nanogui: Re: nanoGui development
Subject:
RE: FW: nanogui development
From:
Greg Haerr ####@####.####
Date:
5 May 1999 23:22:12 -0000
Message-Id: <01BE971C.09148210.greg@censoft.com>
The software mouse cursor clipping that is needed works like this:
When various line draw or pixel plotting routines are called, the mouse cursor
must be turned off before the low level graphics routine executes or when the
mouse cursor moves, the screen will be redrawn to the wrong value. One
implementation of this could have the low level graphics driver turn off the mouse
before drawing. This requires that each low level graphics designer/implementer
know about mice, etc.
Since the code required to determine line/mouse intersection can
be shared with the clipping code for intersection detection, my proposal is to
write (I've already written) a level above bogl which is device INdependent,
which users call instead of the low level directly. This level implements all
mouse cursor clipping as well as all pixel/line clipping. This level also
has an upper level api that allows it to be used by nanogui or by any user
who wants "bigger bogl".
Alex has a CVS tree going for nanogui. I am still trying to get setup under CVS.
Presently, I will get nanogui going to use unmodifed bogl libraries, then we
can worry about integrating them.
FYI: I've already had to write a bogl stub layer because of the bogl architecture
when bogl_vline is in fact a proc ptr, rather than a hard address.
Greg
On Wednesday, May 05, 1999 2:27 PM, Ben Pfaff ####@####.#### wrote:
> Greg Haerr ####@####.#### writes:
>
> The clipping patch by Alan Cox is very similar to the stuff that was
> included by Alex in nanogui v0.1. The problem with it, as discussed in an earlier
> email with Alan, is that some upper level software mouse cursor clipping must
> be performed as well, along with line segment reordering. I am building a
> three-level driver model that will allow the following to take place:
>
> I'm a little unsure what you mean by ``upper level software mouse
> cursor clipping.'' Is this something that's come up on the list
> before, so that I should just read the archives for an explanation? I
> assume you don't just mean ``clipping the mouse cursor to the edges of
> the screen.''
>
> [...description of planned architecture...]
>
> Sounds good to me.
>
> Maybe all this should be done in a shared cvs tree. Is there a
> nanogui cvs already?
>
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