WebGL2RenderingContext: getActiveUniformBlockParameter() method

{{APIRef("WebGL")}}{{AvailableInWorkers}}

The WebGL2RenderingContext.getActiveUniformBlockParameter() method of the WebGL 2 API retrieves information about an active uniform block within a {{domxref("WebGLProgram")}}.

Syntax

getActiveUniformBlockParameter(program, uniformBlockIndex, pname)

Parameters

• program
  • : A {{domxref("WebGLProgram")}} containing the active uniform block.
• uniformBlockIndex
  • : A {{domxref("WebGL_API/Types", "GLuint")}} specifying the index of the active uniform block within the program.
• pname
  • : A {{domxref("WebGL_API/Types", "GLenum")}} specifying which information to query. Possible values:
    • gl.UNIFORM_BLOCK_BINDING
      • : Returns a {{domxref("WebGL_API/Types", "GLuint")}} indicating the uniform buffer binding point.
    • gl.UNIFORM_BLOCK_DATA_SIZE
      • : Returns a {{domxref("WebGL_API/Types", "GLuint")}} indicating the minimum total buffer object size.
    • gl.UNIFORM_BLOCK_ACTIVE_UNIFORMS
      • : Returns a {{domxref("WebGL_API/Types", "GLuint")}} indicating the number of active uniforms in the uniform block.
    • gl.UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES
      • : Returns a {{jsxref("Uint32Array")}} indicating the list of active uniforms in the uniform block.
    • gl.UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER
      • : Returns a {{domxref("WebGL_API/Types", "GLboolean")}} indicating whether the uniform block is referenced by the vertex shader.
    • gl.UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER
      • : Returns a {{domxref("WebGL_API/Types", "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

const blockSize = gl.getActiveUniformBlockParameter(
  program,
  blockIndex,
  gl.UNIFORM_BLOCK_DATA_SIZE,
);

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("WebGL2RenderingContext.getActiveUniforms()")}}