static void kill_enemy( ENEMY *e )
{
player_score += get_points( e->type );
new_explosion( e->current->x, e->current->y, BIG );
remove_enemy( e );
}
static void
missile_explode_asteroid(MISSILE *missile, ASTEROID *asteroid)
{
missile->active = false;
score(asteroid->points);
new_explosion(missile->position);
explode_asteroid(asteroid);
}
static void
check_saucer_asteroid_collisions(LEVEL *level)
{
if(!level->saucer)
return;
LIST *head = list_first(level->asteroids);
while(head && level->saucer) {
ASTEROID *a = (ASTEROID *) head->data;
if(saucer_asteroid_collision(level->saucer, a)) {
new_explosion(a->position);
explode_asteroid(a);
saucer_free(level->saucer);
level->saucer = NULL;
}
head = head->next;
}
}
static void
check_ship_missile_saucer_collisions(LEVEL *level, SHIP *ship)
{
if(!level->saucer)
return;
LIST *head = list_first(ship->missiles);
while(head) {
MISSILE *m = (MISSILE *) head->data;
if(ship_missile_saucer_collision(m, level->saucer)) {
new_explosion(level->saucer->position);
saucer_free(level->saucer);
level->saucer = NULL;
break;
}
head = head->next;
}
}
void ship_hit( SIDE side )
{
static Uint32 last_hit = 0;
if( last_hit == 0 ) {
last_hit = SDL_GetTicks();
} else {
if( last_hit + SHIP_HIT_TIMEOUT > SDL_GetTicks() )
return;
else
last_hit = SDL_GetTicks();
}
new_explosion( ship.current->x, ship.current->y, SMALL );
ship.hp -= 2;
if( ship.hp <= 0 ) {
game_over();
}
}
// modify_scene modifies the global variables g_projectiles and g_explosions
// during the course of an attack sequence. It takes a parameter dt which
// represents the amount of time between frames.
// Return: the number of items left to animate.
int modify_scene(float dt)
{
int i, j, num_impacted;
float t;
struct Projectile *p;
struct Explosion *e;
struct Tank *tank;
Vector v;
float d;
// Go through all the explosions and update them according to the
// amount of time passed.
for(j = 0; j < g_num_explosions; j++)
{
e = &g_explosions[j];
t = update_explosion(e, dt);
}
// Go through all the projectiles and handle the ones that have not yet
// been impacted.
for(j = 0, num_impacted = 0; j < g_num_projectiles; j++)
{
p = &g_projectiles[j];
if(p->o.state != STATE_IMPACTED)
{
t = update_projectile(p, dt);
if(p->o.state == STATE_IMPACTED)
{
printf("Projectile %d has impacted.\n", j);
// If the projectile has impacted, an explosion needs to be
// created which is appropriate to the projectile which has
// impacted, and which takes on properties of the former
// projectile.
e = new_explosion(p);
// Now, using the remaining time that did not get used on the
// projectile, update the new explosion.
t = update_explosion(e, dt - t);
// And play a sound to match
sx3_play_sound(SX3_AUDIO_EXPLOSION);
}
}
if(p->o.state == STATE_IMPACTED) num_impacted++;
}
// FIX ME!! These two checks don't work properly if we have a low
// framerate.
for(j = 0; j < g_num_explosions; j++)
{
e = &g_explosions[j];
for(i = 0; i < g_num_tanks; i++)
{
tank = &g_tanks[i];
// Don't check this tank if it's already been hit
// FIX ME!! This should be on a per-projectile/explosion basis
if(tank->s.temp_damage != 0.0) continue;
// Find the distance between the tank and the explosion, and test
vv_cpy(v, tank->o.props.position);
vv_sub(v, e->props.position);
d = v_mag(v);
if(d < tank->o.props.radius + e->props.radius)
{
// A tank has been hit!
sx3_play_sound(SX3_AUDIO_HIT);
printf("Tank %d hit by explosion %d\n", i, j);
// FIX ME!! This should not be constant damage.
tank->s.temp_damage = 20.0;
}
}
}
for(j = 0; j < g_num_projectiles; j++)
{
p = &g_projectiles[j];
if(p->o.state == STATE_IMPACTED) continue;
for(i = 0; i < g_num_tanks; i++)
{
tank = &g_tanks[i];
// Don't check this tank if it's already been hit
// FIX ME!! This should be on a per-projectile/explosion basis
if(tank->s.temp_damage != 0.0) continue;
// Find the distance between the tank and the projectiles, and test
vv_cpy(v, tank->o.props.position);
vv_sub(v, p->o.props.position);
d = v_mag(v);
if(d < tank->o.props.radius + p->o.props.radius)
{
// A tank has been hit!
sx3_play_sound(SX3_AUDIO_HIT);
printf("Tank %d hit by projectile %d\n", i, j);
// FIX ME!! This should not be constant damage.
tank->s.temp_damage = 40.0;
}
}
}
return g_num_explosions + g_num_projectiles - num_impacted;
}