/*
 *  maximilian.cpp
 *  platform independent synthesis library using portaudio or rtaudio
 *
 *  Created by Mick Grierson on 29/12/2009.
 *  Copyright 2009 Mick Grierson & Strangeloop Limited. All rights reserved.
 *	Thanks to the Goldsmiths Creative Computing Team.
 *	Special thanks to Arturo Castro for the PortAudio implementation.
 *
 *	Permission is hereby granted, free of charge, to any person
 *	obtaining a copy of this software and associated documentation
 *	files (the "Software"), to deal in the Software without
 *	restriction, including without limitation the rights to use,
 *	copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the
 *	Software is furnished to do so, subject to the following
 *	conditions:
 *	
 *	The above copyright notice and this permission notice shall be
 *	included in all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,	
 *	EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 *	OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *	NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 *	HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 *	WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 *	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 *	OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include "maximilian.h"
#include "math.h"


//int channels=2;
//int samplerate=44100; 
//int buffersize=1024;
float chandiv= 1;

int maxiSettings::sampleRate = 44100;
int maxiSettings::channels = 2;
int maxiSettings::bufferSize = 1024;

double sineBuffer[514]={0,0.012268,0.024536,0.036804,0.049042,0.06131,0.073547,0.085785,0.097992,0.1102,0.12241,0.13455,0.1467,0.15884,0.17093,0.18301,0.19507,0.20709,0.21909,0.23105,0.24295,0.25485,0.26669,0.2785,0.29025,0.30197,0.31366,0.32529,0.33685,0.34839,0.35986,0.37128,0.38266,0.39395,0.40521,0.41641,0.42752,0.4386,0.44958,0.46051,0.47137,0.48215,0.49286,0.50351,0.51407,0.52457,0.53497,0.54529,0.55554,0.5657,0.57578,0.58575,0.59567,0.60547,0.6152,0.62482,0.63437,0.6438,0.65314,0.66238,0.67151,0.68057,0.68951,0.69833,0.70706,0.7157,0.72421,0.7326,0.74091,0.74908,0.75717,0.76514,0.77298,0.7807,0.7883,0.79581,0.80316,0.81042,0.81754,0.82455,0.83142,0.8382,0.84482,0.85132,0.8577,0.86392,0.87006,0.87604,0.88187,0.8876,0.89319,0.89862,0.90396,0.90912,0.91415,0.91907,0.92383,0.92847,0.93295,0.93729,0.9415,0.94556,0.94949,0.95325,0.95691,0.96039,0.96375,0.96692,0.97,0.9729,0.97565,0.97827,0.98074,0.98306,0.98523,0.98724,0.98914,0.99084,0.99243,0.99387,0.99515,0.99628,0.99725,0.99808,0.99875,0.99927,0.99966,0.99988,0.99997,0.99988,0.99966,0.99927,0.99875,0.99808,0.99725,0.99628,0.99515,0.99387,0.99243,0.99084,0.98914,0.98724,0.98523,0.98306,0.98074,0.97827,0.97565,0.9729,0.97,0.96692,0.96375,0.96039,0.95691,0.95325,0.94949,0.94556,0.9415,0.93729,0.93295,0.92847,0.92383,0.91907,0.91415,0.90912,0.90396,0.89862,0.89319,0.8876,0.88187,0.87604,0.87006,0.86392,0.8577,0.85132,0.84482,0.8382,0.83142,0.82455,0.81754,0.81042,0.80316,0.79581,0.7883,0.7807,0.77298,0.76514,0.75717,0.74908,0.74091,0.7326,0.72421,0.7157,0.70706,0.69833,0.68951,0.68057,0.67151,0.66238,0.65314,0.6438,0.63437,0.62482,0.6152,0.60547,0.59567,0.58575,0.57578