allow additional onchange handlers

likely to rerender the scene.

glsl/sliders.js

  });
}
function initSliders(gl, program, sliders) {
function initSliders(gl, program, sliders, onChange) {
  return sliders.map(function(slider) {
    switch (slider.type) {
      case "float":
        
        slider.onChange = function(ev) {
          gl.uniform1f(slider.uniform, parseFloat(ev.target.value));
          
          if (onChange) {
            onChange(ev, slider);
          }
        }
        
        break;
        slider.onChange = function(ev, i) {
          slider.values[0] = parseFloat(ev.target.value);
          gl.uniform2f(slider.uniform, slider.values[0], slider.values[1]);
          
          if (onChange) {
            onChange(ev, slider, i);
          }
        }
        
        break;