title: Determine if two rectangles overlap each other?
body: <p>I am trying to write a C++ program that takes the following inputs from the user to construct rectangles (between 2 and 5): height, width, x-pos, y-pos. All of these rectangles will exist parallel to the x and the y axis, that is all of their edges will have slopes of 0 or infinity.</p>
  
  <p>I've tried to implement what is mentioned in <a href="https://stackoverflow.com/questions/115426">this</a> question but I am not having very much luck.</p>
  
  <p>My current implementation does the following:</p>
  
  <pre><code>// Gets all the vertices for Rectangle 1 and stores them in an array -&gt; arrRect1
  // point 1 x: arrRect1[0], point 1 y: arrRect1[1] and so on...
  // Gets all the vertices for Rectangle 2 and stores them in an array -&gt; arrRect2
  
  // rotated edge of point a, rect 1
  int rot_x, rot_y;
  rot_x = -arrRect1[3];
  rot_y = arrRect1[2];
  // point on rotated edge
  int pnt_x, pnt_y;
  pnt_x = arrRect1[2]; 
  pnt_y = arrRect1[3];
  // test point, a from rect 2
  int tst_x, tst_y;
  tst_x = arrRect2[0];
  tst_y = arrRect2[1];
  
  int value;
  value = (rot_x * (tst_x - pnt_x)) + (rot_y * (tst_y - pnt_y));
  cout &lt;&lt; "Value: " &lt;&lt; value;  
  </code></pre>
  
  <p>However I'm not quite sure if (a) I've implemented the algorithm I linked to correctly, or if I did exactly how to interpret this?</p>
  
  <p>Any suggestions?</p>