Parameters

Description

glShaderSource sets the source code in shader to the source code in the array of strings specified by string. Any source code previously stored in the shader object is completely replaced. The number of strings in the array is specified by count. If length is NULL, each string is assumed to be null terminated. If length is a value other than NULL, it points to an array containing a string length for each of the corresponding elements of string. Each element in the length array may contain the length of the corresponding string (the null character is not counted as part of the string length) or a value less than 0 to indicate that the string is null terminated. The source code strings are not scanned or parsed at this time; they are simply copied into the specified shader object.

Notes

glShaderSource is available only if the GL version is 2.0 or greater.

OpenGL copies the shader source code strings when glShaderSource is called, so an application may free its copy of the source code strings immediately after the function returns.

Errors

GL_INVALID_VALUE is generated if shader is not a value generated by OpenGL.

GL_INVALID_OPERATION is generated if shader is not a shader object.

GL_INVALID_VALUE is generated if count is less than 0.

GL_INVALID_OPERATION is generated if glShaderSource is executed between the execution of glBegin and the corresponding execution of glEnd.

Associated Gets

glGetShader with arguments shader and GL_SHADER_SOURCE_LENGTH

glGetShaderSource with argument shader

glIsShader

Examples

GLuint vshader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vshader, 1, &vertex_shader_source, NULL); // vertex_shader_source is a GLchar* containing glsl shader source code
glCompileShader(vshader);

GLint vertex_compiled;
glGetShaderiv(vshader, GL_COMPILE_STATUS, &vertex_compiled);
if (vertex_compiled != GL_TRUE)
{
    GLsizei log_length = 0;
    GLchar message[1024];
    glGetShaderInfoLog(vshader, 1024, &log_length, message);
    // Write the error to a log
}

GLuint fshader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fshader, 1, &fragment_shader_source, NULL); // fragment_shader_source is a GLchar* containing glsl shader source code
glCompileShader(fshader);

GLint fragment_compiled;
glGetShaderiv(fshader, GL_COMPILE_STATUS, &fragment_compiled);
if (fragment_compiled != GL_TRUE)
{
    GLsizei log_length = 0;
    GLchar message[1024];
    glGetShaderInfoLog(fshader, 1024, &log_length, message);
    // Write the error to a log
}

GLuint program = glCreateProgram();

// This step is unnecessary if you use the location specifier in your shader
// e.g. layout (location = 0) in vec3 position;
glBindAttribLocation(program, 0, "position"); // The index passed into glBindAttribLocation is
glBindAttribLocation(program, 1, "texcoord"); // used by glEnableVertexAttribArray. "position"
glBindAttribLocation(program, 2, "normal");   // "texcoord" "normal" and "color" are the names of the
glBindAttribLocation(program, 3, "color");    // respective inputs in your fragment shader.

glAttachShader(program, vshader);
glAttachShader(program, fshader);
glLinkProgram(program);

GLint program_linked;
glGetProgramiv(program, GL_LINK_STATUS, &program_linked);
if (program_linked != GL_TRUE)
{
    GLsizei log_length = 0;
    GLchar message[1024];
    glGetProgramInfoLog(program, 1024, &log_length, message);
    // Write the error to a log
}

Tutorials

open.gl - The Graphics Pipeline

See Also

glCompileShader, glCreateShader, glDeleteShader