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EnigmA Amiga Run 1997 February
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EnigmA AMIGA RUN 15 (1997)(G.R. Edizioni)(IT)[!][issue 1997-02][PLANET CD V].iso
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How2UseGfxV39
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1996-11-25
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How2UseGfxv39
How do I use the OS 3.0 graphics.library in an efficient way
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New Release 3
Date: 25.11.1996
This archive includes some code that shows how you can
use systemfriendly BitBlits. It shows how palette sharing is
handled and how friendbitmaps can be used.
The main goal is to show that it is possible to support both
native ECS/AGA and gfxboards with image blitting stuff and
how you can check out what is the best way to blit images.
The demo opens a window on the public screen (Workbench)
allocates pens for a red, a green and a blue shaded ball.
Also a background pen is allocated and the color is cycled throu
a color table. The balls are moved around the window.
It runs on any displaymode, independend if gfx board or not or
what color depth you use. Colorcycling on 16/24 bit modes is simulated
(though this is not really useable).
Within a talk to another programmer I found that there is some
need of information on this topic. So I thought I should release
such an archive. Feel free to do what ever you want with this archive
(except selling it and making money:) - Basically write better programs:)
As this example could also to be used to write board friendly games,
it is dedicated to these people out there who are still thinking
palette sharing etc. is useless...why can't I have white backgrounds
on some text manipulation programs ?
Also, this demo shows another thing. Try to run the demo on both, EGS
and CyberGraphics. As EGS has an own memory managment, it allocates
the friend bitmap in that memory the window bitmap (or screen bitmap)
lays at. This means, it does allocate bitmap memory on the boards memory
if available. You can imagine that bit blits in onboard RAM is a _bit_
faster then blitting it over the bus all the time. The OS 3 was designed
to support such basic concepts. Unfortuenatly none does really use this
yet...except EGS. If you run the demo you will see that the balls do
still flicker. Imagine to render the balls into an (invisible) friend
bitmap including erasing the old image and blit the whole buffer to the
display bitmap. Imagine, the whole memory is located in board memory.
Guess what happens ? Only the onboard blitter is used to make these transfers.
-> Fast flicker free blitting faster than AGA will ever be...
Currently, this demo does also show that miniterms aren't implemented
in a correct way on 16/24 bit (cg) modes. Mask blitting doesn't seem to work
here...
New:
In my latest archive friend bitmaps did not really work. This has something
to do with the method friends was handled. Now, friend bitmap are supported in a
CyberGraphics compatible way. This means that you must also define a
BMF_MINPLANES flag if you allocate friend bitmaps - it doesn't matter to
check for cybergraphics, as this still works on native Amiga modes.
To the EGS users
----------------
Currently EGS does not support this way to allocate friend bitmaps.
Please check out my latest EGSPlus Release 5 or later.
Since Release 5, the AllocBitMap/FreeBitMap() Functions have been rewritten
so they support cybergraphics compatible Bitmap allocation.
EGSPlus, Release 5 can be found on aminet/gfx/board/EGSPlus.lha
If you have any questions, feel free to contact me.
(Flames will be ignored :)
PS.: The 2410 does not support onboard friends at the moment...we'll see
what's possible here...but it would be interessting if this 34010 is
real that lame and can't move images faster then this 2 MB/sec I
reach over Z2 :)
But first I have to rewrite EGS to support 24 bit intuition...
---
Jürgen Schober
EDV Dienstleistungen
Graz · Austria
call: (+)43-316-674383
e-mail: point@sbox.tu-graz.ac.at (private)
jschober@campusart.com (business)
WWW: http://www.sbox.tu-graz.ac.at/home/point/Welcome.html
http://www.pointdesign.campusart.com/