corrected power usage calculation to exclude area within inner radius

diff --git a/tabakrolletjie/lights.py b/tabakrolletjie/lights.py
index ac6f08e38c279ec39d2847e2b181ca43b5a5eb6a..06f84badbb88c90034e2cfda6f129547093ffebe 100644 (file)
--- a/tabakrolletjie/lights.py
+++ b/tabakrolletjie/lights.py
@@ -313,8 +313,9 @@ class BaseLight(object):
     def power_usage(self):
         if not self.on:
             return 0.0
-        area = math.pi * (self.ray_manager.max_radius ** 2)  # radius
-        area = area * (self.ray_manager.spread / (2 * math.pi))  # spread
+        rm = self.ray_manager
+        area = math.pi * (rm.max_radius ** 2 - rm.min_radius ** 2)  # radius
+        area = area * (rm.spread / (2 * math.pi))  # spread
         return 5 * area * self.intensity / 6400  # 80x80 unit area
 
     def base_damage(self):