I have been making a game and have used rotations to create parts of it.  I am trying to figure out how to determine whether a line that is always at a certain point that is just being rotated, can hit something that is not being rotated and is moving.  Here's the coding without all the variable beginnings-
void setup(){
  size(750,750);
  smooth();
  x1 = 0;
  y1 = 0;
  s1 = 40;
  s2 = 20;
  s3 = 15;
  x2 = 0;
  y2 = -10;
  r = 0;
  shot = false;
  ex1 = random(5,745);
  ey1 = 0;
  ey2 = ey1 - 10;
  ex2 = ex1 - 30;
  ex3 = ex1 + 30;
  ey3 = ey1 + 20;
  es1 = 2;
  es2 = 2;
  b = 5;
  nb = 0;
  exsp = (375 - ex1) / 375;
  eysp =1;
  Explosion = loadImage("ifwt-explosion.jpg");
  op = 255;
  destroyed = false;
}

void mouseClicked(){
  translate(375,375);
  pushMatrix();
  rotate(radians(r));
  shot = true;
  stroke(150,150,0);
  strokeWeight(5);
  line(0,-25,0,-750);
  popMatrix();
}

void draw(){
  background(0);
  if(keyPressed){
    if(key == 'A' || key == 'a'){
      r -= 2;
    }
    if(key == 'D' || key == 'd'){
      r += 2;
    }
  }
  if(r >= 360 || r <= -360){
    r = 0;
  }
  pushMatrix();
  translate(375,375);
  rotate(radians(r));
  fill(240);
  stroke(255,0,0);
  strokeWeight(1);
  ellipse(x1,y1,s1,s1);
  fill(0,255,255);
  ellipse(x2,y2,s2,s3);
  popMatrix();
  constrain(b,0,20);
  stroke(50,op);
  fill(150,op);
  ellipse(ex1,ey1,20,20);
  stroke(150,0,0,op);
  strokeWeight(b);
  noFill();
  ellipse(ex1,ey1,es1,es2);
  b = noise(nb) * 20;
  nb += .02;
  if(ey1 > 385){
    destroyed = true;
  }
  if(destroyed == true){
    op = 255;
      ex1 = random(5,745);
    ey1 =0;
    exsp = (375 - ex1) / 375;
  eysp =1;
  destroyed = false;
  }
  ex1 += exsp;
  ey1 += eysp;
  if(dist(ex1,ey1,375,375) < 20){
    imageMode(CENTER);
    image(Explosion, 375,375);
    op = 0;
  }
}