Initial commit

.gitignore

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+bin/
+*.o
+*.gch

Makefile

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+
+CC ?= gcc
+SRCDIR ?= src
+INCDIR += -I${SRCDIR}
+OBJDIR ?= src
+BINDIR ?= bin
+INSTALLDIR ?= /usr/local/bin
+
+TARGET ?= synththing
+
+CFLAGS += -std=c99
+CFLAGS += `pkg-config --cflags portaudio-2.0`
+LDFLAGS += `pkg-config --libs portaudio-2.0`
+
+UNAME=$(shell uname -s)
+ifeq (${UNAME},FreeBSD) 
+INCDIR += -I/sys/
+endif 
+
+SHELL=/bin/sh
+SRC = $(wildcard ${SRCDIR}/*.c ${SRCDIR}/*/*.c)
+OBJ = ${SRC:${SRCDIR}/%.c=${OBJDIR}/%.o}
+
+
+all: synththing
+
+${OBJ}: $(OBJDIR)/%.o : $(SRCDIR)/%.c
+	@echo CC $<
+	${CC} -o $@ ${INCDIR} -c ${CFLAGS} ${DEFINES} $<
+
+synththing: ${OBJ}
+	@echo CC -o ${BINDIR}/${TARGET}
+	@mkdir -p ${BINDIR}
+	${CC} -I${INCDIR} -o ${BINDIR}/${TARGET} ${OBJ} ${LDFLAGS} ${CFLAGS} ${DEFINES}
+
+clean:
+	@echo cleaning
+	@rm -f syswriter ${OBJ}
+
+remove: clean
+	@echo deleting binary
+	@rm -f ${BINDIR}/${TARGET}
+	@rm -r ${BINDIR}
+
+install: synththing
+	mkdir -p ${INSTALLDIR} 
+	cp ${BINDIR}/${TARGET} ${INSTALLDIR}/${TARGET}
+	chmod 4555 ${INSTALLDIR}/${TARGET}
+
+

src/common.h

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+/*
+ * Filename:    common.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:12:37 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+#ifndef _H_COMMON
+#define _H_COMMON
+#include <stdint.h>
+typedef struct EngineState {
+    uint32_t t;
+    int sample_rate;
+} EngineState;
+#endif

src/filters/svf.c

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+/*
+ * Filename:    svf.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 00:00:40 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#define M_PI   3.14159265358979323846
+#define MAX(a,b) (a>b?a:b)
+#define MIN(a,b) (a<b?a:b)
+
+typedef enum DBO { _6dbo, _12dbo, _18dbo, _24dbo, _36dbo = 6, _48dbo } DBO;
+
+typedef struct SVF {
+    float notch;
+    float low;
+    float high;
+    float band;
+    float drive;
+    float freq;
+    float q;
+    DBO dbo;
+    float out;
+    float(*damp)(struct SVF*);
+    float(*process)(struct SVF*,float in);
+    void(*reset)(struct SVF*);
+} SVF;
+
+
+float svf_damp(SVF *self) {
+    float freq = 2.0*sin(M_PI * MIN(0.25, self->freq/(44100*2)));
+    return MIN(2.0 * (1.0 - powf(self->q,0.25)), MIN(2.0, 2.0/freq - freq * 0.5));
+    // return MIN(2.0 * (1.0 - pow(self->q,0.25)), MIN(2.0, (2.0/freq - freq * 0.5)));
+
+}
+float svf_process(SVF *self,float in) {
+    float a = in;
+    float freq = 2.0*sin(M_PI * MIN(0.25, self->freq/(44100*2)));
+    float damp = self->damp(self);
+    //printf("prefilt status: freq: %f, drive: %f, damp: %f, in: %f, low: %f, notch: %f, high: %f, band: %f\n",self->freq,self->drive, damp,in, self->low, self->notch, self->high, self->band);
+    for (unsigned int i = 0; i <= self->dbo; i++) {
+	self->notch = a - damp * self->band;
+	self->low   = self->low + freq * self->band;
+	self->high  = self->notch - self->low;
+	self->band  = freq * self->high + self->band - self->drive * self->band * self->band * self->band;
+	a = self->low;
+    }
+    self->out = a;
+    //printf("postfilt status: freq: %f, drive: %f, damp: %f, in: %f, low: %f, notch: %f, high: %f, band: %f\n",self->freq,self->drive, damp,in, self->low, self->notch, self->high, self->band);
+    return self->out;
+}
+
+void svf_reset(SVF* self){
+    self->notch = 0;
+    self->low = 0;
+    self->band = 0;
+    self->high = 0;
+    self->out = 0;
+}
+
+SVF* svf_new(float freq,float q,float drive) {
+    SVF *self = malloc(sizeof(SVF));
+    
+    self->freq = freq;
+    self->q = q;
+    self->drive = drive;
+    self->dbo = _12dbo;
+    // functions.
+    self->damp = svf_damp;
+    self->process = svf_process;
+    self->reset = svf_reset;
+    self->reset(self);
+    return self;
+}

