From:	qballlives AT aol DOT com (QBallLives)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Double Buffer
Date:	22 Mar 1998 07:17:18 GMT
Lines:	39
Message-ID:	<1998032207171801.CAA14377@ladder01.news.aol.com>
NNTP-Posting-Host:	ladder01.news.aol.com
Organization:	AOL http://www.aol.com
References:	<1998032123310801 DOT SAA04527 AT ladder03 DOT news DOT aol DOT com>
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

>
>I have this function to create a double buffer, but it always returns 0, yet
>I
>can still write to and copy the double buffer to the screen.
>
>unsigned char *double_buffer = NULL;
>unsigned int buffer_height = 200;
>unsigned int buffer_size = 320 * 200;
>
>int Create_Double_Buffer(int num_lines)
>{
>if ((double_buffer = (unsigned char *)malloc(320 * (num_lines + 1))) == NULL)
>	return(0);
>
>/*  Set the height of the buffer and compute its size */
>
>buffer_height = num_lines;
>buffer_size = 200 * num_lines/2;
>
>/* Fill the buffer with black  (clear) */
>
>memset(double_buffer, 0, 200 * num_lines);
>
>/*  Everything was ok */
>
>return (1);
>
>}

hmmm...
try :

if (!(double_buffer = malloc(320 * num_lines + 1)) )


Jim the loiterer
aloiterer AT juno DOT com
http://www.fortunecity.com/skyscraper/gigahertz/179/index.html

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