/* Adapted from SPEED. */
static ALLEGRO_SAMPLE *generate_ping(void)
{
float osc1, osc2, vol, ramp;
int16_t *p;
int len;
int i;
/* ping consists of two sine waves */
len = 8192;
ping = create_sample_s16(22050, len);
if (!ping)
return NULL;
p = (int16_t *)al_get_sample_data(ping);
osc1 = 0;
osc2 = 0;
for (i=0; i<len; i++) {
vol = (float)(len - i) / (float)len * 4000;
ramp = (float)i / (float)len * 8;
if (ramp < 1.0f)
vol *= ramp;
*p = (sin(osc1) + sin(osc2) - 1) * vol;
osc1 += 0.1;
osc2 += 0.15;
p++;
}
return ping;
}
/* Stop any sample instances which are still playing a sample buffer which
* is about to be destroyed.
*/
static void stop_sample_instances_helper(void *object, void (*func)(void *),
void *userdata)
{
ALLEGRO_SAMPLE_INSTANCE *splinst = object;
/* This is ugly. */
if (func == (void (*)(void *)) al_destroy_sample_instance
&& al_get_sample_data(al_get_sample(splinst)) == userdata
&& al_get_sample_instance_playing(splinst))
{
al_stop_sample_instance(splinst);
}
}
/* Function: al_destroy_sample
*/
void al_destroy_sample(ALLEGRO_SAMPLE *spl)
{
if (spl) {
_al_kcm_foreach_destructor(stop_sample_instances_helper,
al_get_sample_data(spl));
_al_kcm_unregister_destructor(spl);
if (spl->free_buf && spl->buffer.ptr) {
al_free(spl->buffer.ptr);
}
spl->buffer.ptr = NULL;
spl->free_buf = false;
al_free(spl);
}
}
/* initialises the sound system */
void init_sound()
{
float f, osc1, osc2, freq1, freq2, vol, val;
char *p;
int len;
int i;
if (!al_is_audio_installed())
return;
/* zap (firing sound) consists of multiple falling saw waves */
len = 8192;
zap = create_sample_u8(22050, len);
p = (char *)al_get_sample_data(zap);
osc1 = 0;
freq1 = 0.02;
osc2 = 0;
freq2 = 0.025;
for (i=0; i<len; i++) {
vol = (float)(len - i) / (float)len * 127;
*p = 128 + (fmod(osc1, 1) + fmod(osc2, 1) - 1) * vol;
osc1 += freq1;
freq1 -= 0.000001;
osc2 += freq2;
freq2 -= 0.00000125;
p++;
}
/* bang (explosion) consists of filtered noise */
len = 8192;
bang = create_sample_u8(22050, len);
p = (char *)al_get_sample_data(bang);
val = 0;
for (i=0; i<len; i++) {
vol = (float)(len - i) / (float)len * 255;
val = (val * 0.75) + (RAND * 0.25);
*p = 128 + val * vol;
p++;
}
/* big bang (explosion) consists of noise plus rumble */
len = 24576;
bigbang = create_sample_u8(11025, len);
p = (char *)al_get_sample_data(bigbang);
val = 0;
osc1 = 0;
osc2 = 0;
for (i=0; i<len; i++) {
vol = (float)(len - i) / (float)len * 128;
f = 0.5 + ((float)i / (float)len * 0.4);
val = (val * f) + (RAND * (1-f));
*p = 128 + (val + (sin(osc1) + sin(osc2)) / 4) * vol;
osc1 += 0.03;
osc2 += 0.04;
p++;
}
/* ping consists of two sine waves */
len = 8192;
ping = create_sample_u8(22050, len);
p = (char *)al_get_sample_data(ping);
osc1 = 0;
osc2 = 0;
for (i=0; i<len; i++) {
vol = (float)(len - i) / (float)len * 31;
*p = 128 + (sin(osc1) + sin(osc2) - 1) * vol;
osc1 += 0.2;
osc2 += 0.3;
p++;
}
ping_timer = al_install_timer(0.3);
/* set up my lurvely music player :-) */
if (!no_music) {
init_music();
al_start_timer(music_timer);
}
sound_update_thread = al_create_thread(sound_update_proc, NULL);
al_start_thread(sound_update_thread);
}
/* 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));
}
