Calculating area of intersection between two rectangles

Question

//C# Console Application Home assignment

I have 8 coordinates like this:

(x1, y1) (x2, y2) ... (x8, y8) //The first 4 coordinates are for 1st rectangle //The rest for 2nd rectangle

I store the values like this:

int[,] array2D = new int[8,2];
array2d[0,0] = x1;
array2d[0,1] = y1;
array2d[1,0] = x2;
array2d[1,1] = y2;
//...
array[7,0] = x8;
array[7,1] = y8;

I want to calculate area of intersection between those coordinates.

I already have this code to check when the rectangles aren't overlapping (it works):

if (!(array2D[2, 1] <= array2D[4, 1] && array2D[0, 1] >= array2D[6, 1]
                && array2D[2, 0] >= array2D[4, 0] && array2D[0, 0] <= array2D[6, 0]))
            {
//not overlapping
}
{
//overlapping
}

I need help with algorithm to get the area of intersection.

NOTE: Coordinates can have negative values.

Do you need algorithm or you are looking for function in one of the Dot Net libraries? — Rami Yampolsky
Algorithm or function, so i can understand and can complete my code. — M. Coutinho

Jakub Konecki Jakub Konecki · Accepted Answer · 2014-02-07T14:20:30

I would use the Rectangle.Intersect method from System.Drawing. There's no point in reinventing the wheel... ;-)

Returns a third Rectangle structure that represents the intersection of two other Rectangle structures. If there is no intersection, an empty Rectangle is returned.

Calculating area of intersection between two rectangles

2 Answers