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/*
* Example program for the Allegro library.
*/
#include <math.h>
#include "allegro5/allegro.h"
#include "allegro5/allegro_audio.h"
#include "allegro5/allegro_font.h"
#include "common.c"
#define RESERVED_SAMPLES 16
#define PERIOD 5
static ALLEGRO_DISPLAY *display;
static ALLEGRO_FONT *font;
static ALLEGRO_SAMPLE *ping;
static ALLEGRO_TIMER *timer;
static ALLEGRO_EVENT_QUEUE *event_queue;
static ALLEGRO_SAMPLE *create_sample_s16(int freq, int len)
{
char *buf = al_malloc(freq * len * sizeof(int16_t));
return al_create_sample(buf, len, freq, ALLEGRO_AUDIO_DEPTH_INT16,
ALLEGRO_CHANNEL_CONF_1, true);
}
/* 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;
}
int main(int argc, char **argv)
{
ALLEGRO_TRANSFORM trans;
ALLEGRO_EVENT event;
int bps = 4;
bool redraw = false;
unsigned int last_timer = 0;
(void)argc;
(void)argv;
if (!al_init()) {
abort_example("Could not init Allegro.\n");
}
open_log();
al_install_keyboard();
display = al_create_display(640, 480);
if (!display) {
abort_example("Could not create display\n");
}
font = al_create_builtin_font();
if (!font) {
abort_example("Could not create font\n");
}
if (!al_install_audio()) {
abort_example("Could not init sound\n");
}
if (!al_reserve_samples(RESERVED_SAMPLES)) {
abort_example("Could not set up voice and mixer\n");
}
ping = generate_ping();
if (!ping) {
abort_example("Could not generate sample\n");
}
timer = al_create_timer(1.0 / bps);
al_set_timer_count(timer, -1);
event_queue = al_create_event_queue();
al_register_event_source(event_queue, al_get_keyboard_event_source());
al_register_event_source(event_queue, al_get_timer_event_source(timer));
al_register_event_source(event_queue, al_get_display_event_source(display));
al_identity_transform(&trans);
al_scale_transform(&trans, 16.0, 16.0);
al_use_transform(&trans);
al_start_timer(timer);
while (true) {
al_wait_for_event(event_queue, &event);
if (event.type == ALLEGRO_EVENT_TIMER) {
const float speed = pow(21.0/20.0, (event.timer.count % PERIOD));
if (!al_play_sample(ping, 1.0, 0.0, speed, ALLEGRO_PLAYMODE_ONCE, NULL)) {
log_printf("Not enough reserved samples.\n");
}
redraw = true;
last_timer = event.timer.count;
}
else if (event.type == ALLEGRO_EVENT_KEY_CHAR) {
if (event.keyboard.keycode == ALLEGRO_KEY_ESCAPE) {
break;
}
if (event.keyboard.unichar == '+' || event.keyboard.unichar == '=') {
if (bps < 32) {
bps++;
al_set_timer_speed(timer, 1.0 / bps);
}
}
else if (event.keyboard.unichar == '-') {
if (bps > 1) {
bps--;
al_set_timer_speed(timer, 1.0 / bps);
}
}
}
else if (event.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
break;
}
if (redraw && al_is_event_queue_empty(event_queue)) {
ALLEGRO_COLOR c;
if (last_timer % PERIOD == 0)
c = al_map_rgb_f(1, 1, 1);
else
c = al_map_rgb_f(0.5, 0.5, 1.0);
al_clear_to_color(al_map_rgb(0, 0, 0));
al_draw_textf(font, c, 640/32, 480/32 - 4, ALLEGRO_ALIGN_CENTRE,
"%u", last_timer);
al_flip_display();
}
}
close_log(false);
return 0;
}
/* vim: set sts=3 sw=3 et: */
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