This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The WebGL2RenderingContext.vertexAttribIPointer()
method of the WebGL 2 API specifies integer data formats and locations of vertex attributes in a vertex attributes array.
Syntax
void gl.vertexAttribIPointer(index, size, type, stride, offset);
Parameters
index
- A
GLuint
specifying the index of the vertex attribute that is to be modified. size
- A
GLint
specifying the number of components per vertex attribute. Must be 1, 2, 3, or 4. type
- A
GLenum
specifying the data type of each component in the array. Must be one of:gl.BYTE
,gl.UNSIGNED_BYTE
,gl.SHORT
,gl.UNSIGNED_SHORT
,gl.INT
, orgl.UNSIGNED_INT
. stride
- A
GLsizei
specifying the offset in bytes between the beginning of consecutive vertex attributes. offset
- A
GLintptr
specifying an offset in bytes of the first component in the vertex attribute array. Must be a multiple oftype
.
Return value
None.
Description
Very similar to WebGLRenderingContext.vertexAttribPointer()
. The main difference is that while values specified by vertexAttribPointer
are always interpreted as floating-point values in the shader (even if they were originally specified as integers in the buffer), this method allows specifying values which are interpreted as integers in the shader.
Examples
Linear Blend Skinning
//Describe the layout of the buffer: //1. position gl.vertexAttribPointer(0, 3, gl.FLOAT, false, 20, 0); gl.enableVertexAttribArray(0); //2. bone weights, normalized to [0, 1] gl.vertexAttribPointer(1, 4, gl.UNSIGNED_BYTE, true, 20, 12); gl.enableVertexAttribArray(1); //3. bone indices, interpreted as integer gl.vertexAttribIPointer(2, 4, gl.UNSIGNED_BYTE, 20, 16); gl.enableVertexAttribArray(2); //Connect to attributes from the vertex shader gl.bindAttribLocation(shaderProgram, 0, "position"); gl.bindAttribLocation(shaderProgram, 1, "boneWeights"); gl.bindAttribLocation(shaderProgram, 2, "boneIndices");
<script id="shader-vs" type="x-shader/x-vertex">#version 300 es uniform mat4 mvMatrix; uniform mat4 bones[120]; in vec3 position; in vec4 boneWeights; in uvec4 boneIndices;//read as 4-component unsigned integer void main() { vec4 skinnedPosition = bones[boneIndices.s] * vec4(position, 1.0) * boneWeights.s + bones[boneIndices.t] * vec4(position, 1.0) * boneWeights.t + bones[boneIndices.p] * vec4(position, 1.0) * boneWeights.p + bones[boneIndices.q] * vec4(position, 1.0) * boneWeights.q; gl_Position = mvMatrix * skinnedPosition; } </script>
Specifications
Specification | Status | Comment |
---|---|---|
WebGL 2.0 The definition of 'vertexAttribIPointer' in that specification. |
Editor's Draft | Initial definition for WebGL. |
OpenGL ES 3.0 The definition of 'glVertexAttribPointer' in that specification. |
Standard | Man page of the (similar) 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 | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
vertexAttribIPointer | Chrome Full support 56 | Edge Full support 79 | Firefox Full support 51 | IE No support No | Opera Full support 43 | Safari No support No | WebView Android Full support 58 | Chrome Android Full support 58 | Firefox Android Full support 51 | Opera Android Full support 43 | Safari iOS No support No | Samsung Internet Android Full support 7.0 |
Legend
- Full support
- Full support
- No support
- No support