Stunts Forum

Stunts - the Game => Stunts Reverse Engineering => Topic started by: Daniel3D on August 15, 2020, 11:42:17 AM

Title: DOS vs AMIGA and FM Towns versions.
Post by: Daniel3D on August 15, 2020, 11:42:17 AM
Hi folks.

after looking at the files of the 3 different platform versions i've noticed changes that are probably obvious.
First one is a no brainer, the executables are different.
second, the engine is different. also no surprise because it had to run on different hardware.
The changes however are so severe that even the simplest of resource files had to be changed.
For example.
The horizon texture file " ALPINE.PVS " is 7,24 KB in the DOS version.
The horizon texture file " alpine.psh " is 6,04 KB in the AMIGA version
The horizon texture file " ALPINE.RVS " is 12,6 KB in the FM towns version

Different sizes and different names. The FM towns version can be opend in stressed but the image is scrambled.

However. I'm no programer or hacker and I don't understand much of this.
But maybe the differences can give us new insights about the inner workings of stunts.

NB. collision bugs are consistent in the amiga version vs the dos version. E.G. you can still drive trough the roadblock.
Title: Re: DOS vs AMIGA and FM Towns versions.
Post by: GTAManRCR on August 15, 2020, 06:42:54 PM
A funny thing is, when you spin your car in Amiga version, it's faster, than DOS version
Title: Re: DOS vs AMIGA and FM Towns versions.
Post by: Cas on December 11, 2020, 06:56:08 PM
I am not seeing the contents of the files, as I don't have the other versions, but from the file names and size, I can make some guesses. We know that the "P" and the beginning of extensions in DOS Stunts files is for "packed". I don't know how to unpack these files (what the unpacked in Stressed does) but by looking at them from inside, I'd say they're Huffman-compressed. So, because the RVS is larger than the PVS, I would think the "R" stands for "RLE", that is "Run-Length-Encoding", which is a simpler, less CPU demanding compression method... that compresses less. My guess is that the file is compressed that way. The other one is more puzzling. The "SH" in "PSH", following Stunts file naming "conventions" stands for "shape", but it's not like "P3S", so it's a shape, but not a 3D shape. Is there a chance that landscapes in that version of Stunts be polygonal instead of bitmaps?  If so, that would explain why that file is even smaller.