Basic 4 Sided Collision Detection - Page 8

The distance_x = the movieclip red's x axis minus the movie clip green's x axis.
The distance_y = the movie clip red's y axis minus the movie clip green's y axis.

This is a very important part because it is used to calculate the distance between the two.With out it there is no way to check on how close the two object are to each other based on the _x and _y coordinates of both objects.

The next line of actionscript sets up a variable named area . The area is the height and width of each movie clip. This is also very important, because you need to the size of each object in order to get an accurate collision check

Set Variable: "area" = (red_h+red_w)*(green_h+green_w)

The area is red's height and width * (times) green's height and width.

The next line of action script contains all the above information and is the start of the If statement which will check to see if certain conditions are true.

If (distance_x*distance_x+distance_y*distance_y<=area)