nanogui: query (Critical problem)
Subject:
Re: [nanogui] query (Critical problem)
From:
"Greg Haerr" ####@####.####
Date:
22 Jul 2004 06:21:47 +0100
Message-Id: <060e01c46fab$acc1f6a0$3aba46a6@xmission.com>
: Problem with this driver is that due to framebuffer concept we don't know
: when data is updated in framebuffer as this is done by application.
: Is there any solution?
: Is there any standard interface of application with driver which tell
: that data is to be updated from frmebuffer to panel memory?
Certainly one solution is to recode the driver to draw directly to the
LCD, rather than to a framebuffer, then to the LCD. Microwindows
doesn't currently have an "update" entry point that keeps track of
the portions of the framebuffer that were written to, so that
the LCD could be efficiently sync'd up. This capability wouldn't
be too hard to add, I've thought of adding it. However, there would
be a bit of overhead; I suggest keeping a single dirty rectangle
that could keep track of the largest area of modified bits.
However, the lowest level screen entry points assume that previous
pixel draws are completed, especially when asked to perform XOR
drawing, etc.
Regards,
Greg
