Question

I have a rectangle which has known width and height.Now devide rectangle diagonally to form four triangles. Now suppose have a point p(m,n) and i have to decide that the point lies in which triangle out of four triangles.
Please suggest me some good algo.

Answer 1

Interesting question. I think this algorithm should do it, but I haven’t tried it out yet. Assuming that the rectangle is AxB and the point p(m,n).

int section = (m * B < n * A) * 2 + (m > A / 2 || n > B / 2);

The variable section should then be a value between 0 and 3, depending where the point resides. The sections are called:

  0  
2   1
  3

If you wish to name the sections another way feel free to tweak the algo.