Static p5_sys::global::atan2

pub static atan2: Atan2InternalType

Calculates the angle (in radians) from a specified point to the coordinate origin as measured from the positive x-axis. Values are returned as a float in the range from PI to -PI if the angleMode is RADIANS or 180 to -180 if the angleMode is DEGREES. The atan2() function is most often used for orienting geometry to the position of the cursor.

Note: The y-coordinate of the point is the first parameter, and the x-coordinate is the second parameter, due the the structure of calculating the tangent.

Examples

function draw() {
  background(204);
  translate(width / 2, height / 2);
  let a = atan2(mouseY - height / 2, mouseX - width / 2);
  rotate(a);
  rect(-30, -5, 60, 10);
}

Parameters

y y-coordinate of the point

x x-coordinate of the point