SL-10461

Pass projector ambiance as the .w element of the light_attenuation uniform
so that alpha shader can emulate the behavior of proper spot projectors.

1 files changed, 15 insertions, 12 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl b/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
index f1b7a1312f..772859576f 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/alphaF.glsl
@@ -63,7 +63,7 @@ uniform vec2 screen_res;
 
 uniform vec4 light_position[8];
 uniform vec3 light_direction[8];
-uniform vec3 light_attenuation[8]; 
+uniform vec4 light_attenuation[8]; 
 uniform vec3 light_diffuse[8];
 
 #ifdef WATER_FOG
@@ -79,7 +79,7 @@ void calcFragAtmospherics(vec3 inPositionEye, float ambFactor, out vec3 sunlit,
 
 float sampleDirectionalShadow(vec3 pos, vec3 norm, vec2 pos_screen);
 
-vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 diffuse, vec3 v, vec3 n, vec4 lp, vec3 ln, float la, float fa, float is_pointlight)
+vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 diffuse, vec3 v, vec3 n, vec4 lp, vec3 ln, float la, float fa, float is_pointlight, float ambiance)
 {
     //get light vector
     vec3 lv = lp.xyz-v;
@@ -91,13 +91,16 @@ vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 diffuse, vec3 v, vec3 n, vec
 
     vec3 col = vec3(0);
 
-    if (d > 0.0 && la > 0.0 && fa > 0.0)
+    if (d > 0.0 && fa > 0.0)
     {
         //normalize light vector
         lv = normalize(lv);
-    
+        vec3 norm = normalize(n);
+
+        da = max(0.0, dot(norm, lv));
+ 
         //distance attenuation
-        float dist = d/la;
+        float dist = d;
         float dist_atten = clamp(1.0-(dist-1.0*(1.0-fa))/fa, 0.0, 1.0);
         dist_atten *= dist_atten;
         dist_atten *= 2.0;
@@ -106,17 +109,17 @@ vec3 calcPointLightOrSpotLight(vec3 light_col, vec3 diffuse, vec3 v, vec3 n, vec
         float spot = max(dot(-ln, lv), is_pointlight);
         da *= spot*spot; // GL_SPOT_EXPONENT=2
 
-        //angular attenuation
-        da *= max(dot(n, lv), 0.0);     
-
         float lit = max(da * dist_atten,0.0);
 
-        col = light_col * lit * diffuse;
+        float amb_da = (da*da*0.5 + 0.5) * ambiance;
+        amb_da *= dist_atten;
+        amb_da = min(amb_da, 1.0f - lit);
 
+        col.rgb += amb_da * light_col * diffuse;
         // no spec for alpha shader...
     }
-
-    return max(col, vec3(0.0,0.0,0.0));
+    col = max(col, vec3(0));
+    return col;
 }
 
 void main() 
@@ -199,7 +202,7 @@ void main()
 
     vec4 light = vec4(0,0,0,0);
 
-   #define LIGHT_LOOP(i) light.rgb += calcPointLightOrSpotLight(light_diffuse[i].rgb, diff.rgb, pos.xyz, norm, light_position[i], light_direction[i].xyz, light_attenuation[i].x, light_attenuation[i].y, light_attenuation[i].z);
+   #define LIGHT_LOOP(i) light.rgb += calcPointLightOrSpotLight(light_diffuse[i].rgb, diff.rgb, pos.xyz, norm, light_position[i], light_direction[i].xyz, light_attenuation[i].x, light_attenuation[i].y, light_attenuation[i].z, light_attenuation[i].w);
 
     LIGHT_LOOP(1)
     LIGHT_LOOP(2)