From: mert0407 AT sable DOT ox DOT ac DOT uk (George Foot)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Allegro PackFile I/O
Date: Sat, 08 Feb 1997 02:23:32 GMT
Organization: Oxford University
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References: <01bc1556$2282cee0$95ddf4cc AT express DOT ca DOT express DOT ca>
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To: djgpp AT delorie DOT com
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On 8 Feb 1997 00:23:09 GMT, "Chris" <dingfam AT imag DOT net> wrote:

>typedef struct Map {
>	int w, h;
>	char name[8];
>	BITMAP *tiles[60][60];
>} Map;

Fine. What you wrote next was wrong, though...

>	Map *m;
>	pack_fwrite(m->name, 8, fl);

I assume some code goes in between these two lines :) Otherwise, there
is no map to save... Make sure there's a malloc in there somewhere
[e.g. m=(Map *)malloc(sizeof(Map));]

>	pack_iputw(m->w, fl);
fine (assuming the file is open)
>	pack_iputw(m->h, fl);
fine
>	for(x=0; x< 60; x++)
>		for(y=0; y< 60; y++)
>			pack_fwrite(m->tiles[x][y], sizeof(BITMAP), fl);

No. You're saving the wrong thing here... m->tiles[x][y] is a pointer
to the bitmap. So you're writing this to the file followed by a
massive chunk which is nearly as long as the BITMAP struct is. Sorry,
but this is pointless. What you need to save is the image - this
begins at the location pointed to by m->tiles[x][y]->line, and
continues for width*height bytes, I think... Try using this line
instead of the present pack_fwrite line:

 pack_fwrite(m->tiles[x][y]->line,width*height,fl);

The loading routine then becomes:

>And a loading routine which looks like this:
>	Map *m;
	m=(Map *)malloc(sizeof(Map));
>	pack_fread(m->name, 8, fl);
>	m->w = pack_igetw(fl);
>	m->h = pack_igetw(fl);
>	for(x=0; x< 60; x++)
>		for(y=0; y< 60; y++)

At this stage you need to allocate the bitmaps you're putting the
information into, so we add a create_bitmap and correct the pack_fread
as above:

*		{
*		 m->tiles[x][y]=create_bitmap(width,height);
*		 pack_fread(m->tiles[x][y]->line,width*height,fl);
*		}

You should #include <stdlib.h> for the malloc command.

Hope this helps, if not send me your source and I'd be happy to peruse
it.

George Foot