delorie.com/archives/browse.cgi   search  
Mail Archives: djgpp/1998/04/09/22:01:23

From: root AT delorie DOT com (Demandred)
Newsgroups: comp.os.msdos.djgpp
Subject: [Allegro]Translucent blits
Date: Fri, 10 Apr 1998 00:54:06 GMT
Organization: Cerberus Software
Message-ID: <352d6ca9.4966112@news.compusmart.ab.ca>
NNTP-Posting-Host: remote80.compusmart.ab.ca
Lines: 17
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

I'm writing a game that will soon feature Allegro's 8-bit translucent blits.
Naturally, my life would be a lot easier (i.e. I won't have to create various
versions of my "lighting" sprites) if I could vary the "alpha" - the
translucency - of a sprite to be blitted.  Unfortunately, Allegro's
draw_trans_rle_sprite() function doesn't support various alpha values; it
looks like I'd have to create one color mapping table for each alpha that I
want (probably end up being something like 16 of them) and re-assign color_map
depending on the alpha that I want.

Is it worthwhile to create various color tables for various alpha values in
Allegro, or is there an easier way?


--
Demandred, Lord of the 32-bit Registers
http://www.nnetis.ca/~matt/dogfight.html
mail to: demandrd 'at' compusmart 'dot' ab 'dot' ca

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019