This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The WebGL2RenderingContext.getActiveUniformBlockParameter() method of the WebGL 2 API retrieves information about an active uniform block within a WebGLProgram.
Syntax
any gl.getActiveUniformBlockParameter(program, uniformBlockIndex, pname);
Parameters
program- A
WebGLProgramcontaining the active uniform block. uniformBlockIndex- A
GLuintspecifying the index of the active uniform block within the program. pname- A
GLenumspecifying which information to query. Possible values:gl.UNIFORM_BLOCK_BINDING: Returns aGLuintindicating the uniform buffer binding point.gl.UNIFORM_BLOCK_DATA_SIZE: Returns aGLuintindicating the minimum total buffer object size.gl.UNIFORM_BLOCK_ACTIVE_UNIFORMS: Returns aGLuintindicating the number of active uniforms in the uniform block.gl.UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES: Returns aUint32Arrayindicating the list of active uniforms in the uniform block.gl.UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER: Returns aGLbooleanindicating whether the uniform block is referenced by the vertex shader.gl.UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER: Returns aGLbooleanindicating whether the uniform block is referenced by the fragment shader.
Return value
Depends on which information is requested using the pname parameter. If an error occurs, null is returned.
Examples
var blockSize = gl.getActiveUniformBlockParameter(program,
blockIndex, gl.UNIFORM_BLOCK_DATA_SIZE);
Specifications
| Specification | Status | Comment |
|---|---|---|
| WebGL 2.0 The definition of 'getActiveUniformBlockParameter' in that specification. |
Editor's Draft | Initial definition for WebGL. |
| OpenGL ES 3.0 The definition of 'glGetActiveUniformBlockiv' in that specification. |
Standard | Man page of the (similar) OpenGL API. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | No support [2] | Nightly build [1] | No support | No support | No support |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | No support | No support | No support | No support | No support | No support |
[1] WebGL 2 is enabled by default in Firefox Nightly. To enable it in a release version of Firefox, set the preference webgl.enable-prototype-webgl2 to true in about:config.
[2] To use an experimental implementation of WebGL 2 in Chrome, you have to start Chrome with the runtime flag --enable-unsafe-es3-apis.