cig/cultist_war/bresenham.py

import time

t0 = time.time()


def log(*msg):
    print("{} - ".format(str(time.time() - t0)[:5]), *msg)


obstacles = [(1, 0), (1, 1)]


# Version serveur
def can_see_trough(pos):
    return pos not in obstacles


def line(start, target, strict=True):
    """
    adapted from https://github.com/fragkakis/bresenham/blob/master/src/main/java/org/fragkakis/Bresenham.java
    if strict is true, None is return if an obstacle interrupted the line; else a partial line is returned (from start to obstacle)
    """
    line = []

    x0, y0 = start
    x1, y1 = target

    dx = abs(x1 - x0)
    dy = abs(y1 - y0)

    sx = 1 if x0 < x1 else -1
    sy = 1 if y0 < y1 else -1

    err = dx - dy
    x, y = x0, y0

    while 1:
        line.append((x, y))

        if x == x1 and y == y1:
            break

        e2 = 2 * err
        if e2 > (-1 * dy):
            err -= dy
            x += sx

        if e2 < dx:
            err += dx
            y += sy

        if not can_see_trough((x, y)):
            return None if strict else line

    return line


log(line((0, 2), (4, 3)))  # test droite / bas
log(line((0, 5), (4, 3)))  # test droite / haut
log(line((8, 1), (4, 3)))  # test gauche / bas
log(line((8, 5), (4, 3)))  # test gauche / haut

#
# def bresenhamForward(start, target):
#     x0, y0 = start
#     x1, y1 = target
#
#     dx = abs(x1 - x0)
#     dy = abs(y1 - y0)
#
#     sx = 1 if x0 < x1 else -1
#     sy = 1 if y0 < y1 else -1
#
#     err = dx - dy
#     x, y = x0, y0
#
#     while 1:
#         e2 = 2 * err
#         if e2 > (-1 * dy):
#             err -= dy
#             x += sx
#
#         if e2 < dx:
#             err += dx
#             y += sy
#
#         if x == x1 and y == y1:
#             break
#
#         if can_see_trough((x, y)):
#             return []
#
#     return []
#
#
# def bresenhamBackward(start, target):
#     pass
#
#
# def checkBulletPath(start, target):
#     if start[1] > target[1]:
#         return bresenhamForward(start, target)
#     else:
#         return bresenhamBackward(start, target)