fStencilTessellatedCurves[index],
                               "StencilTessellatedCurvesAndTris" + variant,
                               DrawTypeFlags::kNonSimpleShape,
                               stencilFan.get(),
                               stencilCurve.get(),
                               coverStep);

            this->initRenderer(&fStencilTessellatedWedges[index],
                               "StencilTessellatedWedges" + variant,
                               DrawTypeFlags::kNonSimpleShape,
                               stencilWedge.get(),
                               coverStep);
        }

        this->assumeOwnership(std::move(stencilFan));
        this->assumeOwnership(std::move(stencilCurve));
        this->assumeOwnership(std::move(stencilWedge));
    }

    this->assumeOwnership(std::move(coverInverse));
    this->assumeOwnership(std::move(coverFill));

#ifdef SK_ENABLE_VELLO_SHADERS
    fVelloRenderer = std::make_unique<VelloRenderer>(caps);
#endif
}

} // namespace skgpu::graphite