🎉 PARTYMOD! 🎉

_{NOTE: The following was originally posted to Cohost, a site that is going down soon.}

A couple days ago, I released a mod for Mat Hoffman's Pro BMX on PC that makes it much more playable on modern systems (featuring a renderer replacement and a bunch of bug fixes). It's a sister project to my last project, PARTYMOD for THPS2.

I did a writeup for my previous mod and I really liked doing that, so here's another:

Mat Hoffman's Pro BMX was Activision's first attempt at cashing in on their previous success with the Tony Hawk's Pro Skater games, adapting the format to other action sports. It was developed by Runecraft (as far as I can tell...) with an unknown amount of support on the Playstation release being provided by Shaba Games (previously known as a developer of action sports games in their own right), and was developed on Neversoft's engine used for the original THPS (though the game has many features from THPS2, so presumably some code was shared during that game's development). Unlike the THPS series, the Dreamcast port was done in-house by Runecraft (this will be important later on) and the PC port was done by the same team as THPS2, Grey Matter LTI.

I can't get the best read on how this game was developed. The PS1 demo lists only Runecraft as a developer (and the game's text is clearly British, with the use of "portaloo" and saying the Granny secret rider is "going in for tea" after unlocking her), and Shaba Games was also credited for the full release. The game had a considerable delay, with the original demo giving a Fall 2000 release date, but the game ultimately releasing in May 2001 (the game also has a trailer for the Activision O2 sublabel and advertises Mat Hoffman's Pro BMX 2! The game advertises its own sequel!!). The interesting thing is that the art noticeably differs between Dreamcast and PS1:

The final FMV for completing the career as Granny (featuring a... less than skilled rider dressed as an old woman) also is filmed in an LA area park, away from both development teams. Her look also differs drastically between PS1 and Dreamcast and the FMV reflects the PS1 look. Either way, I have trouble figuring out what exactly happened to make the game notably different between its two major releases.

Anyway, let's get to the PC port: the PC port was released last, with the Dreamcast version releasing in September of 2001 (the day after 9/11, and 6 months after the Dreamcast's discontinuation, so you'd be forgiven for not noticing...) and the PC version coming out in October. The PC port is based off of the PS1 release, but uses some assets from the Dreamcast release. Most notably, it uses the Dreamcast versions of all the levels.

Honestly I was kind of dreading working on this release, because the PC release is written in a very strange way. The main executable only initializes some settings, sets up the window and direct3d, then loads one of three DLLs and calls three functions within it before loading another. Each DLL represents a portion of the game: frontend.dll handles the menus, source.dll handles the gameplay, and editor.dll handles the park editor (ported over from THPS2, including many THPS2 menu assets). Each module reinitializes directinput and directsound for some reason. Ultimately I approached this by hooking the DLL loader and patching each DLL as they're loaded. I was thinking of rewriting the executable entirely, but I was concerned about compatibility with speedrun autosplitters (and I was also lazy).

As I'd already patched THPS2 which runs on the same engine, I figured this game would be easy to patch as well. While there were some differences in the renderer, it was pretty straightforward to get my first frames. The interesting thing was the lack of environment I was seeing.

Here I learned that the game was trying to load textures in a format my code didn't recognize. THPS2 only use paletted 4 and 8 bit color textures, MHPB added support for 16-bit color in 3 formats: RGB 5:6:5, RGBA 5:5:5:1, and RGBA 4:4:4:4. This was my first hint that these were actually the real Dreamcast levels, not just the PS1 levels with some Dreamcast retrofits, as Grey Matter had done with THPS2! Those formats were straightforward to implement, and now I had mostly gotten things working. All that remained was redoing some of the sprite code for UI elements, porting over my code to get Bink FMVs working, and fixing some depth issues.

None of the polish work on the renderer was particularly interesting, but it gave me some interesting insight. The game was having some trouble handling certain depth sorting situations (especially with transparency). I figure the game was taking some advantage of the Dreamcast's built in depth peeling, so it could be more relaxed about rendering order. Additionally, that version has rare support for the Dreamcast's bumpmapping!

Another alpha blending issue that I was interested in is that certain textures were drawing with strange colors compared to the Dreamcast release. I think what happened here is that the Dreamcast renderer doesn't support some blending modes that the PS1 renderer did (if they used Treyarch's ports of THPS as a base, this is almost definitely what happened. Similar issues exist in those as well). This results in branding appearing in the wrong colors, which I thought would be a much more urgent issue:

Ultimately I opted to keep those as-is, because they would also affect certain elements that relied upon the correct blending behavior that were brought over from the PS1 release. Someday I would like to see what the PS1 levels would look like loaded into this version of the engine. I figure it would look a whole lot nicer that way. I'd gotten it looking reasonably like the Dreamcast version (I even fixed some texture transparency bugs from the PC release!), with some settings to get it closer to the PS1 look if people would like, which I think is a good compromise for now.

With the renderer done, I moved onto input. I thought this would be the same as the renderer, just porting the THPS2 code into MHPB, but I was wrong! The input handler is entirely new. Previously they were emulating a PS1 controller, but for this they rewrote it entirely and use what is kind of a strange system. They provide a few mechanisms, one to get the current controller state like how things used to work, and another where a 32-bit mask is given which represents action-based controls. I ended up putting the new mechanisms on top of my old playstation controller emulation written for THPS2 because I'm lazy. It was straightforward to write and frankly not that interesting. Rumble support was taken out for this game, which is a slight bummer.

The last interesting note is the game's mouse handling. Both THPS2 and MHPB use the absolute position of the mouse, but THPS2 uses window space positioning and MHPB uses some translation between screen and window space that doesn't work at all. On some modern systems, the pointer will jump somewhere around 64 pixels at a time, making most controls unreachable in its original form. I was able to adapt my THPS2 mouse code easily, making those controls usable for the first time in a while.

Honestly, that's kind of the theme of this port. Things that worked in THPS2 were often broken. I can only imagine that this port was really rushed to just get the game out of the door and recoup some costs. Some rendering features were broken to a potentially harmful degree (glass shards would sometimes take over the screen and start strobing. This was handled correctly in THPS2 but for some reason regressed for MHPB). I'm happy to hopefully get this game into a playable state for anyone wanting to check out the PC version. This game is often forgotten about despite being one of the better action sports games of the time. I want to do some more work to restore some of the PS1 look, but as it is, it's a good version to play with its fast load times.