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
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.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
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