skia2/include/gpu/vk/GrVkBackendContext.h

/*
 * 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 GrVkBackendContext_DEFINED
#define GrVkBackendContext_DEFINED

#include "SkRefCnt.h"

#include "vk/GrVkDefines.h"

#ifdef SK_DEBUG
#define ENABLE_VK_LAYERS
#endif

struct GrVkInterface;

enum GrVkExtensionFlags {
    kEXT_debug_report_GrVkExtensionFlag    = 0x0001,
    kNV_glsl_shader_GrVkExtensionFlag      = 0x0002,
    kKHR_surface_GrVkExtensionFlag         = 0x0004,
    kKHR_swapchain_GrVkExtensionFlag       = 0x0008,
    kKHR_win32_surface_GrVkExtensionFlag   = 0x0010,
    kKHR_android_surface_GrVkExtensionFlag = 0x0020,
    kKHR_xcb_surface_GrVkExtensionFlag     = 0x0040,
};

enum GrVkFeatureFlags {
    kGeometryShader_GrVkFeatureFlag    = 0x0001,
    kDualSrcBlend_GrVkFeatureFlag      = 0x0002,
    kSampleRateShading_GrVkFeatureFlag = 0x0004,
};

// The BackendContext contains all of the base Vulkan objects needed by the GrVkGpu. The assumption
// is that the client will set these up and pass them to the GrVkGpu constructor. The VkDevice
// created must support at least one graphics queue, which is passed in as well. 
// The QueueFamilyIndex must match the family of the given queue. It is needed for CommandPool 
// creation, and any GrBackendObjects handed to us (e.g., for wrapped textures) need to be created
// in or transitioned to that family.
struct GrVkBackendContext : public SkRefCnt {
    VkInstance                        fInstance;
    VkPhysicalDevice                  fPhysicalDevice;
    VkDevice                          fDevice;
    VkQueue                           fQueue;
    uint32_t                          fGraphicsQueueIndex;
    uint32_t                          fMinAPIVersion;
    uint32_t                          fExtensions;
    uint32_t                          fFeatures;
    SkAutoTUnref<const GrVkInterface> fInterface;

    using CanPresentFn = std::function<bool(VkInstance, VkPhysicalDevice,
                                            uint32_t queueFamilyIndex)>;

    // Helper function to create the default Vulkan objects needed by the GrVkGpu object
    // If presentQueueIndex is non-NULL, will try to set up presentQueue as part of device
    // creation using the platform-specific canPresent() function.
    static const GrVkBackendContext* Create(uint32_t* presentQueueIndex = nullptr,
                                            CanPresentFn = CanPresentFn());

    ~GrVkBackendContext() override;
};

#endif