SL-11550

1 files changed, 24 insertions, 26 deletions

diff --git a/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl b/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
index d81a8feb96..0d141342ce 100644
--- a/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
+++ b/indra/newview/app_settings/shaders/class2/windlight/skyV.glsl
@@ -54,17 +54,19 @@ uniform float max_y;
 
 uniform vec4 glow;
 uniform float sun_moon_glow_factor;
+
 uniform vec4 cloud_color;
 
 void main()
 {
 
 	// World / view / projection
-	gl_Position = modelview_projection_matrix * vec4(position.xyz, 1.0);
+    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);
-	//vec3 P = position.xyz + vec3(0,50,0);
 
 	// Set altitude
 	if (P.y > 0.)
@@ -78,7 +80,8 @@ void main()
 
 	// Can normalize then
 	vec3 Pn = normalize(P);
-	float  Plen = length(P);
+
+	float Plen = length(P);
 
 	// Initialize temp variables
 	vec4 temp1 = vec4(0.);
@@ -89,29 +92,28 @@ void main()
 	vec4 light_atten;
 
     float dens_mul = density_multiplier;
-    float dist_mul = max(0.05, distance_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 = blue_density + haze_density;
+	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);
+    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);
+    // 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);
@@ -124,40 +126,36 @@ void main()
 	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;
 
+    vec4 color = (    blue_horizon * blue_weight * (sunlight + ambient_color)
+                + (haze_horizon * haze_weight) * (sunlight * temp2.x + ambient_color)
+             );
 
-	// Haze color above cloud
-	vary_HazeColor = (	  blue_horizon * blue_weight * (sunlight + ambient_color)
-				+ (haze_horizon * haze_weight) * (sunlight * temp2.x + ambient_color)
-			 );	
 
+    // Final atmosphere additive
+    color *= (1. - temp1);
 
 	// Increase ambient when there are more clouds
 	vec4 tmpAmbient = ambient_color;
-	tmpAmbient += (1. - tmpAmbient) * cloud_shadow * 0.5; 
+	tmpAmbient += max(vec4(0), (1. - ambient_color)) * cloud_shadow * 0.5; 
 
 	// Dim sunlight by cloud shadow percentage
-	sunlight *= (1. - cloud_shadow);
+	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)
 			 );	
 
-	// Final atmosphere additive
-	vary_HazeColor *= (1. - temp1);
-	
 	// Attenuate cloud color by atmosphere
 	temp1 = sqrt(temp1);	//less atmos opacity (more transparency) below clouds
 
 	// At horizon, blend high altitude sky color towards the darker color below the clouds
-	vary_HazeColor += (additiveColorBelowCloud - vary_HazeColor) * (1. - sqrt(temp1));
-	
-	// won't compile on mac without this being set
-	//vary_AtmosAttenuation = vec3(0.0,0.0,0.0);
+	color += (additiveColorBelowCloud - color) * (1. - sqrt(temp1));
+
+    // Haze color above cloud
+	vary_HazeColor = color;	
 }