f64ec07b43
Makes volume slider logarithmic when limited to 100% to allow easier changing of volume towards the bottom of the slider. The tooltip remains as the slider location instead of the logarithmic value of the actual volume.
25 lines
1.1 KiB
Objective-C
25 lines
1.1 KiB
Objective-C
/*
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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 "Helper.h"
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#include <math.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^2 when volume is limited to 100% and X^4 when volume is limited to 800%.
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// Input/Output values are in percents.
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double logarithmicToLinear(const double logarithmic, double MAX_VOLUME) {
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return (MAX_VOLUME == 100.0) ? pow((logarithmic / MAX_VOLUME), 0.5) * 100.0 : pow((logarithmic / MAX_VOLUME), 0.25) * 100.0;
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}
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double linearToLogarithmic(const double linear, double MAX_VOLUME) {
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return (MAX_VOLUME == 100.0) ? (linear / 100.0) * (linear / 100.0) * MAX_VOLUME : (linear / 100.0) * (linear / 100.0) * (linear / 100.0) * (linear / 100.0) * MAX_VOLUME;
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}
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// End helper volume function thingies. ONWARDS TO GLORY!
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