,0.5657,0.55554,0.54529,0.53497,0.52457,0.51407,0.50351,0.49286,0.48215,0.47137,0.46051,0.44958,0.4386,0.42752,0.41641,0.40521,0.39395,0.38266,0.37128,0.35986,0.34839,0.33685,0.32529,0.31366,0.30197,0.29025,0.2785,0.26669,0.25485,0.24295,0.23105,0.21909,0.20709,0.19507,0.18301,0.17093,0.15884,0.1467,0.13455,0.12241,0.1102,0.097992,0.085785,0.073547,0.06131,0.049042,0.036804,0.024536,0.012268,0,-0.012268,-0.024536,-0.036804,-0.049042,-0.06131,-0.073547,-0.085785,-0.097992,-0.1102,-0.12241,-0.13455,-0.1467,-0.15884,-0.17093,-0.18301,-0.19507,-0.20709,-0.21909,-0.23105,-0.24295,-0.25485,-0.26669,-0.2785,-0.29025,-0.30197,-0.31366,-0.32529,-0.33685,-0.34839,-0.35986,-0.37128,-0.38266,-0.39395,-0.40521,-0.41641,-0.42752,-0.4386,-0.44958,-0.46051,-0.47137,-0.48215,-0.49286,-0.50351,-0.51407,-0.52457,-0.53497,-0.54529,-0.55554,-0.5657,-0.57578,-0.58575,-0.59567,-0.60547,-0.6152,-0.62482,-0.63437,-0.6438,-0.65314,-0.66238,-0.67151,-0.68057,-0.68951,-0.69833,-0.70706,-0.7157,-0.72421,-0.7326,-0.74091,-0.74908,-0.75717,-0.76514,-0.77298,-0.7807,-0.7883,-0.79581,-0.80316,-0.81042,-0.81754,-0.82455,-0.83142,-0.8382,-0.84482,-0.85132,-0.8577,-0.86392,-0.87006,-0.87604,-0.88187,-0.8876,-0.89319,-0.89862,-0.90396,-0.90912,-0.91415,-0.91907,-0.92383,-0.92847,-0.93295,-0.93729,-0.9415,-0.94556,-0.94949,-0.95325,-0.95691,-0.96039,-0.96375,-0.96692,-0.97,-0.9729,-0.97565,-0.97827,-0.98074,-0.98306,-0.98523,-0.98724,-0.98914,-0.99084,-0.99243,-0.99387,-0.99515,-0.99628,-0.99725,-0.99808,-0.99875,-0.99927,-0.99966,-0.99988,-0.99997,-0.99988,-0.99966,-0.99927,-0.99875,-0.99808,-0.99725,-0.99628,-0.99515,-0.99387,-0.99243,-0.99084,-0.98914,-0.98724,-0.98523,-0.98306,-0.98074,-0.97827,-0.97565,-0.9729,-0.97,-0.96692,-0.96375,-0.96039,-0.95691,-0.95325,-0.94949,-0.94556,-0.9415,-0.93729,-0.93295,-0.92847,-0.92383,-0.91907,-0.91415,-0.90912,-0.90396,-0.89862,-0.89319,-0.8876,-0.88187,-0.87604,-0.87006,-0.86392,-0.8577,-0.85132,-0.84482,-0.8382,-0.83142,-0.82455,-0.81754,-0.81042,-0.80316,-0.79581,-0.7883,-0.7807,-0.77298,-0.76514,-0.75717,-0.74908,-0.74091,-0.7326,-0.72421,-0.7157,-0.70706,-0.69833,-0.68951,-0.68057,-0.67151,-0.66238,-0.65314,-0.6438,-0.63437,-0.62482,-0.6152,-0.60547,-0.59567,-0.58575,-0.57578,-0.5657,-0.55554,-0.54529,-0.53497,-0.52457,-0.51407,-0.50351,-0.49286,-0.48215,-0.47137,-0.46051,-0.44958,-0.4386,-0.42752,-0.41641,-0.40521,-0.39395,-0.38266,-0.37128,-0.35986,-0.34839,-0.33685,-0.32529,-0.31366,-0.30197,-0.29025,-0.2785,-0.26669,-0.25485,-0.24295,-0.23105,-0.21909,-0.20709,-0.19507,-0.18301,-0.17093,-0.15884,-0.1467,-0.13455,-0.12241,-0.1102,-0.097992,-0.085785,-0.073547,-0.06131,-0.049042,-0.036804,-0.024536,-0.012268,0,0.012268
};

void setup();//use this to do any initialisation if you want.

void play(double *channels);//run dac! 

maxiOsc::maxiOsc(){
	phase = 0.0;
//	memset(phases,0,500);
//	memset(freqs,0,500);
}

double maxiOsc::noise() {
	//always the same unless you seed it.
	float r = rand()/(float)RAND_MAX;
	output=r*2-1;
	return(output);
}

double maxiOsc::sinewave(double frequency) {
	output=sin (phase*(TWOPI));
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	return(output);
	
