This is also where a fork occurs in the code based on include/ define. In this part, the BSP/PVS is extensively used. Take care of the Rendition piece of the engine. The goal is mainly to fight network communication latency. Take care of the Prediction piece of the engine as well as collisions. This limit is set from client side and sent to the server.Īn entire section is dedicated to this part.ĬL_SetUpPlayerPrediction, CL_PredictMove and CL_EmitEntities : On server side, a message is sent to a client only if a packet has been received and if the sending rate is below a 'choke' limit.

Regarding the flow control, there is no limitation on client side, updates are sent as fast as possible. Additionally, the last sent command is systematically re-sent. Take care of the Network piece of the engine.ĬL_SendCmd grabs the mouse/keyboard inputs, generates a command, which is then sent.Īs Quake World used UDP, the reliability is mainly replicated via a set of sequence/sequenceACK in the netChannel packet headers. The game starts with a exec quake.rc in the command buffer. Commands are generated mostly via the console, but can also come from the server or even direct keystroke. In every game loop, commands in the buffer are executed. Update engine variable accordingly (world is not rendered if window is minimized for example). Retrieve Windows OS messages, minimizing etc. Setup a code waypoint, if anything bad happens, program jumps back here. VisEdicts are used by the rendition layer, in addition to the POV ( cl.sim*) variables to render the scene. They are picked up by the prediction layer, where collisions are also taken care of and data are outputted under the form of Visibility Edicts ( cl_visedicts) and the POV definition. The network layer (also called Net Channel) outputs world information into the frames variable ( An array of frame_t).

Prediction CL_SetUpPlayerPrediction, CL_PredictMove and CL_EmitEntities.

A quick summary of the code is as follows:įrom here, we can identify the three key elements of Quake World: The entry point WinMain can be found in sys_win.c. A good starting point to study Quake is the qwcl (client) project.

Quake 2 walk through