Gráficos impressionantes no Atari Jaguar

Native for Jaguar

Native is a horizontal 2D sprite based shmup like the old arcade classics R-Type I + II. To play Native you need an Jaguar with BJL/Jagserver/JUGS or Alpine Board to download the game binary to the Jaguar RAM. For the encrypted CD version you need a Jaguar with JaguarCD drive. Work on Native was stopped in december 1997. The Level 1 Demo was released as Freeware on 24.10.1997.

Features:

• 60 frames

• 16 Bit mode (65K colors)

• up to 4 layers of parallax scrolling

• animated background graphics

• horizontal and vertical scrolling

• transparency and lighting effects

• realtime data decrunch

• over 100 objects simultaneous on screen

We were always fascinated by this machine, unfortunately like with every console it is not just possible to sit down und develop, usually you need a devkit. As I recall Jaguar devkits were around 5000$ back then, so that was out of question.

Around 1996, there were some rumours spread that there was a cheap solution from a swedish guy. He modified your Jaguar so you could transfer program from an ST. Funny enough just googleing brought up this:

http://hem.passagen.se/isvar/jaguar_server/jserver.html

The homepage still looks exactly like I remember it from 15 years ago. So we sent our Jaguar to this swedish guy and he did the modification. A couple of days later it arrived and we tested all the examples that were available publicly back then. It was just a couple of programs like Jagtris from 42Bastian Schick and some sprite scaling. All worked very well with this so called JagServer. Years later we discovered that Matthias Domin (the guy who is doing ImpulseX) at the time did exactly the same by sending his Jag to Sweden.

There were no "official" docs available so we worked with the so called "Underground Dox":

http://www.mulle-kybernetik.com/jagdox/dox.html

Of course they were not as good as the later available official ones, but they did their job well.

For all that are not really aware of what the Jaguar is, here's a small summary:

The machine was developed around early 90-92 by basically three people. They did not only build some Custom GFX and Sound Hardware like most other consoles by the time but instead opted to also do their own RISC processors which sounds like a crazy idea for such a small team. The machine consists of a well known 68000 (running at around 13.3mhz) 2 RISC processors, one is called the GPU and is "bundled" with a blitter and a fast sprite processor in a single chip, the other one is called the DSP. Both these chips are 32Bit. The machine comes with 2MB Dram. The GPU chip is sitting on a 64 Bit Data Bus. Very nice specs for the time if you compare them to their closest competitors (by company size) like the Amiga CD32.

As we started with Jaguar, the whole game was done in 68000 assembler as we knew the processor from the Falcon already. The game suffered a lot of slow downs early on as the 68000 has a hard time getting some bus time with heavy sprite processor (its called object processor in the Jaguar) use. These slowdowns were coming from the 68k not being able to create the object list fast enough. Rendering those sprites was no problem, the Jaguar is very fast at putting 2d sprites on the screen.

We then converted the heart of the engine to the GPU. Afterwards the game ran easily at 60 FPS. The whole Native engine has probably around 3kb in the GPU. The blitter is used only very little, some of the graphics are mirrored in Y direction with it, that's all.

The DSP is uncompressing the data as needed, the ICE Packer is used for that task. It would still have been easily possible to add at least Sound FX. I don´t know why we didn´t do that, probably because there was no memory left for samples. The game was developed on a Falcon with 14 MB, a program called Devpac was used for the programming side. For the graphics we used Lightwave for modelling and rendering and our own sprite editor.

Compared to the Dreamcast game Sturmwind the engine shares some similarities, probably because of the same person programming it. I would call the Native engine a subset of the Sturmwind feature set.

Fonte: Duranik