Game Development Reference
In-Depth Information
}
g_pApp->m_pGame->VRenderDiagnostics();
}
This method simply iterates through all the views attached to the game logic,
g_pApp-
>m_pGame
, and calls
VOnRender()
for each one. After that, the game logic calls a
special method for rendering debug information,
VRenderDiagnostics()
. This is a
convenience for programmers who would rather not adhere to the separation between
logic and view just to draw some debug lines on the screen.
A good example of how I use
VRenderDiagnostics()
is drawing physics informa-
tion, such as mesh wireframe of any objects moving on the screen. The physics sys-
tem is purely a game logic object, and the renderer really belongs to the game view. If
you wanted to religiously follow the separation of game logic and game view, you
'
d
have to do something like have the game logic create special
“
line
”
objects and send
messages to the game view that it needs to draw these lines.
That
'
s just dumb, in my opinion. A game logic should be able to use the application
layer
to draw debug data onto the screen. Yes, it
breaks the rules, but yes, you should do it.
—
in this case, DirectX
'
s renderer
—
By now you
ve learned a lot about some of the hidden superstructure of game code,
most notably about
GameCodeApp
,
BaseGameLogic
,
Process
, and
Process
Manager
. You
'
ve probably figured out that most of the subsystems discussed so far
can benefit from cooperative multitasking: animated objects, user interface code, and
more. If you
'
'
re like me, you
'
ve already played with writing your own games, and
you
re itching to put everything together in a tight little game engine. At this point,
you know just enough to be dangerous and could probably strike out on your own to
write a few very simple games. However, there are still quite a few important bits and
pieces you should know if you want to take it to the next level.
For example, you probably never thought about how game engines stuff a few giga-
bytes of game art and sounds through a much smaller memory space. Read the next
chapter and find out.
'
