BuLang Div Style

DIV/BennuGD-inspired Cooperative Process Virtual Machine

This project implements a lightweight virtual machine (VM) inspired by classic game engines like DIV Games Studio and BennuGD. The VM is designed to manage hundreds of independent processes (entities/sprites), each with its own execution context, while sharing common bytecode instructions. The architecture is based on the model described in Crafting Interpreters, adapted to support cooperative multitasking and entity-driven game logic.

• Cooperative Multitasking: Each process (entity) runs independently, advancing a slice of its logic per frame. The VM scheduler executes all active processes in a round-robin fashion, simulating fibers or coroutines.
• Shared Bytecode, Isolated Contexts: All processes share immutable bytecode (function pointers), but each maintains its own stack, instruction pointer, local variables, and execution state.
• Efficient Process Management: Processes can be created and destroyed dynamically, allowing for scalable management of game objects and logic.
• Extensible Interpreter: The VM is built to be extensible, supporting custom opcodes, priorities, and potential messaging between processes.

• Process Creation: When a new process is spawned (e.g., a new enemy or effect), it receives a pointer to the shared function bytecode and initializes its own execution context.
• Execution Loop: The main interpreter loop iterates through all live processes, executing a limited number of instructions per process per frame. This ensures fair CPU time distribution and smooth multitasking.
• Context Isolation: Each process has its own stack, instruction pointer, and local variables, ensuring independent execution even when running the same code.

• 2D retro-style games with many autonomous entities
• Game scripting engines requiring lightweight multitasking
• Educational tools for learning about interpreters and virtual machines

1. Clone the repository
2. Build the project using your preferred C++ toolchain
3. Run the VM with sample bytecode or scripts

• Inspired by DIV Games Studio, BennuGD, and the book Crafting Interpreters by Robert Nystrom.
• Luis Santos AKA DJOKER

This project is open source under the MIT License.