Common Techniques for Defining Shader Code

Introducing three common techniques.

1. Using Variadic Macros

#define VERTEX_SHADER(...) "#version 300 es\n" #__VA_ARGS__
#define FRAGMENT_SHADER(...) "#version 300 es\n" #__VA_ARGS__
 
// Triangle Shader
const char* TriangleVertexShader = VERTEX_SHADER(
       layout(location = 0) in vec4 vPosition;
       void main() {
           gl_Position = vPosition;
       }
);
 
const char* TriangleFragmentShader = FRAGMENT_SHADER(
     precision mediump float;
     out vec4 FragColor;
     void main() {
         FragColor = vec4(0.0, 1.0, 0.0, 1.0);
     }
);

2. Using Raw String Literal

const char* vertexShaderSource = R"(    #version 330 core    layout(location = 0) in vec3 aPos;    void main() {        gl_Position = vec4(aPos, 1.0);    })";
    #version 330 core
    layout(location = 0) in vec3 aPos;
    void main() {
        gl_Position = vec4(aPos, 1.0);
    }
)"

3. Shader Files

vertexShader.glsl

#version 330 core
layout(location = 0) in vec3 aPos;
void main() {
    gl_Position = vec4(aPos, 1.0);
}

Read file in C++:

std::ifstream file("vertexShader.glsl");
std::stringstream buffer;
buffer << file.rdbuf();
std::string vertexShaderSource = buffer.str();