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# docs.GL

OpenGL 4
OpenGL 3
OpenGL 2
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# glCreateShader

## Name

glCreateShader — Creates a shader object

## C Specification

`GLuint glCreateShader(` | GLenum | shaderType`)`;

## Parameters

`shaderType`

  Specifies the type of shader to be created. Must be either `GL_VERTEX_SHADER` or `GL_FRAGMENT_SHADER`.

## Description

`glCreateShader` creates an empty shader object and returns a non-zero value by which it can be referenced. A shader object is used to maintain the source code strings that define a shader. `shaderType` indicates the type of shader to be created. Two types of shaders are supported. A shader of type `GL_VERTEX_SHADER` is a shader that is intended to run on the programmable vertex processor and replace the fixed functionality vertex processing in OpenGL. A shader of type `GL_FRAGMENT_SHADER` is a shader that is intended to run on the programmable fragment processor and replace the fixed functionality fragment processing in OpenGL.

When created, a shader object's `GL_SHADER_TYPE` parameter is set to either `GL_VERTEX_SHADER` or `GL_FRAGMENT_SHADER`, depending on the value of `shaderType`.

## Notes

`glCreateShader` is available only if the GL version is 2.0 or greater.

Like display lists and texture objects, the name space for shader objects may be shared across a set of contexts, as long as the server sides of the contexts share the same address space. If the name space is shared across contexts, any attached objects and the data associated with those attached objects are shared as well.

Applications are responsible for providing the synchronization across API calls when objects are accessed from different execution threads.

## Errors

This function returns 0 if an error occurs creating the shader object.

`GL_INVALID_ENUM` is generated if `shaderType` is not an accepted value.

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

## Associated Gets

glGetShader with a valid shader object and the parameter to be queried

glGetShaderInfoLog with a valid shader object

glGetShaderSource with a valid shader object

glIsShader

## Examples

Compile a program from a vertex shader and a fragment shader.

    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

glAttachShader, glCompileShader, glDeleteShader, glDetachShader, glShaderSource

## Copyright

Copyright © 2003-2005 3Dlabs Inc. Ltd. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. https://opencontent.org/openpub/.

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