From: Simon Cross <hodgestar@gmail.com>
Date: Sun, 4 Sep 2016 20:40:39 +0000 (+0200)
Subject: First working version of light rays.
X-Git-Tag: tabakrolletjie-v1.0.0~246
X-Git-Url: https://git.ctpug.org.za/?a=commitdiff_plain;h=e01ef513c433374cdab9069363f6d27a33a15143;p=tabakrolletjie.git

First working version of light rays.
---

diff --git a/tabakrolletjie/lights.py b/tabakrolletjie/lights.py
index 81740d8..ef84879 100644
--- a/tabakrolletjie/lights.py
+++ b/tabakrolletjie/lights.py
@@ -4,6 +4,53 @@
 import pymunk
 import pymunk.pygame_util
 import pygame.draw
+import pygame.locals as pgl
+
+from .constants import SCREEN_SIZE, LIGHT_CATEGORY
+
+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
+    for y in range(h):
+        yield pymunk.Vec2d(left, y)
+    for x in range(w):
+        yield pymunk.Vec2d(x, top)
+    for y in range(top, -1, -1):
+        yield pymunk.Vec2d(right, y)
+    for x in range(right, -1, -1):
+        yield pymunk.Vec2d(x, bottom)
+
+
+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)
+    if len(vertices) > 2:
+        ray_polys.append(pymunk.Poly(body, vertices))
+    print "NUM POLYS: ", len(ray_polys)
+    return ray_polys
 
 
 class BaseLight(object):
@@ -17,10 +64,13 @@ class BaseLight(object):
     def add(self, space):
         if self.body.space is not None:
             space.remove(self.body, *self.body.shapes)
-        shapes = self.determine_ray_polys(space)
+        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 determine_ray_polys(self, space):
+    def shapes_for_ray_polys(self, space):
         raise NotImplementedError(
             "Lights should implement .determine_ray_polys.")
 
@@ -40,18 +90,28 @@ class SpotLight(BaseLight):
         super(SpotLight, self).__init__(colour, position)
         self.direction = direction
         self.spread = spread
+        self.i = 0
 
-    def determine_ray_polys(self, space):
+    def shapes_for_ray_polys(self, ray_polys):
         x, y = self.position
-        return [pymunk.Poly(self.body, [
-            self.position, [x + 50, y], [x, y + 50]])]
+        return ray_polys #+ [
+        #    pymunk.Poly(self.body, [self.position, [x + 50, y], [x, y + 50]])]
 
     def render(self, surface):
+        subsurface = surface.copy()
+        pygame.draw.circle(
+            surface, (255, 255, 0),
+            pymunk.pygame_util.to_pygame(self.position, surface), 5)
         for shape in self.body.shapes:
             pygame_poly = [
                 pymunk.pygame_util.to_pygame(v, surface) for v in
                 shape.get_vertices()]
-            pygame.draw.polygon(surface, (255, 255, 255), pygame_poly)
+            pygame.draw.polygon(
+                subsurface, (200, 200, 200), pygame_poly, 0)
+            pygame.draw.aalines(
+                subsurface, (200, 200, 200), True, pygame_poly, 1)
+        subsurface.set_alpha(200)
+        surface.blit(subsurface, (0, 0), None)
 
 
 class Lamp(BaseLight):