Merge remote-tracking branch 'origin/main' into DRTVWR-559

2 files changed, 64 insertions, 21 deletions

diff --git a/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl b/indra/newview/app_settings/shaders/class1/deferred/skyF.glsl
index adc2db60b6..849e1c4893 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
@@ -37,9 +48,34 @@ out vec4 frag_data[3];
 
 VARYING vec3 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 +84,18 @@ void main()
     // the fragment) if the sky wouldn't show up because the clouds 
     // are fully opaque.
 
-    vec3 color;
-    color = vary_HazeColor;
+    vec3 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,GBUFFER_FLAG_SKIP_ATMOS); //1.0 in norm.w masks off fog
 
diff --git a/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl b/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
index ff53646fd4..3b24311f2b 100644
--- a/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
+++ b/indra/newview/app_settings/shaders/class1/deferred/skyV.glsl
@@ -33,6 +33,7 @@ ATTRIBUTE vec3 position;
 
 // Output parameters
 VARYING vec3 vary_HazeColor;
+VARYING float vary_LightNormPosDot;
 
 // Inputs
 uniform vec3 camPosLocal;
@@ -70,27 +71,29 @@ void main()
     vec3 rel_pos = position.xyz - camPosLocal.xyz + vec3(0, 50, 0);
 
     // Adj position vector to clamp altitude
-    if (rel_pos.y > 0)
+    if (rel_pos.y > 0.)
     {
         rel_pos *= (max_y / rel_pos.y);
     }
-    if (rel_pos.y < 0)
+    if (rel_pos.y < 0.)
     {
         rel_pos *= (-32000. / rel_pos.y);
     }
 
-    // Can normalize then
-    vec3 rel_pos_norm = normalize(rel_pos);
+    // Normalized
+    vec3  rel_pos_norm = normalize(rel_pos);
+    float rel_pos_len  = length(rel_pos);
 
-    float rel_pos_len = length(rel_pos);
+    // Grab this value and pass to frag shader for rainbows
+    float rel_pos_lightnorm_dot = dot(rel_pos_norm, lightnorm.xyz);
+    vary_LightNormPosDot = rel_pos_lightnorm_dot;
 
     // Initialize temp variables
     vec3 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
-    vec3 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 + vec3(haze_density * 0.25)) * (density_multiplier * max_y);
+    vec3 light_atten = (blue_density + vec3(haze_density * 0.25)) * (density_multiplier * max_y);
 
     // Calculate relative weights
     vec3 combined_haze = abs(blue_density) + vec4(abs(haze_density));
@@ -110,7 +113,7 @@ void main()
     combined_haze = exp(-combined_haze * density_dist);
 
     // Compute haze glow
-    float haze_glow = 1.0 - dot(rel_pos_norm, lightnorm.xyz);
+    float haze_glow = 1.0 - rel_pos_lightnorm_dot;
     // 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)
@@ -121,30 +124,30 @@ void main()
 
     // 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);
+    haze_glow = (sun_moon_glow_factor < 1.0) ? 0.0 : (sun_moon_glow_factor * (haze_glow + 0.25));
 
-    vec3 color =
-        (blue_horizon * blue_weight * (sunlight + ambient_color) + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient_color));
+    // Haze color above cloud
+    vec3 color = (blue_horizon * blue_weight * (sunlight + ambient_color)
+               + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient_color));
 
     // Final atmosphere additive
     color *= (1. - combined_haze);
 
     // Increase ambient when there are more clouds
-    vec3 tmpAmbient = ambient_color;
-    tmpAmbient += max(vec3(0), (1. - ambient_color)) * cloud_shadow * 0.5;
+    vec3 ambient = ambient_color + max(vec3(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
-    vec3 additiveColorBelowCloud =
-        (blue_horizon * blue_weight * (sunlight + tmpAmbient) + (haze_horizon * haze_weight) * (sunlight * haze_glow + tmpAmbient));
+    vec3 add_below_cloud = (blue_horizon * blue_weight * (sunlight + ambient) 
+                         + (haze_horizon * haze_weight) * (sunlight * haze_glow + ambient));
 
     // 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(combined_haze));
+    color += (add_below_cloud - color) * (1. - sqrt(combined_haze));
 
     // Haze color above cloud
     vary_HazeColor = color;