Merged master(DRTVWR-497) into DRTVWR-482

4 files changed, 361 insertions, 442 deletions

diff --git a/indra/newview/app_settings/shaders/class2/deferred/skyF.glsl b/indra/newview/app_settings/shaders/class2/deferred/skyF.glsl
index 1dce85a83b..1485c515a4 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/skyF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/skyF.glsl
@@ -1,24 +1,24 @@
-/** 
+/**
  * @file class2/deferred/skyF.glsl
  *
  * $LicenseInfo:firstyear=2005&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2005, Linden Research, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- * 
+ *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
+ *
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
@@ -32,13 +32,13 @@ uniform mat4 modelview_projection_matrix;
 // Inputs
 uniform vec3 camPosLocal;
 
-uniform vec4 lightnorm;
-uniform vec4 sunlight_color;
-uniform vec4 moonlight_color;
-uniform int sun_up_factor;
-uniform vec4 ambient_color;
-uniform vec4 blue_horizon;
-uniform vec4 blue_density;
+uniform vec4  lightnorm;
+uniform vec4  sunlight_color;
+uniform vec4  moonlight_color;
+uniform int   sun_up_factor;
+uniform vec4  ambient_color;
+uniform vec4  blue_horizon;
+uniform vec4  blue_density;
 uniform float haze_horizon;
 uniform float haze_density;
 
@@ -47,7 +47,7 @@ uniform float density_multiplier;
 uniform float distance_multiplier;
 uniform float max_y;
 
-uniform vec4 glow;
+uniform vec4  glow;
 uniform float sun_moon_glow_factor;
 
 uniform vec4 cloud_color;
@@ -73,16 +73,16 @@ uniform float ice_level;
 
 vec3 rainbow(float d)
 {
-   d = clamp(d, -1.0, 0.0);
-   float rad = (droplet_radius - 5.0f) / 1024.0f;
-   return pow(texture2D(rainbow_map, vec2(rad, d)).rgb, vec3(1.8)) * moisture_level;
+    d         = clamp(d, -1.0, 0.0);
+    float rad = (droplet_radius - 5.0f) / 1024.0f;
+    return pow(texture2D(rainbow_map, vec2(rad, d)).rgb, vec3(1.8)) * moisture_level;
 }
 
 vec3 halo22(float d)
 {
-   d = clamp(d, 0.1, 1.0);
-   float v = sqrt(clamp(1 - (d * d), 0, 1));
-   return texture2D(halo_map, vec2(0, v)).rgb * ice_level;
+    d       = clamp(d, 0.1, 1.0);
+    float v = sqrt(clamp(1 - (d * d), 0, 1));
+    return texture2D(halo_map, vec2(0, v)).rgb * ice_level;
 }
 
 /// Soft clips the light with a gamma correction
@@ -90,115 +90,96 @@ vec3 scaleSoftClip(vec3 light);
 
 void main()
 {
-
     // World / view / projection
-    // Get relative position
-    vec3 P = pos.xyz - camPosLocal.xyz + vec3(0,50,0);
+    // Get relative position (offset why?)
+    vec3 rel_pos = pos.xyz - camPosLocal.xyz + vec3(0, 50, 0);
 
-    // Set altitude
-    if (P.y > 0.)
+    // Adj position vector to clamp altitude
+    if (rel_pos.y > 0.)
     {
-        P *= (max_y / P.y);
+        rel_pos *= (max_y / rel_pos.y);
     }
-    else
+    if (rel_pos.y < 0.)
     {
-        P *= (-32000. / P.y);
+        rel_pos *= (-32000. / rel_pos.y);
     }
 
-    // Can normalize then
-    vec3 Pn = normalize(P);
-    float  Plen = length(P);
+    // Normalized
+    vec3  rel_pos_norm = normalize(rel_pos);
+    float rel_pos_len  = length(rel_pos);
 
     // Initialize temp variables
-    vec4 temp1 = vec4(0.);
-    vec4 temp2 = vec4(0.);
-    vec4 blue_weight;
-    vec4 haze_weight;
     vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
-    vec4 light_atten;
-
-    float dens_mul = density_multiplier;
 
     // Sunlight attenuation effect (hue and brightness) due to atmosphere
     // this is used later for sunlight modulation at various altitudes
-    light_atten = (blue_density + vec4(haze_density * 0.25)) * (dens_mul * max_y);
+    vec4 light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
 
     // Calculate relative weights
-    temp1 = abs(blue_density) + vec4(abs(haze_density));
-    blue_weight = blue_density / temp1;
-    haze_weight = haze_density / temp1;
+    vec4 combined_haze = abs(blue_density) + vec4(abs(haze_density));
+    vec4 blue_weight   = blue_density / combined_haze;
+    vec4 haze_weight   = haze_density / combined_haze;
 
-    // Compute sunlight from P & lightnorm (for long rays like sky)
-    temp2.y = max(0., max(0., Pn.y) * 1.0 + lightnorm.y );
-    temp2.y = 1. / temp2.y;
-    sunlight *= exp( - light_atten * temp2.y);
+    // Compute sunlight from rel_pos & lightnorm (for long rays like sky)
+    float off_axis = 1.0 / max(1e-6, max(0, rel_pos_norm.y) + lightnorm.y);
+    sunlight *= exp(-light_atten * off_axis);
 
