""" May it be a light for you in dark places, when all other lights go out.
"""
+import pymunk
+import pymunk.pygame_util
+import pygame.draw
+
+from .constants import SCREEN_SIZE, LIGHT_CATEGORY
+from .utils import debug_timer
+
+LIGHT_FILTER = pymunk.ShapeFilter(
+ mask=pymunk.ShapeFilter.ALL_MASKS ^ LIGHT_CATEGORY,
+ categories=LIGHT_CATEGORY)
+
+
+def screen_rays(pos):
+ """ An iterable that returns ordered rays from pos to the edge of the
+ screen, starting with the edge point (0, 0) and continuing clockwise
+ in pymunk coordinates.
+ """
+ w, h = SCREEN_SIZE
+ left, right, bottom, top = 0, w, 0, h
+ step = 1
+ for y in range(0, h, step):
+ yield pymunk.Vec2d(left, y)
+ for x in range(0, w, step):
+ yield pymunk.Vec2d(x, top)
+ for y in range(top, -1, -step):
+ yield pymunk.Vec2d(right, y)
+ for x in range(right, -1, -step):
+ yield pymunk.Vec2d(x, bottom)
+
+
+@debug_timer("lights.calculate_ray_polys")
+def calculate_ray_polys(space, body, position):
+ position = pymunk.Vec2d(position)
+ vertices = [position]
+ ray_polys = []
+ for ray in screen_rays(position):
+ info = space.segment_query_first(position, ray, 1, LIGHT_FILTER)
+ point = ray if info is None else info.point
+ vertices.append(point)
+ if len(vertices) > 3:
+ trial_poly = pymunk.Poly(None, vertices)
+ trial_poly.update(pymunk.Transform.identity())
+ query_prev = trial_poly.point_query(vertices[-2])
+ query_pos = trial_poly.point_query(position)
+ if query_prev.distance < -0.01 or query_pos.distance < -0.01:
+ new_poly = pymunk.Poly(body, vertices[:-1])
+ vertices = [position, vertices[-1]]
+ ray_polys.append(new_poly)
+ else:
+ vertices = trial_poly.get_vertices() + [point]
+ if len(vertices) > 2:
+ ray_polys.append(pymunk.Poly(body, vertices))
+ return ray_polys
+
class BaseLight(object):
""" Common light functionality. """
+ COLOURS = {
+ "red": (255, 0, 0),
+ "green": (0, 255, 0),
+ "blue": (0, 255, 255),
+ "yellow": (255, 255, 0),
+ "white": (255, 255, 255),
+ }
+
def __init__(self, colour, position):
+ self.on = True
+ self.body = pymunk.Body(0, 0, pymunk.body.Body.STATIC)
self.colour = colour
self.position = position
if c.__name__.lower() == light_type]
return light_class(**kw)
+ def add(self, space):
+ if self.body.space is not None:
+ space.remove(self.body, *self.body.shapes)
+ shapes = self.shapes_for_ray_polys(
+ calculate_ray_polys(space, self.body, self.position))
+ for shape in shapes:
+ shape.filter = LIGHT_FILTER
+ space.add(self.body, *shapes)
+
+ def shapes_for_ray_polys(self, ray_polys):
+ return ray_polys
+
+ def toggle(self):
+ self.on = not self.on
+
+ def render_light(self, surface):
+ if not self.on:
+ return
+ subsurface = surface.copy()
+ light_colour = self.COLOURS[self.colour]
+ for shape in self.body.shapes:
+ pygame_poly = [
+ pymunk.pygame_util.to_pygame(v, surface) for v in
+ shape.get_vertices()]
+ pygame.draw.polygon(
+ subsurface, light_colour, pygame_poly, 0)
+ pygame.draw.aalines(
+ subsurface, light_colour, True, pygame_poly, 1)
+ subsurface.set_alpha(50)
+ surface.blit(subsurface, (0, 0), None)
+
+ def render_fittings(self, surface):
+ pygame.draw.circle(
+ surface, (255, 255, 0),
+ pymunk.pygame_util.to_pygame(self.position, surface), 5)
+
class SpotLight(BaseLight):
def __init__(
super(SpotLight, self).__init__(colour, position)
self.direction = direction
self.spread = spread
+ self.i = 0
class Lamp(BaseLight):