Mail Archives: djgpp/1998/03/21/18:46:40
From: | hackeroc3 AT aol DOT com (HackerOC3)
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Double Buffer
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Date: | 21 Mar 1998 23:31:08 GMT
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Lines: | 39
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Message-ID: | <1998032123310801.SAA04527@ladder03.news.aol.com>
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NNTP-Posting-Host: | ladder03.news.aol.com
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Organization: | AOL http://www.aol.com
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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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);
}
void main(void)
{
int db;
db = Create_Double_Buffer(200);
printf("%d",db);
fflush(stdout);
getch();
}
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