DRTVWR-559: PBR: Cleanup distance attenuation calcs

1 files changed, 2 insertions, 3 deletions

diff --git a/indra/newview/app_settings/shaders/class3/deferred/multiSpotLightF.glsl b/indra/newview/app_settings/shaders/class3/deferred/multiSpotLightF.glsl
index a9a2b8dcb4..3efc9c1689 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/multiSpotLightF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/multiSpotLightF.glsl
@@ -110,6 +110,7 @@ uniform mat4 inv_proj;
 vec3 BRDFLambertian( vec3 reflect0, vec3 reflect90, vec3 c_diff, float specWeight, float vh );
 vec3 BRDFSpecularGGX( vec3 reflect0, vec3 reflect90, float alphaRoughness, float specWeight, float vh, float nl, float nv, float nh );
 void calcHalfVectors(vec3 lv, vec3 n, vec3 v, out vec3 h, out vec3 l, out float nh, out float nl, out float nv, out float vh, out float lightDist);
+float calcLegacyDistanceAttenuation(float distance, float falloff);
 vec3 colorized_dot(float x);
 bool clipProjectedLightVars(vec3 center, vec3 pos, out float dist, out float l_dist, out vec3 lv, out vec4 proj_tc );
 vec3 getLightIntensitySpot(vec3 lightColor, float lightRange, float lightDistance, vec3 v);
@@ -155,9 +156,7 @@ void main()
     vec3 n;
     vec4 norm = getNormalEnvIntensityFlags(tc, n, envIntensity);
 
-    float dist_atten = 1.0 - (dist + falloff)/(1.0 + falloff);
-    dist_atten *= dist_atten;
-    dist_atten *= 2.0;
+    float dist_atten = calcLegacyDistanceAttenuation(dist, falloff);
     if (dist_atten <= 0.0)
     {
         discard;