/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#ifndef GrVkPipelineState_DEFINED
#define GrVkPipelineState_DEFINED

#include "GrProgramDesc.h"
#include "GrStencilSettings.h"
#include "GrVkDescriptorSetManager.h"
#include "GrVkImage.h"
#include "GrVkPipelineStateDataManager.h"
#include "glsl/GrGLSLProgramBuilder.h"

#include "vk/GrVkDefines.h"

class GrPipeline;
class GrVkCommandBuffer;
class GrVkDescriptorPool;
class GrVkDescriptorSet;
class GrVkGpu;
class GrVkImageView;
class GrVkPipeline;
class GrVkSampler;
class GrVkUniformBuffer;

/**
 * This class holds onto a GrVkPipeline object that we use for draws. Besides storing the acutal
 * GrVkPipeline object, this class is also responsible handling all uniforms, descriptors, samplers,
 * and other similar objects that are used along with the VkPipeline in the draw. This includes both
 * allocating and freeing these objects, as well as updating their values.
 */
class GrVkPipelineState : public SkRefCnt {
public:
    typedef GrGLSLProgramBuilder::BuiltinUniformHandles BuiltinUniformHandles;

    ~GrVkPipelineState();

    GrVkPipeline* vkPipeline() const { return fPipeline; }

    void setData(GrVkGpu*, const GrPrimitiveProcessor&, const GrPipeline&);

    void bind(const GrVkGpu* gpu, GrVkCommandBuffer* commandBuffer);

    void addUniformResources(GrVkCommandBuffer&);

    void freeGPUResources(const GrVkGpu* gpu);

    // This releases resources that only a given instance of a GrVkPipelineState needs to hold onto
    // and don't need to survive across new uses of the GrVkPipelineState.
    void freeTempResources(const GrVkGpu* gpu);

    void abandonGPUResources();

    /**
     * For Vulkan we want to cache the entire VkPipeline for reuse of draws. The Desc here holds all
     * the information needed to differentiate one pipeline from another.
     *
     * The GrProgramDesc contains all the information need to create the actual shaders for the
     * pipeline.
     *
     * For Vulkan we need to add to the GrProgramDesc to include the rest of the state on the
     * pipline. This includes stencil settings, blending information, render pass format, draw face
     * information, and primitive type. Note that some state is set dynamically on the pipeline for
     * each draw  and thus is not included in this descriptor. This includes the viewport, scissor,
     * and blend constant.
     */
    class Desc : public GrProgramDesc {
    public:
        static bool Build(Desc*,
                          const GrPrimitiveProcessor&,
                          const GrPipeline&,
                          const GrStencilSettings&,
                          GrPrimitiveType primitiveType,
                          const GrShaderCaps&);
    private:
        typedef GrProgramDesc INHERITED;
    };

    const Desc& getDesc() { return fDesc; }

private:
    typedef GrVkPipelineStateDataManager::UniformInfoArray UniformInfoArray;
    typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;

    GrVkPipelineState(GrVkGpu* gpu,
                      const GrVkPipelineState::Desc&,
                      GrVkPipeline* pipeline,
                      VkPipelineLayout layout,
                      const GrVkDescriptorSetManager::Handle& samplerDSHandle,
                      const BuiltinUniformHandles& builtinUniformHandles,
                      const UniformInfoArray& uniforms,
                      uint32_t vertexUniformSize,
                      uint32_t fragmentUniformSize,
                      uint32_t numSamplers,
                      GrGLSLPrimitiveProcessor* geometryProcessor,
                      GrGLSLXferProcessor* xferProcessor,
                      const GrGLSLFragProcs& fragmentProcessors);

    // Each pool will manage one type of descriptor. Thus each descriptor set we use will all be of
    // one VkDescriptorType.
    struct DescriptorPoolManager {
        DescriptorPoolManager(VkDescriptorSetLayout layout, VkDescriptorType type,
                              uint32_t descCount, GrVkGpu* gpu)
            : fDescLayout(layout)
            , fDescType(type)
            , fDescCountPerSet(descCount)
            , fCurrentDescriptorCount(0)
            , fPool(nullptr) {
            SkASSERT(descCount < kMaxDescLimit >> 2);
            fMaxDescriptors = fDescCountPerSet << 2;
            this->getNewPool(gpu);
        }

        ~DescriptorPoolManager() {
            SkASSERT(!fDescLayout);
            SkASSERT(!fPool);
        }

        void getNewDescriptorSet(GrVkGpu* gpu, VkDescriptorSet* ds);

        void freeGPUResources(const GrVkGpu* gpu);
        void abandonGPUResources();

