def camera(i, j):
# int, int -> vector a
alpha = math.tan(fovx/2)*((i - (width/2))/(width/2))
beta = math.tan(fovy/2)*(((height/2) - j)/(height/2))
dirn = vr.add_vector(vr.add_vector(vr.scale_mul(alpha, side(geo)),
vr.scale_mul(beta, up(geo))),
forward(geo))
dirn = vr.normalize(dirn)
return ry.make_ray(eye, dirn)
def intersect_lights(scene, lights, pos, normal):
# scene, light, vector -> float
color = 1
for light in lights:
dirn = vr.normalize(vr.sub_vector(lt.get_pos(light), pos))
new_ray = ry.make_ray(pos, dirn)
t, n = intersect_scene(scene, new_ray)
if not t:
dot_or_0 = max([vr.dot_prod(dirn, normal), 0])
incr = dot_or_0 * lt.get_brightness(light)
color += incr
if color:
return min([8, color])
