diff --git a/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
index 140d788ffffa3de5df6f2f8a3ecbc8af67f6e52e..05e6e6a9f940b2b9577479cd0c9416c7e237c74a 100644
--- a/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
+++ b/indra/newview/app_settings/shaders/class1/windlight/atmosphericsFuncs.glsl
@@ -1,141 +1,119 @@
-/**
+/**
* @file class1\windlight\atmosphericsFuncs.glsl
*
* $LicenseInfo:firstyear=2005&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2019, Linden Research, Inc.
- *
+ *
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
- *
+ *
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
+ *
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
-uniform vec4 lightnorm;
-uniform vec4 sunlight_color;
-uniform vec4 moonlight_color;
-uniform int sun_up_factor;
-uniform vec4 ambient_color;
-uniform vec4 blue_horizon;
-uniform vec4 blue_density;
+uniform vec4 lightnorm;
+uniform vec4 sunlight_color;
+uniform vec4 moonlight_color;
+uniform int sun_up_factor;
+uniform vec4 ambient_color;
+uniform vec4 blue_horizon;
+uniform vec4 blue_density;
uniform float haze_horizon;
uniform float haze_density;
uniform float cloud_shadow;
uniform float density_multiplier;
uniform float distance_multiplier;
uniform float max_y;
-uniform vec4 glow;
+uniform vec4 glow;
uniform float scene_light_strength;
-uniform mat3 ssao_effect_mat;
-uniform int no_atmo;
+uniform mat3 ssao_effect_mat;
+uniform int no_atmo;
uniform float sun_moon_glow_factor;
-float getAmbientClamp()
-{
- return 1.0f;
-}
+float getAmbientClamp() { return 1.0f; }
-
-void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive, out vec3 atten, bool use_ao)
+void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, out vec3 sunlit, out vec3 amblit, out vec3 additive,
+ out vec3 atten, bool use_ao)
{
- vec3 P = inPositionEye;
-
- //(TERRAIN) limit altitude
- if (P.y > max_y) P *= ( max_y / P.y);
- if (P.y < -max_y) P *= (-max_y / P.y);
-
- vec3 tmpLightnorm = lightnorm.xyz;
+ vec3 rel_pos = inPositionEye;
- vec3 Pn = normalize(P);
- float Plen = length(P);
-
- vec4 temp1 = vec4(0);
- vec3 temp2 = vec3(0);
- vec4 blue_weight;
- vec4 haze_weight;
- vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
- vec4 light_atten;
+ //(TERRAIN) limit altitude
+ rel_pos.y = clamp(rel_pos.y, -max_y, max_y);
- float dens_mul = density_multiplier;
- float dist_mul = distance_multiplier;
+ vec3 rel_pos_norm = normalize(rel_pos);
+ float rel_pos_len = length(rel_pos);
+ vec4 sunlight = (sun_up_factor == 1) ? sunlight_color : moonlight_color;
- //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);
- //I had thought blue_density and haze_density should have equal weighting,
- //but attenuation due to haze_density tends to seem too strong
+ // sunlight attenuation effect (hue and brightness) due to atmosphere
+ // this is used later for sunlight modulation at various altitudes
+ vec4 light_atten = (blue_density + vec4(haze_density * 0.25)) * (density_multiplier * max_y);
+ // 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);
- blue_weight = blue_density / temp1;
- haze_weight = vec4(haze_density) / temp1;
+ vec4 combined_haze = blue_density + vec4(haze_density);
+ vec4 blue_weight = blue_density / combined_haze;
+ vec4 haze_weight = vec4(haze_density) / combined_haze;
- //(TERRAIN) compute sunlight from lightnorm only (for short rays like terrain)
- temp2.y = max(0.0, tmpLightnorm.y);
- if (abs(temp2.y) > 0.000001f)
- {
- temp2.y = 1. / abs(temp2.y);
- }
- temp2.y = max(0.0000001f, temp2.y);
- sunlight *= exp(-light_atten * temp2.y);
+ //(TERRAIN) compute sunlight from lightnorm y component. Factor is roughly cosecant(sun elevation) (for short rays like terrain)
+ float above_horizon_factor = 1.0 / max(1e-6, lightnorm.y);
+ sunlight *= exp(-light_atten * above_horizon_factor); // for sun [horizon..overhead] this maps to an exp curve [0..1]
// main atmospheric scattering line integral
- temp2.z = Plen * dens_mul;
+ float density_dist = rel_pos_len * density_multiplier;
- // Transparency (-> temp1)
- // ATI Bugfix -- can't store temp1*temp2.z*dist_mul in a variable because the ati
+ // Transparency (-> combined_haze)
+ // ATI Bugfix -- can't store combined_haze*density_dist*distance_multiplier in a variable because the ati
// compiler gets confused.
