From:	Damian Yerrick <Bullcr_pd_yerrick AT hotmail DOT comRemoveBullcr_p>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Dos char set
Organization:	Pin Eight Software http://pineight.8m.com/
Message-ID:	<0fifjsgugpmpuvrkkp0rnthddapuliqrf0@4ax.com>
References:	<8h7nqr$6u9$1 AT nnrp1 DOT deja DOT com>
X-Newsreader:	Forte Agent 1.7/32.534
MIME-Version:	1.0
Lines:	26
X-Trace:	/K+neRjWIXvM1br9ap/xpiEoNdfUlRvn7vcpn3vb3P8W13gONsCcvhpI/fNerrj4eDh8wWSunNzm!gLgqfo7kS5ZarAZIt6EIPLxj042YvLaXmuc4gB+v46WxFQ/7o2s8uYoWMWAuAEVhU+LUSHSTtvS2!l7TG
X-Complaints-To:	abuse AT gte DOT net
X-Abuse-Info:	Please be sure to forward a copy of ALL headers
X-Abuse-Info:	Otherwise we will be unable to process your complaint properly
NNTP-Posting-Date:	Fri, 02 Jun 2000 14:53:07 GMT
Distribution:	world
Date:	Fri, 02 Jun 2000 14:53:07 GMT
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

On Fri, 02 Jun 2000 07:30:34 GMT, rob89 AT my-deja DOT com wrote:

>After this I could have some sort of for loop which goes through the
>rows and columns and checks if there is a pixel there and if there is,
>display it on the screen using some function(say putpixel.). The code
>has the following line which checks if there is a pixel in the
>corresponding location:
>
>if((ch_table[string[index]][row] << column) & 0x80)
>
>I completely understand ch_table[string[index]][row] part, which first
>of all goes to the character to be displayed, but then I don't
>understand why we have to shift left (<< column) and most importantly
>why do we have to use masking (&0x80).

The ROM font is stored as a monochrome bitmap to save space in ROM
(each row is one byte), and you have to use shifting to convert a
monochrome bitmap to 8-bit.

-- 
Damian Yerrick
"I refuse to listen to those who refuse to listen to reason."
See the whole sig: http://www.rose-hulman.edu/~yerricde/sig.html

This is McAfee VirusScan. Add these two lines to your signature to
prevent the spread of signature viruses.  http://www.mcafee.com/

- Raw text -