1 files changed, 44 insertions, 6 deletions
diff --git a/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl b/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl
index 331249dc33..de22312d3c 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl
@@ -25,6 +25,17 @@
  
 /*[EXTRA_CODE_HERE]*/
 
+// Inputs
+VARYING vec4 vary_HazeColor;
+VARYING float vary_LightNormPosDot;
+
+uniform sampler2D rainbow_map;
+uniform sampler2D halo_map;
+
+uniform float moisture_level;
+uniform float droplet_radius;
+uniform float ice_level;
+
 #ifdef DEFINE_GL_FRAGCOLOR
 out vec4 frag_data[3];
 #else
@@ -35,11 +46,34 @@ out vec4 frag_data[3];
 // The fragment shader for the sky
 /////////////////////////////////////////////////////////////////////////
 
-VARYING vec4 vary_HazeColor;
+vec3 rainbow(float d)
+{
+    // 'Interesting' values of d are -0.75 .. -0.825, i.e. when view vec nearly opposite of sun vec
+    // Rainbox tex is mapped with REPEAT, so -.75 as tex coord is same as 0.25.  -0.825 -> 0.175. etc.
+    // SL-13629
+    // Unfortunately the texture is inverted, so we need to invert the y coord, but keep the 'interesting'
+    // part within the same 0.175..0.250 range, i.e. d = (1 - d) - 1.575
+    d         = clamp(-0.575 - d, 0.0, 1.0);
+
+    // With the colors in the lower 1/4 of the texture, inverting the coords leaves most of it inaccessible.
+    // So, we can stretch the texcoord above the colors (ie > 0.25) to fill the entire remaining coordinate
+    // space. This improves gradation, reduces banding within the rainbow interior. (1-0.25) / (0.425/0.25) = 4.2857
+    float interior_coord = max(0.0, d - 0.25) * 4.2857;
+    d = clamp(d, 0.0, 0.25) + interior_coord;
+
+    float rad = (droplet_radius - 5.0f) / 1024.0f;
+    return pow(texture2D(rainbow_map, vec2(rad+0.5, 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;
+}
 
 /// Soft clips the light with a gamma correction
 vec3 scaleSoftClip(vec3 light);
-vec3 srgb_to_linear(vec3 c);
 
 void main()
 {
@@ -48,14 +82,18 @@ void main()
     // the fragment) if the sky wouldn't show up because the clouds 
     // are fully opaque.
 
-    vec4 color;
-    color = vary_HazeColor;
+    vec4 color = vary_HazeColor;
 
+    float  rel_pos_lightnorm = vary_LightNormPosDot;
+    float optic_d = rel_pos_lightnorm;
+    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).
-    frag_data[0] = vec4(color.rgb, 0.0);
+    // 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