Second Life viewer sources 1.13.2.12

1 files changed, 91 insertions, 0 deletions

diff --git a/linden/indra/llcommon/llcriticaldamp.cpp b/linden/indra/llcommon/llcriticaldamp.cpp
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+/** 
+ * @file llcriticaldamp.cpp
+ * @brief Implementation of the critical damping functionality.
+ *
+ * Copyright (c) 2002-2007, Linden Research, Inc.
+ * 
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlife.com/developers/opensource/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at http://secondlife.com/developers/opensource/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ */
+
+#include "linden_common.h"
+#include <math.h>
+
+#include "llcriticaldamp.h"
+
+//-----------------------------------------------------------------------------
+// static members
+//-----------------------------------------------------------------------------
+LLFrameTimer LLCriticalDamp::sInternalTimer;
+std::map<F32, F32> LLCriticalDamp::sInterpolants;
+F32 LLCriticalDamp::sTimeDelta;
+
+//-----------------------------------------------------------------------------
+// LLCriticalDamp()
+//-----------------------------------------------------------------------------
+LLCriticalDamp::LLCriticalDamp()
+{
+        sTimeDelta = 0.f;
+}
+
+// static
+//-----------------------------------------------------------------------------
+// updateInterpolants()
+//-----------------------------------------------------------------------------
+void LLCriticalDamp::updateInterpolants()
+{
+        sTimeDelta = sInternalTimer.getElapsedTimeAndResetF32();
+
+        F32 time_constant;
+
+        for (std::map<F32, F32>::iterator iter = sInterpolants.begin();
+                 iter != sInterpolants.end(); iter++)
+        {
+                time_constant = iter->first;
+                F32 new_interpolant = 1.f - pow(2.f, -sTimeDelta / time_constant);
+                new_interpolant = llclamp(new_interpolant, 0.f, 1.f);
+                sInterpolants[time_constant] = new_interpolant;
+        }
+} 
+
+//-----------------------------------------------------------------------------
+// getInterpolant()
+//-----------------------------------------------------------------------------
+F32 LLCriticalDamp::getInterpolant(const F32 time_constant, BOOL use_cache)
+{
+        if (time_constant == 0.f)
+        {
+                return 1.f;
+        }
+
+        if (use_cache && sInterpolants.count(time_constant))
+        {
+                return sInterpolants[time_constant];
+        }
+        
+        F32 interpolant = 1.f - pow(2.f, -sTimeDelta / time_constant);
+        interpolant = llclamp(interpolant, 0.f, 1.f);
+        if (use_cache)
+        {
+                sInterpolants[time_constant] = interpolant;
+        }
+
+        return interpolant;
+}