Game Development Reference
In-Depth Information
The Startup Trigger
The Startup trigger is utilized by attempting operations while some game function is
in the process of starting up or immediately after that while code values and states are
in their initial conditions. This could be a highly noticeable activity, such as a
“Loading please wait…�? screen or something that's behind the scenes such as loading
data for a room you've just entered.
Particular code vulnerabilities exist during the startup period. These do not present
themselves at any other time in the game. Code variables are being initialized.
Graphics information is being loaded, buffered, and rendered. Information is read
from and/or written to disk.
As an example, here is a summary of the events that take place in the Unreal engine in
order to start up a new level:
1. The GameInfo's
InitGame()
event is called
2. The GameInfo's
SetGrammar()
event is called
3. All Actors'
PreBeginPlay()
events are called
4. All Actors'
BeginPlay()
events are called
5. All Actors' zones are set
6. All Actors' volumes are set
7. All Actors'
PostBeginPlay()
events are called
8. All Actors'
PostNetBeginPlay()
events are called
9. All Actors'
SetInitialState()
events are called
10. All Actors either with
bShouldBaseAtStartup
=
True
and
Physics
set to
PHYS_None
or
PHYS_Rotating
or with an Attach Tag get their base set
Startup defects are triggered by operations that take place during the Game Start period.
These operations can be user-initiated or caused by the game platform. Interrupting
any part of this sequence could mean that some essential operation will not complete
its work or may not get to run at all. The Startup trigger accounts for bugs that will
only show up as a result of the initial conditions that result from the game's initial-
ization and startup processes. That means that defects that occur the very first time
you use a game capability—a new map, item, powerup, or spell, for example—should
also be classified as Startup defects.
The Exception Trigger
Special portions of the game code are exercised by the Exception trigger. Exception han-
dling in a game is normally recognized by the player. Audio “bonks�? or alert boxes are
