Game Development Reference
In-Depth Information
The systemWait function definition
The
levelInscreen
is very similar to the
instructionsScreen
, but instead of using the
STATE_SYSTEM_WAIT_FOR_CLOSE
state, it uses the
STATE_SYSTEM_WAIT
state. What's the difference?
The
STATE_SYSTEM_WAIT
state calls a function that counts for a specified number of frame ticks
before moving on to the
nextSystemFunction
rather than waiting for the click of the OK button.
When the
systemState
is switched to the
STATE_SYSTEM_WAIT
state, it calls the
systemWait
function repeatedly (on each frame tick) until the
waitCount
is greater than the
waitTime
set in the
systemLevelIn
function. When the
waitCount
is reached, we dispatch a
WAIT_COMPLETE
event that
calls the
waitCompleteListener
(see the next section). Currently, there is only one
systemState
that uses the
systemWait
function, so there is only one item in the
case
statement. We could add
many states that use this
systemWait
function though, so we have it set up for later expansion.
The waitCompleteListener function definition
The
waitCompleteListener
function is triggered when the
WAIT_COMPLETE
event is fired off from
the
levelInScreen
. It can be used for more screens by updating the
switch:case
statement.
Once the
waitCompleteListener
fires off, it switches on the
lastSystemState
because the
currentSystemState
is now the
STATE_SYSTEM_WAIT
. This allows us to share a single listener
function for all uses of the
WAIT_COMPLETE
event. It then switches state to the
nextSystemState
when it calls
switchSystemState(nextSystemState)
. In this example, the
nextSystemState
is
systemGameplay
.
The systemGameplay() function definition
The
systemGameplay
function is the heart of the
gameTimer
. It is associated with the
STATE_SYSTEM_GAME_PLAY
state. The
game.runGame
function is called on each frame tick when
systemGamePlay
is the
systemFunction
reference. The
Game
class instance (
game
) will handle all of
the game's processing within the
game.runGame
function.
private function systemGameplay():void {
game.runGame();
}
The custom event listener functions
The last four functions inside
GameFrameWork.as
are listener functions for simple and complex
custom events that are needed by the
Game
instance class to communicate with
Main
class, as
well as the
levelInScreen
and
scoreBoard
class instances. We'll briefly explain each here so you
have a complete version of all the
Main.as
code in one place. Their use inside those classes will
be examined later as we go through the
Game
,
ScoreBoard
, and
CustomEvent
classes.
The scoreBoardUpdateListener function definition for
Main.as
The
scoreBoardUpdateListener
receives updates from the
Game
class instance that are passed to
the
ScoreBoard
through a
CustomEventScoreBoardUpdate
instance.
The
scoreBoardUpdateListener
passes data, represented by a simple key/value pair of
String
object class instances to the
ScoreBoard
class instance. The
element
variable will contain a string
