dolphin/Source/Core/VideoBackends/Vulkan/Constants.h

// Copyright 2016 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#pragma once

#include "Common/BitField.h"
#include "VideoBackends/Vulkan/VulkanLoader.h"

namespace Vulkan
{
// Number of command buffers. Having two allows one buffer to be
// executed whilst another is being built.
constexpr size_t NUM_COMMAND_BUFFERS = 2;

// Staging buffer usage - optimize for uploads or readbacks
enum STAGING_BUFFER_TYPE
{
  STAGING_BUFFER_TYPE_UPLOAD,
  STAGING_BUFFER_TYPE_READBACK
};

// Descriptor sets
enum DESCRIPTOR_SET
{
  DESCRIPTOR_SET_UNIFORM_BUFFERS,
  DESCRIPTOR_SET_PIXEL_SHADER_SAMPLERS,
  DESCRIPTOR_SET_SHADER_STORAGE_BUFFERS,
  NUM_DESCRIPTOR_SETS
};

// Uniform buffer bindings within the first descriptor set
enum UNIFORM_BUFFER_DESCRIPTOR_SET_BINDING
{
  UBO_DESCRIPTOR_SET_BINDING_PS,
  UBO_DESCRIPTOR_SET_BINDING_VS,
  UBO_DESCRIPTOR_SET_BINDING_GS,
  NUM_UBO_DESCRIPTOR_SET_BINDINGS
};

// Maximum number of attributes per vertex (we don't have any more than this?)
constexpr size_t MAX_VERTEX_ATTRIBUTES = 16;

// Number of pixel shader texture slots
constexpr size_t NUM_PIXEL_SHADER_SAMPLERS = 8;

// Total number of binding points in the pipeline layout
constexpr size_t TOTAL_PIPELINE_BINDING_POINTS =
    NUM_UBO_DESCRIPTOR_SET_BINDINGS + NUM_PIXEL_SHADER_SAMPLERS + 1;

// Format of EFB textures
constexpr VkFormat EFB_COLOR_TEXTURE_FORMAT = VK_FORMAT_R8G8B8A8_UNORM;
constexpr VkFormat EFB_DEPTH_TEXTURE_FORMAT = VK_FORMAT_D32_SFLOAT;
constexpr VkFormat EFB_DEPTH_AS_COLOR_TEXTURE_FORMAT = VK_FORMAT_R32_SFLOAT;

// Format of texturecache textures
constexpr VkFormat TEXTURECACHE_TEXTURE_FORMAT = VK_FORMAT_R8G8B8A8_UNORM;

// Textures that don't fit into this buffer will be uploaded with a separate buffer (see below).
constexpr size_t INITIAL_TEXTURE_UPLOAD_BUFFER_SIZE = 16 * 1024 * 1024;
constexpr size_t MAXIMUM_TEXTURE_UPLOAD_BUFFER_SIZE = 64 * 1024 * 1024;

// Textures greater than 1024*1024 will be put in staging textures that are released after
// execution instead. A 2048x2048 texture is 16MB, and we'd only fit four of these in our
// streaming buffer and be blocking frequently. Games are unlikely to have textures this
// large anyway, so it's only really an issue for HD texture packs, and memory is not
// a limiting factor in these scenarios anyway.
constexpr size_t STAGING_TEXTURE_UPLOAD_THRESHOLD = 1024 * 1024 * 4;

// Streaming uniform buffer size
constexpr size_t INITIAL_UNIFORM_STREAM_BUFFER_SIZE = 16 * 1024 * 1024;
constexpr size_t MAXIMUM_UNIFORM_STREAM_BUFFER_SIZE = 32 * 1024 * 1024;

// Push constant buffer size for utility shaders
constexpr u32 PUSH_CONSTANT_BUFFER_SIZE = 128;

// Rasterization state info
union RasterizationState {
  BitField<0, 2, VkCullModeFlags> cull_mode;
  BitField<2, 7, VkSampleCountFlagBits> samples;
  BitField<9, 1, VkBool32> per_sample_shading;
  BitField<10, 1, VkBool32> depth_clamp;

  u32 bits;
};

// Depth state info
union DepthStencilState {
  BitField<0, 1, VkBool32> test_enable;
  BitField<1, 1, VkBool32> write_enable;
  BitField<2, 3, VkCompareOp> compare_op;

  u32 bits;
};

// Blend state info
union BlendState {
  struct
  {
    union {
      BitField<0, 1, VkBool32> blend_enable;
      BitField<1, 3, VkBlendOp> blend_op;
      BitField<4, 5, VkBlendFactor> src_blend;
      BitField<9, 5, VkBlendFactor> dst_blend;
      BitField<14, 3, VkBlendOp> alpha_blend_op;
      BitField<17, 5, VkBlendFactor> src_alpha_blend;
      BitField<22, 5, VkBlendFactor> dst_alpha_blend;
      BitField<27, 4, VkColorComponentFlags> write_mask;
      u32 low_bits;
    };
    union {
      BitField<0, 1, VkBool32> logic_op_enable;
      BitField<1, 4, VkLogicOp> logic_op;
      u32 high_bits;
    };
  };

  u64 bits;
};

// Sampler info
union SamplerState {
  BitField<0, 1, VkFilter> min_filter;
  BitField<1, 1, VkFilter> mag_filter;
  BitField<2, 1, VkSamplerMipmapMode> mipmap_mode;
  BitField<3, 2, VkSamplerAddressMode> wrap_u;
  BitField<5, 2, VkSamplerAddressMode> wrap_v;
  BitField<7, 8, u32> min_lod;
  BitField<15, 8, u32> max_lod;
  BitField<23, 6, s32> lod_bias;    // tm0.lod_bias (8 bits) / 32 gives us 0-7.
  BitField<29, 3, u32> anisotropy;  // max_anisotropy = 1 << anisotropy, max of 16, so range 0-4.

  u32 bits;
};

}  // namespace Vulkan