Example/GLSL Full Compile Linking: Difference between revisions

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Line 17: Line 17:
glCompileShader(vertexShader);
glCompileShader(vertexShader);


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


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


// Use the infoLog as you see fit.
// In this simple program, we'll just leave
// In this simple program, we'll just leave
return;
return;
Line 49: Line 49:


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


// The maxLength includes the NULL character
// The maxLength includes the NULL character
GLchar infoLog[maxLength];
std::vector<GLchar> infoLog(maxLength);
glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, infoLog);
glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, &infoLog[0]);
// Use infoLog as you see fit.
// We don't need the shader anymore.
// We don't need the shader anymore.
glDeleteShader(fragmentShader);
glDeleteShader(fragmentShader);
// Either of them. Don't leak shaders.
// Either of them. Don't leak shaders.
glDeleteShader(vertexShader);
glDeleteShader(vertexShader);
// Use the infoLog as you see fit.
// In this simple program, we'll just leave
// In this simple program, we'll just leave
Line 82: Line 82:


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


// The maxLength includes the NULL character
// The maxLength includes the NULL character
GLchar infoLog[maxLength];
std::vector<GLchar> infoLog(maxLength);
glGetProgramInfoLog(program, maxLength, &maxLength, infoLog);
glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]);
 
// Use the infoLog as you see fit.
 
// We don't need the program anymore.
// We don't need the program anymore.
glDeleteProgram(program);
glDeleteProgram(program);
Line 101: Line 99:
glDeleteShader(fragmentShader);
glDeleteShader(fragmentShader);


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

Latest revision as of 11:11, 3 January 2018

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);