duncanspumpkin's comments

duncanspumpkin | 4 years ago | on: Prince of Persia open-source port based on the DOS version disassembly

For OpenRCT2 I just used a debugger Ollydbg to be precise. As it was hand written assembly disassemblers produced nonsense output.

duncanspumpkin | 4 years ago | on: Microcontroller VGA Interface Projects

I followed Ben's guide to make a little ATTiny 2 colour VGA output of a clock counting down. https://github.com/duncanspumpkin/ATTiny-B-W-VGA

It was quite a challenge building it into such a tiny controller. Was doing it for a University project where we wanted to have the clock started from an external source so needed to keep one I/O free for that input. It ended up with every I/O pin of the 8 pin micro having a use.

duncanspumpkin | 4 years ago | on: SpaceCadetPinball – Decompilation of 3D Pinball for Windows

For OpenRCT2 thats not quite how we did it. We didn't use IDA decomp output as its useless with Chris Sawyer calling conventions you had to just read the assembly. We did name things as per IDA when things were completely unknown hence why there was lots of sub_XXXX functions and byte_XXXX. I personally just used OllyDbg and read the assembly and wrote equivalent C code. I've a few videos of implementing functions for OpenRCT2 and OpenLoco if you are interested.

duncanspumpkin | 5 years ago | on: GTA III and Vice City fully reverse engineered: re3

Hey, whatever happened to openrw? I remember trying to get into that back in 2017 but looks like this project ended up superseding it.

duncanspumpkin | 8 years ago | on: An open source re-implementation of RollerCoaster Tycoon 2

RCT Classic is one way of getting the files but it's cheaper to buy RCT2 then load it in OpenRCT2. But to each their own as long as you're having fun.

duncanspumpkin | 8 years ago | on: An open source re-implementation of RollerCoaster Tycoon 2

Yes its always been a thought that we should do a Dolphin style progress blog but at present there is no one available to write one.

duncanspumpkin | 8 years ago | on: An open source re-implementation of RollerCoaster Tycoon 2

The main advantage that Chris used in RCT2 to optimise his code was that he could vary his calling convention however he felt. Most of the time all variables were passed in registers instead of the stack. This can make for some impressive speed ups.

duncanspumpkin | 8 years ago | on: An open source re-implementation of RollerCoaster Tycoon 2

There is actually no DirectX at all in RCT2 source code. The game has its own software renderer that outputs direct to the screen buffer.

duncanspumpkin | 8 years ago | on: An open source re-implementation of RollerCoaster Tycoon 2

We have had numerous bugs like this in the past. At one point there was a bug where all guests would destroy everything they walked past.

duncanspumpkin | 9 years ago | on: The cruellest RollerCoaster Tycoon park created

The AI is actually very primitive for navigating mazes. It is the same AI for every character and does not vary with ride tastes. All the AI does is prefer walking in straight lines and when it reaches a forced decision it takes either direction with equal rating. It does not have any idea where the exit is or do anything fancy. It can easily end up going round the same area on repeat.

Source I read the x86 assembly.