trying to call function from main.cpp to wave.cpp

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Hi guys,
I have created a program with QMainWindow on Qt Creator called wave and I have a function called generate_sine() in my main.cpp which I wish to call in my wave.cpp under my pushButton function. How do I do this?
What I tried was: I defined the function in main.cpp, I declared it in the header file(wave.h), and I tried to call/implement it in my wave file(wave.cpp) under the function: on_pushButton_clicked(). This is the way to do it in c++ programming, but its not working. Any help would be greatly appreciated.
Code is below for viewing:

main.cpp:
defining function:
...(some code)...

Code:

static int generate_sine(const snd_pcm_channel_area_t *areas, 
                           snd_pcm_uframes_t offset,
                           int count, double *_phase)
 {
         static double max_phase = 2. * M_PI;
         double phase = *_phase;
         double step = max_phase*freq/(double)rate;
         unsigned char *samples[channels];
         int steps[channels];
         unsigned int chn;
         int format_bits = snd_pcm_format_width(format);
         unsigned int maxval = (1 << (format_bits - 1)) - 1;
         int bps = format_bits / 8;  // bytes per sample 
         int phys_bps = snd_pcm_format_physical_width(format) / 8;
         int big_endian = snd_pcm_format_big_endian(format) == 1;
         int to_unsigned = snd_pcm_format_unsigned(format) == 1;
         int is_float = (format == SND_PCM_FORMAT_FLOAT_LE ||
                         format == SND_PCM_FORMAT_FLOAT_BE);
	 float amplitude_scale = amplitude/8.56;
 
 
	 // verify and prepare the contents of areas 
         for (chn = 0; chn < channels; chn++) {
                 if ((areas[chn].first % 8) != 0) {
                         printf("areas[%i].first == %i, aborting...\n", chn, areas[chn].first);
                         exit(EXIT_FAILURE);
                 }
                 samples[chn] = (((unsigned char *)areas[chn].addr) + (areas[chn].first / 8));
                 if ((areas[chn].step % 16) != 0) {
                          printf("areas[%i].step == %i, aborting...\n", chn, areas[chn].step);
                         exit(EXIT_FAILURE);
                 }
                 steps[chn] = areas[chn].step / 8;
                 samples[chn] += offset * steps[chn];
         }
         // fill the channel areas 
         while (count-- > 0) {
                 union {
                         float f;
                         int i;
                 } fval;
                 int res, i;
                 if (is_float) {
                         fval.f = amplitude_scale * sin(phase) * maxval;
                         res = fval.i;
                 } else
                         res = amplitude_scale * sin(phase) * maxval;
                 if (to_unsigned)
                         res ^= 1U << (format_bits - 1);
                 for (chn = 0; chn < channels; chn++) {
                         // Generate data in native endian format 
                         if (big_endian) {
                                 for (i = 0; i < bps; i++)
                                         *(samples[chn] + phys_bps - 1 - i) = (res >> i * 8) & 0xff;
                         } else {
                                 for (i = 0; i < bps; i++)
                                         *(samples[chn] + i) = (res >>  i * 8) & 0xff;
                         }
                         samples[chn] += steps[chn];
                 }
                 phase += step;
                 if (phase >= max_phase)
                         phase -= max_phase;
         }
         *_phase = phase;
 }......some code...

wave.cpp:

Code:

...(some code)...
 void wave::on_pushButton_clicked()
{
        freq = ui->frequency->text().toDouble();
        ampl = ui->amplitude->text().toDouble();
        snd_pcm_t *handle;
        signed short *samples;
        snd_pcm_channel_area_t *areas;
        double phase = 0;
        signed short *ptr;
        int err, cptr;
 
            while (isTrue) {
                    generate_sine(areas, 0, period_size, &phase);   .................[B].calling function[/B]
 
                    ptr = samples;
                    cptr = period_size;
                    while (cptr > 0) {
                            err = snd_pcm_writei(handle, ptr, cptr);
                            if (err == -EAGAIN)
                                    continue;
                            if (err < 0) {
                                    if (xrun_recovery(handle, err) < 0) {
                                            printf("Write error: %s\n", snd_strerror(err));
                                            exit(EXIT_FAILURE);
                                    }
                                    break;  /* skip one period */
                            }
                            ptr += err * channels;
                            cptr -= err;
                    }
            }...(some code)...

wave.h:
declaring function:

Code:

....(some code)...
class wave : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit wave(QWidget *parent = 0);
    ~wave();
 
private slots:
    void on_pushButton_clicked();
 
    void on_pushButton_2_clicked();
private:
    Ui::wave *ui;
    static int generate_sine(const snd_pcm_channel_area_t *areas,
                               snd_pcm_uframes_t offset,
                             int count, double *_phase) ; 
 
};

5th August 2011, 20:38
stampede

Re: trying to call function from main.cpp to wave.cpp
declare the function in header "generate_sine.h":
Code:

// generate_sine.h #include something extern void generate_sine( const snd_pcm_channel_area_t *areas, snd_pcm_uframes_t offset, int count, double *_phase );
and put the implementation in "generate_sine.cpp" (without the "static" keyword).
Add the sources to .pro file.
Then include "generate_sine.h" in "main.cpp" or wherever else you want to use the method.

Re: trying to call function from main.cpp to wave.cpp

Quote:

Originally Posted by stampede

declare the function in header "generate_sine.h":

Code:

// generate_sine.h
 
#include something
 
extern void generate_sine( const snd_pcm_channel_area_t *areas, 
                           snd_pcm_uframes_t offset,
                           int count, double *_phase );

and put the implementation in "generate_sine.cpp" (without the "static" keyword).
Add the sources to .pro file.
Then include "generate_sine.h" in "main.cpp" or wherever else you want to use the method.

