luma.gl/docs/api-reference/webgl/context/with-parameters.md

withParameters

Finally, luma.gl enables a 'stateless' WebGL programming model. In this model, state settings can be passed as parameters to rendering commands, or applied temporarily using withParameters rather than being set and unset directly on the global state. For more information, see the remarks.

The following functions are provided:

• withParameters - Runs a function with a set of parameters temporarily applied

Usage

Set parameters temporarily for a function call (automatically restoring them after the call)

const returnValue = withParameters(gl, {
  depthTest: true
}, () = {
  // execute code with new parameters temporarily applied
  program.draw(...);
  ...
  // parameters will be restored even the function throws an exception
  if (...) {
    throw new Error('Exception after setting parameters');
  }

  // Return value of the function will be returned from `withParameters`
  return true;
});

// previous parameters are restored here
program.draw(...);

Methods

withParameters

Executes a function after temporarily setting the parameters. Will restore the parameters to their previously value after the completion of the function, even if the function exits with an exception.

withParameters(gl, {...params}, func)

• gl {WebGLRenderingContext} - context
• params {Object} - any parameter names accepted by setParameters

Returns: the value returned by func, if any.