Static p5_sys::global::mouseWheel

pub static mouseWheel: MouseWheelInternalType

The function mouseWheel() is executed every time a vertical mouse wheel event is detected either triggered by an actual mouse wheel or by a touchpad.

The event.delta property returns the amount the mouse wheel have scrolled. The values can be positive or negative depending on the scroll direction (on OS X with "natural" scrolling enabled, the signs are inverted).

Browsers may have different default behaviors attached to various mouse events. To prevent any default behavior for this event, add "return false" to the end of the method.

Due to the current support of the "wheel" event on Safari, the function may only work as expected if "return false" is included while using Safari.

Examples

let pos = 25;

function draw() {
  background(237, 34, 93);
  fill(0);
  rect(25, pos, 50, 50);
}

function mouseWheel(event) {
  print(event.delta);
  //move the square according to the vertical scroll amount
  pos += event.delta;
  //uncomment to block page scrolling
  //return false;
}

Parameters

event? optional WheelEvent callback argument.