Merged in davep/DRTVWR-440 (pull request #33)

SL-12233 Fix for disagreement between fullbright implementations with ALM on and off.

indra/newview/app_settings/shaders/class1/deferred/emissiveF.glsl

@@ -44,7 +44,6 @@ void main()
 	float shadow = 1.0;
 
 	vec4 color = diffuseLookup(vary_texcoord0.xy)*vertex_color;
-	color.rgb = pow(color.rgb, vec3(2.2));
 	color.rgb = fullbrightAtmosTransport(color.rgb);
 
 	color.rgb = fullbrightScaleSoftClip(color.rgb);

indra/newview/app_settings/shaders/class1/deferred/fullbrightF.glsl

@@ -79,10 +79,8 @@ void main()
 	color.rgb = fogged.rgb;
 	color.a   = fogged.a;
 #else
-    color.rgb = srgb_to_linear(color.rgb);
     color.rgb = fullbrightAtmosTransport(color.rgb);
 	color.rgb = fullbrightScaleSoftClip(color.rgb);
-    color.rgb = linear_to_srgb(color.rgb);
     color.a   = final_alpha;
 #endif
 

indra/newview/app_settings/shaders/class1/deferred/materialF.glsl

@@ -44,6 +44,9 @@ vec4 applyWaterFogView(vec3 pos, vec4 color);
 vec3 atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
 vec3 scaleSoftClipFrag(vec3 l);
 
+vec3 fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
+vec3 fullbrightScaleSoftClip(vec3 light);
+
 void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten, bool use_ao);
 
 vec3 srgb_to_linear(vec3 cs);
@@ -323,18 +326,23 @@ void main()
     
     if (emissive_brightness >= 1.0)	// fullbright, skip lighting calculations
     {
-        // just do atmos attenuation (ad hoc 60% factor to match release viewer)
-        color = atmosFragLighting(diffuse_srgb.rgb, additive, atten*0.6);
-        color = scaleSoftClipFrag(color);
+        color = fullbrightAtmosTransportFrag(diffuse_srgb.rgb, additive, atten);
+        color = fullbrightScaleSoftClip(color);
+
         al = diffuse_srgb.a;
     }
     else // not fullbright, calculate lighting
     {
         vec3 refnormpersp = normalize(reflect(pos.xyz, norm));
 
+        //we're in sRGB space, so gamma correct this dot product so 
+        // lighting from the sun stays sharp
         float da = clamp(dot(normalize(norm.xyz), light_dir.xyz), 0.0, 1.0);
         da = pow(da, 1.0 / 1.3);
 
+        //darken ambient for normals perpendicular to light vector so surfaces in shadow 
+        // and facing away from light still have some definition to them.
+        // do NOT gamma correct this dot product so ambient lighting stays soft
         float ambient = min(abs(dot(norm.xyz, sun_dir.xyz)), 1.0);
         ambient *= 0.5;
         ambient *= ambient;

indra/newview/app_settings/shaders/class2/windlight/transportF.glsl

@@ -49,10 +49,15 @@ vec3 atmosTransport(vec3 light)
      return atmosTransportFrag(light, getAdditiveColor(), getAtmosAttenuation());
 }
 
-vec3 fullbrightAtmosTransport(vec3 light)
+vec3 fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten)
 {
     float brightness = dot(light.rgb * 0.5, vec3(0.3333)) + 0.1;
-    return atmosTransportFrag(light * 0.5, getAdditiveColor() * brightness, getAtmosAttenuation());
+    return atmosTransportFrag(light * 0.5, additive * brightness, atten);
+}
+
+vec3 fullbrightAtmosTransport(vec3 light)
+{
+    return fullbrightAtmosTransportFrag(light, getAdditiveColor(), getAtmosAttenuation());
 }
 
 vec3 fullbrightShinyAtmosTransport(vec3 light)

indra/newview/app_settings/shaders/class3/windlight/transportF.glsl

@@ -49,10 +49,15 @@ vec3 atmosTransport(vec3 light)
      return atmosTransportFrag(light, getAdditiveColor(), getAtmosAttenuation());
 }
 
-vec3 fullbrightAtmosTransport(vec3 light)
+vec3 fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten)
 {
     float brightness = dot(light.rgb, vec3(0.33333));
-    return atmosTransportFrag(light * 0.5, getAdditiveColor() * (brightness * 0.5 + 0.5), getAtmosAttenuation());
+    return atmosTransportFrag(light * 0.5, additive * (brightness * 0.5 + 0.5), atten);
+}
+
+vec3 fullbrightAtmosTransport(vec3 light)
+{
+    return atmosTransportFrag(light, getAdditiveColor(), getAtmosAttenuation());
 }
 
 vec3 fullbrightShinyAtmosTransport(vec3 light)