     // Distance
-    temp2.z = Plen * dens_mul;
+    float density_dist = rel_pos_len * density_multiplier;
 
-    // Transparency (-> temp1)
-    // ATI Bugfix -- can't store temp1*temp2.z in a variable because the ati
+    // Transparency (-> combined_haze)
+    // ATI Bugfix -- can't store combined_haze*density_dist in a variable because the ati
     // compiler gets confused.
-    temp1 = exp(-temp1 * temp2.z);
+    combined_haze = exp(-combined_haze * density_dist);
 
     // Compute haze glow
-    temp2.x = dot(Pn, lightnorm.xyz);
-    temp2.x = 1. - temp2.x;
-        // temp2.x is 0 at the sun and increases away from sun
-    temp2.x = max(temp2.x, .001);   
-        // Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
-    temp2.x *= glow.x;
-        // Higher glow.x gives dimmer glow (because next step is 1 / "angle")
-    temp2.x = pow(temp2.x, glow.z);
-        // glow.z should be negative, so we're doing a sort of (1 / "angle") function
+    float haze_glow = dot(rel_pos_norm, lightnorm.xyz);
+    haze_glow       = 1. - haze_glow;
+    // haze_glow is 0 at the sun and increases away from sun
+    haze_glow = max(haze_glow, .001);
+    // Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
+    haze_glow *= glow.x;
+    // Higher glow.x gives dimmer glow (because next step is 1 / "angle")
+    haze_glow = pow(haze_glow, glow.z);
+    // glow.z should be negative, so we're doing a sort of (1 / "angle") function
 
     // Add "minimum anti-solar illumination"
-    temp2.x += .25;
-
-    temp2.x *= sun_moon_glow_factor;
+    // For sun, add to glow.  For moon, remove glow entirely. SL-13768
+    haze_glow = (sun_moon_glow_factor < 1.0) ? 0.0 : (sun_moon_glow_factor * (haze_glow + 0.25));
 
     // Haze color above cloud
-    vec4 color = (    blue_horizon * blue_weight * (sunlight + ambient_color)
-                + (haze_horizon * haze_weight) * (sunlight * temp2.x + ambient_color)
-             ); 
+    vec4 color = blue_horizon * blue_weight * (sunlight + ambient_color) 
+               + haze_horizon * haze_weight * (sunlight * haze_glow + ambient_color);
 
     // Final atmosphere additive
-    color *= (1. - temp1);
+    color *= (1. - combined_haze);
 
     // Increase ambient when there are more clouds
-    vec4 tmpAmbient = ambient_color;
-    tmpAmbient += max(vec4(0), (1. - ambient_color)) * cloud_shadow * 0.5; 
+    // TODO 9/20: DJH what does this do?  max(0,(1-ambient)) will change the color
+    vec4 ambient = ambient_color + max(vec4(0), (1. - ambient_color)) * cloud_shadow * 0.5;
 
     // Dim sunlight by cloud shadow percentage
     sunlight *= max(0.0, (1. - cloud_shadow));
 
     // Haze color below cloud
-    vec4 additiveColorBelowCloud = (blue_horizon * blue_weight * (sunlight + tmpAmbient)
-                + (haze_horizon * haze_weight) * (sunlight * temp2.x + tmpAmbient)
-             ); 
+    vec4 add_below_cloud = blue_horizon * blue_weight * (sunlight + ambient) 
+                         + haze_horizon * haze_weight * (sunlight * haze_glow + ambient);
 
-    
-    
     // Attenuate cloud color by atmosphere
-    temp1 = sqrt(temp1);    //less atmos opacity (more transparency) below clouds
+    combined_haze = sqrt(combined_haze);  // less atmos opacity (more transparency) below clouds
 
     // At horizon, blend high altitude sky color towards the darker color below the clouds
-    color += (additiveColorBelowCloud - color) * (1. - sqrt(temp1));
-    
-    float optic_d = dot(Pn, lightnorm.xyz);
-
-    vec3 halo_22 = halo22(optic_d);
+    color += (add_below_cloud - color) * (1. - sqrt(combined_haze));
 
+    float optic_d = dot(rel_pos_norm, lightnorm.xyz);
+    vec3  halo_22 = halo22(optic_d);
     color.rgb += rainbow(optic_d);
-
     color.rgb += halo_22;
-
     color.rgb *= 2.;
     color.rgb = scaleSoftClip(color.rgb);
 
-    /// Gamma correct for WL (soft clip effect).
+    // Gamma correct for WL (soft clip effect).
     frag_data[0] = vec4(color.rgb, 1.0);
-    frag_data[1] = vec4(0.0,0.0,0.0,0.0);
-    frag_data[2] = vec4(0.0,0.0,0.0,1.0); //1.0 in norm.w masks off fog
+    frag_data[1] = vec4(0.0, 0.0, 0.0, 0.0);
+    frag_data[2] = vec4(0.0, 0.0, 0.0, 1.0);  // 1.0 in norm.w masks off fog
 }
-
diff --git a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
index b0dff0c628..f4db53e0b7 100644
--- a/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
+++ b/indra/newview/app_settings/shaders/class2/deferred/softenLightF.glsl
@@ -1,24 +1,24 @@
-/** 
+/**
  * @file class2/deferred/softenLightF.glsl
  *
  * $LicenseInfo:firstyear=2007&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2007, Linden Research, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- * 
+ *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
+ *
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
@@ -39,7 +39,7 @@ uniform sampler2DRect specularRect;
 uniform sampler2DRect normalMap;
 uniform sampler2DRect lightMap;
 uniform sampler2DRect depthMap;
-uniform samplerCube environmentMap;
+uniform samplerCube   environmentMap;
 uniform sampler2D     lightFunc;
 
