calling display update..

[BIGBEN]

Interesting... thanks for sharing!

you don't have juggle a global pointer to display

I really do not see why global variables are bad for games?

Why people need to pass pDisplay to functions initializing 4byte pointer in any drawing function each time it is called (which will cost in time and size).

I really do not see a reason why

Please help me to understand the benefits of passing pointer to the Display each time.

[jaguard]

the main this is that it does a little at a time, so the display gets updated frequently and you don't have juggle a global pointer to display or use a bunch of getDisplay's stacked up in one function.

I wonder, how many of such switchcases I will need to do, considering that in my game(which is, btw being released today or tomorrow, depending on your time zone ) there are a ~1700 gfx files to be loaded(though they are in a pak file, it woundn't matter).

[fast_rx]

The main benefit for me is knowing I'm not going to start using a display pointer that's already been ->Update()'d or never started with GetDisplay(), or a double ->Update() which seems to cause a crash.

I've spent a lot of time tracking down problems like that - so I've changed the way I do things. It's more of a problem I've created myself by poor programming.

The other reason for me is code reuse... If I pass the display pointer into the functions, I don't care what I named it or what the scope is.

For instance, I have a class that contains all information about enemy tanks. So I call enemies.Draw(display)
If I don't pass the display, how is this class going to get the display pointer? The global is in another .cpp file, so you'd at least have to declare it extern, right?

I'm not trying to tell anyone the way to code, just the way I'm doing it to keep me from shooting myself in the foot.

[BIGBEN]

If I pass the display pointer into the functions, I don't care what I named it or what the scope is.

If I don't pass the display, how is this class going to get the display pointer? The global is in another .cpp file, so you'd at least have to declare it extern, right?

I'm not trying to tell anyone the way to code, just the way I'm doing it to keep me from shooting myself in the foot.

Funny, but for the same reasons (not to care about the name & scope) I do use it as global pointer, all I need is (as you said):

extern pDisplay;
in Globals.h

Not trying to shoot in your feet

Thanks for telling your experience.

I wonder, how many of such switchcases I will need to do, considering that in my game(which is, btw being released today or tomorrow, depending on your time zone ) there are a ~1700 gfx files to be loaded

You don't need switches at all, if you just load files by passing name as a string that is loaded by string number (from external txt or by resource string).

[Presto]

In my main Game class I have the following:

Code: Select all

1  2  3  4  5	void CMyGame::DrawScreen() {   pDisplay->Update();   pDisplay = GetDisplay(); }
	5 lines; 1 keywds; 0 nums; 15 ops; 0 strs; 0 coms    Syntactic Coloring v0.4 - Dan East

In the rare case where I need to call Update() outside of the main game loop, I use pMyGame->DrawScreen(); which updates the screen and then gets a new pointer to it. Both pDisplay and pMyGame are global variables.

-John

[jaguard]

In my main Game class I have the following:

Code: Select all

1  2  3  4  5	void CMyGame::DrawScreen() {   pDisplay->Update();   pDisplay = GetDisplay(); }
	5 lines; 1 keywds; 0 nums; 15 ops; 0 strs; 0 coms    Syntactic Coloring v0.4 - Dan East

That's what I did in a first place. And this is where ipaq hx 2xxx(WM5) hangs. I didn't entirely understand what happened there, but I now have special functions like this:

Code: Select all

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18	// To make sure that display is always updated before draw is occured. void displayGetDisplay() {     if (g_displayState == 1)     {         GamePointer->UpdateDisplayPointer();         g_displayState = 0;     } } void displayUpdate() {     if (g_displayState == 0)     {         display->Update();         g_displayState = 1;     } }
	18 lines; 4 keywds; 4 nums; 34 ops; 0 strs; 1 coms    Syntactic Coloring v0.4 - Dan East

UpdateDisplayPointer is a realisation of display = GetDisplay();

So I make sure that every time I call draw or update I have correct display pointer.
Looks like it works.