Chip 2005 November/CDVD1105.ISO/Software/Freeware/programare/bass/c/synth/synth.c

C/C++ Source or Header | 2005-09-08 | 4.8 KB | 155 lines

// BASS Simple Synth, copyright (c) 2001-2005 Ian Luck.

#include <windows.h>
#include <stdio.h>
#include <conio.h>
#include <math.h>
#include "bass.h"

/* display error messages */
void Error(char *text)
{
    printf("Error(%d): %s\n",BASS_ErrorGetCode(),text);
    BASS_Free();
    ExitProcess(0);
}


#define PI 3.14159265358979323846
#define TABLESIZE 2048
int sinetable[TABLESIZE];    // sine table
#define KEYS 20
WORD keys[KEYS]={
    'Q','2','W','3','E','R','5','T','6','Y','7','U',
    'I','9','O','0','P',219,187,221
};
#define MAXVOL    4000    // higher value = longer fadeout
int vol[KEYS]={0},pos[KEYS];    // keys' volume & pos


/* stream writer */
DWORD CALLBACK WriteStream(HSTREAM handle, short *buffer, DWORD length, DWORD user)
{
    int n,s;
    DWORD c;
    float f;
    memset(buffer,0,length);
    for (n=0;n<KEYS;n++) {
        if (!vol[n]) continue;
        f=pow(2.0,(n+3)/12.0)*TABLESIZE*440.0/44100.0;
        for (c=0;c<length/4 && vol[n];c++) {
            s=sinetable[(int)((pos[n]++)*f)&(TABLESIZE-1)]*vol[n]/MAXVOL;
            s+=(int)buffer[c*2];
            if (s>32767) s=32767;
            else if (s<-32768) s=-32768;
            buffer[c*2+1]=buffer[c*2]=s; // left and right channels are the same
            if (vol[n]<MAXVOL) vol[n]--;
        }
    }
    return length;
}

void main(int argc, char **argv)
{
    BASS_INFO info;
    HSTREAM str;
    char *fxname[9]={"CHORUS","COMPRESSOR","DISTORTION","ECHO",
        "FLANGER","GARGLE","I3DL2REVERB","PARAMEQ","REVERB"};
    HFX fx[9]={0}; // effect handles
    INPUT_RECORD keyin;
    int r;
    DWORD buflen;

    printf("BASS Simple Sinewave Synth\n"
            "--------------------------\n");

    /* check that BASS 2.2 was loaded */
    if (BASS_GetVersion()!=MAKELONG(2,2)) {
        printf("BASS version 2.2 was not loaded\n");
        return;
    }

    /* 10ms update period */
    BASS_SetConfig(BASS_CONFIG_UPDATEPERIOD,10);

    /* setup output - get latency */
    if (!BASS_Init(-1,44100,BASS_DEVICE_LATENCY,0,NULL))
        Error("Can't initialize device");

    /* build sine table */
    for (r=0;r<TABLESIZE;r++)
        sinetable[r]=(int)(sin(2.0*PI*(double)r/TABLESIZE)*7000.0);

    BASS_GetInfo(&info);
    printf("device latency: %dms\n",info.latency);
    printf("device minbuf: %dms\n",info.minbuf);
    printf("ds version: %d (effects %s)\n",info.dsver,info.dsver<8?"disabled":"enabled");

    /* default buffer size = update period + 'minbuf' */
    buflen=BASS_SetConfig(BASS_CONFIG_BUFFER,10+info.minbuf);

    /* create a stream, stereo so that effects sound nice */
    str=BASS_StreamCreate(44100,2,0,WriteStream,0);
    printf("press these keys to play:\n\n"
            "  2 3  5 6 7  9 0  =\n"
            " Q W ER T Y UI O P[ ]\n\n"
            "press -/+ to de/increase the buffer\n"
            "press spacebar to quit\n\n");

    if (info.dsver>=8) // DX8 effects available
        printf("press F1-F9 to toggle effects\n\n");

    printf("using a %dms buffer\r",buflen);

    BASS_ChannelPlay(str,FALSE);

    while (ReadConsoleInput(GetStdHandle(STD_INPUT_HANDLE),&keyin,1,&r)) {
        int key;
        if (keyin.EventType!=KEY_EVENT) continue;
        if (keyin.Event.KeyEvent.wVirtualKeyCode==VK_SPACE) break;
        if (keyin.Event.KeyEvent.bKeyDown && keyin.Event.KeyEvent.wVirtualKeyCode==VK_SUBTRACT) {
            /* recreate stream with smaller buffer */
            BASS_StreamFree(str);
            buflen=BASS_SetConfig(BASS_CONFIG_BUFFER,buflen-1);
            printf("using a %dms buffer\t\t\r",buflen);
            str=BASS_StreamCreate(44100,2,0,WriteStream,0);
            /* set effects on the new stream */
            for (r=0;r<9;r++) if (fx[r]) fx[r]=BASS_ChannelSetFX(str,BASS_FX_CHORUS+r,0);
            BASS_ChannelPlay(str,FALSE);
        }
        if (keyin.Event.KeyEvent.bKeyDown && keyin.Event.KeyEvent.wVirtualKeyCode==VK_ADD) {
            /* recreate stream with larger buffer */
            BASS_StreamFree(str);
            buflen=BASS_SetConfig(BASS_CONFIG_BUFFER,buflen+1);
            printf("using a %dms buffer\t\t\r",buflen);
            str=BASS_StreamCreate(44100,2,0,WriteStream,0);
            /* set effects on the new stream */
            for (r=0;r<9;r++) if (fx[r]) fx[r]=BASS_ChannelSetFX(str,BASS_FX_CHORUS+r,0);
            BASS_ChannelPlay(str,FALSE);
        }
        if (keyin.Event.KeyEvent.bKeyDown && keyin.Event.KeyEvent.wVirtualKeyCode>=VK_F1
            && keyin.Event.KeyEvent.wVirtualKeyCode<=VK_F9) {
            r=keyin.Event.KeyEvent.wVirtualKeyCode-VK_F1;
            if (fx[r]) {
                BASS_ChannelRemoveFX(str,fx[r]);
                fx[r]=0;
                printf("effect %s = OFF\t\t\r",fxname[r]);
            } else {
                /* set the effect, not bothering with parameters (use defaults) */
                if (fx[r]=BASS_ChannelSetFX(str,BASS_FX_CHORUS+r,0))
                    printf("effect %s = ON\t\t\r",fxname[r]);
            }
        }
        for (key=0;key<KEYS;key++)
            if (keyin.Event.KeyEvent.wVirtualKeyCode==keys[key]) break;
        if (key==KEYS) continue;
        if (keyin.Event.KeyEvent.bKeyDown && vol[key]!=MAXVOL) {
            pos[key]=0;
            vol[key]=MAXVOL; // start key
        } else if (!keyin.Event.KeyEvent.bKeyDown && vol[key])
            vol[key]--; // trigger key fadeout
    }

    BASS_Free();
}