}

double maxiOsc::sinebuf4(double frequency) {
	double remainder;
	double a,b,c,d,a1,a2,a3;
	phase += 512./(maxiSettings::sampleRate/(frequency));
	if ( phase >= 511 ) phase -=512;
	remainder = phase - floor(phase);
	
	if (phase==0) {
		a=sineBuffer[(long) 512];
		b=sineBuffer[(long) phase];
		c=sineBuffer[(long) phase+1];
		d=sineBuffer[(long) phase+2];
		
	} else {
		a=sineBuffer[(long) phase-1];
		b=sineBuffer[(long) phase];
		c=sineBuffer[(long) phase+1];
		d=sineBuffer[(long) phase+2];
		
	}
	
	a1 = 0.5f * (c - a);
	a2 = a - 2.5 * b + 2.f * c - 0.5f * d;
	a3 = 0.5f * (d - a) + 1.5f * (b - c);
	output = double (((a3 * remainder + a2) * remainder + a1) * remainder + b);
	return(output);
}

double maxiOsc::sinebuf(double frequency) {
	double remainder;
 	phase += 512./(maxiSettings::sampleRate/(frequency*chandiv));
	if ( phase >= 511 ) phase -=512;
	remainder = phase - floor(phase);
	output = (double) ((1-remainder) * sineBuffer[1+ (long) phase] + remainder * sineBuffer[2+(long) phase]);
	return(output);
}

double maxiOsc::coswave(double frequency) {
	output=cos (phase*(TWOPI));
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	return(output);
	
}

double maxiOsc::phasor(double frequency) {
	output=phase;
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	return(output);
} 

double maxiOsc::square(double frequency) {
	if (phase<0.5) output=-1;
	if (phase>0.5) output=1;
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	return(output);
}

double maxiOsc::pulse(double frequency, double duty) {
	if (duty<0.) duty=0;
	if (duty>1.) duty=1;
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	if (phase<duty) output=-1.;
	if (phase>duty) output=1.;
	return(output);
}

double maxiOsc::phasor(double frequency, double startphase, double endphase) {
	output=phase;
	if (phase<startphase) {
		phase=startphase;
	}
	if ( phase >= endphase ) phase = startphase;
	phase += ((endphase-startphase)/(maxiSettings::sampleRate/(frequency)));
	return(output);
}


double maxiOsc::saw(double frequency) {
	
	output=phase;
	if ( phase >= 1.0 ) phase -= 2.0;
	phase += (1./(maxiSettings::sampleRate/(frequency)));
	return(output);
	
} 

double maxiOsc::triangle(double frequency, double phase) {
	output=tri*2;
	if ( phase >= 1.0 ) phase -= 1.0;
	phase += (1./(maxiSettings::sampleRate/(frequency*chandiv)));
	if (phase <= 0.5 ) {
		tri = phase;
	} else {	
		tri =(1-phase);
	}
	return(output);
	
} 

//I like this.
double maxiEnvelope::line(int numberofsegments,double segments[1000]) {
	if (isPlaying==1) {//only make a sound once you've been triggered
		
	period=2./(segments[valindex+1]*0.004);
	nextval=segments[valindex+2];
	currentval=segments[valindex];
	if (currentval-amplitude > 0.0000001 && valindex < numberofsegments) {
		amplitude += ((currentval-startval)/(maxiSettings::sampleRate/period));
	} else if (currentval-amplitude < -0.0000001 && valindex < numberofsegments) {
		amplitude -= (((currentval-startval)*(-1))/(maxiSettings::sampleRate/period));
	} else if (valindex >numberofsegments-1) {
		valindex=numberofsegments-2;
	} else {
		valindex=valindex+2;
		startval=currentval;
	}
	output=amplitude;
		
	}
	else {
		output=0;

	}
	return(output);
}

//and this
void maxiEnvelope::trigger(int index, double amp) {
	isPlaying=1;//ok the envelope is being used now.
	valindex=index;
	amplitude=amp;
	
}

//and this
double maxiDelayline::dl(double input, int size, double feedback)  {
	if ( phase >=size ) phase = 0;
	memory[phase]=(memory[phase]*feedback)+(input*feedback)*0.5;
	phase+=1;
	output=memory[phase+1];
	return(output);
	
