src/include/dawn_native/VulkanBackend.h

// Copyright 2018 The Dawn Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef DAWNNATIVE_VULKANBACKEND_H_
#define DAWNNATIVE_VULKANBACKEND_H_

#include <dawn/dawn_wsi.h>
#include <dawn_native/DawnNative.h>

#include <vulkan/vulkan.h>

#include <vector>

namespace dawn_native { namespace vulkan {

    DAWN_NATIVE_EXPORT VkInstance GetInstance(WGPUDevice device);

    DAWN_NATIVE_EXPORT PFN_vkVoidFunction GetInstanceProcAddr(WGPUDevice device, const char* pName);

    DAWN_NATIVE_EXPORT DawnSwapChainImplementation
    CreateNativeSwapChainImpl(WGPUDevice device, ::VkSurfaceKHR surface);
    DAWN_NATIVE_EXPORT WGPUTextureFormat
    GetNativeSwapChainPreferredFormat(const DawnSwapChainImplementation* swapChain);

    struct DAWN_NATIVE_EXPORT ExternalImageDescriptorVk : ExternalImageDescriptor {
      public:
        // The following members may be ignored if |ExternalImageDescriptor::isInitialized| is false
        // since the import does not need to preserve texture contents.

        // See https://www.khronos.org/registry/vulkan/specs/1.1/html/chap7.html. The acquire
        // operation old/new layouts must match exactly the layouts in the release operation. So
        // we may need to issue two barriers releasedOldLayout -> releasedNewLayout ->
        // cTextureDescriptor.usage if the new layout is not compatible with the desired usage.
        // The first barrier is the queue transfer, the second is the layout transition to our
        // desired usage.
        VkImageLayout releasedOldLayout = VK_IMAGE_LAYOUT_GENERAL;
        VkImageLayout releasedNewLayout = VK_IMAGE_LAYOUT_GENERAL;

      protected:
        using ExternalImageDescriptor::ExternalImageDescriptor;
    };

    struct ExternalImageExportInfoVk : ExternalImageExportInfo {
      public:
        // See comments in |ExternalImageDescriptorVk|
        // Contains the old/new layouts used in the queue release operation.
        VkImageLayout releasedOldLayout;
        VkImageLayout releasedNewLayout;

      protected:
        using ExternalImageExportInfo::ExternalImageExportInfo;
    };

// Can't use DAWN_PLATFORM_LINUX since header included in both Dawn and Chrome
#ifdef __linux__

        // Common properties of external images represented by FDs. On successful import the file
        // descriptor's ownership is transferred to the Dawn implementation and they shouldn't be
        // used outside of Dawn again. TODO(enga): Also transfer ownership in the error case so the
        // caller can assume the FD is always consumed.
        struct DAWN_NATIVE_EXPORT ExternalImageDescriptorFD : ExternalImageDescriptorVk {
          public:
            int memoryFD;  // A file descriptor from an export of the memory of the image
            std::vector<int> waitFDs;  // File descriptors of semaphores which will be waited on

          protected:
            using ExternalImageDescriptorVk::ExternalImageDescriptorVk;
        };

        // Descriptor for opaque file descriptor image import
        struct DAWN_NATIVE_EXPORT ExternalImageDescriptorOpaqueFD : ExternalImageDescriptorFD {
            ExternalImageDescriptorOpaqueFD();

            VkDeviceSize allocationSize;  // Must match VkMemoryAllocateInfo from image creation
            uint32_t memoryTypeIndex;     // Must match VkMemoryAllocateInfo from image creation
        };

        // Descriptor for dma-buf file descriptor image import
        struct DAWN_NATIVE_EXPORT ExternalImageDescriptorDmaBuf : ExternalImageDescriptorFD {
            ExternalImageDescriptorDmaBuf();

            uint32_t stride;       // Stride of the buffer in bytes
            uint64_t drmModifier;  // DRM modifier of the buffer
        };

        // Info struct that is written to in |ExportVulkanImage|.
        struct DAWN_NATIVE_EXPORT ExternalImageExportInfoFD : ExternalImageExportInfoVk {
          public:
            // Contains the exported semaphore handles.
            std::vector<int> semaphoreHandles;

          protected:
            using ExternalImageExportInfoVk::ExternalImageExportInfoVk;
        };

        struct DAWN_NATIVE_EXPORT ExternalImageExportInfoOpaqueFD : ExternalImageExportInfoFD {
            ExternalImageExportInfoOpaqueFD();
        };

        struct DAWN_NATIVE_EXPORT ExternalImageExportInfoDmaBuf : ExternalImageExportInfoFD {
            ExternalImageExportInfoDmaBuf();
        };

#endif  // __linux__

        // Exports a signal semaphore from a wrapped texture. This must be called on wrapped
        // textures before they are destroyed. On failure, returns -1
        // TODO(enga): Remove after updating Chromium to use ExportVulkanImage.
        DAWN_NATIVE_EXPORT int ExportSignalSemaphoreOpaqueFD(WGPUDevice cDevice,
                                                             WGPUTexture cTexture);

        // Imports external memory into a Vulkan image. Internally, this uses external memory /
        // semaphore extensions to import the image and wait on the provided synchronizaton
        // primitives before the texture can be used.
        // On failure, returns a nullptr.
        DAWN_NATIVE_EXPORT WGPUTexture WrapVulkanImage(WGPUDevice cDevice,
                                                       const ExternalImageDescriptorVk* descriptor);

        // Exports external memory from a Vulkan image. This must be called on wrapped textures
        // before they are destroyed. It writes the semaphore to wait on and the old/new image
        // layouts to |info|. Pass VK_IMAGE_LAYOUT_UNDEFINED as |desiredLayout| if you don't want to
        // perform a layout transition.
        DAWN_NATIVE_EXPORT bool ExportVulkanImage(WGPUTexture cTexture,
                                                  VkImageLayout desiredLayout,
                                                  ExternalImageExportInfoVk* info);

}}  // namespace dawn_native::vulkan

#endif  // DAWNNATIVE_VULKANBACKEND_H_