1 files changed, 137 insertions, 0 deletions

diff --git a/linden/indra/newview/app_settings/shaders/class2/windlight/atmosphericsV.glsl b/linden/indra/newview/app_settings/shaders/class2/windlight/atmosphericsV.glsl
new file mode 100644
index 0000000..e40372e
--- /dev/null
+++ b/linden/indra/newview/app_settings/shaders/class2/windlight/atmosphericsV.glsl
@@ -0,0 +1,137 @@
+/**
+ * @file atmosphericsV.glsl
+ *
+ * Copyright (c) 2005-$CurrentYear$, Linden Research, Inc.
+ * $License$
+ */
+
+// varying param funcs
+void setSunlitColor(vec3 v);
+void setAmblitColor(vec3 v);
+void setAdditiveColor(vec3 v);
+void setAtmosAttenuation(vec3 v);
+void setPositionEye(vec3 v);
+
+vec3 getAdditiveColor();
+
+//varying vec4 vary_CloudUVs;
+//varying float vary_CloudDensity;
+
+// Inputs
+uniform vec4 morphFactor;
+uniform vec3 camPosLocal;
+//uniform vec4 camPosWorld;
+
+uniform vec4 lightnorm;
+uniform vec4 sunlight_color;
+uniform vec4 ambient;
+uniform vec4 blue_horizon;
+uniform vec4 blue_density;
+uniform vec4 haze_horizon;
+uniform vec4 haze_density;
+uniform vec4 cloud_shadow;
+uniform vec4 density_multiplier;
+uniform vec4 distance_multiplier;
+uniform vec4 max_y;
+uniform vec4 glow;
+
+void calcAtmospherics(vec3 inPositionEye) {
+
+        vec3 P = inPositionEye;
+        setPositionEye(P);
+        
+        //(TERRAIN) limit altitude
+        if (P.y > max_y.x) P *= (max_y.x / P.y);
+        if (P.y < -max_y.x) P *= (-max_y.x / P.y);
+
+        vec3 tmpLightnorm = lightnorm.xyz;
+
+        vec3 Pn = normalize(P);
+        float  Plen = length(P);
+
+        vec4 temp1 = vec4(0);
+        vec3 temp2 = vec3(0);
+        vec4 blue_weight;
+        vec4 haze_weight;
+        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 * 1.0 + vec4(haze_density.r) * 0.25) * (density_multiplier.x * max_y.x);
+                //I had thought blue_density and haze_density should have equal weighting,
+                //but attenuation due to haze_density tends to seem too strong
+
+        temp1 = blue_density + vec4(haze_density.r);
+        blue_weight = blue_density / temp1;
+        haze_weight = vec4(haze_density.r) / temp1;
+
+        //(TERRAIN) compute sunlight from lightnorm only (for short rays like terrain)
+        temp2.y = max(0.0, tmpLightnorm.y);
+        temp2.y = 1. / temp2.y;
+        sunlight *= exp( - light_atten * temp2.y);
+
+        // main atmospheric scattering line integral
+        temp2.z = Plen * density_multiplier.x;
+
+        // Transparency (-> temp1)
+        // ATI Bugfix -- can't store temp1*temp2.z*distance_multiplier.x in a variable because the ati
+        // compiler gets confused.
+        temp1 = exp(-temp1 * temp2.z * distance_multiplier.x);
+
+        //final atmosphere attenuation factor
+        setAtmosAttenuation(temp1.rgb);
+        //vary_AtmosAttenuation = distance_multiplier / 10000.;
+        //vary_AtmosAttenuation = density_multiplier * 100.;
+        //vary_AtmosAttenuation = vec4(Plen / 100000., 0., 0., 1.);
+
+        //compute haze glow
+        //(can use temp2.x as temp because we haven't used it yet)
+        temp2.x = dot(Pn, tmpLightnorm.xyz);
+        temp2.x = 1. - temp2.x;
+                //temp2.x is 0 at the sun and increases away from sun
+        temp2.x = max(temp2.x, .03);    //was glow.y
+                //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
+
+        //add "minimum anti-solar illumination"
+        temp2.x += .25;
+
+
+        //increase ambient when there are more clouds
+        vec4 tmpAmbient = ambient + (vec4(1.) - ambient) * cloud_shadow.x * 0.5;
+
+        //haze color
+        setAdditiveColor(
+                vec3(blue_horizon * blue_weight * (sunlight*(1.-cloud_shadow.x) + tmpAmbient)
+          + (haze_horizon.r * haze_weight) * (sunlight*(1.-cloud_shadow.x) * temp2.x
+                  + tmpAmbient)));
+
+        //brightness of surface both sunlight and ambient
+        setSunlitColor(vec3(sunlight * .5));
+        setAmblitColor(vec3(tmpAmbient * .25));
+        setAdditiveColor(getAdditiveColor() * vec3(1.0 - temp1));
+
+        // vary_SunlitColor = vec3(0);
+        // vary_AmblitColor = vec3(0);
+        // vary_AdditiveColor = vec4(Pn, 1.0);
+
+        /*
+        const float cloudShadowScale = 100.;
+        // Get cloud uvs for shadowing
+        vec3 cloudPos = inPositionEye + camPosWorld - cloudShadowScale / 2.;
+        vary_CloudUVs.xy = cloudPos.xz / cloudShadowScale;
+
+        // We can take uv1 and multiply it by (TerrainSpan / CloudSpan)
+//      cloudUVs *= (((worldMaxZ - worldMinZ) * 20) /40000.);
+        vary_CloudUVs *= (10000./40000.);
+
+        // Offset by sun vector * (CloudAltitude / CloudSpan)
+        vary_CloudUVs.x += tmpLightnorm.x / tmpLightnorm.y * (3000./40000.);
+        vary_CloudUVs.y += tmpLightnorm.z / tmpLightnorm.y * (3000./40000.);
+        */
+}
+