1. Avoiding erase the mouse cursor
How can I display images on the screen without erasing the mouse cursor and
without turning off the mouse while displaying ?
---
Ricardo Niederberger Cabral
rnc at infolink.com.br
2. Re: Avoiding erase the mouse cursor
> How can I display images on the screen without erasing the mouse cursor
and
> without turning off the mouse while displaying ?
I'm afraid I fail to see why turning off the mouse pointer before
displaying an image is a problem. You can always turn it back on once you
have finished updating the screen. I'm not sure there is a way you can keep
the mouse pointer on while updating the screen without having it
overwritten or accidentally captured as part of a screen grab, at least not
at the application level anyways. I suppose you could accomplish it at a
lower level of the machine.
David Gay
"A Beginner's Guide To Euphoria"
http://www.geocities.com/SiliconValley/Vista/4346
3. Re: Avoiding erase the mouse cursor
>> How can I display images on the screen without erasing the mouse cursor
>and without turning off the mouse while displaying ?
>
>I'm afraid I fail to see why turning off the mouse pointer before
>displaying an image is a problem. You can always turn it back on once you
>have finished updating the screen. I'm not sure there is a way you can
keep
>the mouse pointer on while updating the screen without having it
>overwritten or accidentally captured as part of a screen grab, at least
not
>at the application level anyways. I suppose you could accomplish it at a
>lower level of the machine.
The problem of turning off the mouse while updating the
screen is when you need to update a big area of the screen and for many
times. That's the point, I don't know nothing about low level machine
code...
---
Ricardo Niederberger Cabral
rnc at infolink.com.br
4. Re: Avoiding erase the mouse cursor
> I suppose you could accomplish it at a
> lower level of the machine.
The only way I can see you could acomplish this is to write a
interrrupt handler that's activated each time you access video
memory. This is a complex thing, and has two withdraws:
1.- Uses memory resources
2.- Slows down video memory access
In conclusion: The best choice is to
mouse_pointer(0)/mouse_pointer(1) each time you write to videoMem.
This is quite fast (just a INT call).
Regards,
Daniel Berstein
danielberstein at usa.net
http://www.geocities.com/SiliconValley/Heights/9316
5. Re: Avoiding erase the mouse cursor
- Posted by Anders Eurenius <c96aes at OXE.CS.UMU.SE>
Jul 30, 1997
-
Last edited Jul 31, 1997
> > How can I display images on the screen without erasing the mouse cursor
> > and without turning off the mouse while displaying ?
>
> I'm afraid I fail to see why turning off the mouse pointer before
> displaying an image is a problem. You can always turn it back on once you
> have finished updating the screen. I'm not sure there is a way you can keep
> the mouse pointer on while updating the screen without having it
> overwritten or accidentally captured as part of a screen grab, at least not
> at the application level anyways. I suppose you could accomplish it at a
Anyone care to elaborate on how the mouse pointer gets there in the first
place? From what I've heard, the avg PC gfxcard doesn't have any sprites...
(Stooopid! Had we had sprites it would all be very simple, because sprites, by
definition, don't alter the background.)
I would (if I could, wanted to, etc.) go "bare metal", and draw picture,
pointer, whatever, myself from machine code. Appart from the simple "control
freak"-factor, (knowing what's actually happening) it prolly also avoids some
of the somewhat less than clever system routines...
Write logic in high-level, loops in metal...
> lower level of the machine.
This is the solution to a lot of problems!
As for the mouse pointer, it's not a problem, it's a symptom. I'm looking
forward to seeing some of the out-of-the-box graphics-engines in progress...
> David Gay http://www.geocities.com/SiliconValley/Vista/4346
Anders Eurenius
-------------------------------------------------------------------
Anders Eurenius <c96aes at cs.umu.se> ICQ UIN:1453793
Computer Science/Engineering student at the university of Umeaa
-------------------------------------------------------------------
6. Re: Avoiding erase the mouse cursor
>The only way I can see you could acomplish this is to write a
>interrrupt handler that's activated each time you access video
>memory. This is a complex thing, and has two withdraws:
>1.- Uses memory resources
>2.- Slows down video memory access
>In conclusion: The best choice is to
>mouse_pointer(0)/mouse_pointer(1) each time you write to videoMem.
>This is quite fast (just a INT call).
The problem is: I can't simply disappear the mouse while some sprites are
running around the screen, that would look very strange in a game like
Warcraft, imagine that every time you move an unit and while it's walking
the mouse is hidden or blinking...
I need a method to avoid a sprite drawing over the mouse pointer.
---
Ricardo Niederberger Cabral
rnc at infolink.com.br
7. Re: Avoiding erase the mouse cursor
At 14:33 31-07-97 -0300, you wrote:
>---------------------- Information from the mail header -----------------------
>Sender: Euphoria Programming for MS-DOS <EUPHORIA at
>MIAMIU.ACS.MUOHIO.EDU>
>Poster: Ricardo Niederberger Cabral <rnc at INFOLINK.COM.BR>
>Subject: Re: Avoiding erase the mouse cursor
>-------------------------------------------------------------------------------
>
>>The only way I can see you could acomplish this is to write a
>>interrrupt handler that's activated each time you access video
>>memory. This is a complex thing, and has two withdraws:
>>1.- Uses memory resources
>>2.- Slows down video memory access
>>In conclusion: The best choice is to
>>mouse_pointer(0)/mouse_pointer(1) each time you write to videoMem.
>>This is quite fast (just a INT call).
>
>The problem is: I can't simply disappear the mouse while some sprites are
>running around the screen, that would look very strange in a game like
>Warcraft, imagine that every time you move an unit and while it's walking
>the mouse is hidden or blinking...
>I need a method to avoid a sprite drawing over the mouse pointer.
>
>---
>Ricardo Niederberger Cabral
>rnc at infolink.com.br
>
>
Check for overlapping between mouse cursor and the current sprite to draw
and only
hide the mouse cursor if the sprite overlap it.
Yearlier somenone ask where the mouse cursor is coming from.
The mouse cursor is manage by the mouse driver itself (mouse.com or
mouse.sys) and the programming interface to this driver is interrupt #33
Jacques Deschenes
Baie-Comeau, Quebec
Canada
desja at globetrotter.qc.ca
