//
// Modified By:   Craig Stuart Sapp <craig@ccrma.stanford.edu>
// Creation Date: Fri Feb  7 13:09:01 PST 2003
// Last Modified: Fri Feb  7 13:09:04 PST 2003
// Filename:      thru.c
// Source:        Ichiro Fujinaga: Max/MSP Externals Tutorial, 2002, v2.41, p.31
// Web Address:   http://peabody.sapp.org/class/dmp2/lab/thru/thru.c
// Syntax:        C; Max4/MSP2 External Object; CodeWarrior 6.0
// OS:            Mac OS 9; PPC
//
// Description:   Demonstration of how to receive and send signal data
//                without modifying the data.
//

#include "ext.h"
#include "z_dsp.h"

typedef struct {
   t_pxobject msp_data;  // must always be the first field; used by MSP
} MyObject;

void* object_data;     // pointer to data for object (created in setup());

// function declarations:
void   main            (void);
void*  create_object   (void);
void   MessageDSP      (MyObject* mo, t_signal** signal, short* count);
t_int* Perform         (t_int *parameters);


//////////////////////////////////////////////////////////////////////////
//
// Initialization functions:
//


void main(void) {
   setup((t_messlist**)&object_data, // the pointer for object data
         (method)create_object,      // your function that initializes object
         (method)dsp_free,           // your function that deinitializes object
         (short)sizeof(MyObject),    // size of your object data struct
         NULL,                       // your menu function
         A_NOTHING);                 // A list of default parameters types
                                     // ending with A_NOTHING

   addmess((method)MessageDSP, "dsp", A_CANT, A_NOTHING);
   dsp_initclass();
}



//////////////////////////////
//
// create_object -- object initializing function.  This function is
//    called by the setup() function inside of main().  Place code
//    here which will be used to initialized your data structure,
//    as well as the actual creation of the data storage itself.
//    The setup function will cause the pointer object_data to point
//    to the created data storage.
//

void* create_object(void) {
   MyObject *mo = (MyObject*)newobject(object_data);  // create data storage 
   dsp_setup((t_pxobject*)mo, 1);           // inlet 1
   outlet_new((t_pxobject*)mo, "signal");   // outlet 1
   return mo;                               // return pointer to data storage
}


//////////////////////////////////////////////////////////////////////////
//
// Behavior functions:
//


//////////////////////////////
//
// MessageDSP -- What to do when a "dsp" message arrives into the object.
//

void MessageDSP(MyObject* mo, t_signal** signal, short* count) {
   #pragma unused(mo)
   #pragma unused(count)
   dsp_add(Perform, 4, 4, signal[0]->s_vec, signal[1]->s_vec, signal[0]->s_n);
}



//////////////////////////////
//
// Perform -- do the action for one sample group (number of samples
//   specified by the value w[3], which is to copy the input data into 
//   the output data.
//

t_int* Perform(t_int *parameters) {
   long     pcount  = (long)    (parameters[1]);
   t_float *input   = (t_float*)(parameters[2]);
   t_float *output  = (t_float*)(parameters[3]);
   long     count   = (long)    (parameters[4]);
   long     i;

   for (i=0; i<count; i++) {
      output[i] = input[i];
   }
   
   return parameters+pcount+1;   // return pointer to next item in DSP chain
}