 uniform float blur_size;
@@ -50,7 +50,7 @@ uniform mat3 env_mat;
 
 uniform vec3 sun_dir;
 uniform vec3 moon_dir;
-uniform int sun_up_factor;
+uniform int  sun_up_factor;
 VARYING vec2 vary_fragcoord;
 
 uniform mat4 inv_proj;
@@ -61,10 +61,10 @@ vec4 getPositionWithDepth(vec2 pos_screen, float depth);
 
 void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten, bool use_ao);
 float getAmbientClamp();
-vec3 atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
-vec3 scaleSoftClipFrag(vec3 l);
-vec3 fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
-vec3 fullbrightScaleSoftClip(vec3 light);
+vec3  atmosFragLighting(vec3 l, vec3 additive, vec3 atten);
+vec3  scaleSoftClipFrag(vec3 l);
+vec3  fullbrightAtmosTransportFrag(vec3 light, vec3 additive, vec3 atten);
+vec3  fullbrightScaleSoftClip(vec3 light);
 
 vec3 linear_to_srgb(vec3 c);
 vec3 srgb_to_linear(vec3 c);
@@ -73,128 +73,85 @@ vec3 srgb_to_linear(vec3 c);
 vec4 applyWaterFogView(vec3 pos, vec4 color);
 #endif
 
-void main() 
+void main()
 {
-    vec2 tc = vary_fragcoord.xy;
-    float depth = texture2DRect(depthMap, tc.xy).r;
-    vec4 pos = getPositionWithDepth(tc, depth);
-    vec4 norm = texture2DRect(normalMap, tc);
+    vec2  tc           = vary_fragcoord.xy;
+    float depth        = texture2DRect(depthMap, tc.xy).r;
+    vec4  pos          = getPositionWithDepth(tc, depth);
+    vec4  norm         = texture2DRect(normalMap, tc);
     float envIntensity = norm.z;
-    norm.xyz = getNorm(tc);
-    
-    vec3 light_dir = (sun_up_factor == 1) ? sun_dir : moon_dir;
-    float da = clamp(dot(norm.xyz, light_dir.xyz), 0.0, 1.0);
-    float light_gamma = 1.0/1.3;
-    da = pow(da, light_gamma);
-    
+    norm.xyz           = getNorm(tc);
+
+    vec3  light_dir   = (sun_up_factor == 1) ? sun_dir : moon_dir;
+    float da          = clamp(dot(norm.xyz, light_dir.xyz), 0.0, 1.0);
+    float light_gamma = 1.0 / 1.3;
+    da                = pow(da, light_gamma);
+
     vec4 diffuse = texture2DRect(diffuseRect, tc);
-    
-    vec4 spec = texture2DRect(specularRect, vary_fragcoord.xy);
+    vec4 spec    = texture2DRect(specularRect, vary_fragcoord.xy);
 
     vec2 scol_ambocc = texture2DRect(lightMap, vary_fragcoord.xy).rg;
-    scol_ambocc = pow(scol_ambocc, vec2(light_gamma));
+    scol_ambocc      = pow(scol_ambocc, vec2(light_gamma));
+    float scol       = max(scol_ambocc.r, diffuse.a);
+    float ambocc     = scol_ambocc.g;
 
-    float scol = max(scol_ambocc.r, diffuse.a); 
+    vec3  color = vec3(0);
+    float bloom = 0.0;
 
-    float ambocc = scol_ambocc.g;
+    vec3 sunlit;
+    vec3 amblit;
+    vec3 additive;
+    vec3 atten;
+    calcAtmosphericVars(pos.xyz, light_dir, ambocc, sunlit, amblit, additive, atten, true);
 
