surface_shader.h

#ifndef OE_RENDER_SURFACE_SHADER_H
#define OE_RENDER_SURFACE_SHADER_H
 
#include <string>
#include <glm/mat4x4.hpp>
 
#include "shader_base.h"
 
namespace oe::render
{
    struct SurfaceShader : public ShaderBase
    {
        SurfaceShader(const std::string& source_code, const std::string& name = "");

        void setDepthFunctionName(const std::string& name)
        {
            define("SHADER_DEPTH_ENTRYPOINT", name);
        }
    };
 
    static constexpr const char* surface_shader_headers = R"(
    // Input surface option
    struct SurfaceInput
    {
        vec2 tex_coords_0;
        vec2 tex_coords_1;
        vec3 color;
    };
 
    // Result surface option
    struct SurfaceOutput
    {
        vec4 albedo;
        vec3 emissive;
        vec3 normal;
 
        float roughness;
        float metalness;
        float ao;
 
        // These following 3 are only for refractive surfaces
        float ior;
        float transmission;
        float thickness;
 
        bool use_pbr;
    };
 
    #define RENDER_PASS_DEPTH 1
    #define RENDER_PASS_FORWARD 2
    #define RENDER_PASS_DEFERRED 3
 
    #define GEOMETRY_PASS_SOLID 1
    #define GEOMETRY_PASS_SKINNED 2
 
    // Read a normal texture and extract a normal
    vec3 OE_UNPACK_NORMAL_MAP(sampler2D TEX, vec2 TEX_COORDS);
 
    // Convert color stored into sRGB into linear
    vec3 OE_CONVERT_SRGB_TO_LINEAR(vec3 X);
 
    // Surface shaders should implement this function
    void surface(in SurfaceInput surface_input, inout SurfaceOutput result);
    )";
}
 
#endif