nanogui: Re: Herc in Microwin
Subject:
RE: Herc in Microwin
From:
Greg Haerr ####@####.####
Date:
8 Sep 1999 20:00:47 -0000
Message-Id: <01BEFA01.D9F70B30.greg@censoft.com>
On Wednesday, September 08, 1999 11:44 AM, Bjorn Eriksson
####@####.#### wrote:
: >: I looked at the code and at the moment it just uses a loop to draw the
line
: >: pixel by pixel. How does it need to be improved??
: >:
: > Are you familiar with the Herc memory/screen layout? Instead of
: >looping for each bit, the C code needs to set up to 8 pixels at a time
with a
: >single MOV instruction. This entails pre-calculating the bits in the
screen memory
: >and writing it once.
:
: Oh, wait a second. I've got some very, very old C-code somewhere on my
very old 386SX 16MHz PC somewhere. Nah, I wouldn't bother considering it's
ten years old and I was fairly new to C at the time... :-)
:
: Well, if you're unfamiliar with the hercules screen-memory layout it
might provide some guidance. Here's a bit of code for TurboC 2.0: (please
don't comment the code-quality)
: [snip]
Totally cool! This is exactly the code that Thomas Stuart needs to speed
up
the Herc support.
Thomas - go ahead and use Bjorn's code for the horizontal line draw
speedup.
Let me know if you have questions. BTW, Bjorn's code is incorrectly called
"vert_line"
it really draws a horizontal line. We won't get any speedups on the
vertical
line drawing.
Greg
