Max 5 API Reference

minimetro.c

/* 
    minimetro
    Copyright 2004 - Cycling '74
    jeremy bernstein - jeremy@bootsquad.com 
*/

#include "ext.h"
#include "ext_common.h"
#include "ext_obex.h"

typedef struct _minimetro 
{
    t_object                    ob;
    void                        *obex;
    double                      speed;
    void                        *clock;
    long                        state;
    long                        id;
} t_minimetro;

void minimetro_init(void);
void *minimetro_new(long id, long speed);
void minimetro_free(t_minimetro *x);

void minimetro_clock(t_minimetro *x);
void minimetro_onoff(t_minimetro *x, long onoff);
void minimetro_speed(t_minimetro *x, void *attr, long ac, t_atom *av);

void *minimetro_class;
            
void minimetro_init(void)
{   
    t_class *c;
    void    *attr;
    long    attrflags = 0;
    
    c = class_new("minimetro", (method)minimetro_new, (method)minimetro_free, 
        (short)sizeof(t_minimetro), 0L, A_CANT, 0); // A_CANT so that we can have arbitrary args
    
    // initialize the common symbols, since we want to use them
    common_symbols_init();
    
    // register the byte offset of obex with the class
    class_obexoffset_set(c, calcoffset(t_minimetro, obex));
    
    // add some methods
    class_addmethod(c, (method)minimetro_onoff, "onoff", A_LONG, 0);
    // add some attributes
    attr = attr_offset_new("speed", _sym_float64, attrflags, 
        (method)0L, (method)minimetro_speed, calcoffset(t_minimetro, speed));
    class_addattr(c, attr);
    
    // we do not need this class to instantiate inside of the Max UI; ergo CLASS_NOBOX
    class_register(CLASS_NOBOX, c);
    minimetro_class = c;
}

void minimetro_onoff(t_minimetro *x, long onoff)
{
    if (onoff && !x->state) {
        clock_fdelay(x->clock, x->speed);
        x->state = 1;
    }
    else if (!onoff && x->state) {
        clock_unset(x->clock);
        x->state = 0;
    }
}

void minimetro_clock(t_minimetro *x)
{
    // send a notification. in our case, this causes the parent object to bang
    object_notify(x, _sym_bang, (void *)x->id);
    clock_fdelay(x->clock, x->speed);
}

void minimetro_speed(t_minimetro *x, void *attr, long ac, t_atom *av)
{
    if (ac && av) { // we wait until the next tick to change the tempo
        x->speed = atom_getfloat(av);
    }
}


void minimetro_free(t_minimetro *x)
{
    clock_unset(x->clock); // just in case
    freeobject((t_object *)x->clock);
    object_obex_free(x);
}

void *minimetro_new(long id, long speed)
{
    t_minimetro *x;
    t_symbol *name;

    // we use object_alloc here, rather than newobject
    if (x = (t_minimetro *)object_alloc(minimetro_class)) {
        // get the outlet id sent in
        x->id = id;
        x->speed = (speed < 0.) ? 0. : speed;       
        x->clock = clock_new(x, (method)minimetro_clock);
        x->state = 0;
    }
    return (x);
}

Copyright © 2008, Cycling '74