This extension implements some performance-sensitive components of PocketMine-MP's internal chunk handling system in C++ for better performance and lower memory usage.

At the time of writing:

• \pocketmine\world\format\PalettedBlockArray: This class implements paletted block-storages as per modern MCPE since 1.2.13.
• \pocketmine\world\format\io\SubChunkConverter: This class contains a series of helper methods for upgrading legacy world terrain.
• \pocketmine\world\format\LightArray: Implements a 16x16x16 nibble array used for light storage.

• gsl: Subtree merge of https://github.com/microsoft/GSL
• lib: Library code implementing various chunk components. The code in here is unfettered by PHP and can be used on its own.
• src: Binding code that glues together PHP and the C++ chunkutils2 components.
• tests: .phpt tests for the extension which can be run with PHP's run-tests.php tool (or make test when using PHP's build system)