/* 
 * guttersynth.h
 * Part of libguttersynth
 * 
 * Copyright Tom Mudd 2019, Richard Knight 2021, 2022
 * 
 * Ported to C by Richard Knight
 * from https://github.com/tommmmudd/guttersynthesis by Tom Mudd
 * 
 */

#ifndef GUTTER_H
#define GUTTER_H

#ifdef __cplusplus
extern "C" {
#endif

#include <stdio.h>
#include <stdlib.h>

// support for either single or double precision
#ifndef FLT
    
#ifdef USE_FLOAT
#define FLT float
#else
#define FLT double
#endif
   
#endif
    
    
// internal/private dcblock state variables
typedef struct dcblock_session_ {
    FLT xm1;
    FLT ym1;
    FLT r;
} dcblock_session;

// internal/private state variables
typedef struct gutter_internal_ {
    void (*dealloc)(void*);
    int samplerate;
    FLT finalY;
    FLT duffX;
    FLT duffY;
    FLT dx;
    FLT dy;
    FLT t;
    FLT* prevX1;
    FLT* prevX2;
    FLT* prevY1;
    FLT* prevY2;
    FLT* V;
    FLT* K;
    FLT* norm;
    FLT* a0;
    FLT* a1;
    FLT* a2;
    FLT* b1;
    FLT* b2;
    FLT* y;
    dcblock_session dcblock;
} gutter_internal;

// state with public variables
typedef struct gutter_state_ {
    int bankCount;
    int filterCount;

    FLT gamma;
    FLT omega;
    FLT c;
    FLT dt;
    FLT singleGain;
    FLT* gains;
    FLT* filterFreqs;
    FLT* Q;
    int enableAudioInput;
    int filtersOn;
    int smoothing;
    int distortionMethod;
    gutter_internal gi;
} gutter_state;


// synthesise single sample with input
FLT gutter_process_input(gutter_state* s, FLT audioInput);

// synthesise single sample
FLT gutter_process(gutter_state* s);

// synthesise specified number of samples with input
void gutter_process_input_samples(gutter_state* s, FLT* audioInput, FLT* audioOutput, int nsamps);

// synthesise specified number of samples
void gutter_process_samples(gutter_state* s, FLT* audioOutput, int nsamps);

// reset state
void gutter_reset(gutter_state* s);

// clean up memory etc
void gutter_cleanup(gutter_state* s);

// calculate filter coefficients
void gutter_calccoeffs(gutter_state* s);

// initialise with custom memory allocator and deallocator
gutter_state* gutter_init_ca(int bankCount, int filterCount, int samplerate, 
    void* (*allocator)(size_t), void (*deallocator)(void*));

// initialise with standard malloc and free
gutter_state* gutter_init(int bankCount, int filterCount, int samplerate);

// randomise filters
void gutter_randomisefilters(gutter_state* s);

// set distortion method
int gutter_setdistortionmethod(gutter_state* s, int method);

// set frequency of a filter in a bank
int gutter_setfreq(gutter_state*, int bank, int filter, FLT value);

// set Q of a filter in a bank
int gutter_setq(gutter_state* s, int bank, int filter, FLT value);

// set gain of a filter in a bank
int gutter_setgain(gutter_state* s, int bank, int filter, FLT value);

// set Q of all filters
void gutter_setqall(gutter_state* s, FLT value);

#ifdef __cplusplus
}
#endif

#endif /* GUTTER_H */