GP2Lap Experiments
Re: GP2Lap Experiments
Your work is truly excellent. I've started making the 14 cars from 1994! I'm going to try to make more of them little by little...
Re: GP2Lap Experiments
Great to see someone working with the gp2lap source code. Im wondering if an autosave feature would be possible? I'd prefer it to save each lap or choose the save intervals instead of the gpxpatch implementation where it keeps overwriting the previous autosave.
I also noticed a bug for ATL where the lap counted seems to be 1 lap behind, the winner will register the victory at the commencement of the final lap as shown on ATL
I also noticed a bug for ATL where the lap counted seems to be 1 lap behind, the winner will register the victory at the commencement of the final lap as shown on ATL
Re: GP2Lap Experiments
Wouldn't this create a big stutter when the game was saved? I mean in dosbox, where it freezes for a fraction of a second.
Re: GP2Lap Experiments
I honestly don't know, it doesn't cause any ill effects in gp3 but that doesn't use dosbox. If so it would be annoying though. The only reason I want it is to autosave the replay while I'm racing instead of having to go out and do it manually which breaks my rhythm
Re: GP2Lap Experiments
I was able to try x86gp2 and hatcher implemented an autosave, I'm not sure if he can help 'port' it to gp2lap, or if he has any interest at all in the dos version. There's a few things in x86gp2 that would greatly improve the dos gp2. I know most will not be possible, but some things I think can work for dos. For example the replay, gp2video creates a bug that makes the marshalls stay in the middle of the track, also makes smoke and flame not visible. The slight workaround for that is to save the game a few times during the race to keep 'clean' replay files and NEVER replay during an actual race. This also mitigates against the bug where an alternate reality can take place which ruins your result, a bug of gp2video which I never experienced in gp2replay.. Gp2video also disables the ability to save hotlaps which means the telemetry no longer works which removes depth from the overall Sim.
The compromise is to use gp2replay which doesn't have the bugs and doesn't compromise telemetry, but that has a max replay time of 300 seconds. So in other words you need to break immersion to save every few laps to get anything that even resembles a full race replay. The thing is, that 300sec limitation was only put in place because at the time there was no way to fast forward the replay. according to the author Gp2replay has the ability for a full replay or in any case a replay that lasts longer than 300sec. Hatcher's replay can ff or rw from what I see, which gp2replay can't but gp2video can, or in gp2lap pressing the 'f' key will speed up time for gp2replay which is a reasonable compromise but there's no rewind and no way to exit the replay or skip to end. That's why Rafa put the 300 second limit.
The other idea would be to autosave the hotlap replays and find a way to seamlessly 'stitch' them together, the only downside I think the in and out laps would be lost. No big deal because a gp2replay save at the end of the outlap can recover it.
As you can see at the moment there's no perfect solution to get full replays in dos gp2, which is a shame because its as pleasurable to watch the race as it is to drive in it
The compromise is to use gp2replay which doesn't have the bugs and doesn't compromise telemetry, but that has a max replay time of 300 seconds. So in other words you need to break immersion to save every few laps to get anything that even resembles a full race replay. The thing is, that 300sec limitation was only put in place because at the time there was no way to fast forward the replay. according to the author Gp2replay has the ability for a full replay or in any case a replay that lasts longer than 300sec. Hatcher's replay can ff or rw from what I see, which gp2replay can't but gp2video can, or in gp2lap pressing the 'f' key will speed up time for gp2replay which is a reasonable compromise but there's no rewind and no way to exit the replay or skip to end. That's why Rafa put the 300 second limit.
The other idea would be to autosave the hotlap replays and find a way to seamlessly 'stitch' them together, the only downside I think the in and out laps would be lost. No big deal because a gp2replay save at the end of the outlap can recover it.
As you can see at the moment there's no perfect solution to get full replays in dos gp2, which is a shame because its as pleasurable to watch the race as it is to drive in it
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Max Power Racing
- Posts: 2
- Joined: Fri Aug 28, 2026 2:43 am
Re: GP2Lap Experiments
Hello all! Nice to have new GP2 forum.
I start posting with link to my short video (my personal GP2Lap mod) --> https://www.youtube.com/watch?v=uGGxEXo9Jto
And yes, those front wheels actually move!
If anyone wants to develop the idea further, I’m happy to share my modified files/source changes. My coding skills pretty much end here.
Since it works inside GP2/GP2Lap, there are naturally more limitations than with an external Windows overlay.
At the moment it only works for the player car, and you need to use the 7 key to hide the wheels when switching to external cameras. There are also some small side effects when using other GP2Lap overlays, but nothing that has bothered me enough to keep digging into the code.
The animation uses GP2’s own wheel-speed data, so the front wheels react individually to speed and lock-ups, and they also move with steering. The tyres are drawn in two parts so they can appear correctly around the mirrors in cockpit view.
I developed this together with ChatGPT, which helped me understand and modify the GP2Lap source code. I did the testing, memory-data investigation and cockpit work, while ChatGPT helped with the coding and source-code side of the project.
The whole thing started as a very small experiment to see if I could draw anything at all through GP2Lap. The first successful test was literally a red pixel.
If someone with more coding experience wants to continue from this, I’d be very interested to see where it could go.
I start posting with link to my short video (my personal GP2Lap mod) --> https://www.youtube.com/watch?v=uGGxEXo9Jto
And yes, those front wheels actually move!
If anyone wants to develop the idea further, I’m happy to share my modified files/source changes. My coding skills pretty much end here.
Since it works inside GP2/GP2Lap, there are naturally more limitations than with an external Windows overlay.
At the moment it only works for the player car, and you need to use the 7 key to hide the wheels when switching to external cameras. There are also some small side effects when using other GP2Lap overlays, but nothing that has bothered me enough to keep digging into the code.
The animation uses GP2’s own wheel-speed data, so the front wheels react individually to speed and lock-ups, and they also move with steering. The tyres are drawn in two parts so they can appear correctly around the mirrors in cockpit view.
I developed this together with ChatGPT, which helped me understand and modify the GP2Lap source code. I did the testing, memory-data investigation and cockpit work, while ChatGPT helped with the coding and source-code side of the project.
The whole thing started as a very small experiment to see if I could draw anything at all through GP2Lap. The first successful test was literally a red pixel.
If someone with more coding experience wants to continue from this, I’d be very interested to see where it could go.
Re: GP2Lap Experiments
Nice work Max. It's nice to see people still learning and working on new things with gp2!