There are multiple tickers in the game:
- Gameplay:
P_Ticker() - Stasusbar:
ST_Ticker() - The automap display:
AM_Ticker() - User HUD messages:
HU_Ticker()(e.g, picked up X item) - Screen-wipe/intermission:
WI_Ticker() - The end-of-game:
F_Ticker() - Demo playback:
D_PageTicker()
Each of these is called according to the game state set. Additionally to these there are game actions - these select a particular action tha tthe game must do, for example new-game, load/save-game, load-level.