nanogui: Thread: Scrolling

Just one more item before I release my 16-color bare hardware VGA driver.
I wonder if anyone has done fast scrolling.  Right now, I'm redrawing
from the text buffer but that isnt going to make it.  Would a scanline
read followed by a scanline write be faster?

Later,
FM

--
Frank W. Miller
Cornfed Systems Inc
www.cornfed.com

: Just one more item before I release my 16-color bare hardware VGA driver.
: I wonder if anyone has done fast scrolling.  Right now, I'm redrawing
: from the text buffer but that isnt going to make it.  Would a scanline
: read followed by a scanline write be faster?

Frank - there are two ways this could be done.  The best way is that
we need bitblt, something I'm planning on adding soon, but I want to 
use it in conjunction with off screen drawing capabilities, so it's an
architecture change.  The other issue is that currently the text draw routine
checks each and every pixel for clipping before output.  There is a piece
of commented out code that I've left for a fast driver entry point to output
text without clipping, when the mid level can allow it.  This is in GdText.
So another answer is to (almost) duplicate the GdText code in a new driver
entry point for fast text drawing, called when clipping is not needed.

	I can do all this for you if you like, go ahead and release
your driver, and I'll take a look at it.

Greg