WebGL2RenderingContext.getActiveUniformBlockParameter()

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 WebGLProgram containing the active uniform block.
uniformBlockIndex
A GLuint specifying the index of the active uniform block within the program.
pname
A GLenum specifying which information to query. Possible values:
  • gl.UNIFORM_BLOCK_BINDING: Returns a GLuint indicating the uniform buffer binding point.
  • gl.UNIFORM_BLOCK_DATA_SIZE: Returns a GLuint indicating the minimum total buffer object size.
  • gl.UNIFORM_BLOCK_ACTIVE_UNIFORMS: Returns a GLuint indicating the number of active uniforms in the uniform block.
  • gl.UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES: Returns a Uint32Array indicating the list of active uniforms in the uniform block.
  • gl.UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER: Returns a GLboolean indicating whether the uniform block is referenced by the vertex shader.
  • gl.UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER: Returns a GLboolean indicating 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 Edge Firefox Internet Explorer Opera Safari Servo
Basic SupportNo support1No support51.0No supportNo supportNo supportNo support
Feature Android Chrome for Android Edge Mobile Firefox for Android IE Mobile Opera Mobile Safari Mobile
Basic SupportNo supportNo supportNo supportNo supportNo supportNo supportNo support

1. To use an experimental implementation of WebGL 2 in Chrome, you have to start Chrome with the runtime flag --enable-unsafe-es3-apis.

See also

Document Tags and Contributors

 Contributors to this page: teoli, fscholz
 Last updated by: teoli,