        VkDescriptorSetLayout  fDescLayout;
        VkDescriptorType       fDescType;
        uint32_t               fDescCountPerSet;
        uint32_t               fMaxDescriptors;
        uint32_t               fCurrentDescriptorCount;
        GrVkDescriptorPool*    fPool;

    private:
        static const uint32_t kMaxDescLimit = 1 << 10;

        void getNewPool(GrVkGpu* gpu);
    };

    void writeUniformBuffers(const GrVkGpu* gpu);

    void writeSamplers(
            GrVkGpu* gpu,
            const SkTArray<const GrResourceIOProcessor::TextureSampler*>& textureBindings,
            bool allowSRGBInputs);

    /**
    * We use the RT's size and origin to adjust from Skia device space to vulkan normalized device
    * space and to make device space positions have the correct origin for processors that require
    * them.
    */
    struct RenderTargetState {
        SkISize         fRenderTargetSize;
        GrSurfaceOrigin fRenderTargetOrigin;

        RenderTargetState() { this->invalidate(); }
        void invalidate() {
            fRenderTargetSize.fWidth = -1;
            fRenderTargetSize.fHeight = -1;
            fRenderTargetOrigin = (GrSurfaceOrigin)-1;
        }

        /**
        * Gets a vec4 that adjusts the position from Skia device coords to Vulkans normalized device
        * coords. Assuming the transformed position, pos, is a homogeneous vec3, the vec, v, is
        * applied as such:
        * pos.x = dot(v.xy, pos.xz)
        * pos.y = dot(v.zw, pos.yz)
        */
        void getRTAdjustmentVec(float* destVec) {
            destVec[0] = 2.f / fRenderTargetSize.fWidth;
            destVec[1] = -1.f;
            if (kBottomLeft_GrSurfaceOrigin == fRenderTargetOrigin) {
                destVec[2] = -2.f / fRenderTargetSize.fHeight;
                destVec[3] = 1.f;
            } else {
                destVec[2] = 2.f / fRenderTargetSize.fHeight;
                destVec[3] = -1.f;
            }
        }
    };

    // Helper for setData() that sets the view matrix and loads the render target height uniform
    void setRenderTargetState(const GrRenderTarget*);

    // GrVkResources
    GrVkPipeline* fPipeline;

    // Used for binding DescriptorSets to the command buffer but does not need to survive during
    // command buffer execution. Thus this is not need to be a GrVkResource.
    VkPipelineLayout fPipelineLayout;

    // The DescriptorSets need to survive until the gpu has finished all draws that use them.
    // However, they will only be freed by the descriptor pool. Thus by simply keeping the
    // descriptor pool alive through the draw, the descritor sets will also stay alive. Thus we do
    // not need a GrVkResource versions of VkDescriptorSet. We hold on to these in the
    // GrVkPipelineState since we update the descriptor sets and bind them at separate times;
    VkDescriptorSet fDescriptorSets[2];

    // Once we move samplers over to use the resource provider for descriptor sets we will not need
    // the above array and instead just use GrVkDescriptorSet like the uniform one here.
    const GrVkDescriptorSet* fUniformDescriptorSet;
    const GrVkDescriptorSet* fSamplerDescriptorSet;

    const GrVkDescriptorSetManager::Handle fSamplerDSHandle;

    // Meta data so we know which descriptor sets we are using and need to bind.
    int fStartDS;
    int fDSCount;

    std::unique_ptr<GrVkUniformBuffer> fVertexUniformBuffer;
    std::unique_ptr<GrVkUniformBuffer> fFragmentUniformBuffer;

    // GrVkResources used for sampling textures
    SkTDArray<GrVkSampler*> fSamplers;
    SkTDArray<const GrVkImageView*> fTextureViews;
    SkTDArray<const GrVkResource*> fTextures;

    // Tracks the current render target uniforms stored in the vertex buffer.
    RenderTargetState fRenderTargetState;
    BuiltinUniformHandles fBuiltinUniformHandles;

    // Processors in the GrVkPipelineState
    std::unique_ptr<GrGLSLPrimitiveProcessor> fGeometryProcessor;
    std::unique_ptr<GrGLSLXferProcessor> fXferProcessor;
    GrGLSLFragProcs fFragmentProcessors;

    Desc fDesc;

    GrVkPipelineStateDataManager fDataManager;

    int fNumSamplers;

    friend class GrVkPipelineStateBuilder;
};

#endif