-    vec3 color = vec3(0);
-    float bloom = 0.0;
+    color.rgb = amblit;
+
+    float ambient = min(abs(dot(norm.xyz, sun_dir.xyz)), 1.0);
+    ambient *= 0.5;
+    ambient *= ambient;
+    ambient = (1.0 - ambient);
+    color.rgb *= ambient;
+
+    vec3 sun_contrib = min(da, scol) * sunlit;
+    color.rgb += sun_contrib;
+    color.rgb *= diffuse.rgb;
+
+    vec3 refnormpersp = normalize(reflect(pos.xyz, norm.xyz));
+
+    if (spec.a > 0.0)  // specular reflection
     {
-        vec3 sunlit;
-        vec3 amblit;
-        vec3 additive;
-        vec3 atten;
-    
-        calcAtmosphericVars(pos.xyz, light_dir, ambocc, sunlit, amblit, additive, atten, true);
-
-        color.rgb = amblit;
-
-        float ambient = min(abs(dot(norm.xyz, sun_dir.xyz)), 1.0);
-        ambient *= 0.5;
-        ambient *= ambient;
-        ambient = (1.0 - ambient);
-
-        color.rgb *= ambient;
-
-        vec3 sun_contrib = min(da, scol) * sunlit;
-
-        color.rgb += sun_contrib;
-
-        color.rgb *= diffuse.rgb;
-
-        vec3 refnormpersp = normalize(reflect(pos.xyz, norm.xyz));
-
-        if (spec.a > 0.0) // specular reflection
-        {
-
-#if 1 //EEP
-            vec3 npos = -normalize(pos.xyz);
-
-            //vec3 ref = dot(pos+lv, norm);
-            vec3 h = normalize(light_dir.xyz+npos);
-            float nh = dot(norm.xyz, h);
-            float nv = dot(norm.xyz, npos);
-            float vh = dot(npos, h);
-            float sa = nh;
-            float fres = pow(1 - dot(h, npos), 5)*0.4+0.5;
-
-            float gtdenom = 2 * nh;
-            float gt = max(0, min(gtdenom * nv / vh, gtdenom * da / vh));
-            
-            if (nh > 0.0)
-            {
-                float scontrib = fres*texture2D(lightFunc, vec2(nh, spec.a)).r*gt/(nh*da);
-                vec3 sp = sun_contrib*scontrib / 6.0;
-                sp = clamp(sp, vec3(0), vec3(1));
-                bloom += dot(sp, sp) / 4.0;
-                color += sp * spec.rgb;
-            }
-#else //PRODUCTION
-            float sa = dot(refnormpersp, light_dir.xyz);
-            vec3 dumbshiny = sunlit*(texture2D(lightFunc, vec2(sa, spec.a)).r);
-            
-            // add the two types of shiny together
-            vec3 spec_contrib = dumbshiny * spec.rgb;
-            bloom = dot(spec_contrib, spec_contrib) / 6;
-            color.rgb += spec_contrib;
-#endif
+        float sa        = dot(refnormpersp, light_dir.xyz);
+        vec3  dumbshiny = sunlit * scol * (texture2D(lightFunc, vec2(sa, spec.a)).r);
+
+        // add the two types of shiny together
+        vec3 spec_contrib = dumbshiny * spec.rgb;
+        bloom             = dot(spec_contrib, spec_contrib) / 6;
+        color.rgb += spec_contrib;
+    }
+
+    color.rgb = mix(color.rgb, diffuse.rgb, diffuse.a);
 
-        }
-       
-       color.rgb = mix(color.rgb, diffuse.rgb, diffuse.a);
-
-        if (envIntensity > 0.0)
-        { //add environmentmap
-            vec3 env_vec = env_mat * refnormpersp;
-            vec3 reflected_color = textureCube(environmentMap, env_vec).rgb;
-            color = mix(color.rgb, reflected_color, envIntensity);
-        }
-       
-        if (norm.w < 0.5)
-        {
-            color = mix(atmosFragLighting(color, additive, atten), fullbrightAtmosTransportFrag(color, additive, atten), diffuse.a);
-            color = mix(scaleSoftClipFrag(color), fullbrightScaleSoftClip(color), diffuse.a);
-        }
-
-        #ifdef WATER_FOG
-            vec4 fogged = applyWaterFogView(pos.xyz,vec4(color, bloom));
-            color = fogged.rgb;
-            bloom = fogged.a;
-        #endif
+    if (envIntensity > 0.0)
+    {  // add environmentmap
+        vec3 env_vec         = env_mat * refnormpersp;
+        vec3 reflected_color = textureCube(environmentMap, env_vec).rgb;
+        color                = mix(color.rgb, reflected_color, envIntensity);
+    }
 
+    if (norm.w < 0.5)
+    {
+        color = mix(atmosFragLighting(color, additive, atten), fullbrightAtmosTransportFrag(color, additive, atten), diffuse.a);
+        color = mix(scaleSoftClipFrag(color), fullbrightScaleSoftClip(color), diffuse.a);
     }
 
-// linear debuggables
-//color.rgb = vec3(final_da);
-//color.rgb = vec3(ambient);
-//color.rgb = vec3(scol);
-//color.rgb = diffuse_srgb.rgb;
+#ifdef WATER_FOG
+    vec4 fogged = applyWaterFogView(pos.xyz, vec4(color, bloom));
+    color       = fogged.rgb;
+    bloom       = fogged.a;
+#endif
 
     // convert to linear as fullscreen lights need to sum in linear colorspace
     // and will be gamma (re)corrected downstream...
-    
     frag_color.rgb = srgb_to_linear(color.rgb);
-    frag_color.a = bloom;
+    frag_color.a   = bloom;
 }
-
diff --git a/indra/newview/app_settings/shaders/class2/windlight/cloudsV.glsl b/indra/newview/app_settings/shaders/class2/windlight/cloudsV.glsl
index 2c1475d547..1f881eb44b 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/cloudsV.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/cloudsV.glsl
@@ -1,24 +1,24 @@
-/** 
+/**
  * @file class2\wl\cloudsV.glsl
  *
  * $LicenseInfo:firstyear=2005&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2005, Linden Research, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- * 
+ *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
+ *
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
@@ -33,25 +33,26 @@ ATTRIBUTE vec2 texcoord0;
 ///////////////////////////////////////////////////////////////////////////////
 
