[AD] Docs save_bitmap modification.

[Grzegorz Adam Hankiewicz <gradha@xxxxxxxxxx>]

Hi.

Proposed change based on Neil Roy's screen capture comment on agp ml.

-- 
 Grzegorz Adam Hankiewicz   gradha@xxxxxxxxxx   http://gradha.infierno.org/

Index: allegro._tx
===================================================================
RCS file: /cvsroot/alleg/allegro/docs/src/allegro._tx,v
retrieving revision 1.61
diff -u -r1.61 allegro._tx
--- allegro._tx	11 Jul 2002 14:23:40 -0000	1.61
+++ allegro._tx	11 Jul 2002 22:36:21 -0000
@@ -2888,11 +2888,14 @@
    Writes a bitmap into a file, using the specified palette, which should be 
    an array of 256 RGB structures. Returns non-zero on error. The output 
    format is determined from the filename extension: at present this 
-   function supports BMP, PCX and TGA formats. One thing to watch out for: 
-   if you use this to dump the screen into a file you may end up with an 
-   image much larger than you were expecting, because Allegro often creates 
-   virtual screens larger than the visible screen. You can get around this 
-   by using a sub-bitmap to specify which part of the screen to save, eg:
+   function supports BMP, PCX and TGA formats.
+
+   Two things to watch out for: on some video cards it may be faster to copy
+   the screen to a bitmap and save the latter, and if you use this to dump
+   the screen into a file you may end up with an image much larger than you
+   were expecting, because Allegro often creates virtual screens larger than
+   the visible screen. You can get around this by using a sub-bitmap to
+   specify which part of the screen to save, eg:
 <codeblock>
       BITMAP *bmp;
       PALETTE pal;