How to make a simple radar

Dingo

Hi. A pretty new beginner here.

If you have any ellipse, how can i make a line(x1, y1, x2, y2) where x1 and y1 are in the middle of the ellipse (i know this part), but where x2 and y2 continuously make the line go around the ellipse's perimeter? Thanks in advance

TfGuy44

There are a couple of ways.

void setup(){
  size(800,400);
  noFill();
}

void draw(){
  float m = map(millis()%10000,0,10000,0,TWO_PI);
  background(0);
  stroke(255,128,128);
  translate(200,200);
  ellipse(0,0,380,380);
  pushMatrix();
  rotate(m);
  line(0,0,190,0);
  popMatrix();

  translate(400,0);
  stroke(128,128,255);
  ellipse(0,0,380,380);
  line(0,0,190*cos(m),190*sin(m));
}