shader.hpp

#ifndef LIBSBX_GRAPHICS_PIPELINE_SHADER_HPP_
#define LIBSBX_GRAPHICS_PIPELINE_SHADER_HPP_
 
#include <filesystem>
#include <map>
#include <unordered_map>
#include <optional>
 
#include <spirv_cross/spirv_cross.hpp>
 
#include <vulkan/vulkan.hpp>
 
#include <libsbx/utility/noncopyable.hpp>
 
namespace sbx::graphics {
 
class shader : public utility::noncopyable {
 
public:
 
  enum class data_type : std::uint8_t {
    unknown,
    boolean,
    int32,
    uint32,
    float32,
    vec2,
    ivec2,
    uvec2,
    vec3,
    ivec3,
    uvec3,
    vec4,
    ivec4,
    uvec4,
    mat2,
    imat2,
    umat2,
    mat3,
    imat3,
    umat3,
    mat4,
    imat4,
    umat4,
    sampler2d,
    sampler2d_array,
    separate_sampler,
    separate_image2d,
    separate_image2d_array,
    storage_image,
    subpass_input,
    structure
  }; // enum class data_type
 
  class uniform {
 
  public:
 
    explicit uniform(std::uint32_t binding, std::uint32_t offset, std::uint32_t size, data_type type, bool is_readonly, bool is_writeonly, VkShaderStageFlags stage_flags)
    : _binding{binding},
      _offset{offset},
      _size{size},
      _type{type},
      _is_readonly{is_readonly},
      _is_writeonly{is_writeonly},
      _stage_flags{stage_flags} { }
 
    auto binding() const noexcept -> std::uint32_t {
      return _binding;
    }
 
    auto offset() const noexcept -> std::uint32_t {
      return _offset;
    }
 
    auto size() const noexcept -> std::uint32_t {
      return _size;
    }
 
    auto type() const noexcept -> data_type {
      return _type;
    }
 
    auto is_readonly() const noexcept -> bool {
      return _is_readonly;
    }
 
    auto is_writeonly() const noexcept -> bool {
      return _is_writeonly;
    }
 
    auto stage_flags() const noexcept -> VkShaderStageFlags {
      return _stage_flags;
    }
 
    auto add_stage_flag(VkShaderStageFlags stage) noexcept -> void {
      _stage_flags |= stage;
    }
 
    auto operator==(const uniform& other) const noexcept -> bool {
      return _binding == other._binding && _offset == other._offset && _size == other._size && _type == other._type && _is_readonly == other._is_readonly && _is_writeonly == other._is_writeonly && _stage_flags == other._stage_flags;
    }
 
  private:
 
    std::uint32_t _binding{};
    std::uint32_t _offset{};
    std::uint32_t _size{};
    data_type _type{};
    bool _is_readonly{};
    bool _is_writeonly{};
    VkShaderStageFlags _stage_flags{};
 
  }; // class uniform
 
class uniform_block {
 
  public:
 
    enum class type : std::uint8_t {
      uniform,
      storage,
      push
    }; // enum class type
 
    explicit uniform_block(std::uint32_t binding, std::uint32_t size, VkShaderStageFlags stage_flags, type type, std::map<std::string, uniform> uniforms = {})
    : _binding{binding},
      _size{size},
      _stage_flags{stage_flags},
      _type{type},
      _uniforms{std::move(uniforms)} { }
 
    auto binding() const noexcept -> std::uint32_t {
      return _binding;
    }
 
    auto size() const noexcept -> std::uint32_t {
      return _size;
    }
 
    auto stage_flags() const noexcept -> VkShaderStageFlags {
      return _stage_flags;
    }
 
    auto add_stage_flag(VkShaderStageFlags stage) noexcept -> void {
      _stage_flags |= stage;
    }
 
    auto buffer_type() const noexcept -> type {
      return _type;
    }
 
    auto uniforms() const noexcept -> const std::map<std::string, uniform>& {
      return _uniforms;
    }
 
    auto find_uniform(const std::string& name) const noexcept -> std::optional<uniform> {
      if (auto entry = _uniforms.find(name); entry != _uniforms.end()) {
        return entry->second;
      }
 
      return std::nullopt;
    }
 
    auto operator==(const uniform_block& other) const noexcept -> bool {
      return _binding == other._binding && _size == other._size && _stage_flags == other._stage_flags && _type == other._type && _uniforms == other._uniforms;
    }
 
  private:
 
    std::uint32_t _binding{};
    std::uint32_t _size{};
    VkShaderStageFlags _stage_flags{};
    type _type{};
    std::map<std::string, uniform> _uniforms{};
 
  }; // class uniform_block
 
  class attribute {
 
  public:
 
    explicit attribute(std::uint32_t binding, std::uint32_t size, VkShaderStageFlags stage_flags, data_type type)
    : _binding{binding},
      _size{size},
      _stage_flags{stage_flags},
      _type{type} { }
 
    auto binding() const noexcept -> std::uint32_t {
      return _binding;
    }
 
    auto size() const noexcept -> std::uint32_t {
      return _size;
    }
 
    auto stage_flags() const noexcept -> VkShaderStageFlags {
      return _stage_flags;
    }
 
    auto type() const noexcept -> data_type {
      return _type;
    }
 
    auto operator==(const attribute& other) const noexcept -> bool {
      return _binding == other._binding && _size == other._size && _stage_flags == other._stage_flags && _type == other._type;
    }
 
  private:
 
    std::uint32_t _binding{};
    std::uint32_t _size{};
    VkShaderStageFlags _stage_flags{};
    data_type _type{};
 
  }; // class attribute
 
  struct define {
    std::string name{};
    std::string value{};
  }; // struct define
 
  shader(const std::filesystem::path& path, VkShaderStageFlagBits stage, const std::vector<define>& defines = {});
 
  ~shader();
 
  auto handle() const noexcept -> const VkShaderModule&;
 
  operator const VkShaderModule&() const noexcept;
 
  auto stage() const noexcept -> VkShaderStageFlagBits;
 
  auto uniforms() const noexcept -> const std::map<std::string, uniform>& {
    return _uniforms;
  }
 
  auto uniform_blocks() const noexcept -> const std::map<std::string, uniform_block>& {
    return _uniform_blocks;
  }
 
private:
 
  auto _create_reflection(const spirv_cross::Compiler& compiler) -> void;
 
  auto _get_data_type(const spirv_cross::SPIRType& type) -> data_type;
 
  auto _data_type_to_string(data_type type) -> std::string;
 
  std::map<std::string, uniform> _uniforms{};
  std::map<std::string, uniform_block> _uniform_blocks{};
 
  VkShaderStageFlagBits _stage{};
  VkShaderModule _handle{};
 
}; // class shader
 
} // namespace sbx::graphics
 
#endif // LIBSBX_GRAPHICS_PIPELINE_SHADER_HPP_