 // Output parameters
-VARYING vec4 vary_CloudColorSun;
-VARYING vec4 vary_CloudColorAmbient;
+VARYING vec4  vary_CloudColorSun;
+VARYING vec4  vary_CloudColorAmbient;
 VARYING float vary_CloudDensity;
-VARYING vec2 vary_texcoord0;
-VARYING vec2 vary_texcoord1;
-VARYING vec2 vary_texcoord2;
-VARYING vec2 vary_texcoord3;
+
+VARYING vec2  vary_texcoord0;
+VARYING vec2  vary_texcoord1;
+VARYING vec2  vary_texcoord2;
+VARYING vec2  vary_texcoord3;
 VARYING float altitude_blend_factor;
 
 // Inputs
 uniform vec3 camPosLocal;
 
-uniform vec4 lightnorm;
-uniform vec4 sunlight_color;
-uniform vec4 moonlight_color;
-uniform int sun_up_factor;
-uniform vec4 ambient_color;
-uniform vec4 blue_horizon;
-uniform vec4 blue_density;
+uniform vec4  lightnorm;
+uniform vec4  sunlight_color;
+uniform vec4  moonlight_color;
+uniform int   sun_up_factor;
+uniform vec4  ambient_color;
+uniform vec4  blue_horizon;
+uniform vec4  blue_density;
 uniform float haze_horizon;
 uniform float haze_density;
 
@@ -59,141 +60,133 @@ uniform float cloud_shadow;
 uniform float density_multiplier;
 uniform float max_y;
 
-uniform vec4 glow;
+uniform vec4  glow;
 uniform float sun_moon_glow_factor;
 
 uniform vec4 cloud_color;
 
 uniform float cloud_scale;
 
+// NOTE: Keep these in sync!
+//       indra\newview\app_settings\shaders\class1\deferred\skyV.glsl
+//       indra\newview\app_settings\shaders\class1\deferred\cloudsV.glsl
+//       indra\newview\app-settings\shaders\class2\windlight\cloudsV.glsl
+//       indra\newview\lllegacyatmospherics.cpp
+//       indra\newview\llsettingsvo.cpp
 void main()
 {
+    // World / view / projection
+    gl_Position = modelview_projection_matrix * vec4(position.xyz, 1.0);
+
+    // Texture coords
+    // SL-13084 EEP added support for custom cloud textures -- flip them horizontally to match the preview of Clouds > Cloud Scroll
+    vary_texcoord0 = vec2(-texcoord0.x, texcoord0.y);  // See: LLSettingsVOSky::applySpecial
 
-	// World / view / projection
-	gl_Position = modelview_projection_matrix * vec4(position.xyz, 1.0);
+    vary_texcoord0.xy -= 0.5;
+    vary_texcoord0.xy /= cloud_scale;
+    vary_texcoord0.xy += 0.5;
 
-	vary_texcoord0 = texcoord0;
+    vary_texcoord1 = vary_texcoord0;
+    vary_texcoord1.x += lightnorm.x * 0.0125;
+    vary_texcoord1.y += lightnorm.z * 0.0125;
 
-	// Get relative position
-	vec3 P = position.xyz - camPosLocal.xyz + vec3(0,50,0);
+    vary_texcoord2 = vary_texcoord0 * 16.;
+    vary_texcoord3 = vary_texcoord1 * 16.;
+
+    // Get relative position
+    vec3 rel_pos = position.xyz - camPosLocal.xyz + vec3(0, 50, 0);
 
