From: Simon Cross <hodgestar@gmail.com>
Date: Wed, 7 Sep 2016 19:12:07 +0000 (+0200)
Subject: Move ray manipulation into a separate module.
X-Git-Tag: tabakrolletjie-v1.0.0~201
X-Git-Url: https://git.ctpug.org.za/?p=tabakrolletjie.git;a=commitdiff_plain;h=3c1acdcd43a2d901ae165e2a278c5ed31ebca4dd

Move ray manipulation into a separate module.
---

diff --git a/tabakrolletjie/lights.py b/tabakrolletjie/lights.py
index 285ca2e..097abd2 100644
--- a/tabakrolletjie/lights.py
+++ b/tabakrolletjie/lights.py
@@ -7,9 +7,8 @@ import pygame.display
 import pygame.draw
 import pygame.locals as pgl
 
-from .constants import (
-    SCREEN_SIZE, LIGHT_CATEGORY, FITTINGS_CATEGORY)
-from .utils import debug_timer
+from .constants import LIGHT_CATEGORY, FITTINGS_CATEGORY
+from .rays import calculate_ray_polys
 
 LIGHT_FILTER = pymunk.ShapeFilter(
     mask=pymunk.ShapeFilter.ALL_MASKS ^ (
@@ -25,49 +24,6 @@ FITTINGS_FILTER = pymunk.ShapeFilter(
 LIT_BY_FILTER = pymunk.ShapeFilter(mask=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 LightManager(object):
     """ Manages a set of lights. """
 
@@ -161,7 +117,7 @@ class BaseLight(object):
         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))
+            calculate_ray_polys(space, self.body, self.position, LIGHT_FILTER))
         for shape in shapes:
             shape.filter = LIGHT_FILTER
         self.fitting.filter = FITTINGS_FILTER
diff --git a/tabakrolletjie/rays.py b/tabakrolletjie/rays.py
new file mode 100644
index 0000000..1892edf
--- /dev/null
+++ b/tabakrolletjie/rays.py
@@ -0,0 +1,50 @@
+""" Light ray manipulation. Pew. Pew. Pew. Wommmm. """
+
+import pymunk
+import pymunk.pygame_util
+
+from .constants import SCREEN_SIZE
+from .utils import debug_timer
+
+
+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("rays.calculate_ray_polys")
+def calculate_ray_polys(space, body, position, light_filter):
+    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