src/filters/svf.h

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+/*
+ * Filename:    svf.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 00:00:40 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+#ifndef _H_FILTERS_SVF
+#define _H_FILTERS_SVF
+#include <math.h>
+#include <stdlib.h>
+
+#define MIN(X, Y) (((X) < (Y)) ? (X) : (Y))
+
+typedef enum DBO { _6dbo, _12dbo, _18dbo, _24dbo, _36dbo = 6, _48dbo } DBO;
+
+typedef struct SVF {
+    float notch;
+    float low;
+    float high;
+    float band;
+    float drive;
+    float freq;
+    float q;
+    DBO dbo;
+    float out;
+    float(*damp)(struct SVF*);
+    float(*process)(struct SVF*,float in);
+    void(*reset)(struct SVF*);
+} SVF;
+
+
+float svf_damp(SVF *self);
+float svf_process(SVF *self,float in);
+void svf_reset(SVF* self);
+SVF* svf_new(float freq,float q,float drive);
+#endif

src/synths/basic.c

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+/*
+ * Filename:    basic.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:08:31 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#include "../common.h"
+#include "../utils/envelope.h"
+#include <stdlib.h>
+#include <math.h>
+typedef enum Waveform {_waveform_sine, _waveform_saw} Waveform;
+typedef struct Basic {
+    float freq;
+    Waveform shape;
+    int gate;
+    Envelope Env;
+    float(*process)(struct Basic *, EngineState*);
+} Basic;
+    
+
+float basic_process(Basic *self, EngineState *t) {
+    float out;
+    switch (self->shape) {
+    case _waveform_saw:
+	out = fmod((self->freq+1) * t->t / 44100,1.0);
+	break;
+    default:
+	out = 0.0F;
+	break;
+    }
+    
+    return out;
+}
+
+Basic* basic_new(Waveform w, Envelope e) {
+    Basic *b = malloc(sizeof(Envelope));
+    b->shape = w;
+    b->process = basic_process;
+    return b;
+}
+    

src/synths/basic.h

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+/*
+ * Filename:    basic.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:37:08 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+#include "../common.h"
+#include "../utils/envelope.h"
+
+#ifndef _H_BASIC
+#define _H_BASIC
+
+typedef enum Waveform {_waveform_sine, _waveform_saw} Waveform;
+typedef struct Basic {
+    float freq;
+    Waveform shape;
+    int gate;
+    Envelope Env;
+    float(*process)(struct Basic *, EngineState*);
+} Basic;
+
+float basic_process(Basic *self, EngineState *t);
+Basic* basic_new(Waveform w, Envelope e);
+#endif

