示例#1
0
    def process_case3(self, angle):
        l1 = Edge.length(self.curr_polygon.next(), self.curr_polygon.curr_point)
        l2 = Edge.length(self.curr_polygon.curr_point, self.curr_polygon.prev())

        p2 = self.curr_polygon.curr_point
        p1 = self.curr_polygon.prev()
        a = l2

        index = self.curr_polygon.curr_index

        if l1 < l2:
            p1 = self.curr_polygon.curr_point
            p2 = self.curr_polygon.next()
            a = l1
            index += 1

            p_middle = Point.new((p1.x + p2.x) / 2.0, (p1.y + p2.y) / 2.0)

        m = 2.0 * (p2.x - p1.x)
        n = 2.0 * (p2.y - p1.y)
        k = ((p2.x ** 2) + (p2.y ** 2)) - ((p1.x ** 2) + (p1.y ** 2))

        p = p2.y - p1.y
        q = p1.x - p2.x
        l = p1.x * p2.y - p2.x * p1.y + Math.sqrt(3.0) * a * a / 2.0

        det = n * p - q * m
        x_new = (l * n - k * q) / det
        y_new = (k * p - l * m) / det

        p = Point.new(x_new, y_new)

        if self.curr_polygon.has_point(p):
            return [p, index]

        # find symmetric point
        p_new = Point(2.0 * p.x - p_middle.x, 2.0 * p.y - p_middle.y)
        if p_new in self.curr_polygon:
            return [p_new, index]

        raise RuntimeError("doh doh doh 3")