}

double maxiDelayline::dl(double input, int size, double feedback, int position)  {
	if ( phase >=size ) phase = 0;
	if ( position >=size ) position = 0;
	memory[phase]=(memory[phase]*feedback)+(input*feedback)*chandiv;
	phase+=1;
	output=memory[position];
	return(output);
	
}

//I particularly like these. cutoff between 0 and 1
double maxiFilter::lopass(double input, double cutoff) {
	output=outputs[0] + cutoff*(input-outputs[0]);
	outputs[0]=output;
	return(output);
}
//as above
double maxiFilter::hipass(double input, double cutoff) {
	output=input-(outputs[0] + cutoff*(input-outputs[0]));
	outputs[0]=output;
	return(output);
}
//awesome. cuttof is freq in hz. res is between 1 and whatever. Watch out!
double maxiFilter::lores(double input,double cutoff1, double resonance) {
	cutoff=cutoff1*0.5;
	if (cutoff<10) cutoff=10;
	if (cutoff>(maxiSettings::sampleRate*0.25)) cutoff=(maxiSettings::sampleRate*0.25);
	if (resonance<1.) resonance = 1.;
	z=cos(TWOPI*cutoff/maxiSettings::sampleRate);
	c=2-2*z;
	double r=(sqrt(2.0)*sqrt(-pow((z-1.0),3.0))+resonance*(z-1))/(resonance*(z-1));
	x=x+(input-y)*c;
	y=y+x;
	x=x*r;
	output=y;
	return(output);
}

//working hires filter
double maxiFilter::hires(double input,double cutoff1, double resonance) {
	cutoff=cutoff1*0.5;
	if (cutoff<10) cutoff=10;
	if (cutoff>(maxiSettings::sampleRate*0.25)) cutoff=(maxiSettings::sampleRate*0.25);
	if (resonance<1.) resonance = 1.;
	z=cos(TWOPI*cutoff/maxiSettings::sampleRate);
	c=2-2*z;
	double r=(sqrt(2.0)*sqrt(-pow((z-1.0),3.0))+resonance*(z-1))/(resonance*(z-1));
	x=x+(input-y)*c;
	y=y+x;
	x=x*r;
	output=input-y;
	return(output);
}

//This works a bit. Needs attention.
double maxiFilter::bandpass(double input,double cutoff1, double resonance) {
	cutoff=cutoff1;
	if (cutoff>(maxiSettings::sampleRate*0.5)) cutoff=(maxiSettings::sampleRate*0.5);
	if (resonance>=1.) resonance=0.999999;
	z=cos(TWOPI*cutoff/maxiSettings::sampleRate);
	inputs[0] = (1-resonance)*(sqrt(resonance*(resonance-4.0*pow(z,2.0)+2.0)+1));
	inputs[1] = 2*z*resonance;
	inputs[2] = pow((resonance*-1),2);
	
	output=inputs[0]*input+inputs[1]*outputs[1]+inputs[2]*outputs[2];
	outputs[2]=outputs[1];
	outputs[1]=output;
	return(output);
}

//stereo bus
double *maxiMix::stereo(double input,double two[2],double x) {
	if (x>1) x=1;
	if (x<0) x=0;
	two[0]=input*sqrt(1.0-x);
	two[1]=input*sqrt(x);
	return(two);
} 

//quad bus
double *maxiMix::quad(double input,double four[4],double x,double y) {
	if (x>1) x=1;
	if (x<0) x=0;
	if (y>1) y=1;
	if (y<0) y=0;
	four[0]=input*sqrt((1.0-x)*y);
	four[1]=input*sqrt((1.0-x)*(1.0-y));
	four[2]=input*sqrt(x*y);
	four[3]=input*sqrt(x*(1.0-y));
	return(four);
}