     // fade clouds beyond a certain point so the bottom of the sky dome doesn't look silly at high altitude
-    altitude_blend_factor = clamp((P.y + 512.0) / max_y, 0.0, 1.0);
-
-	// Set altitude
-	if (P.y > 0.)
-	{
-		P *= (max_y / P.y);
-	}
-	else
-	{
-		P *= (-32000. / P.y);
-	}
-
-	// Can normalize then
-	vec3 Pn = normalize(P);
-	float  Plen = length(P);
-
-	// Initialize temp variables
-	vec4 temp1 = vec4(0.);
-	vec4 temp2 = vec4(0.);
-	vec4 blue_weight;
-	vec4 haze_weight;
-	//vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
-	vec4 sunlight = sunlight_color;
-	vec4 light_atten;
-
-    float dens_mul = density_multiplier;
-
-	// Sunlight attenuation effect (hue and brightness) due to atmosphere
-	// this is used later for sunlight modulation at various altitudes
-	light_atten = (blue_density + vec4(haze_density * 0.25)) * (dens_mul * max_y);
-
-	// Calculate relative weights
-	temp1 = abs(blue_density) + vec4(abs(haze_density));
-	blue_weight = blue_density / temp1;
-	haze_weight = haze_density / temp1;
-
-	// Compute sunlight from P & lightnorm (for long rays like sky)
-	temp2.y = max(0., max(0., Pn.y) * 1.0 + lightnorm.y );
-	temp2.y = 1. / temp2.y;
-	sunlight *= exp( - light_atten * temp2.y);
-
-	// Distance
-	temp2.z = Plen * dens_mul;
-
-	// Transparency (-> temp1)
-	// ATI Bugfix -- can't store temp1*temp2.z in a variable because the ati
-	// compiler gets confused.
-	temp1 = exp(-temp1 * temp2.z);
-
-
-	// Compute haze glow
-	temp2.x = dot(Pn, lightnorm.xyz);
-	temp2.x = 1. - temp2.x;
-		// temp2.x is 0 at the sun and increases away from sun
-	temp2.x = max(temp2.x, .001);	
-		// Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
-	temp2.x *= glow.x;
-		// Higher glow.x gives dimmer glow (because next step is 1 / "angle")
-	temp2.x = pow(temp2.x, glow.z);
-		// glow.z should be negative, so we're doing a sort of (1 / "angle") function
-
-    temp2.x *= sun_moon_glow_factor;
-
-	// Add "minimum anti-solar illumination"
-	temp2.x += .25;
-
-	// Increase ambient when there are more clouds
-	vec4 tmpAmbient = ambient_color;
-	tmpAmbient += (1. - tmpAmbient) * cloud_shadow * 0.5; 
-
-	// Dim sunlight by cloud shadow percentage
-	sunlight *= (1. - cloud_shadow);
-
-	// Haze color below cloud
-	vec4 additiveColorBelowCloud = (	  blue_horizon * blue_weight * (sunlight + tmpAmbient)
-				+ (haze_horizon * haze_weight) * (sunlight * temp2.x + tmpAmbient)
-			 );	
-
-	// CLOUDS
-	temp2.y = max(0., lightnorm.y * 2.);
-	temp2.y = 1. / temp2.y;
-	sunlight *= exp( - light_atten * temp2.y);
-
-	// Cloud color out
-	vary_CloudColorSun = (sunlight * temp2.x) * cloud_color;
-	vary_CloudColorAmbient = tmpAmbient * cloud_color;
-	
-	// Attenuate cloud color by atmosphere
-	temp1 = sqrt(temp1);	//less atmos opacity (more transparency) below clouds
-	vary_CloudColorSun *= temp1;
-	vary_CloudColorAmbient *= temp1;
-	vec4 oHazeColorBelowCloud = additiveColorBelowCloud * (1. - temp1);
-
-	// Make a nice cloud density based on the cloud_shadow value that was passed in.
-	vary_CloudDensity = 2. * (cloud_shadow - 0.25);
-
-
-	// Texture coords
-	vary_texcoord0 = texcoord0;
-	vary_texcoord0.xy -= 0.5;
-	vary_texcoord0.xy /= cloud_scale;
-	vary_texcoord0.xy += 0.5;
-
-	vary_texcoord1 = vary_texcoord0;
-	vary_texcoord1.x += lightnorm.x * 0.0125;
-	vary_texcoord1.y += lightnorm.z * 0.0125;
-
-	vary_texcoord2 = vary_texcoord0 * 16.;
-	vary_texcoord3 = vary_texcoord1 * 16.;
-
-	// Combine these to minimize register use
-	vary_CloudColorAmbient += oHazeColorBelowCloud;
-
-	// needs this to compile on mac
-	//vary_AtmosAttenuation = vec3(0.0,0.0,0.0);
-
-	// END CLOUDS
+    altitude_blend_factor = clamp((rel_pos.y + 512.0) / max_y, 0.0, 1.0);
+
+    // Adj position vector to clamp altitude
+    if (rel_pos.y > 0.)
+    {
+        rel_pos *= (max_y / rel_pos.y);
+    }
+    if (rel_pos.y < 0.)
+    {
+        rel_pos *= (-32000. / rel_pos.y);
+    }
+
+    // Can normalize then
+    vec3  rel_pos_norm = normalize(rel_pos);
+    float rel_pos_len  = length(rel_pos);
+
+    // Initialize temp variables
+    vec4 sunlight = sunlight_color;
+    vec4 light_atten;
+
+    // Sunlight attenuation effect (hue and brightness) due to atmosphere
+    // this is used later for sunlight modulation at various altitudes
+    light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
+
+    // Calculate relative weights
+    vec4 combined_haze = abs(blue_density) + vec4(abs(haze_density));
+    vec4 blue_weight   = blue_density / combined_haze;
+    vec4 haze_weight   = haze_density / combined_haze;
+
+    // Compute sunlight from rel_pos & lightnorm (for long rays like sky)
+    float off_axis = 1.0 / max(1e-6, max(0., rel_pos_norm.y) + lightnorm.y);
+    sunlight *= exp(-light_atten * off_axis);
+
+    // Distance
+    float density_dist = rel_pos_len * density_multiplier;
+
+    // Transparency (-> combined_haze)
+    // ATI Bugfix -- can't store combined_haze*density_dist in a variable because the ati
+    // compiler gets confused.
+    combined_haze = exp(-combined_haze * density_dist);
+
+    // Compute haze glow
+    float haze_glow = 1.0 - dot(rel_pos_norm, lightnorm.xyz);
+    // haze_glow is 0 at the sun and increases away from sun
+    haze_glow = max(haze_glow, .001);
+    // Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
+    haze_glow *= glow.x;
+    // Higher glow.x gives dimmer glow (because next step is 1 / "angle")
+    haze_glow = pow(haze_glow, glow.z);
+    // glow.z should be negative, so we're doing a sort of (1 / "angle") function
+
+    haze_glow *= sun_moon_glow_factor;
+
+    // Add "minimum anti-solar illumination"
+    // For sun, add to glow.  For moon, remove glow entirely. SL-13768
+    haze_glow = (sun_moon_glow_factor < 1.0) ? 0.0 : (haze_glow + 0.25);
+
+    // Increase ambient when there are more clouds
+    vec4 tmpAmbient = ambient_color;
+    tmpAmbient += (1. - tmpAmbient) * cloud_shadow * 0.5;
+
+    // Dim sunlight by cloud shadow percentage
+    sunlight *= (1. - cloud_shadow);
+
+    // Haze color below cloud
+    vec4 additiveColorBelowCloud =
+        (blue_horizon * blue_weight * (sunlight + tmpAmbient) + (haze_horizon * haze_weight) * (sunlight * haze_glow + tmpAmbient));
+
+    // CLOUDS
+    off_axis = 1.0 / max(1e-6, lightnorm.y * 2.);
+    sunlight *= exp(-light_atten * off_axis);
+
+    // Cloud color out
+    vary_CloudColorSun     = (sunlight * haze_glow) * cloud_color;
+    vary_CloudColorAmbient = tmpAmbient * cloud_color;
+
+    // Attenuate cloud color by atmosphere
+    combined_haze = sqrt(combined_haze);  // less atmos opacity (more transparency) below clouds
+    vary_CloudColorSun *= combined_haze;
+    vary_CloudColorAmbient *= combined_haze;
+    vec4 oHazeColorBelowCloud = additiveColorBelowCloud * (1. - combined_haze);
+
+    // Make a nice cloud density based on the cloud_shadow value that was passed in.
+    vary_CloudDensity = 2. * (cloud_shadow - 0.25);
+
+    // Combine these to minimize register use
+    vary_CloudColorAmbient += oHazeColorBelowCloud;
+
+    // needs this to compile on mac
+    // vary_AtmosAttenuation = vec3(0.0,0.0,0.0);
+
+    // END CLOUDS
 }
-
diff --git a/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl b/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
index 0d141342ce..a0a33b8642 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
@@ -1,28 +1,28 @@
-/** 
+/**
  * @file class2\wl\skyV.glsl
  *
  * $LicenseInfo:firstyear=2005&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2005, Linden Research, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- * 
+ *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- * 
+ *
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  */
- 
+
 uniform mat4 modelview_projection_matrix;
 
