cars-storage.cpp

Car *
get_new_car(Memory *memory, Cars *cars)
{
  CarsBlock *block = cars->first_block;
  while (block && block->next_free_in_block == CARS_PER_BLOCK)
  {
    block = block->next_block;
  }

  if (!block)
  {
    // No blocks left
    if (cars->free_chain)
    {
      block = cars->free_chain;
      cars->free_chain = block->next_block;
      log(L_CarsStorage, u8("Getting car block from free chain"));
    }
    else
    {
      block = push_struct(memory, CarsBlock);

#ifdef DEBUG_BLOCK_COLORS
      static u32 C = 0;
      block->c = get_color(++C);
      C %= 27;
#endif

      log(L_CarsStorage, u8("Allocating new car block"));
    }

    block->next_free_in_block = 0;

    block->next_block = cars->first_block;
    cars->first_block = block;
  }

  Car *result = block->cars + block->next_free_in_block++;
  return result;
}


void
delete_all_cars(Cars *cars)
{
  CarsBlock *block = cars->first_block;
  if (block)
  {
    while (true)
    {
      // Clear partical sources
      Car *car;
      for (u32 car_index = 0;
           car_index < block->next_free_in_block;
           ++car_index)
      {
        car = block->cars + car_index;
        if (car->particle_source)
        {
          car->particle_source->t0 = 0;
        }
      }

      if (block->next_block)
      {
        block = block->next_block;
      }
      else
      {
        break;
      }
    }

    // Put free chain on end of current block chain,
    //   then put block chain on free chain
    block->next_block = cars->free_chain;
    cars->free_chain = cars->first_block;
    cars->first_block = 0;
  }
}


void
rm_car(CarsBlock *block, u32 index_in_block)
{
  Car *car = block->cars + index_in_block;
  car->particle_source->t0 = 0;

  --block->next_free_in_block;
  if (index_in_block != block->next_free_in_block)
  {
    *car = block->cars[block->next_free_in_block];
  }
}


void
update_dead_cars(Cars *cars)
{
  CarsBlock *cars_block = cars->first_block;
  CarsBlock *prev_block = 0;

  u32 first_car_not_checked_in_block = 0;

  while (cars_block)
  {
    Car *car = cars_block->cars + first_car_not_checked_in_block;

    if (car->dead)
    {
      log(L_CarsStorage, u8("Deleting car"));
      rm_car(cars_block, first_car_not_checked_in_block);

      if (cars_block->next_free_in_block == 0)
      {
        log(L_CarsStorage, u8("Deallocating car block"));

        // Reconnect previous block's link
        if (cars->first_block == cars_block)
        {
          cars->first_block = cars_block->next_block;
        }
        else
        {
          prev_block->next_block = cars_block->next_block;
        }

        CarsBlock *next_block = cars_block->next_block;

        cars_block->next_block = cars->free_chain;
        cars->free_chain = cars_block;

        first_car_not_checked_in_block = 0;
        cars_block = next_block;
        continue;
      }

    }
    else
    {
      ++first_car_not_checked_in_block;
    }

    if (first_car_not_checked_in_block >= cars_block->next_free_in_block)
    {
      first_car_not_checked_in_block = 0;
      prev_block = cars_block;
      cars_block = cars_block->next_block;
    }
  }
}


Car *
cars_iterator(Cars *cars, CarsIterator *iterator)
{
  Car *result = 0;

  // Check if this is a new iterator
  if (iterator->cars_block == 0)
  {
    iterator->cars_block = cars->first_block;
    iterator->car_index = 0;
  }

  if (iterator->cars_block &&
      iterator->car_index >= iterator->cars_block->next_free_in_block)
  {
    iterator->cars_block = iterator->cars_block->next_block;
    iterator->car_index = 0;
  }

  // Check we haven't reached the end
  if (iterator->cars_block)
  {
    result = iterator->cars_block->cars + iterator->car_index;
    ++iterator->car_index;
  }

  return result;
}


Car *
get_car_with_id(Cars *cars, u32 car_id)
{
  Car *result = 0;
  CarsIterator iter = {};
  Car *car;

  while ((car = cars_iterator(cars, &iter)))
  {
    if (car->id == car_id)
    {
      result = car;
      break;
    }
  }

  return result;
}