From 75532cda084c34c09b759eb120d00bfcc7d61ea5 Mon Sep 17 00:00:00 2001
From: Geenz <geenz@geenzo.com>
Date: Thu, 19 May 2016 20:52:28 -0400
Subject: [PATCH] Document evalLightAttenuation's parameters.

---
 libraries/model/src/model/Light.slh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libraries/model/src/model/Light.slh b/libraries/model/src/model/Light.slh
index 6211505090..46eb352d16 100644
--- a/libraries/model/src/model/Light.slh
+++ b/libraries/model/src/model/Light.slh
@@ -98,6 +98,9 @@ float getLightShowContour(Light l) {
     return l._control.w;
 }
 
+// Light is the light source its self, d is the light's distance, and ulightvec is the unnormalized light vector.
+// Note that ulightvec should be calculated as light position - fragment position.
+// Additionally, length(light position) != dot(light position, light position).
 float evalLightAttenuation(Light l, float d, vec3 ulightvec) {
     float radius = getLightRadius(l);
     float denom = d / radius + 1.0;