DRTVWR-559 Revert skies to be very close to release and disable tone mapping when probe ambiance is zero.

Hack for desaturating legacy materials has been removed for performance and quality reasons.

Adds a new setting for auto adjusting legacy skies.  This is the PBR "opt out" button.  If disabled, legacy skies will disable tonemapping, automatic probe ambiance, and HDR/exposure.  If enabled, legacy skies will behave as if probe ambiance and HDR scale are 1.0, and ambient will be cut in half.  

HDR scale will act as a sky brightener, but will automatically adjust dynamic exposure so the sky will be properly exposed.  If you want relatively even exposure all the time, set HDR Scale to 1.0.  If you want a high range of exposures between indoor/dark areas and outdoor/bright areas, increase HDR Scale.

Also tuned up SSAO (thanks Rye!).

Reviewed with Brad.

1 files changed, 16 insertions, 19 deletions

diff --git a/indra/newview/llsettingsvo.cpp b/indra/newview/llsettingsvo.cpp
index de11f580a8..6321dbc085 100644
--- a/indra/newview/llsettingsvo.cpp
+++ b/indra/newview/llsettingsvo.cpp
@@ -718,45 +718,42 @@ void LLSettingsVOSky::applySpecial(void *ptarget, bool force)
 
     F32 g = getGamma();
 
+    static LLCachedControl<bool> should_auto_adjust(gSavedSettings, "RenderSkyAutoAdjustLegacy", true);
+
+    static LLCachedControl<F32> cloud_shadow_scale(gSavedSettings, "RenderCloudShadowAmbianceFactor", 0.125f);
+    F32 probe_ambiance = getTotalReflectionProbeAmbiance(cloud_shadow_scale);
+
     if (irradiance_pass)
     { // during an irradiance map update, disable ambient lighting (direct lighting only) and desaturate sky color (avoid tinting the world blue)
-        shader->uniform3fv(LLShaderMgr::AMBIENT_LINEAR, LLVector3::zero.mV);
         shader->uniform3fv(LLShaderMgr::AMBIENT, LLVector3::zero.mV);
     }
     else
     {
-        if (psky->getReflectionProbeAmbiance() == 0.f)
+        if (psky->getReflectionProbeAmbiance() != 0.f)
         {
-            LLVector3 ambcol(ambient.mV);
-            F32 cloud_shadow = psky->getCloudShadow();
-            LLVector3 tmpAmbient = ambcol + ((LLVector3::all_one - ambcol) * cloud_shadow * 0.5f);
-
-            shader->uniform3fv(LLShaderMgr::AMBIENT_LINEAR, linearColor3v(tmpAmbient));
-            shader->uniform3fv(LLShaderMgr::AMBIENT, tmpAmbient.mV);
+            shader->uniform3fv(LLShaderMgr::AMBIENT, getAmbientColor().mV);
+            shader->uniform1f(LLShaderMgr::SKY_HDR_SCALE, sqrtf(g)*2.0); // use a modifier here so 1.0 maps to the "most desirable" default and the maximum value doesn't go off the rails
+        }
+        else if (psky->canAutoAdjust() && should_auto_adjust)
+        { // auto-adjust legacy sky to take advantage of probe ambiance 
+            shader->uniform3fv(LLShaderMgr::AMBIENT, (ambient * 0.5f).mV);
+            shader->uniform1f(LLShaderMgr::SKY_HDR_SCALE, 2.f);
+            probe_ambiance = 1.f;
         }
         else
         {
-            shader->uniform3fv(LLShaderMgr::AMBIENT_LINEAR, linearColor3v(getAmbientColor() / 3.f)); // note magic number 3.f comes from SLIDER_SCALE_SUN_AMBIENT
+            shader->uniform1f(LLShaderMgr::SKY_HDR_SCALE, 1.f);
             shader->uniform3fv(LLShaderMgr::AMBIENT, LLVector3(ambient.mV));
         }
     }
 
-    shader->uniform3fv(LLShaderMgr::BLUE_HORIZON_LINEAR, linearColor3v(getBlueHorizon() / 2.f)); // note magic number of 2.f comes from SLIDER_SCALE_BLUE_HORIZON_DENSITY
-    shader->uniform3fv(LLShaderMgr::BLUE_DENSITY_LINEAR, linearColor3v(getBlueDensity() / 2.f));
-
-    shader->uniform3fv(LLShaderMgr::SUNLIGHT_LINEAR, linearColor3v(sunDiffuse));
-    shader->uniform3fv(LLShaderMgr::MOONLIGHT_LINEAR,linearColor3v(moonDiffuse));
-
-    static LLCachedControl<F32> cloud_shadow_scale(gSavedSettings, "RenderCloudShadowAmbianceFactor", 0.125f);
-    shader->uniform1f(LLShaderMgr::REFLECTION_PROBE_AMBIANCE, getTotalReflectionProbeAmbiance(cloud_shadow_scale));
+    shader->uniform1f(LLShaderMgr::REFLECTION_PROBE_AMBIANCE, probe_ambiance);
 
     shader->uniform1i(LLShaderMgr::SUN_UP_FACTOR, getIsSunUp() ? 1 : 0);
     shader->uniform1f(LLShaderMgr::SUN_MOON_GLOW_FACTOR, getSunMoonGlowFactor());
     shader->uniform1f(LLShaderMgr::DENSITY_MULTIPLIER, getDensityMultiplier());
     shader->uniform1f(LLShaderMgr::DISTANCE_MULTIPLIER, getDistanceMultiplier());
 
-    shader->uniform1f(LLShaderMgr::HAZE_DENSITY_LINEAR, sRGBtoLinear(getHazeDensity()));
-
     shader->uniform1f(LLShaderMgr::GAMMA, g);
 }