WebGLRenderingContext.vertexAttrib[1234]f[v]()

The WebGLRenderingContext.vertexAttrib[1234]f[v]() methods of the WebGL API specify constant values for generic vertex attributes.

Syntax

void gl.vertexAttrib1f(index, v0);
void gl.vertexAttrib2f(index, v0, v1);
void gl.vertexAttrib3f(index, v0, v1, v2);
void gl.vertexAttrib4f(index, v0, v1, v2, v3);

void gl.vertexAttrib1fv(index, value);
void gl.vertexAttrib2fv(index, value);
void gl.vertexAttrib3fv(index, value);
void gl.vertexAttrib4fv(index, value);

Parameters

index
A GLuint specifying the position of the vertex attribute to be modified.
v0, v1, v2, v3
A floating point Number for the vertex attribute value.
value

A Float32Array for floating point vector vertex attribute values.

Return value

None.

Description

While vertex attributes are usually used to specify values which are different for each vertex (using vertexAttribPointer), it can be useful to specify a constant value. For example, if you have a shader which has a color vertex attribute, but you want to draw everything in a single color, you can use vertexAttrib to achieve that without creating a buffer filled with only one value or having to create a separate shader which uses a uniform for the color.

This value will be used if a bound array buffer has not been enabled with enableVertexAttribArray.

Attributes may be matrices, in which case columns of the matrix must be loaded into successive vertex attribute slots.

The values set with vertexAttribPointer are context-global, i.e. they aren't part of the shader state (like generix vertex attribute indexes to shader variable bindings) and aren't part of the vertex array object state (like enabled vertex attribute arrays). The only way to change the values is by calling this function again.

Examples

const a_foobar = gl.getAttribLocation(shaderProgram, 'foobar');
//either set each component individually:
gl.vertexAttrib3f(a_foobar, 10.0, 5.0, 2.0);
//or provide a Float32Array:
const floatArray = new Float32Array([10.0, 5.0, 2.0]);
gl.vertexAttrib3fv(a_foobar, floatArray);

 

// we want to load the following 3x3 matrix into attribute named "matrix3x3"
// 0 1 2
// 3 4 5
// 6 7 8
const matrix3x3Location = gl.getAttribLocation(shaderProgram, 'matrix3x3');
gl.vertexAttrib3f(matrix3x3Location,     0, 3, 6);
gl.vertexAttrib3f(matrix3x3Location + 1, 1, 4, 7);
gl.vertexAttrib3f(matrix3x3Location + 2, 2, 5, 8);

Specifications

Specification Status Comment
WebGL 1.0
The definition of 'vertexAttrib' in that specification.
Recommendation Initial definition.
OpenGL ES 2.0
The definition of 'glVertexAttrib' in that specification.
Standard Man page of the OpenGL API.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 9Edge Full support 12Firefox Full support 4IE Full support 11Opera Full support 12Safari Full support 5.1WebView Android Full support YesChrome Android Full support 25Edge Mobile Full support YesFirefox Android Full support YesOpera Android Full support 12Safari iOS Full support 8.1Samsung Internet Android Full support Yes

Legend

Full support  
Full support

See also

Document Tags and Contributors

Contributors to this page: aleonhard, Jedipedia, fscholz, teoli
Last updated by: aleonhard,