SL-10303

Modify sun disc shader to better position itself within the sun glow and to
fade as the sun approaches the horizon (to mask where the position difference is greatest).

2 files changed, 19 insertions, 11 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/sunDiscF.glsl b/indra/newview/app_settings/shaders/class1/deferred/sunDiscF.glsl
index 3557c0766e..c66f3f62b2 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/sunDiscF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/sunDiscF.glsl
@@ -40,17 +40,21 @@ uniform sampler2D diffuseMap;
 uniform sampler2D altDiffuseMap;
 uniform float blend_factor; // interp factor between sunDisc A/B
 VARYING vec2 vary_texcoord0;
+VARYING float sun_fade;
 
 void main() 
 {
-	vec4 sunDiscA = texture2D(diffuseMap, vary_texcoord0.xy);
-	vec4 sunDiscB = texture2D(altDiffuseMap, vary_texcoord0.xy);
+    vec4 sunDiscA = texture2D(diffuseMap, vary_texcoord0.xy);
+    vec4 sunDiscB = texture2D(altDiffuseMap, vary_texcoord0.xy);
     vec4 c     = mix(sunDiscA, sunDiscB, blend_factor);
     c.rgb = clamp(c.rgb, vec3(0), vec3(1));
-	c.rgb = pow(c.rgb, vec3(0.7f));
-	c.rgb = fullbrightAtmosTransport(c.rgb);
+    c.rgb = pow(c.rgb, vec3(0.7f));
+    c.rgb = fullbrightAtmosTransport(c.rgb);
     c.rgb = fullbrightScaleSoftClip(c.rgb);
-	frag_data[0] = c;
+
+    c.a *= sun_fade;
+
+    frag_data[0] = c;
     frag_data[1] = vec4(0.0f);
     frag_data[2] = vec4(0.0, 1.0, 0.0, 1.0);
 }
diff --git a/indra/newview/app_settings/shaders/class1/deferred/sunDiscV.glsl b/indra/newview/app_settings/shaders/class1/deferred/sunDiscV.glsl
index c67ed8e6d9..0d117c6bc7 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/sunDiscV.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/sunDiscV.glsl
@@ -31,18 +31,22 @@ ATTRIBUTE vec3 position;
 ATTRIBUTE vec2 texcoord0;
 
 VARYING vec2 vary_texcoord0;
+VARYING float sun_fade;
 
 void calcAtmospherics(vec3 eye_pos);
 
 void main()
 {
-	//transform vertex
-	vec4 vert = vec4(position.xyz - vec3(0, 0, 50), 1.0);
-	vec4 pos  = modelview_projection_matrix*vert;
+    //transform vertex
+    vec3 offset = vec3(0, 0, 50);
+    vec4 vert = vec4(position.xyz - offset, 1.0);
+    vec4 pos  = modelview_projection_matrix*vert;
 
-	gl_Position = pos;
-	
+    sun_fade = smoothstep(0.3, 1.0, (position.z + 50) / 512.0f);
+
+    gl_Position = pos;
+    
     calcAtmospherics(pos.xyz);
 
-	vary_texcoord0 = (texture_matrix0 * vec4(texcoord0,0,1)).xy;
+    vary_texcoord0 = (texture_matrix0 * vec4(texcoord0,0,1)).xy;
 }