From 07c207346f63d464e45efe0be3aae64138982279 Mon Sep 17 00:00:00 2001
From: Leyla Farazha <leyla@lindenlab.com>
Date: Fri, 30 Apr 2010 15:59:59 -0700
Subject: updated media attenuation function reviewed by Richard

---
 indra/newview/app_settings/settings.xml | 26 ++++++++++++++++++++++++--
 indra/newview/llviewermedia.cpp         | 19 +++++++++----------
 2 files changed, 33 insertions(+), 12 deletions(-)

(limited to 'indra')

diff --git a/indra/newview/app_settings/settings.xml b/indra/newview/app_settings/settings.xml
index 6f11a6d616..266ed2b5fd 100644
--- a/indra/newview/app_settings/settings.xml
+++ b/indra/newview/app_settings/settings.xml
@@ -5838,7 +5838,7 @@
         <key>Value</key>
             <real>1.0</real>
         </map>
-  <key>MediaRollOffFactor</key>
+  <key>MediaRollOffRate</key>
   <map>
     <key>Comment</key>
     <string>Multiplier to change rate of media attenuation</string>
@@ -5847,7 +5847,29 @@
     <key>Type</key>
     <string>F32</string>
     <key>Value</key>
-    <real>10.0</real>
+    <real>0.2</real>
+  </map>
+  <key>MediaRollOffMin</key>
+  <map>
+    <key>Comment</key>
+    <string>Adjusts the distance at which media attentuation starts</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>7.0</real>
+  </map>
+  <key>MediaRollOffMax</key>
+  <map>
+    <key>Comment</key>
+    <string>Distance at which media volume is set to 0</string>
+    <key>Persist</key>
+    <integer>1</integer>
+    <key>Type</key>
+    <string>F32</string>
+    <key>Value</key>
+    <real>30.0</real>
   </map>
   <key>RecentItemsSortOrder</key>
     <map>
diff --git a/indra/newview/llviewermedia.cpp b/indra/newview/llviewermedia.cpp
index c8f3374f38..076a9609e3 100644
--- a/indra/newview/llviewermedia.cpp
+++ b/indra/newview/llviewermedia.cpp
@@ -1918,22 +1918,21 @@ void LLViewerMediaImpl::updateVolume()
 		// always scale the volume by the global media volume 
 		F32 volume = mRequestedVolume * LLViewerMedia::getVolume();
 
-		// attenuate if this is not parcel media
-		if (!mIsParcelMedia) 
+		if (mProximityCamera > 0) 
 		{
-			if (mProximityCamera > gSavedSettings.getF32("MediaRollOffMaxDistance"))
+			if (mProximityCamera > gSavedSettings.getF32("MediaRollOffMax"))
 			{
 				volume = 0;
 			}
-			else
+			else if (mProximityCamera > gSavedSettings.getF32("MediaRollOffMin"))
 			{
-				// attenuated volume = volume * roll_off rate / distance^2
-				// adjust distance by saved setting so we can tune the distance at which attenuation begins
-				// the actual start distance is sqrt(MediaRollOffMaxDistance)+MediaRollOffStartAdjustment
-				F64 adjusted_distance = mProximityCamera - gSavedSettings.getF32("MediaRollOffStart");
-
+				// attenuated_volume = v / ( 1 + (roll_off_rate * (d - min))^2
+				// the +1 is there so that for distance 0 the volume stays the same
+				F64 adjusted_distance = mProximityCamera - gSavedSettings.getF32("MediaRollOffMin");
+				F64 attenuation = gSavedSettings.getF32("MediaRollOffRate") * adjusted_distance;
+				attenuation = attenuation * attenuation;
 				// the attenuation multiplier should never be more than one since that would increase volume
-				volume = volume * llmin(1.0, gSavedSettings.getF32("MediaRollOffRate")/adjusted_distance*adjusted_distance);
+				volume = volume * llmin(1.0, 1 /(attenuation + 1));
 			}
 		}
 
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