Two Rectangles intersection

Majid Laissi picture Majid Laissi · Nov 15, 2012 · Viewed 65.2k times · Source

I have two rectangles characterized by 4 values each :

Left position X, top position Y, width W and height H:

X1, Y1, H1, W1
X2, Y2, H2, W2

Rectangles are not rotated, like so:

+--------------------> X axis
|
|    (X,Y)      (X+W, Y)
|    +--------------+
|    |              |
|    |              |
|    |              |
|    +--------------+
v    (X, Y+H)     (X+W,Y+H)

Y axis

What is the best solution to determine whether the intersection of the two rectangles is empty or not?

Answer

Tao Peng picture Tao Peng · Nov 15, 2012
if (X1+W1<X2 or X2+W2<X1 or Y1+H1<Y2 or Y2+H2<Y1):
    Intersection = Empty
else:
    Intersection = Not Empty

If you have four coordinates – ((X,Y),(A,B)) and ((X1,Y1),(A1,B1)) – rather than two plus width and height, it would look like this:

if (A<X1 or A1<X or B<Y1 or B1<Y):
    Intersection = Empty
else:
    Intersection = Not Empty