void move_bullets(void)
{
BULLET *bullet = bullet_list;
while (bullet) {
bullet->y -= BULLET_SPEED;
/* if the bullet is at the top of the screen, delete it */
if (bullet->y < 8) {
bullet = delete_bullet(bullet);
goto bullet_updated;
}
else {
/* shot an asteroid? */
if (asteroid_collision(bullet->x, bullet->y, 20)) {
score += 10;
play_sample(data[BOOM_SPL].dat, 255, PAN(bullet->x), 1000, FALSE);
/* delete the bullet that killed the alien */
bullet = delete_bullet(bullet);
goto bullet_updated;
}
}
bullet = bullet->next;
bullet_updated:;
}
}
/* the main music player function */
static void music_player()
{
int i, note;
for (i=0; i<NUM_PARTS; i++) {
if (part_time[i] <= 0) {
note = part_pos[i][0];
part_time[i] = part_pos[i][1];
al_stop_sample_instance(part_voice[i]);
if (i == 3) {
if (note == 1) {
al_set_sample(part_voice[i], bd);
al_set_sample_instance_pan(part_voice[i], PAN(128));
}
else if (note == 2) {
al_set_sample(part_voice[i], snare);
al_set_sample_instance_pan(part_voice[i], PAN(160));
}
else {
al_set_sample(part_voice[i], hihat);
al_set_sample_instance_pan(part_voice[i], PAN(96));
}
al_play_sample_instance(part_voice[i]);
}
else {
if (note > 0) {
al_set_sample_instance_speed(part_voice[i], freq_table[note]/22050.0);
al_play_sample_instance(part_voice[i]);
}
}
part_pos[i] += 2;
if (!part_pos[i][1])
part_pos[i] = part_ptr[i];
}
part_time[i]--;
}
}
/* this code is sick */
static void init_music()
{
float vol, val;
char *p;
int i;
if (!al_is_audio_installed())
return;
/* sine waves (one straight and one with oscillator sync) for the bass */
sine = create_sample_u8(22050, 64);
p = (char *)al_get_sample_data(sine);
for (i=0; i<64; i++) {
*p = 128 + (sin((float)i * M_PI / 32.0) + sin((float)i * M_PI / 12.0)) * 8.0;
p++;
}
/* square wave for melody #1 */
square = create_sample_u8(22050, 64);
p = (char *)al_get_sample_data(square);
for (i=0; i<64; i++) {
*p = (i < 32) ? 120 : 136;
p++;
}
/* saw wave for melody #2 */
saw = create_sample_u8(22050, 64);
p = (char *)al_get_sample_data(saw);
for (i=0; i<64; i++) {
*p = 120 + (i*4 & 255) / 16;
p++;
}
/* bass drum */
bd = create_sample_u8(22050, 1024);
p = (char *)al_get_sample_data(bd);
for (i=0; i<1024; i++) {
vol = (float)(1024-i) / 16.0;
*p = 128 + (sin((float)i / 48.0) + sin((float)i / 32.0)) * vol;
p++;
}
/* snare drum */
snare = create_sample_u8(22050, 3072);
p = (char *)al_get_sample_data(snare);
val = 0;
for (i=0; i<3072; i++) {
vol = (float)(3072-i) / 24.0;
val = (val * 0.9) + (RAND * 0.1);
*p = 128 + val * vol;
p++;
}
/* hihat */
hihat = create_sample_u8(22050, 1024);
p = (char *)al_get_sample_data(hihat);
for (i=0; i<1024; i++) {
vol = (float)(1024-i) / 192.0;
*p = 128 + (sin((float)i / 4.2) + RAND) * vol;
p++;
}
/* start up the player */
for (i=0; i<256; i++)
freq_table[i] = (int)(350.0 * pow(2.0, (float)i/12.0));
for (i=0; i<NUM_PARTS; i++) {
part_pos[i] = part_ptr[i];
part_time[i] = 0;
}
part_voice[0] = al_create_sample_instance(sine);
part_voice[1] = al_create_sample_instance(square);
part_voice[2] = al_create_sample_instance(saw);
part_voice[3] = al_create_sample_instance(bd);
al_attach_sample_instance_to_mixer(part_voice[0], al_get_default_mixer());
al_attach_sample_instance_to_mixer(part_voice[1], al_get_default_mixer());
al_attach_sample_instance_to_mixer(part_voice[2], al_get_default_mixer());
al_attach_sample_instance_to_mixer(part_voice[3], al_get_default_mixer());
al_set_sample_instance_playmode(part_voice[0], ALLEGRO_PLAYMODE_LOOP);
al_set_sample_instance_playmode(part_voice[1], ALLEGRO_PLAYMODE_LOOP);
al_set_sample_instance_playmode(part_voice[2], ALLEGRO_PLAYMODE_LOOP);
al_set_sample_instance_playmode(part_voice[3], ALLEGRO_PLAYMODE_ONCE);
al_set_sample_instance_gain(part_voice[0], 192/255.0);
al_set_sample_instance_gain(part_voice[1], 192/255.0);
al_set_sample_instance_gain(part_voice[2], 192/255.0);
al_set_sample_instance_gain(part_voice[3], 255/255.0);
al_set_sample_instance_pan(part_voice[0], PAN(128));
al_set_sample_instance_pan(part_voice[1], PAN(224));
al_set_sample_instance_pan(part_voice[2], PAN(32));
al_set_sample_instance_pan(part_voice[3], PAN(128));
music_timer = al_install_timer(ALLEGRO_BPS_TO_SECS(22));
}