 ATTRIBUTE vec3 position;
@@ -37,13 +37,13 @@ VARYING vec4 vary_HazeColor;
 // Inputs
 uniform vec3 camPosLocal;
 
-uniform vec4 lightnorm;
-uniform vec4 sunlight_color;
-uniform vec4 moonlight_color;
-uniform int sun_up_factor;
-uniform vec4 ambient_color;
-uniform vec4 blue_horizon;
-uniform vec4 blue_density;
+uniform vec4  lightnorm;
+uniform vec4  sunlight_color;
+uniform vec4  moonlight_color;
+uniform int   sun_up_factor;
+uniform vec4  ambient_color;
+uniform vec4  blue_horizon;
+uniform vec4  blue_density;
 uniform float haze_horizon;
 uniform float haze_density;
 
@@ -52,110 +52,98 @@ uniform float density_multiplier;
 uniform float distance_multiplier;
 uniform float max_y;
 
-uniform vec4 glow;
+uniform vec4  glow;
 uniform float sun_moon_glow_factor;
 
 uniform vec4 cloud_color;
 
 void main()
 {
-
-	// World / view / projection
+    // World / view / projection
     vec4 pos = modelview_projection_matrix * vec4(position.xyz, 1.0);
 
-	gl_Position = pos;
-	
-	// Get relative position
-	vec3 P = position.xyz - camPosLocal.xyz + vec3(0,50,0);
-
-	// Set altitude
-	if (P.y > 0.)
-	{
-		P *= (max_y / P.y);
-	}
-	else
-	{
-		P *= (-32000. / P.y);
-	}
-
-	// Can normalize then
-	vec3 Pn = normalize(P);
-
-	float Plen = length(P);
-
-	// Initialize temp variables
-	vec4 temp1 = vec4(0.);
-	vec4 temp2 = vec4(0.);
-	vec4 blue_weight;
-	vec4 haze_weight;
-	vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
-	vec4 light_atten;
-
-    float dens_mul = density_multiplier;
-
-	// Sunlight attenuation effect (hue and brightness) due to atmosphere
-	// this is used later for sunlight modulation at various altitudes
-	light_atten = (blue_density + vec4(haze_density * 0.25)) * (dens_mul * max_y);
-
-	// Calculate relative weights
-	temp1 = abs(blue_density) + vec4(abs(haze_density));
-	blue_weight = blue_density / temp1;
-	haze_weight = haze_density / temp1;
-
-	// Compute sunlight from P & lightnorm (for long rays like sky)
-    temp2.y = max(0., max(0., Pn.y) * 1.0 + lightnorm.y );
-    temp2.y = 1. / temp2.y;
-    sunlight *= exp( - light_atten * temp2.y);
-
-	// Distance
-	temp2.z = Plen * dens_mul;
-
-	// Transparency (-> temp1)
-    // ATI Bugfix -- can't store temp1*temp2.z in a variable because the ati
-    // compiler gets confused.
-    temp1 = exp(-temp1 * temp2.z);
+    gl_Position = pos;
+
+    // Get relative position
+    vec3 rel_pos = position.xyz - camPosLocal.xyz + vec3(0, 50, 0);
+
+    // Adj position vector to clamp altitude
+    if (rel_pos.y > 0.)
+    {
+        rel_pos *= (max_y / rel_pos.y);
+    }
+    if (rel_pos.y < 0.)
+    {
+        rel_pos *= (-32000. / rel_pos.y);
+    }
 
