From: litmusdragon AT mailcity DOT com (Litmus Dragon)
Newsgroups: comp.os.msdos.djgpp
Subject: Couple of problems using DJGPP/Allegro
Date: Tue, 18 Apr 2000 01:46:52 GMT
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To: djgpp AT delorie DOT com
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Reply-To: djgpp AT delorie DOT com

I'm having two problems in DJGPP+Allegro WIP version.

The first is with a program that I've made called Dragon Engine.  It's both 
a role playing game engine and an editor.  About three months ago I added a 
VERY large set of arrays to the program (defined as int 
roomtile[5000][13][13], int roomtile[5000][13][13], and some more).  The 
program compiled and ran fine, everything seemed to be ok, but soon I saw 
that variables were not holding their values.  Variables which were NOT 
zero, were returning 0 as their value.  Memory seemed to have been 
corrupted.  I removed the enormous arrays and the problems went away.  
Since then, however, with the addition of variables here and there, I'm 
close to that upper limit again.  If I add too many variables to the 
program, I get the same problems, where variables are not holding their 
values.

At this point I should mention that I am self-taught.  Never taken a C 
class, learned in the context of "I'm having this problem, what is causing 
it?" or "I want to do this, how do I do it?" and reading documentation I've 
obtained from the web.  I think that somehow I need to tell the program to 
give me more memory to work with, but I don't know how to do that.  I think 
that malloc is somehow relevant, but I'm unclear on how to take a set of 
variables that I am using and convert that into a number of bytes to pass 
to malloc.  Or maybe I am on the wrong track.

The second problem is in high resolutions with allegro and DJGPP.
This program is in 800x600, and has a series of menus.  Everytime you 
switch to another menu, I have a routine which loads a random background 
and pastes it behind the menus.  Eventually, the program crashes.  
Sometimes when the first background is loaded, sometimes after 10 have 
loaded successfully.  Here is the relevant code (I hope):

void randm(int x)
     {
     rdm=(random()%x)+1;
     }

void randombak()
     {
     char temp[40];
     randm(10);
     show_mouse(NULL);
     clear(screen);
     sprintf(temp, "backs\\backrd%d.pcx", rdm);
     scrn=load_pcx(temp, temp_palette);
     blit(scrn, screen, 0, 0, 0, 0, 320, 200);
     show_mouse(screen);
     }

Can somebody please help.  I'm driven to frustration by these roadblocks.  
:)

-- 
/_itmus /)ragon
-=UDIC=-
email: litmusdragon AT mailcity DOT com
The Dragon Engine Homepage: http://www4.50megs.com/litmus/de.html