Memory
To be able to efficiently allocate memory for dynamically created objects, VUEngine makes use of a MemoryPool construct rather than working with WRAM directly.
Basically, what the engine does is to divide the available WRAM into a number of configurable sized pools to fill in objects based on the number of bytes that they occupy plus 4 bytes used as a header.
To optimally suit the game’s needs, developers can and should configure memory pools in a number of ways:
- The total number of pools: there can be as many as needed
- The block size of each pool
- The number of objects that each pool can hold
Under the best possible scenario, that is, when the classes’ virtual tables are allocated in DRAM, the required memory by VUEngine to show an empty Stage without any Actors or preloaded Textures is about 4 KB of the Virtual Boy’s 64 KB of WRAM, 2 KB of them being needed for the program’s stack. Therefore, the absolute maximum amount of WRAM that can be reserved for the MemoryPool before overflowing the stack is about 60 KB. However, the more the game’s Stages are populated, the more memory will be required by the stack and the lower the MemoryPool’s maximum size. It is strongly recommended to configure the MemoryPool to suit the game’s specific needs as accurately as possible to not waste memory. During the development of any game, the need will arise to constantly refine the MemoryPool’s configuration, to account for changes in the memory requirements of the game’s objects.
To check in realtime the ‘MemoryPool’s usage, use the following call in a suitable place:
MemoryPool::printDetailedUsage(1, 1);