it got cancelled

i am going to fucking kill myself xd

tomatenmhark: caniseeu

Implementation of an algorithm to check if a unit can see another unit with the given obstacles on the map, using only integers, because perfection and/or float hate i guess

try it

spec

The algorithm works on a n*m grid of squares, where each square may or may not be an obstacle.
Obstacles take up the entire square except for the edges, so there is an infinitely small gap between obstacles. Units can see through this gap, for example in the following situation:

          o
          |
   ###
   ###
      ###
      ###
 o
 |

This algorithm checks if one unit can attack another. The conditions for this is that there is a line of sight between the two units, specifically between the centers of the squares on which the two units are positioned.
To avoid inaccuracies, this implementation uses only integers instead of floats.

api

A grid is represented as {width}/{height}/{grid}, where {grid} is a string of length {width}*{height}, which contains the squares of the actual grid in order left-to-right, then down a line. Each character is either numeric, representing an obstacle, or alphabetic (a-Z), representing anything else.
The above grid could be represented as eeeue0eeee0eueee:

eeeu
e0ee
ee0e
ueee

Where e = empty, u = unit, 0 = normal obstacle.

/check/{w}/{h}/{grid}/{x1}/{y1}/{x2}/{y2} responds with 200 Ok if there is a line of sight between (x1,y1) and (x2,y2) on the grid, or 404 Not Found otherwise.
/checkall/{w}/{h}/{grid}/{x1}/{y1} responds with a same-size grid where each square is either "y" (there is a line of sight) or "0" (there is not).