/* File: WOODS.C - Sound example */

#include <conio.h>
#include <dos.h>
#include <stdlib.h>
#include <time.h>

typedef unsigned char far *display_buffer;
typedef unsigned char byte;
typedef unsigned word;

static enum {BIRD1 =1, BIRD2, BIRD3, BIRD4};

void who_is_singing(const int bird);
void singing_bird(const int bird, const word duration, const int pitch, const int note);

#define _calcaddr(x, y) \
	(display_buffer)MK_FP(_displaybufferbase, \
	 160 * ((y) - 1) + 2 * ((x) - 1))

#define _outch(addr, c, attr) \
	(*(word far *)(addr) = (byte)(c) | (byte)(attr) << 8)

word _displaybufferbase;

int main(void)
{
    int bird;
    struct text_info info;

    gettextinfo(&info);
    _displaybufferbase = (info.currmode == C80) ? 0xb800 : 0xb000;

    cprintf("Press any key to stop singing\r\n");
    randomize();
    do {
	bird = random(4) + 1;
	who_is_singing(bird);
	singing_bird(bird, random(2000) + 300,
		     random(4000) + 200, random(2));
        delay(random(500) + 50);
    } while (!kbhit());
    getch(); /* clear key input buffer */
    nosound();
    putch('\r');
    clreol();

    return(0);
}

void who_is_singing(const int bird)
{
    const static byte *order[] = {
   "", "pretty", "small", "charming", "lovely"
    };

    putch('\r');
    clreol();
    cprintf("A %s bird is now singing...", order[bird]);
}

void song(const byte note)
{
    _outch(_calcaddr(wherex(), wherey()), (note == 0) ? '\x0e' : '\x0d', 0x0f);
    gotoxy(wherex() + 1, wherey());
}

void singing_bird(const int bird, const word duration, const int pitch, const int note)
{
    int i = 1, j, k;

    switch (bird) {
    case BIRD1: for (; i < duration; i++) {
		    sound(pitch + i);
		    if (i % 50 == 0) song(note);
		}
		break;
    case BIRD2: for (; i < duration; i++) {
		    sound(pitch + i);
		    if (i % 50 == 0) song(note);
		}
		nosound();
		delay(100);
		for (j = i + i / 10; i > j; i--) {
		    sound(pitch + i);
		    if (i % 50 == 0) song(note);
		}
		break;
    case BIRD3: for (k = 1; k < random(20) + 10; k++) {
		    sound(pitch);
		    delay(30);
		    song(note);
		    sound(pitch + pitch / 10);
		    delay(30);
		}
		break;
    case BIRD4: k = pitch + pitch / 10;
		for (i = random(5) + 10; i > 1; i--) {
		    for (j = pitch; j < k; j += 10) {
			sound(j);
			delay(6);
		    }
		    nosound();
		    song(note);
		    delay(40);
		}
		break;
    } /* switch */
    nosound();
}