Hi,
I tried this, it didn't work. Still getting the same error:

Code:

undefined reference to `wave::generate_sine(_snd_pcm_channel_area const*, unsigned long, int, double*)

generate_sine.cpp:

Code:

#include <stdio.h>
#include <cstdio>
#include <stdlib.h>
#include <cstdlib>
#include <string.h>
#include <cstring>
#include <sched.h>
#include <errno.h>
#include <getopt.h>
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <math.h>
#include <cmath>
#include <iostream>
using namespace std;
 
static const char *device = "plughw:0,0";              // playback device
static snd_pcm_format_t format = SND_PCM_FORMAT_S16;    // sample format- change to 24-bit
static unsigned int rate = 96000;                       // stream rate
static unsigned int channels = 128;                     // count of channels
static unsigned int buffer_time = 500000;               // ring buffer length in us
static unsigned int period_time = 100000;               // period time in us
static double freq;                                     // sinusoidal wave frequency in Hz
static int verbose = 0;                                 // verbose flag
static int resample = 1;                                // enable alsa-lib resampling
static int period_event = 0; 				// produce poll event after each period
static snd_pcm_sframes_t buffer_size;
static snd_pcm_sframes_t period_size;
static snd_output_t *output = NULL;
static double ampl;
static snd_pcm_t *h;
static double amplitude;
 
 
int generate_sine(const snd_pcm_channel_area_t *areas,
                           snd_pcm_uframes_t offset,
                         int count, double *_phase)
 
{
 
            static double max_phase = 2. * M_PI;
            double phase = *_phase;
            double step = max_phase*freq/(double)rate;
            unsigned char *samples[channels];
            int steps[channels];
            unsigned int chn;
            int format_bits = snd_pcm_format_width(format);
            unsigned int maxval = (1 << (format_bits - 1)) - 1;
            int bps = format_bits / 8;  /* bytes per sample */
            int phys_bps = snd_pcm_format_physical_width(format) / 8;
            int big_endian = snd_pcm_format_big_endian(format) == 1;
            int to_unsigned = snd_pcm_format_unsigned(format) == 1;
            int is_float = (format == SND_PCM_FORMAT_FLOAT_LE ||
                            format == SND_PCM_FORMAT_FLOAT_BE);
 
            float amplitude_scale = amplitude/8.56;
 
            /* verify and prepare the contents of areas */
            for (chn = 0; chn < channels; chn++) {
                    if ((areas[chn].first % 8) != 0) {
                            printf("areas[%i].first == %i, aborting...\n", chn, areas[chn].first);
                            exit(EXIT_FAILURE);
                    }
                    samples[chn] = /*(signed short *)*/(((unsigned char *)areas[chn].addr) + (areas[chn].first / 8));
                    if ((areas[chn].step % 16) != 0) {
                             printf("areas[%i].step == %i, aborting...\n", chn, areas[chn].step);
                            exit(EXIT_FAILURE);
                    }
                    steps[chn] = areas[chn].step / 8;
                    samples[chn] += offset * steps[chn];
            }
            /* fill the channel areas */
            while (count-- > 0) {
                    union {
                            float f;
                            int i;
                    } fval;
                    int res, i;
                    if (is_float) {
                            fval.f = amplitude_scale * sin(phase) * maxval;
                            res = fval.i;
                    } else
                            res = amplitude_scale * sin(phase) * maxval;
                    if (to_unsigned)
                            res ^= 1U << (format_bits - 1);
                    for (chn = 0; chn < channels; chn++) {
                            /* Generate data in native endian format */
                            if (big_endian) {
                                    for (i = 0; i < bps; i++)
                                            *(samples[chn] + phys_bps - 1 - i) = (res >> i * 8) & 0xff;
                            } else {
                                    for (i = 0; i < bps; i++)
                                            *(samples[chn] + i) = (res >>  i * 8) & 0xff;
                            }
                            samples[chn] += steps[chn];
                    }
                    phase += step;
                    if (phase >= max_phase)
                            phase -= max_phase;
            }
            *_phase = phase;
    }

generate_sine.h:

Code:

#ifndef GENERATE_SINE_H
#define GENERATE_SINE_H
#include <alsa/asoundlib.h>
#include <QMainWindow>
#include <QObject>
 
extern void generate_sine(const snd_pcm_channel_area_t *areas,
snd_pcm_uframes_t offset,
int count, double *_phase );
 
#endif // GENERATE_SINE_H

wave.pro:

Code:

QT       += core gui
 
TARGET = Wave
TEMPLATE = app
 
 
SOURCES += main.cpp\
        wave.cpp \
    generate_sine.cpp
 
HEADERS  += wave.h \
    generate_sine.h
 
 
LIBS     += -lasound
 
 
FORMS    += wave.ui

Added after 20 minutes:

Quote:

Originally Posted by stampede

declare the function in header "generate_sine.h":

Code:

// generate_sine.h
 
#include something
 
extern void generate_sine( const snd_pcm_channel_area_t *areas, 
                           snd_pcm_uframes_t offset,
                           int count, double *_phase );

Hey thanks for the reply. This does allow me to call it in other files, but it doesn't let me call it under the on_pushButton_clicked() function. It gives me the error:

Code:

undefined reference to `wave::generate_sine(_snd_pcm_channel_area const*, unsigned long, int, double*)

5th August 2011, 22:39
stampede

Re: trying to call function from main.cpp to wave.cpp
Code:

undefined reference to `wave::generate_sine
Have you declared this method elsewhere ? For example, in wave namespace (or class) ? Can you show how you want to use it ?