cars-storage.h

const u32 CARS_PER_BLOCK = 512;

// Car storage needs to:
// - Add car
// - Remove car (Remove all cars with marker)
// - Loop through all cars
//
// Therefore linked list of blocks, with free list for deallocated blocks.
// - When adding a car:
//   - Loop through blocks until found one with space
//   - If all blocks full
//     - Try get block from free_chain
//       - Else allocate new block
//     - Add to start of chain
// - When removing a car:
//   - Set dead flag
//   - update_dead_cars routine:
//     - For all cars with dead flag:
//       - If no cars left in block
//         - Add to start of free_chain
//         - Re-link previous block to next block


struct Car
{
  b32 update_next_frame;
  b32 dead;
  u32 id;

  s32 value;

  WorldSpace cell_pos;

  vec2 direction;

  u32 pause_left;
  vec2 unpause_direction;

  CellType updated_cell_type;

  ParticleSource *particle_source;
};


struct CarsBlock
{
  Car cars[CARS_PER_BLOCK];
  u32 next_free_in_block;
  CarsBlock *next_block;

#ifdef DEBUG_BLOCK_COLORS
  vec4 c;
#endif
};


struct Cars
{
  CarsBlock *first_block;
  CarsBlock *free_chain;
};


struct CarsIterator
{
  CarsBlock *cars_block;
  u32 car_index;
};