america.c

C.Game.Programming.For.Dummies.原码

/*
 * Music playing routine
 * Borland compilers only!
 */

#include <dos.h>

void playsound(int note,int duration);

void main()
{

/*
 * The song being played, "America the Beautiful,"
 * is stored as a series of frequencies and durations
 * in a two-dimensional array.
 *
 * The song[][2] declaration defines the array as
 * a set of pairs; the compiler figures the size of
 * the thing.
 *
 * The first item, song[x][0], is the note's frequency.
 * The second item, song[x][1], is the duration in
 * millisonds. I've used 125 as an 8th note; 250 for
 * a quarter note; 375 for a dotted-quarter note;
 * and 750 for a dotted half note; a whole note
 * would have been 1000, or one second.
 *
 * A null byte ends the song.
 */

    int song[][2] = {
        392,250, 392,375, 330,125, 330,250,
        392,250, 392,375, 294,125, 294,250,
        330,250, 349,250, 392,250, 440,250,
        494,250, 392,750, 392,250, 392,375,
        330,125, 330,250, 392,250, 392,375,
        294,125, 294,250, 587,250, 554,250,
        587,250, 659,250, 440,250, 587,750,
        392,250, 659,375, 659,125, 587,250,
        523,250, 523,375, 494,125, 494,250,
        523,250, 587,250, 494,250, 440,250,
        392,250, 523,750, 523,250, 523,375,
        440,125, 440,250, 523,250, 523,375,
        392,125, 392,250, 392,250, 440,250,
        523,250, 392,250, 587,250, 523,750,
        0, 0
    };
    int x = 0;

/*
 * The while loop continues to fetch new items
 * from the song[][] array until zero is read.
 * Variable X keeps track of the elements.
 *
 * A delay of 1/10 sec. is made after each note
 * is played by the playsound() function. Otherwise
 * the notes would all run together and sound
 * gross. (Comment it out to hear what I mean.)
 */

    while(song[x++][0])
    {
        playsound(song[x][0],song[x][1]);
        delay(100);
    }
}

/*
 * The playsound function uses Borland C's
 * sound and delay functions play a sound on
 * the PC's speaker. sound() accepts a frequency
 * value and delay() accepts a millisecond value
 *
 * The nosound() function turns the PC's speaker
 * off
 */

void playsound(int note,int duration)
{
    sound(note);
    delay(duration);
    nosound();
}