pub fn pump_mcp(world: &mut World) -> Result<(), EntityAccessError>Expand description
Run one MCP turn without a window event loop.
A headless host calls this between its own frames. Commands are applied before the next frame, just as they are between two window callbacks. A command for a world the host steps is queued as a job of that world, so the turn ends by draining those queues: the reply must not wait for a frame the client has not asked for yet.