/*

 * 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 skgpu_graphite_BackendTexture_DEFINED

#define skgpu_graphite_BackendTexture_DEFINED

#include "include/core/SkRefCnt.h"

#include "include/core/SkSize.h"

#include "include/gpu/graphite/GraphiteTypes.h"

#include "include/gpu/graphite/TextureInfo.h"

#ifdef SK_DAWN

#include "include/gpu/graphite/dawn/DawnTypes.h"

#endif

#ifdef SK_METAL

#include "include/gpu/graphite/mtl/MtlGraphiteTypes.h"

#endif

#ifdef SK_VULKAN

#include "include/gpu/vk/VulkanTypes.h"

#include "include/private/gpu/vk/SkiaVulkan.h"

#endif

namespace skgpu {

class MutableTextureState;

}

namespace skgpu::graphite {

class SK_API BackendTexture {

public:

    BackendTexture();

#ifdef SK_DAWN

    // Create a BackendTexture from a WGPUTexture. Texture info will be queried from the texture.

    //

    // This is the recommended way of specifying a BackendTexture for Dawn. See the note below on

    // the constructor that takes a WGPUTextureView for a fuller explanation.

    //

    // The BackendTexture will not call retain or release on the passed in WGPUTexture. Thus, the

    // client must keep the WGPUTexture valid until they are no longer using the BackendTexture.

    // However, any SkImage or SkSurface that wraps the BackendTexture *will* retain and release

    // the WGPUTexture.

    BackendTexture(WGPUTexture texture);

    // Create a BackendTexture from a WGPUTexture. Texture planeDimensions, plane aspect and

    // info have to be provided. This is intended to be used only when accessing a plane

    // of a WGPUTexture.

    //

    // The BackendTexture will not call retain or release on the passed in WGPUTexture. Thus, the

    // client must keep the WGPUTexture valid until they are no longer using the BackendTexture.

    // However, any SkImage or SkSurface that wraps the BackendTexture *will* retain and release

    // the WGPUTexture.

    BackendTexture(SkISize planeDimensions, const DawnTextureInfo& info, WGPUTexture texture);

    // Create a BackendTexture from a WGPUTextureView. Texture dimensions and

    // info have to be provided.

    //

    // Using a WGPUTextureView rather than a WGPUTexture is less effecient for operations that

    // require buffer transfers to or from the texture (e.g. methods on graphite::Context that read

    // pixels or SkSurface::writePixels). In such cases an intermediate copy to or from a

    // WGPUTexture is required. Thus, it is recommended to use this functionality only for cases

    // where a WGPUTexture is unavailable, in particular when using wgpu::SwapChain.

    //

    // The BackendTexture will not call retain or release on the passed in WGPUTextureView. Thus,

    // the client must keep the WGPUTextureView valid until they are no longer using the

    // BackendTexture. However, any SkImage or SkSurface that wraps the BackendTexture *will* retain

    // and release the WGPUTextureView.

    BackendTexture(SkISize dimensions, const DawnTextureInfo& info, WGPUTextureView textureView);

#endif

#ifdef SK_METAL

    // The BackendTexture will not call retain or release on the passed in CFTypeRef. Thus the

    // client must keep the CFTypeRef valid until they are no longer using the BackendTexture.

    BackendTexture(SkISize dimensions, CFTypeRef mtlTexture);

#endif

#ifdef SK_VULKAN

    BackendTexture(SkISize dimensions,

                   const VulkanTextureInfo&,

                   VkImageLayout,

                   uint32_t queueFamilyIndex,

                   VkImage,

                   VulkanAlloc);

#endif

    BackendTexture(const BackendTexture&);

    ~BackendTexture();

    BackendTexture& operator=(const BackendTexture&);

    bool operator==(const BackendTexture&) const;

    bool operator!=(const BackendTexture& that) const { return !(*this == that); }

    bool isValid() const { return fInfo.isValid(); }

    BackendApi backend() const { return fInfo.backend(); }

    SkISize dimensions() const { return fDimensions; }

    const TextureInfo& info() const { return fInfo; }

    // If the client changes any of the mutable backend of the GrBackendTexture they should call

    // this function to inform Skia that those values have changed. The backend API specific state

    // that can be set from this function are:

    //

    // Vulkan: VkImageLayout and QueueFamilyIndex

    void setMutableState(const skgpu::MutableTextureState&);

#ifdef SK_DAWN

    WGPUTexture getDawnTexturePtr() const;

    WGPUTextureView getDawnTextureViewPtr() const;

#endif

#ifdef SK_METAL

    CFTypeRef getMtlTexture() const;

#endif

#ifdef SK_VULKAN

    VkImage getVkImage() const;

    VkImageLayout getVkImageLayout() const;

    uint32_t getVkQueueFamilyIndex() const;

    const VulkanAlloc* getMemoryAlloc() const;

#endif

private:

    friend class VulkanResourceProvider;    // for getMutableState

    sk_sp<MutableTextureState> getMutableState() const;

    SkISize fDimensions;

    TextureInfo fInfo;

    sk_sp<MutableTextureState> fMutableState;

#ifdef SK_VULKAN

    // fMemoryAlloc == VulkanAlloc() if the client has already created their own VkImage and

    // will destroy it themselves as opposed to having Skia create/destroy it via

    // Recorder::createBackendTexture and Context::deleteBackendTexture.

    VulkanAlloc fMemoryAlloc = VulkanAlloc();

#endif

    union {

#ifdef SK_DAWN

        struct {

            WGPUTexture fDawnTexture;

            WGPUTextureView fDawnTextureView;

        };

#endif

#ifdef SK_METAL

        CFTypeRef fMtlTexture;

#endif

#ifdef SK_VULKAN

        VkImage fVkImage = VK_NULL_HANDLE;

#endif

        void* fEnsureUnionNonEmpty;

    };

};

} // namespace skgpu::graphite

#endif // skgpu_graphite_BackendTexture_DEFINED