//ambisonic bus
double *maxiMix::ambisonic(double input,double eight[8],double x,double y,double z) {
	if (x>1) x=1;
	if (x<0) x=0;
	if (y>1) y=1;
	if (y<0) y=0;
	if (z>1) y=1;
	if (z<0) y=0;
	eight[0]=input*(sqrt((1.0-x)*y)*1.0-z);
	eight[1]=input*(sqrt((1.0-x)*(1.0-y))*1.0-z);
	eight[2]=input*(sqrt(x*y)*1.0-z);
	eight[3]=input*(sqrt(x*(1.0-y))*1.0-z);
	eight[4]=input*(sqrt((1.0-x)*y)*z);
	eight[5]=input*(sqrt((1.0-x)*(1.0-y))*z);
	eight[6]=input*sqrt((x*y)*z);
	eight[7]=input*sqrt((x*(1.0-y))*z);
	return(eight);
}


bool maxiSample::load(string fileName, int channel) {
	myPath = fileName;
	readChannel=channel;
	return read();
}

void maxiSample::trigger() {
	position = 0;
}

bool maxiSample::read()
{
	bool result;
	ifstream inFile( myPath.c_str(), ios::in | ios::binary);
	result = inFile;
	if (inFile) {
		bool datafound = false;
		inFile.seekg(4, ios::beg);
		inFile.read( (char*) &myChunkSize, 4 ); // read the ChunkSize
		
		inFile.seekg(16, ios::beg);
		inFile.read( (char*) &mySubChunk1Size, 4 ); // read the SubChunk1Size
		
		//inFile.seekg(20, ios::beg);
		inFile.read( (char*) &myFormat, sizeof(short) ); // read the file format.  This should be 1 for PCM
		
		//inFile.seekg(22, ios::beg);
		inFile.read( (char*) &myChannels, sizeof(short) ); // read the # of channels (1 or 2)
		
		//inFile.seekg(24, ios::beg);
		inFile.read( (char*) &mySampleRate, sizeof(int) ); // read the samplerate
		
		//inFile.seekg(28, ios::beg);
		inFile.read( (char*) &myByteRate, sizeof(int) ); // read the byterate
		
		//inFile.seekg(32, ios::beg);
		inFile.read( (char*) &myBlockAlign, sizeof(short) ); // read the blockalign
		
		//inFile.seekg(34, ios::beg);
		inFile.read( (char*) &myBitsPerSample, sizeof(short) ); // read the bitspersample
		
		//ignore any extra chunks
		char chunkID[5]="";
		chunkID[4] = 0;
		int filePos = 36;
		while(!datafound && !inFile.eof()) {
			inFile.seekg(filePos, ios::beg);
			inFile.read((char*) &chunkID, sizeof(char) * 4);
			inFile.seekg(filePos + 4, ios::beg);
			inFile.read( (char*) &myDataSize, sizeof(int) ); // read the size of the data
			filePos += 8;
			if (strcmp(chunkID,"data") == 0) {
				datafound = true;
			}else{
				filePos += myDataSize;
			}
		}
		
		// read the data chunk
		myData = (char*) malloc(myDataSize * sizeof(char));
		inFile.seekg(filePos, ios::beg);
		inFile.read(myData, myDataSize);
		length=myDataSize*(0.5/myChannels);
		inFile.close(); // close the input file
		
		if (myChannels>1) {
			int position=0;
			int channel=readChannel*2;
			for (int i=channel;i<myDataSize+6;i+=(myChannels*2)) {
				myData[position]=myData[i];
				myData[position+1]=myData[i+1];
				position+=2;
			}
		}
		
	}else {
		cout << "ERROR: Could not load sample: " <<myPath << endl;
	}
	
	
	return result; // this should probably be something more descriptive
}


double maxiSample::play() {
//	long length=myDataSize*(1./myChannels);
	double remainder;
	short* buffer = (short *)myData;
	position=(position+1);
	remainder = position - (long) position;
	if ((long) position>length) position=0;
	output = (double) ((1-remainder) * buffer[1+ (long) position] + remainder * buffer[2+(long) position])/32767;//linear interpolation
	return(output);
}

double maxiSample::playOnce() {
//	long length=myDataSize*(0.5/myChannels);
	double remainder;
	short* buffer = (short *)myData;
	position=(position+1);
	remainder = position - (long) position;
	if ((long) position<length)
		output = (double) ((1-remainder) * buffer[1+ (long) position] + remainder * buffer[2+(long) position])/32767;//linear interpolation
	else 
		output=0;

	return(output);
}

double maxiSample::play(double speed) {
	double remainder;
	long a,b;
//	long length=myDataSize*0.5;	
	short* buffer = (short *)myData;
	position=position+((speed*chandiv*myChannels)/(maxiSettings::sampleRate/mySampleRate));
	if (speed >=0) {
		
		if ((long) position>=length-1) position=1;
		remainder = position - floor(position);
		if (position+1<length) {
			a=position+1;
			
