Question

I wish my first post wasn’t so newbie. I’ve been working with openframeworks, so far so good, but as I’m new to programming I’m having a real headache returning the right value from an int function. I would like the int to increment up until the Boolean condition is met and then decrement to zero. The int is used to move through an array from beginning to end and then back. When I put the guts of the function into the method that I’m using the int in, everything works perfectly, but very messy and I wonder how computationally expensive it is to put there, it just seems that my syntactic abilities are lacking to do otherwise. Advice appreciated, and thanks in advance.

int testApp::updown(int j){

if(j==0){
    arp =true;

}
else if (j==7){
    arp = false; 

}

if(arp == true){
    j++;

}

else if(arp == false){
    j--;

}

    return (j);

}

and then its called like this in an audioRequest block of the library I’m working with:

for (int i = 0; i < bufferSize; i++){


 if ((int)timer.phasor(sorSpeed)) {

            z = updown(_j);
            noteOut = notes [z];

            cout<<arp;
            cout<<z;

        }

EDIT: For addition of some information. Removed the last condition of the second if statement, it was there because I was experiencing strange happenings where j would start walking off the end of the array.

Excerpt of testApp.h

int z, _j=0;
Boolean arp;

EDIT 2: I’ve revised this now, it works, apologies for asking something so rudimentary and with such terrible code to go with. I do appreciate the time that people have taken to comment here. Here are my revised .cpp and my .h files for your perusal. Thanks again.

#include "testApp.h"
#include <iostream>
using namespace std;



testApp::~testApp() {

}

void testApp::setup(){


sampleRate          = 44100;
initialBufferSize   = 1024;

//MidiIn.openPort();
//ofAddListener(MidiIn.newMessageEvent, this, &testApp::newMessage);

j = 0;
z= 0;
state = 1;


tuning = 440;
inputNote = 127;
octave = 4;
sorSpeed = 2;
freqOut = (tuning/32) * pow(2,(inputNote-69)/12);
finalOut = freqOut * octave;



notes[7] = finalOut+640;
notes[6] = finalOut+320;
notes[5] = finalOut+160; 
notes[4] = finalOut+840;
notes[3] = finalOut+160;
notes[2] = finalOut+500;
notes[1] = finalOut+240;
notes[0] = finalOut;


ofSoundStreamSetup(2,0,this, sampleRate, initialBufferSize, 4);/* Call this last ! */


}

void testApp::update(){



}

void testApp::draw(){



}

int testApp::updown(int &_j){

int tmp;

if(_j==0){
    arp = true;
}

else if(_j==7) {
    arp = false; 
}


if(arp == true){
    _j++;
}

else if(arp == false){
    _j--;
}

tmp = _j;
return (tmp);

}

void testApp::audioRequested    (float * output, int bufferSize, int nChannels){


    for (int i = 0; i < bufferSize; i++){


        if ((int)timer.phasor(sorSpeed)) {


            noteOut = notes [updown(z)];


            }


    mymix.stereo(mySine.sinewave(noteOut),outputs,0.5);


    output[i*nChannels    ] = outputs[0]; 
    output[i*nChannels + 1] = outputs[1];

    }
}

testApp.h

class testApp : public ofBaseApp{

public:
    ~testApp();/* destructor is very useful */
    void setup();
    void update();
    void draw();

    void keyPressed  (int key);
    void keyReleased(int key);
    void mouseMoved(int x, int y );
    void mouseDragged(int x, int y, int button);
    void mousePressed(int x, int y, int button);
    void mouseReleased(int x, int y, int button);
    void windowResized(int w, int h);
    void dragEvent(ofDragInfo dragInfo);
    void gotMessage(ofMessage msg);

    void newMessage(ofxMidiEventArgs &args);

    ofxMidiIn MidiIn;

    void audioRequested     (float * input, int bufferSize, int nChannels); /* output method */
    void audioReceived  (float * input, int bufferSize, int nChannels); /* input method */

    Boolean arp;
    int     initialBufferSize; /* buffer size */
    int     sampleRate;
    int    updown(int &intVar);


    /* stick you maximilian stuff below */

    double filtered,sample,outputs[2];
    maxiFilter filter1;
    ofxMaxiMix mymix;
    ofxMaxiOsc sine1;
    ofxMaxiSample beats,beat;
    ofxMaxiOsc mySine,myOtherSine,timer;

    int currentCount,lastCount,i,j,z,octave,sorSpeed,state;
    double notes[8];
    double noteOut,freqOut,tuning,finalOut,inputNote;

};

Answer 1

It’s pretty hard to piece this all together. I do think you need to go back to basics a bit, but all the same I think I can explain what is going on.

1. You initialise _j to 0 and then never modify the value of _j.
2. You therefore call updown passing 0 as the parameter every time.
3. updown returns a value of 1 when the input is 0.

Perhaps you meant to pass z to updown when you call it, but I cannot be sure.

Are you really declaring global variables in your header file? That’s not good. Try to use local variables and/or parameters as much as possible. Global variables are pretty evil, especially declared in the header file like that!