shader_data_type.hpp

Go to the documentation of this file.

 
#pragma once
 
#include "gl_functions.hpp"
 
#include <cstddef>
#include <cstdint>
#include <exception>
 
#ifdef STAPLEGL_DEBUG
#include <cstdio>
#endif // STAPLEGL_DEBUG
 
namespace staplegl::shader_data_type {
 
enum class shader_array_type : std::uint8_t {
    float32_arr,
    vec2_arr,
    vec3_arr,
    vec4_arr,
    mat3_arr,
    mat4_arr,
};
 
enum class u_type : std::uint8_t {
    
    float32,
    vec2,
    vec3,
    vec4,
    mat3,
    mat4,
};
 
constexpr static auto size(u_type type) -> std::size_t
{
    switch (type) {
    case u_type::float32:
        return sizeof(float);
    case u_type::vec2:
        return sizeof(float) * 2;
    case u_type::vec3:
        return sizeof(float) * 3;
    case u_type::vec4:
        return sizeof(float) * 4;
    case u_type::mat3: // internally padded to use 3 vec4s
        return size(u_type::vec4) * 3;
    case u_type::mat4:
        return size(u_type::vec4) * 4;
    default:
#ifdef STAPLEGL_DEBUG
        std::fprintf(stderr, STAPLEGL_LINEINFO ", invalid shader enum %d\n",
            static_cast<int>(type));
#endif // STAPLEGL_DEBUG
        std::terminate();
    }
}
 
constexpr static auto to_opengl_type(u_type type) -> std::uint32_t
{
    switch (type) {
    case u_type::vec2:
        return GL_FLOAT_VEC2;
    case u_type::vec3:
        return GL_FLOAT_VEC3;
    case u_type::vec4:
        return GL_FLOAT_VEC4;
    case u_type::mat3:
        return GL_FLOAT_MAT3;
    case u_type::mat4:
        return GL_FLOAT_MAT4;
    case u_type::float32:
        return GL_FLOAT;
    default:
 
#ifdef STAPLEGL_DEBUG
        std::fprintf(stderr, STAPLEGL_LINEINFO ", invalid shader enum %d\n",
            static_cast<int>(type));
#endif // STAPLEGL_DEBUG
        std::terminate();
    }
}
 
constexpr static auto to_opengl_underlying_type(u_type type) -> std::uint32_t
{
    switch (type) {
    case u_type::vec2:
    case u_type::vec3:
    case u_type::vec4:
    case u_type::mat3:
    case u_type::mat4:
    case u_type::float32:
        return GL_FLOAT;
    default:
#ifdef STAPLEGL_DEBUG
        std::fprintf(stderr, STAPLEGL_LINEINFO ", invalid shader enum %d\n",
            static_cast<int>(type));
#endif // STAPLEGL_DEBUG
        std::terminate();
    }
}
 
constexpr static auto component_count(u_type type) -> std::uint16_t
{
    switch (type) {
    case u_type::vec2:
        return 2;
    case u_type::vec3:
        return 3;
    case u_type::vec4:
        return 4;
    case u_type::mat3:
        return 12;
    case u_type::mat4:
        return 16;
    case u_type::float32:
        return 1;
    default:
#ifdef STAPLEGL_DEBUG
        std::fprintf(stderr, STAPLEGL_LINEINFO ", invalid shader enum %d\n",
            static_cast<int>(type));
#endif // STAPLEGL_DEBUG
        std::terminate();
    }
}
};