Taichi Python function to draw a polygon (excerpt functions from a class)

taichi_polygon_func.py

'''
Original: http://www.dgp.toronto.edu/~mac/e-stuff/point_in_polygon.py
'''
@ti.func
def polygon(self, x: ti.template(), y: ti.template(), rgba: vec4):
    x_min, x_max = x.min(), x.max()
    y_min, y_max = y.min(), y.max()
    l = len(x)
    for i, j in ti.ndrange(x_max-x_min, y_max-y_min):
        p = [x_min+i, y_min+j]
        if self._is_inside(p,x,y,l) != 0:
            self.px.rgba[p[0],p[1]] = rgba
@ti.func
def _is_inside(self,p,x,y,l):
    is_inside = 0
    if self._polygon_mode == 'crossing':
        is_inside = self._is_inside_crossing(p,x,y,l)
    elif self._polygon_mode == 'winding':
        is_inside = self._is_inside_winding(p,x,y,l)
    return is_inside
@ti.func
def _is_inside_crossing(self,p,x,y,l):
    n = 0
    v0, v1 = ti.Vector([0.0,0.0]), ti.Vector([0.0,0.0])
    for i in range(l):
        i1 = i + 1 if i < l - 1 else 0
        v0, v1 = [x[i], y[i]], [x[i1], y[i1]]
        if (v0[1] <= p[1] and v1[1] > p[1]) or \
            (v0[1] > p[1] and v1[1] <= p[1]):
            vt = (p[1] - v0[1]) / (v1[1] - v0[1])
            if p[0] < v0[0] + vt * (v1[0] - v0[0]):
                n += 1
    return n % 2
@ti.func
def _is_inside_winding(self,p,x,y,l):
    n = 0
    v0, v1 = ti.Vector([0.0,0.0]), ti.Vector([0.0,0.0])
    for i in range(l):
        i1 = i + 1 if i < l - 1 else 0
        v0, v1 = [x[i], y[i]], [x[i1], y[i1]]
        if v0[1] <= p[1] and v1[1] > p[1] and \
            (v0 - v1).cross(p - v1) > 0:
            n += 1
        elif v1[1] <= p[1] and (v0-v1).cross(p-v1) < 0:
            n -= 1
    return n