28 lines
841 B
Matlab
28 lines
841 B
Matlab
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/*
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* Helper.c
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* CogAudio
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*
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* Created by Andre Reffhaug on 2/17/08.
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* Copyright 2008 __MyCompanyName__. All rights reserved.
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*
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*/
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#include <math.h>
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#include "Helper.h"
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//These functions are helpers for the process of converting volume from a linear to logarithmic scale.
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//Numbers that goes in to audioPlayer should be logarithmic. Numbers that are displayed to the user should be linear.
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//Here's why: http://www.dr-lex.34sp.com/info-stuff/volumecontrols.html
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//We are using the approximation of X^4.
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//Input/Output values are in percents.
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double logarithmicToLinear(double logarithmic)
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{
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return pow((logarithmic/MAX_VOLUME), 0.25) * 100.0;
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}
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double linearToLogarithmic(double linear)
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{
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return (linear/100) * (linear/100) * (linear/100) * (linear/100) * MAX_VOLUME;
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}
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//End helper volume function thingies. ONWARDS TO GLORY!
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