gistfile1.py

    def getLine(self, x1, y1, x2, y2):
        """Bresenham's line algorithm"""
        points = []
        issteep = abs(y2 - y1) > abs(x2 - x1)
        if issteep:
            x1, y1 = y1, x1
            x2, y2 = y2, x2
        rev = False
        if x1 > x2:
            x1, x2 = x2, x1
            y1, y2 = y2, y1
            rev = True
        deltax = x2 - x1
        deltay = abs(y2 - y1)
        error = int(deltax / 2)
        y = y1
        ystep = None
        if y1 < y2:
            ystep = 1
        else:
            ystep = -1
        for x in range(x1, x2 + 1):
            if issteep:
                points.append((y, x))
            else:
                points.append((x, y))
            error -= deltay
            if error < 0:
                y += ystep
                error += deltax
        # Reverse the list if the coordinates were reversed
        if rev:
            points.reverse()
        return points