src/synththing.c

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+/*
+ * Filename:    synththing.c
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:52:12 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+
+#include <math.h>
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <portaudio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include "common.h"
+#include "synths/basic.h"
+#include "filters/svf.h"
+#include "utils/envelope.h"
+
+
+
+#define SAMPLE_RATE (44100)
+
+
+
+Basic saw;
+SVF filt;
+static EngineState data;
+
+int mycallback( const void *input,
+		void *output,
+		unsigned long frameCount,
+		const PaStreamCallbackTimeInfo* timeInfo,
+		PaStreamCallbackFlags statusFlags,
+		void *userData ) {
+    
+    EngineState *data = (EngineState*)userData;
+    float *out = (float*) output;
+    unsigned int i;
+    
+    for( i=0; i<frameCount; i++ )
+	{
+	    //filt.process(&filt, (saw.process(&saw,data)));
+	    //float a = filt.low;
+	    float a = 0.5 * saw.process(&saw,data);
+	    filt.process(&filt,a);
+	    a = filt.low;
+	    *out++ = a;
+	    *out++ = a;
+	    data->t++;
+	}
+    return 0;
+}
+
+int main(int argc, char**argv) {
+    
+    /* portaudio boilerplate crap */
+    PaError err;
+    err = Pa_Initialize();
+    const   PaDeviceInfo *deviceInfo;
+    int numDevices;
+    numDevices = Pa_GetDeviceCount();
+    if( numDevices < 0 )
+	{
+	    printf( "ERROR: Pa_CountDevices returned 0x%x\n", numDevices );
+	    err = numDevices;
+	    goto error;
+	}
+    
+    for(int i=0; i<numDevices; i++ )
+	{
+	    deviceInfo = Pa_GetDeviceInfo( i );
+	    
+	    printf("name: %s\n"
+		   "max channels\tin: %d\tout: %d\n"
+		   "samplerate: %f",deviceInfo->name,deviceInfo->maxInputChannels,deviceInfo->maxOutputChannels,deviceInfo->defaultSampleRate);
+	}
+		  
+    Envelope b = *envelope_new();
+    saw = *basic_new(_waveform_saw, b);
+    saw.freq = 440;
+    filt = *svf_new(7000.0f, 0.99f, 0.000001f);
+    //data.sample_rate=SAMPLE_RATE;
+    PaStream *stream;
+    /* Open an audio I/O stream. */
+    err = Pa_OpenDefaultStream( &stream,
+                                0,          
+                                2,         
+                                paFloat32,
+                                SAMPLE_RATE,
+                                256,
+                                mycallback,
+                                &data );
+					
+    if( err != paNoError ) goto error;
+    err = Pa_StartStream( stream );
+    if( err != paNoError ) goto error;
+    /* start anything intersting */
+    saw.gate = true;
+    for (int freq = 7000; freq >= 60; freq--) {
+	filt.freq = freq;
+	usleep(500);
+    }
+    sleep(1);
+    
+    /* more crap */
+ error:
+    printf( "PortAudio error: %s\n", Pa_GetErrorText( err ) );
+    err = Pa_Terminate();
+    if( err != paNoError )
+	printf(  "PortAudio error: %s\n", Pa_GetErrorText( err ) );
+    
+}

src/utils/envelope.c

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+/*
+ * Filename:    envelope.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:15:02 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+#include "../common.h"
+#ifndef _H_ENVELOPE
+#define _H_ENVELOPE
+#include <stdbool.h>
+#include <stdlib.h>
+
+typedef struct Envelope {
+    // these values are in samples.
+    unsigned int attack;
+    unsigned int decay;
+    unsigned int release;
+    float sustain_level;
+    float max_level;
+    float min_level;
+    bool gate;
+    float(*process)(struct Envelope *,EngineState *);
+    
+} Envelope;
+
+float envelope_process(Envelope *self, EngineState *t) {
+    return self->gate ? self->max_level : self-> min_level;
+}
+Envelope* envelope_new() {
+    Envelope *e = malloc(sizeof(Envelope));
+    e->process = envelope_process;
+    e->max_level = 1.0f;
+    e->min_level = 0.0f;
+    return e;
+}
+
+#endif

src/utils/envelope.h

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+/*
+ * Filename:    envelope.h
+ *
+ * Description:
+ *
+ *
+ * Version:     
+ * Created:     Wed Oct 30 17:15:02 2019
+ * Revision:    None
+ * Author:      Rachel Fae Fox (foxiepaws),fox@foxiepa.ws
+ *
+ */
+
+#ifndef _H_ENVELOPE
+#define _H_ENVELOPE
+#include <stdbool.h>
+#include "../common.h"
+
+typedef struct Envelope {
+    // these values are in samples.
+    unsigned int attack;
+    unsigned int decay;
+    unsigned int release;
+    float sustain_level;
+    float max_level;
+    float min_level;
+    bool gate;
+    float(*process)(struct Envelope *, EngineState *);
+    
+} Envelope;
+
+float envelope_process(Envelope *self, EngineState *t);
+Envelope* envelope_new();
+
+#endif