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Diffstat (limited to 'desiredata/doc/6.externs/dspobj~.c')
-rw-r--r-- | desiredata/doc/6.externs/dspobj~.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/desiredata/doc/6.externs/dspobj~.c b/desiredata/doc/6.externs/dspobj~.c new file mode 100644 index 00000000..5c3fa86b --- /dev/null +++ b/desiredata/doc/6.externs/dspobj~.c @@ -0,0 +1,67 @@ +#include "m_pd.h" +#ifdef NT +#pragma warning( disable : 4244 ) +#pragma warning( disable : 4305 ) +#endif + +/* ------------------------ dspobj~ ----------------------------- */ + +/* tilde object to take absolute value. */ + +static t_class *dspobj_class; + +typedef struct _dspobj +{ + t_object x_obj; /* obligatory header */ + t_float x_f; /* place to hold inlet's value if it's set by message */ +} t_dspobj; + + /* this is the actual performance routine which acts on the samples. + It's called with a single pointer "w" which is our location in the + DSP call list. We return a new "w" which will point to the next item + after us. Meanwhile, w[0] is just a pointer to dsp-perform itself + (no use to us), w[1] and w[2] are the input and output vector locations, + and w[3] is the number of points to calculate. */ +static t_int *dspobj_perform(t_int *w) +{ + t_float *in = (t_float *)(w[1]); + t_float *out = (t_float *)(w[2]); + int n = (int)(w[3]); + while (n--) + { + float f = *(in++); + *out++ = (f > 0 ? f : -f); + } + return (w+4); +} + + /* called to start DSP. Here we call Pd back to add our perform + routine to a linear callback list which Pd in turn calls to grind + out the samples. */ +static void dspobj_dsp(t_dspobj *x, t_signal **sp) +{ + dsp_add(dspobj_perform, 3, sp[0]->s_vec, sp[1]->s_vec, sp[0]->s_n); +} + +static void *dspobj_new(void) +{ + t_dspobj *x = (t_dspobj *)pd_new(dspobj_class); + outlet_new(&x->x_obj, gensym("signal")); + x->x_f = 0; + return (x); +} + + /* this routine, which must have exactly this name (with the "~" replaced + by "_tilde) is called when the code is first loaded, and tells Pd how + to build the "class". */ +void dspobj_tilde_setup(void) +{ + dspobj_class = class_new(gensym("dspobj~"), (t_newmethod)dspobj_new, 0, + sizeof(t_dspobj), 0, A_DEFFLOAT, 0); + /* this is magic to declare that the leftmost, "main" inlet + takes signals; other signal inlets are done differently... */ + CLASS_MAINSIGNALIN(dspobj_class, t_dspobj, x_f); + /* here we tell Pd about the "dsp" method, which is called back + when DSP is turned on. */ + class_addmethod(dspobj_class, (t_method)dspobj_dsp, gensym("dsp"), 0); +} |