Web/API/WebGLRenderingContext/vertexAttrib

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

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`vertexAttrib1f`	Chrome Full support 9	Edge Full support 12	Firefox Full support 4	IE Full support 11	Opera Full support 12	Safari Full support 5.1	WebView Android Full support Yes	Chrome Android Full support 25	Firefox Android Full support Yes	Opera Android Full support 12	Safari iOS Full support 8	Samsung Internet Android Full support 1.5

Legend

Full support: Full support