Wren

A multiplayer game engine written in C++ / DirectX 11.

Game Loop

WrenClient:

1. Process UDP Packets a) if any PlayerCorrection events are received, correct player's state
2. if 0.016~ seconds have elapsed, update simulation a) playerController.Update() -if player is moving, check if destination is reached. if so, set player's loc to destination -if player not moving and right click is held, start moving and set destination b) camera.update() c) playerController.GeneratePlayerUpdate() -generate player update based on current state -increment update counter -send PlayerUpdate packet to server d) objectManager.Update() -move player according to their current movementVector e) publish events -first sort uiComponents by z-index -pass event to each uiComponent from back to front (higher z-index elements will get events first) -if no uiComponents stopped event propagation, pass event to all gameObjects
3. Render

WrenServer:

1. Process UDP Packets a) if any PlayerUpdate events are received, verify that state is the same between client and server. if not, sent PlayerCorrection event
2. if 0.016~ seconds have elapsed, update simulation a) objectManager.Update() -move player according to their current movementVector b) publish events -first sort uiComponents by z-index -pass event to each uiComponent from back to front (higher z-index elements will get events first) -if no uiComponents stopped event propagation, pass event to all gameObjects

Gotchyas

Be careful using mouse position for calculations - I experienced an issue where a MouseMove event triggered copying and dragging and item, and the source inventory slot was determined by mouse position. But the first time the MouseEvent was detected, the mouse had actually moved like 100 pixels from it's initial click location (due to some weird issue with the trackpad on my laptop), so items were duping. Be very careful with this.