		}
		else {
			a=length-1;
		}
		if (position+2<length)
		{
		b=position+2;
		}
		else {
		b=length-1;
		}
		
		output = (double) ((1-remainder) * buffer[a] + remainder * buffer[b])/32767;//linear interpolation
} else {
		if ((long) position<0) position=length;
		remainder = position - floor(position);
		if (position-1>=0) {
			a=position-1;
				
			}
			else {
				a=0;
			}
	if (position-2>=0) {
		b=position-2;
			}
			else {
				b=0;
			}
		output = (double) ((-1-remainder) * buffer[a] + remainder * buffer[b])/32767;//linear interpolation
	}	
	return(output);
}

double maxiSample::play(double frequency, double start, double end) {
	return play(frequency, start, end, position);
}

double maxiSample::play(double frequency, double start, double end, double &pos) {
	double remainder;
	//	long length=myDataSize;

	if (end>=length) end=length-1;
	long a,b;
	short* buffer = (short *)myData;
	if (frequency >0.) {
		if (pos<start) {
			pos=start;
		}
		
		if ( pos >= end ) pos = start;
		pos += ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = pos - floor(pos);
		long posl = floor(pos);
		if (posl+1<length) {
			a=posl+1;
			
		}
		else {
			a=posl-1;
		}
		if (posl+2<length) {
			b=posl+2;
		}
		else {
			b=length-1;
		}

		output = (double) ((1-remainder) * buffer[a] +
						   remainder * buffer[b])/32767;//linear interpolation
	} else {
		frequency=frequency-(frequency+frequency);
		if ( pos <= start ) pos = end;
		pos -= ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = pos - floor(pos);
		long posl = floor(pos);
		if (posl-1>=0) {
			a=posl-1;
		}
		else {
			a=0;
		}
		if (posl-2>=0) {
			b=posl-2;
		}
		else {
			b=0;
		}		
		output = (double) ((-1-remainder) * buffer[a] +
						   remainder * buffer[b])/32767;//linear interpolation
		
	}
	
	return(output);
}


//better cubic inerpolation. Cobbled together from various (pd externals, yehar, other places).
double maxiSample::play4(double frequency, double start, double end) {
	double remainder;
	double a,b,c,d,a1,a2,a3;
	short* buffer = (short*)myData;
	if (frequency >0.) {
		if (position<start) {
			position=start;
		}
		if ( position >= end ) position = start;
		position += ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		if (position>0) {
			a=buffer[(int)(floor(position))-1];

		} else {
			a=buffer[0];
			
		}
		
		b=buffer[(long) position];
		if (position<end-2) {
			c=buffer[(long) position+1];

		} else {
			c=buffer[0];

		}
		if (position<end-3) {
			d=buffer[(long) position+2];

		} else {
			d=buffer[0];
		}
		a1 = 0.5f * (c - a);
		a2 = a - 2.5 * b + 2.f * c - 0.5f * d;
		a3 = 0.5f * (d - a) + 1.5f * (b - c);
		output = (double) (((a3 * remainder + a2) * remainder + a1) * remainder + b) / 32767;
		
	} else {
		frequency=frequency-(frequency+frequency);
		if ( position <= start ) position = end;
		position -= ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		if (position>start && position < end-1) {
			a=buffer[(long) position+1];
			
		} else {
			a=buffer[0];
			
		}
		
		b=buffer[(long) position];
		if (position>start) {
			c=buffer[(long) position-1];
			
		} else {
			c=buffer[0];
			
		}
		if (position>start+1) {
			d=buffer[(long) position-2];
			
		} else {
			d=buffer[0];
		}
		a1 = 0.5f * (c - a);
		a2 = a - 2.5 * b + 2.f * c - 0.5f * d;
		a3 = 0.5f * (d - a) + 1.5f * (b - c);
		output = (double) (((a3 * remainder + a2) * -remainder + a1) * -remainder + b) / 32767;
		
