title: Find angle between two points
body: <p>I am trying to make an image move towards my mouse pointer. Basically, I get the angle between the points, and move along the x axis by the cosine of the angle, and move along the y axis the sine of the angle.</p>
  <p>However, I don't have a good way of calculating the angle. I get the difference in x and the difference in y, and use arctangent of Δy/Δx. The resulting angle in quadrant 1 is correct, but the other three quadrants are <em>wrong</em>. Quadrant 2 ranges from -1 to -90 degrees. Quadrant 3 is always equal to quadrant 1, and quadrant 4 always equals quadrant 4. <strong>Is there an equation that I can use to find the angle between the two points from 1-360 degrees?</strong></p>
  <p>Note: I cannot use atan2(), and I do not know what a vector is.</p>