npan~.c

#include "MSPd.h"
#define OBJECT_NAME "npan~"

#define SPEAKERMAX (1024)

static t_class *npan_class;


typedef struct _npan
{
	t_object x_obj;
	double pi_over_two;
	double twopi;
    float x_f;
	int outcount;
    t_float *input_locvec;
    t_float *panner_locvec;
} t_npan;

void *npan_new(t_symbol *s, short argc, t_atom *argv);
t_int *npan_perform(t_int *w);
void npan_dsp(t_npan *x, t_signal **sp);
void npan_free(t_npan *x);

void npan_tilde_setup(void){
    npan_class = class_new(gensym("npan~"), (t_newmethod)npan_new,
                  (t_method)npan_free, sizeof(t_npan),0,A_GIMME,0);
	CLASS_MAINSIGNALIN(npan_class, t_npan, x_f);
    class_addmethod(npan_class, (t_method)npan_dsp, gensym("dsp"),0);
    potpourri_announce(OBJECT_NAME);
}

void *npan_new(t_symbol *s, short argc, t_atom *argv)
{
	t_npan *x;
    x = (t_npan *)pd_new(npan_class);
	int i;
	x->outcount = (int) atom_getfloatarg(0, argc, argv);
	if( x->outcount < 2 || x->outcount > SPEAKERMAX ){
		
		error("npan~: output count %d exceeded range limits of 2 to %d",x->outcount, SPEAKERMAX);
        x->outcount = SPEAKERMAX;
	}
    inlet_new(&x->x_obj, &x->x_obj.ob_pd, gensym("signal"),gensym("signal")); // create 2nd inlet
	for(i = 0; i < x->outcount; i++){
		outlet_new(&x->x_obj, gensym("signal"));
	}
    x->input_locvec = (t_float *) calloc(8192, 1);
    x->panner_locvec = (t_float *) calloc(8192, 1);
    x->pi_over_two = 1.5707963267948965;
	x->twopi = 6.283185307179586;
	return x;
}

void npan_free(t_npan *x)
{
    free(x->panner_locvec);
    free(x->input_locvec);
}

t_int *npan_perform(t_int *w)
{
    t_npan *x = (t_npan*) w[1];
    int outcount = x->outcount;
	t_float *input = (t_float*) w[2];
	t_float *panner = (t_float*) w[3];
    t_float *outlet1, *outlet2, *cleanoutlet;
    t_float *input_locvec = x->input_locvec;
    t_float *panner_locvec = x->panner_locvec;
    
	double gain1, gain2;
	double insamp;
	int chan1, chan2;
	double panloc, frak;
	int i,j;
	
	double pi_over_two = x->pi_over_two;
    t_int n = w[4 + outcount];
	// copy inputs
    for(i = 0; i < n; i++){
        input_locvec[i] = input[i];
        panner_locvec[i] = panner[i];
    }
	// clean all outlets
	for( i = 0; i < outcount; i++ ){
		cleanoutlet = (t_float*) w[4 + i];
        for(j = 0; j < n; j++){
            cleanoutlet[j] = 0.0;
        }
	}
	for(i = 0; i < n; i++){
        insamp = input_locvec[i];
		panloc = panner_locvec[i];
		if( panloc < 0 )
			panloc = 0.0;
		if( panloc >= 1 ) // wrap around (otherwise crash on outlet out of range)
			panloc = 0.0;
		panloc *= (double) outcount;
		chan1 = floor( panloc );
		chan2 = (chan1 + 1) % outcount;
		frak = ( panloc - chan1 ) * pi_over_two;
		gain1 = cos( frak );
		gain2 = sin( frak );
		outlet1 = (t_float*) w[chan1 + 4]; // add offset
		outlet2 = (t_float*) w[chan2 + 4];
		
		outlet1[i] = insamp * gain1;
		outlet2[i] = insamp * gain2;
	}
    return (w + outcount + 5);
}




void npan_dsp(t_npan *x, t_signal **sp)
{
	long i;
    t_int **sigvec;
    int pointer_count = x->outcount + 4;
    sigvec  = (t_int **) calloc(pointer_count, sizeof(t_int *));
	for(i = 0; i < pointer_count; i++){
		sigvec[i] = (t_int *) calloc(sizeof(t_int),1);
	}
	sigvec[0] = (t_int *)x; // first pointer is to the object
	sigvec[pointer_count - 1] = (t_int *)sp[0]->s_n; // last pointer is to vector size (N)
	for(i = 1; i < pointer_count - 1; i++){ // now attach the inlet and all outlets
		sigvec[i] = (t_int *)sp[i-1]->s_vec;
	}
    dsp_addv(npan_perform, pointer_count, (t_int *) sigvec);
    free(sigvec);
}