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diff --git a/linden/indra/llaudio/windgen.h b/linden/indra/llaudio/windgen.h
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+/** 
+ * @file windgen.h
+ * @brief Templated wind noise generation
+ *
+ * $LicenseInfo:firstyear=2002&license=viewergpl$
+ * 
+ * Copyright (c) 2002-2008, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * 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.
+ * $/LicenseInfo$
+ */
+#ifndef WINDGEN_H
+#define WINDGEN_H
+
+#include "llcommon.h"
+#include "llrand.h"
+
+template <class MIXBUFFERFORMAT_T>
+class LLWindGen
+{
+public:
+        LLWindGen() :
+                mTargetGain(0.f),
+                mTargetFreq(100.f),
+                mTargetPanGainR(0.5f),
+                mbuf0(0.0),
+                mbuf1(0.0),
+                mbuf2(0.0),
+                mbuf3(0.0),
+                mbuf4(0.0),
+                mbuf5(0.0),
+                mY0(0.0),
+                mY1(0.0),
+                mCurrentGain(0.f),
+                mCurrentFreq(100.f),
+                mCurrentPanGainR(0.5f) {};
+
+        static const U32 getInputSamplingRate() {return mInputSamplingRate;}
+
+        // newbuffer = the buffer passed from the previous DSP unit.
+        // numsamples = length in samples-per-channel at this mix time.
+        // stride = number of bytes between start of each sample.
+        // NOTE: generates L/R interleaved stereo
+        MIXBUFFERFORMAT_T* windGenerate(MIXBUFFERFORMAT_T *newbuffer, int numsamples, int stride)
+        {
+                U8 *cursamplep = (U8*)newbuffer;
+                
+                double bandwidth = 50.0F;
+                double a0,b1,b2;
+                
+                // calculate resonant filter coeffs
+                b2 = exp(-(F_TWO_PI) * (bandwidth / mInputSamplingRate));
+                
+                while (numsamples--)
+                {
+                        mCurrentFreq = (float)((0.999 * mCurrentFreq) + (0.001 * mTargetFreq));
+                        mCurrentGain = (float)((0.999 * mCurrentGain) + (0.001 * mTargetGain));
+                        mCurrentPanGainR = (float)((0.999 * mCurrentPanGainR) + (0.001 * mTargetPanGainR));
+                        b1 = (-4.0 * b2) / (1.0 + b2) * cos(F_TWO_PI * (mCurrentFreq / mInputSamplingRate));
+                        a0 = (1.0 - b2) * sqrt(1.0 - (b1 * b1) / (4.0 * b2));
+                        double nextSample;
+                        
+                        // start with white noise
+                        nextSample = ll_frand(2.0f) - 1.0f;
+                        
+#if 1 // LLAE_WIND_PINK apply pinking filter
+                        mbuf0 = 0.997f * mbuf0 + 0.0126502f * nextSample; 
+                        mbuf1 = 0.985f * mbuf1 + 0.0139083f * nextSample;
+                        mbuf2 = 0.950f * mbuf2 + 0.0205439f * nextSample;
+                        mbuf3 = 0.850f * mbuf3 + 0.0387225f * nextSample;
+                        mbuf4 = 0.620f * mbuf4 + 0.0465932f * nextSample;
+                        mbuf5 = 0.250f * mbuf5 + 0.1093477f * nextSample;
+                        
+                        nextSample = mbuf0 + mbuf1 + mbuf2 + mbuf3 + mbuf4 + mbuf5;
+#endif
+                        
+#if 1 //LLAE_WIND_RESONANT // do a resonant filter on the noise
+                        nextSample = (double)( a0 * nextSample - b1 * mY0 - b2 * mY1 );
+                        
+                        mY1 = mY0;
+                        mY0 = nextSample;
+#endif
+                        
+                        nextSample *= mCurrentGain;
+                        
+                        MIXBUFFERFORMAT_T       sample;
+                        
+                        sample = llfloor(((F32)nextSample*32768.f*(1.0f - mCurrentPanGainR))+0.5f);
+                        *(MIXBUFFERFORMAT_T*)cursamplep = llclamp(sample, (MIXBUFFERFORMAT_T)-32768, (MIXBUFFERFORMAT_T)32767);
+                        cursamplep += stride;
+
+                        sample = llfloor(((F32)nextSample*32768.f*mCurrentPanGainR)+0.5f);
+                        *(MIXBUFFERFORMAT_T*)cursamplep = llclamp(sample, (MIXBUFFERFORMAT_T)-32768, (MIXBUFFERFORMAT_T)32767);
+                        cursamplep += stride;
+                }
+                
+                return newbuffer;
+        }
+
+        F32 mTargetGain;
+        F32 mTargetFreq;
+        F32 mTargetPanGainR;
+
+private:
+        static const U32 mInputSamplingRate = 44100;
+        F64 mbuf0;
+        F64 mbuf1;
+        F64 mbuf2;
+        F64 mbuf3;
+        F64 mbuf4;
+        F64 mbuf5;
+        F64 mY0;
+        F64 mY1;
+        F32 mCurrentGain;
+        F32 mCurrentFreq;
+        F32 mCurrentPanGainR;
+};
+
+#endif