nanogui: Screen update methods
Subject:
Re: [nanogui] Re: Screen update methods
From:
Junior ####@####.####
Date:
26 May 2007 16:59:51 +0100
Message-Id: <D82F4A69800.0000011Fejr@inbox.com>
> -----Original Message-----
> From: ####@####.####
> Sent: Fri, 25 May 2007 17:16:41 -0700
> To: ####@####.####
> Subject: Re: [nanogui] Re: Screen update methods
>
> On Fri, May 25, 2007 at 01:58:53PM -0800, Junior wrote:
>> [vertical retrace] actually crossed my mind and I was looking into how
>> to implement it, especially with a memory mapped framebuffer with no
>> sync being used. This seem to be a framebuffer driver addition than
>> an application, yes?
>
> it depends on the memory protection on your target. you may not be able
> to directly peek at the video hardware from your application in
> userland, in which case it would have to be done in the (kernel)
> framebuffer driver.
>
>> I've done some tracing and what seem to be really killing me is this
>> linear16_drawhorizline function. That makes things worse and I haven't
>> figured out when it's called and buy how. It seems that drawing
>> background color calles it but I'm not sure.
>
> background color calls down to rectangle draw which calls down to
> horizontal line. you might want to start a new driver based on
> fblin16.c and do some optimizations.
What's really bothering me is why are the lowlevel driver called to write any data
to the framebuffer when it's being called to draw them on a pixmap. I seem to be missing
something here and I'm hoping someone could tell me what that is.
I only expect the blit function to be called when I explicitly copy data from the offscreen
pixmap to the active window. Is this not true? Any drawing I've done I've done on a pixmap
so I can do one block copy to the framebuffer.
--Jr.
