Example/GLSL Full Compile Linking

Full compile/link of a Vertex and Fragment Shader.

// Read our shaders into the appropriate buffers
std::string vertexSource = // Get source code for vertex shader.
std::string fragmentSource = // Get source code for fragment shader.

// Create an empty vertex shader handle
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);

// Send the vertex shader source code to GL
// Note that std::string's .c_str is NULL character terminated.
const GLchar *source = (const GLchar *)vertexSource.c_str();
glShaderSource(vertexShader, 1, &source, 0);

// Compile the vertex shader
glCompileShader(vertexShader);

GLint isCompiled = 0;
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled);
if(isCompiled == GL_FALSE)
{
	GLint maxLength = 0;
	glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);

	// The maxLength includes the NULL character
	std::vector<GLchar> infoLog(maxLength);
	glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &infoLog[0]);
	
	// We don't need the shader anymore.
	glDeleteShader(vertexShader);

	// Use the infoLog as you see fit.
	
	// In this simple program, we'll just leave
	return;
}

// Create an empty fragment shader handle
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

// Send the fragment shader source code to GL
// Note that std::string's .c_str is NULL character terminated.
source = (const GLchar *)fragmentSource.c_str();
glShaderSource(fragmentShader, 1, &source, 0);

// Compile the fragment shader
glCompileShader(fragmentShader);

glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &isCompiled);
if (isCompiled == GL_FALSE)
{
	GLint maxLength = 0;
	glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength);

	// The maxLength includes the NULL character
	std::vector<GLchar> infoLog(maxLength);
	glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, &infoLog[0]);
	
	// We don't need the shader anymore.
	glDeleteShader(fragmentShader);
	// Either of them. Don't leak shaders.
	glDeleteShader(vertexShader);

	// Use the infoLog as you see fit.
	
	// In this simple program, we'll just leave
	return;
}

// Vertex and fragment shaders are successfully compiled.
// Now time to link them together into a program.
// Get a program object.
GLuint program = glCreateProgram();

// Attach our shaders to our program
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);

// Link our program
glLinkProgram(program);

// Note the different functions here: glGetProgram* instead of glGetShader*.
GLint isLinked = 0;
glGetProgramiv(program, GL_LINK_STATUS, (int *)&isLinked);
if (isLinked == GL_FALSE)
{
	GLint maxLength = 0;
	glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);

	// The maxLength includes the NULL character
	std::vector<GLchar> infoLog(maxLength);
	glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]);
	
	// We don't need the program anymore.
	glDeleteProgram(program);
	// Don't leak shaders either.
	glDeleteShader(vertexShader);
	glDeleteShader(fragmentShader);

	// Use the infoLog as you see fit.
	
	// In this simple program, we'll just leave
	return;
}

// Always detach shaders after a successful link.
glDetachShader(program, vertexShader);
glDetachShader(program, fragmentShader);