	}
	
	return(output);
}

double maxiSample::bufferPlay(unsigned char &bufferin,long length) {
	double remainder;
	short* buffer = (short *)bufferin;
	position=(position+1);
	remainder = position - (long) position;
	if ((long) position>length) position=0;
	output = (double) ((1-remainder) * buffer[1+ (long) position] + remainder * buffer[2+(long) position])/32767;//linear interpolation
	return(output);
}

double maxiSample::bufferPlay(unsigned char &bufferin,double speed,long length) {
	double remainder;
	long a,b;
	short* buffer = (short *)bufferin;
	position=position+((speed*chandiv*myChannels)/(maxiSettings::sampleRate/mySampleRate));
	if (speed >=0) {
		
		if ((long) position>=length-1) position=1;
		remainder = position - floor(position);
		if (position+1<length) {
			a=position+1;
			
		}
		else {
			a=length-1;
		}
		if (position+2<length)
		{
			b=position+2;
		}
		else {
			b=length-1;
		}
		
		output = (double) ((1-remainder) * buffer[a] + remainder * buffer[b])/32767;//linear interpolation
	} else {
		if ((long) position<0) position=length;
		remainder = position - floor(position);
		if (position-1>=0) {
			a=position-1;
			
		}
		else {
			a=0;
		}
		if (position-2>=0) {
			b=position-2;
		}
		else {
			b=0;
		}
		output = (double) ((-1-remainder) * buffer[a] + remainder * buffer[b])/32767;//linear interpolation
	}	
	return(output);
}

double maxiSample::bufferPlay(unsigned char &bufferin,double frequency, double start, double end) {
	double remainder;
	length=end;
	long a,b;
	short* buffer = (short *)bufferin;
	if (frequency >0.) {
		if (position<start) {
			position=start;
		}
		
		if ( position >= end ) position = start;
		position += ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		long pos = floor(position);
		if (pos+1<length) {
			a=pos+1;
			
		}
		else {
			a=pos-1;
		}
		if (pos+2<length) {
			b=pos+2;
		}
		else {
			b=length-1;
		}
		
		output = (double) ((1-remainder) * buffer[a] +
						   remainder * buffer[b])/32767;//linear interpolation
	} else {
		frequency=frequency-(frequency+frequency);
		if ( position <= start ) position = end;
		position -= ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		long pos = floor(position);
		if (pos-1>=0) {
			a=pos-1;
		}
		else {
			a=0;
		}
		if (pos-2>=0) {
			b=pos-2;
		}
		else {
			b=0;
		}		
		output = (double) ((-1-remainder) * buffer[a] +
						   remainder * buffer[b])/32767;//linear interpolation
		
	}
	
	return(output);
}

//better cubic inerpolation. Cobbled together from various (pd externals, yehar, other places).
double maxiSample::bufferPlay4(unsigned char &bufferin,double frequency, double start, double end) {
	double remainder;
	double a,b,c,d,a1,a2,a3;
	short* buffer = (short*)bufferin;
	if (frequency >0.) {
		if (position<start) {
			position=start;
		}
		if ( position >= end ) position = start;
		position += ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		if (position>0) {
			a=buffer[(int)(floor(position))-1];
			
		} else {
			a=buffer[0];
			
		}
		
		b=buffer[(long) position];
		if (position<end-2) {
			c=buffer[(long) position+1];
			
		} else {
			c=buffer[0];
			
		}
		if (position<end-3) {
			d=buffer[(long) position+2];
			
		} else {
			d=buffer[0];
		}
		a1 = 0.5f * (c - a);
		a2 = a - 2.5 * b + 2.f * c - 0.5f * d;
		a3 = 0.5f * (d - a) + 1.5f * (b - c);
		output = (double) (((a3 * remainder + a2) * remainder + a1) * remainder + b) / 32767;
		
	} else {
		frequency=frequency-(frequency+frequency);
		if ( position <= start ) position = end;
		position -= ((end-start)/(maxiSettings::sampleRate/(frequency*chandiv)));
		remainder = position - floor(position);
		if (position>start && position < end-1) {
			a=buffer[(long) position+1];
			
		} else {
			a=buffer[0];
			
		}
		
		b=buffer[(long) position];
		if (position>start) {
			c=buffer[(long) position-1];
			
		} else {
			c=buffer[0];
			
		}
		if (position>start+1) {
			d=buffer[(long) position-2];
			
		} else {
			d=buffer[0];
		}
		a1 = 0.5f * (c - a);
		a2 = a - 2.5 * b + 2.f * c - 0.5f * d;
		a3 = 0.5f * (d - a) + 1.5f * (b - c);
		output = (double) (((a3 * remainder + a2) * -remainder + a1) * -remainder + b) / 32767;
		