-	// Compute haze glow
-	temp2.x = dot(Pn, lightnorm.xyz);
-	temp2.x = 1. - temp2.x;
-		// temp2.x is 0 at the sun and increases away from sun
-	temp2.x = max(temp2.x, .001);	
-		// Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
-	temp2.x *= glow.x;
-		// Higher glow.x gives dimmer glow (because next step is 1 / "angle")
-	temp2.x = pow(temp2.x, glow.z);
-		// glow.z should be negative, so we're doing a sort of (1 / "angle") function
+    // Can normalize then
+    vec3 rel_pos_norm = normalize(rel_pos);
 
-	// Add "minimum anti-solar illumination"
-	temp2.x += .25;
+    float rel_pos_len = length(rel_pos);
 
-    vec4 color = (    blue_horizon * blue_weight * (sunlight + ambient_color)
-                + (haze_horizon * haze_weight) * (sunlight * temp2.x + ambient_color)
-             );
+    // Initialize temp variables
+    vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
+    vec4 light_atten;
 
+    // Sunlight attenuation effect (hue and brightness) due to atmosphere
+    // this is used later for sunlight modulation at various altitudes
+    light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
+
+    // Calculate relative weights
+    vec4 combined_haze = abs(blue_density) + vec4(abs(haze_density));
+    vec4 blue_weight   = blue_density / combined_haze;
+    vec4 haze_weight   = haze_density / combined_haze;
+
+    // Compute sunlight from rel_pos & lightnorm (for long rays like sky)
+    float off_axis = 1.0 / max(1e-6, max(0., rel_pos_norm.y) + lightnorm.y);
+    sunlight *= exp(-light_atten * off_axis);
+
+    // Distance
+    float density_dist = rel_pos_len * density_multiplier;
+
+    // Transparency (-> combined_haze)
+    // ATI Bugfix -- can't store combined_haze*density_dist in a variable because the ati
+    // compiler gets confused.
+    combined_haze = exp(-combined_haze * density_dist);
+
+    // Compute haze glow
+    float haze_glow = 1.0 - dot(rel_pos_norm, lightnorm.xyz);
+    // haze_glow is 0 at the sun and increases away from sun
+    haze_glow = max(haze_glow, .001);
+    // Set a minimum "angle" (smaller glow.y allows tighter, brighter hotspot)
+    haze_glow *= glow.x;
+    // Higher glow.x gives dimmer glow (because next step is 1 / "angle")
+    haze_glow = pow(haze_glow, glow.z);
+    // glow.z should be negative, so we're doing a sort of (1 / "angle") function
+
+    // Add "minimum anti-solar illumination"
+    // For sun, add to glow.  For moon, remove glow entirely. SL-13768
+    haze_glow = (sun_moon_glow_factor < 1.0) ? 0.0 : (haze_glow + 0.25);
+
+    vec4 color =
+        (blue_horizon * blue_weight * (sunlight + ambient_color) + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient_color));
 
     // Final atmosphere additive
-    color *= (1. - temp1);
+    color *= (1. - combined_haze);
 
-	// Increase ambient when there are more clouds
-	vec4 tmpAmbient = ambient_color;
-	tmpAmbient += max(vec4(0), (1. - ambient_color)) * cloud_shadow * 0.5; 
+    // Increase ambient when there are more clouds
+    vec4 tmpAmbient = ambient_color;
+    tmpAmbient += max(vec4(0), (1. - ambient_color)) * cloud_shadow * 0.5;
 
-	// Dim sunlight by cloud shadow percentage
-	sunlight *= max(0.0, (1. - cloud_shadow));
+    // Dim sunlight by cloud shadow percentage
+    sunlight *= max(0.0, (1. - cloud_shadow));
 
-	// Haze color below cloud
-	vec4 additiveColorBelowCloud = (	  blue_horizon * blue_weight * (sunlight + tmpAmbient)
-				+ (haze_horizon * haze_weight) * (sunlight * temp2.x + tmpAmbient)
-			 );	
+    // Haze color below cloud
+    vec4 additiveColorBelowCloud =
+        (blue_horizon * blue_weight * (sunlight + tmpAmbient) + (haze_horizon * haze_weight) * (sunlight * haze_glow + tmpAmbient));
 
-	// Attenuate cloud color by atmosphere
-	temp1 = sqrt(temp1);	//less atmos opacity (more transparency) below clouds
+    // Attenuate cloud color by atmosphere
+    combined_haze = sqrt(combined_haze);  // less atmos opacity (more transparency) below clouds
 
-	// At horizon, blend high altitude sky color towards the darker color below the clouds
-	color += (additiveColorBelowCloud - color) * (1. - sqrt(temp1));
+    // At horizon, blend high altitude sky color towards the darker color below the clouds
+    color += (additiveColorBelowCloud - color) * (1. - sqrt(combined_haze));
 
     // Haze color above cloud
-	vary_HazeColor = color;	
+    vary_HazeColor = color;
 }
-