- temp1 = exp(-temp1 * temp2.z * dist_mul);
+ combined_haze = exp(-combined_haze * density_dist * distance_multiplier);
+
+ // final atmosphere attenuation factor
+ atten = combined_haze.rgb;
- //final atmosphere attenuation factor
- atten = temp1.rgb;
-
- //compute haze glow
- //(can use temp2.x as temp because we haven't used it yet)
- temp2.x = dot(Pn, tmpLightnorm.xyz);
+ // compute haze glow
+ float haze_glow = dot(rel_pos_norm, lightnorm.xyz);
// dampen sun additive contrib when not facing it...
- // SL-13539: This "if" clause causes an "additive" white artifact at roughly 77 degreees.
+ // SL-13539: This "if" clause causes an "additive" white artifact at roughly 77 degreees.
// if (length(light_dir) > 0.01)
- {
- temp2.x *= max(0.0f, dot(light_dir, Pn));
- }
- temp2.x = 1. - temp2.x;
- //temp2.x is 0 at the sun and increases away from sun
- temp2.x = max(temp2.x, .001); //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;
-
- temp2.x *= sun_moon_glow_factor;
-
- vec4 amb_color = ambient_color;
-
- //increase ambient when there are more clouds
+ haze_glow *= max(0.0f, dot(light_dir, rel_pos_norm));
+
+ haze_glow = 1. - haze_glow;
+ // 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)
+ haze_glow *= glow.x;
+ // higher glow.x gives dimmer glow (because next step is 1 / "angle")
+ haze_glow = pow(haze_glow, glow.z);
+ // glow.z should be negative, so we're doing a sort of (1 / "angle") function
+
+ // add "minimum anti-solar illumination"
+ haze_glow += .25;
+
+ haze_glow *= sun_moon_glow_factor;
+
+ vec4 amb_color = ambient_color;
+
+ // increase ambient when there are more clouds
vec4 tmpAmbient = amb_color + (vec4(1.) - amb_color) * cloud_shadow * 0.5;
-
+
/* decrease value and saturation (that in HSV, not HSL) for occluded areas
* // for HSV color/geometry used here, see http://gimp-savvy.com/BOOK/index.html?node52.html
* // The following line of code performs the equivalent of:
* float ambAlpha = tmpAmbient.a;
* float ambValue = dot(vec3(tmpAmbient), vec3(0.577)); // projection onto <1/rt(3), 1/rt(3), 1/rt(3)>, the neutral white-black axis
* vec3 ambHueSat = vec3(tmpAmbient) - vec3(ambValue);
- * tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat, ambAlpha);
+ * tmpAmbient = vec4(RenderSSAOEffect.valueFactor * vec3(ambValue) + RenderSSAOEffect.saturationFactor *(1.0 - ambFactor) * ambHueSat,
+ * ambAlpha);
*/
if (use_ao)
{
@@ -145,13 +123,12 @@ void calcAtmosphericVars(vec3 inPositionEye, vec3 light_dir, float ambFactor, ou
// Similar/Shared Algorithms:
// indra\llinventory\llsettingssky.cpp -- LLSettingsSky::calculateLightSettings()
// indra\newview\app_settings\shaders\class1\windlight\atmosphericsFuncs.glsl -- calcAtmosphericVars()
- //haze color
- vec3 cs = sunlight.rgb * (1.-cloud_shadow);
- additive = (blue_horizon.rgb * blue_weight.rgb) * (cs + tmpAmbient.rgb)
- + (haze_horizon * haze_weight.rgb) * (cs * temp2.x + tmpAmbient.rgb);
+ // haze color
+ vec3 cs = sunlight.rgb * (1. - cloud_shadow);
+ additive = (blue_horizon.rgb * blue_weight.rgb) * (cs + tmpAmbient.rgb) + (haze_horizon * haze_weight.rgb) * (cs * haze_glow + tmpAmbient.rgb);
- //brightness of surface both sunlight and ambient
+ // brightness of surface both sunlight and ambient
sunlit = sunlight.rgb * 0.5;
amblit = tmpAmbient.rgb * .25;
- additive *= vec3(1.0 - temp1);
+ additive *= vec3(1.0 - combined_haze);
}