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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 1.0
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 compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
Basic support 9 12 4 11 12 5.1
Mobile
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support Yes 25 Yes Yes 12 8.1 Yes

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/vertexAttrib