Random and If Else help

Processing Coding Questions
10

reason is, when x2 < x1 it still looks like a normal rectangle, but your lower right corner is left from your upper right corner so both corners are swapped.

And then your ifs won’t work I guess

Code

here is my way is collision detection according to the link above:

//int time;

//coordinates for drawing rectangles
float x1;    
float y1; 
float x2; 
float y2;

void setup() {
  size(400, 400);
  background(255);

  //turn of any fill
  noFill();

  // frameRate(3);
}

void draw() {
  stroke(0, 255, 0); //green
  rect(width/2-100, height/2-100, 200, 200); 

  x1 = random(0, width-10);
  y1 = random(0, height-10);

  x2 = random(x1+1, width);
  y2 = random(y1+1, height);

  // if ok
  if (!intersectionRectRect (
    width/2-100, height/2-100, 200, 200, 
    x1, y1, x2-x1, y2-y1)) {

    //draw rectangles based on x,y coordinates in each quad
    stroke(0);
    //upper left
    line(x1, y1, x2, y1);
    line(x2, y1, x2, y2);
    line(x2, y2, x1, y2);
    line(x1, y2, x1, y1);
  }
}

//----------------------------------------------------------------------------------

// RECTANGLE/RECTANGLE intersection 
boolean intersectionRectRect(float r1x, float r1y, float r1w, float r1h, 
  float r2x, float r2y, float r2w, float r2h) {

  // are the sides of one rectangle touching the other?

  if (r1x + r1w >= r2x &&  // r1 right edge past r2 left
    r1x <= r2x + r2w &&    // r1 left edge past r2 right
    r1y + r1h >= r2y &&    // r1 top edge past r2 bottom
    r1y <= r2y + r2h) {    // r1 bottom edge past r2 top
    return true;
  }
  return false;
}
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