	}
	
	return(output);
}


void maxiSample::getLength() {
	length=myDataSize*0.5;	
}

/* This is a basic compressor. Can also do expansion. It takes standard args for ratio and threshold
 although threshold is in linear amplitude at the moment. It has some crotchety old excuse for gain compensation
 which will do for now, but if you do choose to use it for expansion, watch out as it will bite you in the bum*/

double maxiDyn::compress(double input, double ratio, double threshold) {
	
	if (fabs(input)>threshold) {
		if (input>0.) {
			output = 1-threshold+(((input-threshold)/ratio)+threshold);
		} else {
			output = 1-threshold+(((input+threshold)/ratio)-threshold);
		}

	}
	
	else {
		output=input+(1-threshold);
	}
	return output;
}

/*reasonably happy with this. input is the input signal to gate, threshold is the threshold of the gate (default 0.9),
 holdtime is how long you want to hold after the attack finishes (default 1 sample). The envelopes are old school digital.
 An attack of 1 is instant (default). An attack of 0.0015 is a few hundred ms. Likewise, a release 
 of 0. is instant and a release of 0.9995 (default) is a few hundred ms. When I can be arsed I'll work out
 what this ends up as in seconds and do the conversion. I may never be arsed. It seems a waste. */
double maxiDyn::gate(double input, double threshold, long holdtime, double attack, double release) {
		
	if (fabs(input)>threshold && attackphase!=1){ 
		holdcount=0;
		releasephase=0;
		attackphase=1;
		amplitude=0;
	}
	
	if (attackphase==1 && amplitude<1) {
		amplitude+=(1*attack);
		output=input*amplitude;
	}
	
	if (amplitude>=1) {
		attackphase=0;
		holdphase=1;
	}
	
	if (holdcount<holdtime && holdphase==1) {
		output=input;
		holdcount++;
	}
	
	if (holdcount==holdtime) {
		holdphase=0;
		releasephase=1;
	}
	
	if (releasephase==1 && amplitude>0.) {
		output=input*(amplitude*=release);

	}
	
	return output;
}

/* Lots of people struggle with the envelope generators so here's a new easy one. It takes mental numbers for attack and release tho */
double maxiEnv::ar(double input, double attack, double release, long holdtime, int trigger) {
	
	if (trigger==1 && attackphase!=1 && holdphase!=1){ 
		holdcount=0;
		releasephase=0;
		attackphase=1;
	}
	
	if (attackphase==1) {
		amplitude+=(1*attack);
		output=input*amplitude;
	}
	
	if (amplitude>=1) {
		amplitude=1;
		attackphase=0;
		holdphase=1;
	}
	
	if (holdcount<holdtime && holdphase==1) {
		output=input;
		holdcount++;
	}
	
	if (holdcount==holdtime && trigger==1) {
		output=input;
	}
	
	if (holdcount==holdtime && trigger!=1) {
		holdphase=0;
		releasephase=1;
	}

	if (releasephase==1 && amplitude>0.) {
		output=input*(amplitude*=release);
		
	}
	
	return output;
}

double maxiEnv::adsr(double input, double attack, double decay, double sustain, double release, long holdtime, int trigger) {
	
	if (trigger==1 && attackphase!=1 && holdphase!=1 && decayphase!=1){ 
		holdcount=0;
		decayphase=0;
		sustainphase=0;
		releasephase=0;
		attackphase=1;
	}
	
	if (attackphase==1) {
		amplitude+=(1*attack);
		output=input*amplitude;
	}
	
	if (amplitude>=1) {
		amplitude=1;
		attackphase=0;
		decayphase=1;
	}
	
	if (decayphase==1) {
		output=input*(amplitude*=decay);	
		if (amplitude<=sustain) {
			decayphase=0;
			holdphase=1;
		}
	}
	
	if (holdcount<holdtime && holdphase==1) {
		output=input*amplitude;
		holdcount++;
	}
	
	if (holdcount==holdtime && trigger==1) {
		output=input*amplitude;
	}
	
	if (holdcount==holdtime && trigger!=1) {
		holdphase=0;
		releasephase=1;
	}
	
	if (releasephase==1 && amplitude>0.) {
		output=input*(amplitude*=release);
		
	}
	
	return output;
}