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Let say that we have two rectangles, defined with their bottom-left and top-right corners. For example: rect1 (x1, y1)(x2, y2) and rect2 (x3, y3)(x4, y4). I'm trying to find the coordinates(bottom-left and top-right) of the intersected rectangle.
Any ideas, algorithm, pseudo code, would be greatly appreciated.
p.s. I found similar questions but they check only if 2 rectangle intersect.
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In order to check that two rectangles intersect all that's needed is x1 < x4 && x3 < x2 && y1 < y4 && y3 < y2 . That's it. (I used strict inequalities to exclude touching rectangles.)
Rectangle rect1 = new Rectangle(100, 100, 200, 240); Rectangle rect2 = new Rectangle(120, 80, 80, 120); Rectangle intersection = rect1. intersection(rect2); say (x1, y1), (x2, y2) are bottom-left and bottom-right corners of Rect1 respectively, (x3, y3), (x4, y4) are those of Rect2.
Suppose there is a rectangle that is represented as a list [x1, y1, x2, y2], where (x1, y1) is the coordinates of its bottom-left corner, and (x2, y2) is the coordinates of its top-right corner. Now two rectangles overlap if the area of their intersection is positive.
If the input rectangles are normalized, i.e. you already know that x1 < x2, y1 < y2 (and the same for the second rectangle), then all you need to do is calculate
int x5 = max(x1, x3); int y5 = max(y1, y3); int x6 = min(x2, x4); int y6 = min(y2, y4); and it will give you your intersection as rectangle (x5, y5)-(x6, y6). If the original rectangles do not intersect, the result will be a "degenerate" rectangle (with x5 >= x6 and/or y5 >= y6), which you can easily check for.
P.S. As usual, small details will depend on whether you have to consider touching rectangles as intersecting.
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