AEDSPUtilities.h

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//
//  AEDSPUtilities.h
//  TheAmazingAudioEngine
//
//  Created by Michael Tyson on 1/04/2016.
//  Copyright © 2016 A Tasty Pixel. All rights reserved.
//
//  This software is provided 'as-is', without any express or implied
//  warranty.  In no event will the authors be held liable for any damages
//  arising from the use of this software.
//
//  Permission is granted to anyone to use this software for any purpose,
//  including commercial applications, and to alter it and redistribute it
//  freely, subject to the following restrictions:
//
//  1. The origin of this software must not be misrepresented; you must not
//     claim that you wrote the original software. If you use this software
//     in a product, an acknowledgment in the product documentation would be
//     appreciated but is not required.
//
//  2. Altered source versions must be plainly marked as such, and must not be
//     misrepresented as being the original software.
//
//  3. This notice may not be removed or altered from any source distribution.
//

#ifdef __cplusplus
extern "C" {
#endif

#import <Foundation/Foundation.h>
#import <AudioToolbox/AudioToolbox.h>
#import "AEAudioBufferListUtilities.h"

void AEDSPApplyGain(const AudioBufferList * bufferList, float gain, UInt32 frames);

void AEDSPApplyRamp(const AudioBufferList * bufferList, float * start, float step, UInt32 frames);

void AEDSPApplyEqualPowerRamp(const AudioBufferList * bufferList, float * start, float step, UInt32 frames, float * scratch);

void AEDSPApplyGainSmoothed(const AudioBufferList * bufferList, float targetGain, float * currentGain, UInt32 frames);

void AEDSPApplyGainWithRamp(const AudioBufferList * bufferList, float targetGain, float * currentGain, UInt32 frames,
                                    UInt32 rampDuration);
    
void AEDSPApplyGainSmoothedMono(float * buffer, float targetGain, float * currentGain, UInt32 frames);

void AEDSPApplyVolumeAndBalance(const AudioBufferList * bufferList, float targetVolume, float * currentVolume,
                                float targetBalance, float * currentBalance, UInt32 frames);


void AEDSPMix(const AudioBufferList * bufferList1, const AudioBufferList * bufferList2, float gain1, float gain2,
              BOOL monoToStereo, UInt32 frames, const AudioBufferList * output);

void AEDSPMixMono(const float * buffer1, const float * buffer2, float gain1, float gain2, UInt32 frames, float * output);

#define AEDSPSilence AEAudioBufferListSilence

static inline float AEDSPGenerateOscillator(float rate, float * position) {
    float x = *position;
    x *= x;
    x -= 1.0;
    x *= x;
    *position += rate;
    if ( *position > 1.0 ) *position -= 2.0;
    return x;
}

static inline double AEDSPDecibelsToRatio(double decibels) {
    return pow(10.0, decibels / 20.0);
}

static inline double AEDSPRatioToDecibels(double ratio) {
    return 20.0 * log10(ratio);
}

#ifdef __cplusplus
}
#endif