From: "Rylan" <rylan AT intekom DOT co DOT za>
Newsgroups: comp.os.msdos.djgpp
Subject: Allegro Bitmap Sizes
Date: Sun, 5 Jul 1998 16:49:34 +0200
Organization: The South African Internet Exchange.
Lines: 42
Message-ID: <6no490$343@news1.saix.net>
Reply-To: "Rylan" <rylan AT inbtekom DOT co DOT za>
NNTP-Posting-Host: pc25-01-p09.saix.net
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk

Hi,

I've run accros a little strange thingy:

This code

void gintro_dorylan_fade(int px,int py,BITMAP *pbmp)
{

 for (loop = 0; loop < (pbmp->w); loop++)
 {

  for (loop2 = 0; loop2 < (pbmp->h); loop2++)
  {
   pbmp->line[loop2][loop] =
     ((BITMAP *)datafile[Rylan_BMP].dat)->line[loop2][loop];
  }

 }

 blit(pbmp,screen,0,0,0,0,pbmp->w,pbmp->h);

}

draws only HALF the width of the Allegro bitmap on the screen. Yet, if I
look at this particular bitmap in the grabber, the width is given as 276
pixels, which is the same value in datafile[Rylan_BMP].dat->w. However,
using 2 x 276 with the above code (the two nested loops) draws the whole
bitmap. Why? Why does this not apply to the height
(datafile[Rylan_BMP].dat->h?) Is this some kind of optimization?

BTW: GFX mode for this is 640x480x16bit.

Please reply by mail if at all possible!

Fanx

--
Spawned By Rylan
Is truth beauty or beauty truth?