bool EnemyZone::_SpawnEnemy(uint32 enemy_index) {
// When spawning an enemy in a random zone location, sometimes it is occupied by another
// object or that section is unwalkable. We try only a few different spawn locations before
// giving up. Otherwise this function could potentially take a noticable amount of time to complete
const int8 SPAWN_RETRIES = 40;
if (enemy_index >= _enemies.size()) {
IF_PRINT_WARNING(MAP_DEBUG) << "function called with an out-of-range index argument: " << enemy_index << endl;
return false;
}
uint16 x, y; // Used to retain random position coordinates in the zone
int8 retries = SPAWN_RETRIES; // Number of times to try finding a valid spawning location
bool collision; // Holds the result of a collision detection check
// Select a random position inside the zone to place the spawning enemy. To do this, we need to diable the no_collision
// property of the enemy sprite.
bool saved_no_collision = _enemies[enemy_index]->no_collision;
_enemies[enemy_index]->no_collision = false; // This must be temporarily
MapZone* spawning_zone = NULL;
if (HasSeparateSpawnZone() == false) {
spawning_zone = this;
}
else {
spawning_zone = _spawn_zone;
}
// Try to find a suitable spawn location
do {
spawning_zone->_RandomPosition(x, y);
_enemies[enemy_index]->SetXPosition(x, 0.0f);
_enemies[enemy_index]->SetYPosition(y, 0.0f);
collision = MapMode::CurrentInstance()->GetObjectSupervisor()->DetectCollision(_enemies[enemy_index], NULL);
} while (collision && --retries > 0);
// If we didn't find a suitable spawning location, reset the collision info
// on the enemy sprite and we will retry on the next call to this function
if (collision) {
_enemies[enemy_index]->no_collision = saved_no_collision;
return false;
}
// Otherwise, spawn the enemy and reset the spawn timer
else {
_spawn_timer.Reset();
_spawn_timer.Run();
_enemies[enemy_index]->ChangeStateSpawn();
_active_enemies++;
return true;
}
}
void EnemyZone::Update() {
// When spawning an enemy in a random zone location, sometimes it is occupied by another
// object or that section is unwalkable. We try only a few different spawn locations before
// giving up and waiting for the next call to Update(). Otherwise this function could
// potentially take a noticable amount of time to complete
const int8 SPAWN_RETRIES = 5;
if (_enemies.empty() == true)
return;
// Spawn new enemies only if there is at least one enemy that is not active
if (_active_enemies >= _enemies.size())
return;
// Update the regeneration timer and return if the spawn time has not yet been reached
_spawn_timer.Update();
if (_spawn_timer.IsFinished() == false) {
return;
}
// Otherwise, select a DEAD enemy to spawn
uint32 index = 0;
for (uint32 i = 0; i < _enemies.size(); i++) {
if (_enemies[i]->IsDead() == true) {
index = i;
break;
}
}
float x, y; // Used to retain random position coordinates in the zone
int8 retries = SPAWN_RETRIES; // Number of times to try finding a valid spawning location
bool collision; // Holds the result of a collision detection check
// Select a random position inside the zone to place the spawning enemy
_enemies[index]->no_collision = false;
MapZone* spawning_zone = NULL;
if (HasSeparateSpawnZone() == false) {
spawning_zone = this;
}
else {
spawning_zone = _spawn_zone;
}
// If there is a collision, retry a different location
do {
spawning_zone->_RandomPosition(x, y);
_enemies[index]->SetPosition(x, y);
collision = MapMode::CurrentInstance()->GetObjectSupervisor()->DetectCollision(_enemies[index],
_enemies[index]->GetXPosition(),
_enemies[index]->GetYPosition(),
NULL);
} while (collision && --retries > 0);
// If we didn't find a suitable spawning location, reset the collision info
// on the enemy sprite and we will retry on the next call to this function
if (collision) {
_enemies[index]->no_collision = true;
}
// Otherwise, spawn the enemy and reset the spawn timer
else {
_spawn_timer.Reset();
_spawn_timer.Run();
_enemies[index]->ChangeStateSpawning();
_active_enemies++;
}
} // void EnemyZone::Update()
