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DrTypo

+AtariAge Subscriber
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DrTypo last won the day on May 5 2013

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About DrTypo

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    Chopper Commander
  • Birthday 04/23/1977

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    Paris, France

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  1. I'm not elite enough to attempt such a task. But it does overflow when things are a bit far. @Clint Thompson I don't think I'll implement an auto-spin feature. However I'll try to have U235 SE play some music. I expect the impact to be minimal. From my experience, U235 SE has hardly any effect on the rest of the system.
  2. I implemented backface culling. More info in the original post.
  3. I make the 3D meshes in Blender and export them as .obj files. Then I convert them in raw structures for my engine using a tool I made.
  4. After Tube2020, I decided to make a more complete 3d engine. It is still a very simple engine and lacks many features. It displays only flat shaded triangles and does rotations only around Y axis. So what to say about it? It's not very fast despite the fact that it uses the GPU and blitter. On my PAL machine, it runs in 3 frames (16.6 fps) while computing about 254 triangles. Possible optimisations are: improve depth sorting: if I remove depth sorting, it runs in 2 frames (25 fps). To do depth sorting I uses comb sort, which is an optimized bubble sort. Shell sort would probably be better. Another optimisation would be to do depth sorting only on the objects and use convex objects. backface culling: I didn't implement backface culling (because lazyness). This would likely speed things up quite bit. use the DSP for transformation and clipping, the GPU for rasterisation. reduces the amount of transformations: there are duplicate vertices that are transformed multiple times. This could be improved. Doing this would take time and also run into the 4K limit of the GPU (except using DSP, this would help a lot with the 4K limit but good-bye U235 sound engine). The routine could easily be split into 2 chunks for the GPU (transformation/clipping and rasterisation). Anyway, doing fast 3D on the Jag is not easy (who knew?). Now I understand Checkered Flag (which probably uses a faster engine than this one). But I don't understand No Second Prize on the Atari ST. Edit: I implemented backface culling and things are indeed quite a bit faster. It now runs in 2 frames (25fps). The effects of backface culling are two-fold: there are fewer triangles the rasterize will attempt to draw and fewer triangles to depth sort. By the way I'll explain the meaning of the numbers on screen: the first is the size of the routine in bytes. I can check that I stay within the 4096 bytes limitation of the GPU. the second one is the number of triangles rendered. the third one is a bit hard to grasp: it's the number of ticks (1/50th ou 1/60th of a second depending on your region) used to render 50 frames. So if the number is 50, one frame takes one tick. You are at full framerate (50fps or 60fps). If the number is 100, one frame takes two ticks you're at half framerate (25fps or 30fps). engine.zip
  5. DrTypo

    Tube2020

    This is the final version. I don't plan to add anything.
  6. Thank you for the correction!
  7. DrTypo

    Tube2020

    Thank you for all these videos @Saturn
  8. DrTypo

    Tube2020

    I put the release candidate. There is a total of 9 tracks. I added a invert-y switch.
  9. DrTypo

    Tube2020

    Thank you for your video @Saturn By the way, there is something that was not clear in gravity mode. You can run on the bottom track, it won't slow you down. Basically it plays more like a regular racer.
  10. DrTypo

    Tube2020

    I made a quick capture of playing Tube2020 in Virtual Jaguar using fraps: Tube2020 sample I showed that it is possible to pass the red blocks in the track Gamma
  11. DrTypo

    Tube2020

    @KevinMos3 Yes, the red block slow you down and if you are stopped, it's game over. You have to be fast enough to pass them. The green block speeds you up, providing you release the accelerator: don't push button A when you pass green blocks.
  12. DrTypo

    Tube2020

    @UHATEIT It is close to the final version. I will add a few more tracks and the option cubanismo suggested. @cubanismo Glad that you and your daughter like it! I wrote the 3D code from scratch. It is a very limited 3D code so I could skip a lot of things that are usually done in 3D. Good suggestion! I will add an invert-y option.
  13. DrTypo

    Tube2020

    I added a gravity switch in the title screen and 2 new tracks.
  14. Now this is evil I had a PowerPC machine a long time ago but I didn't do much assembly with it, mostly C++. @ggn Thank you for looking into this. Actually I did use the VS debugger . But the various arrays (kwtab, kwaccept, kwcheck) confuse me.
  15. DrTypo

    Tube2020

    @JagChris Yes, I used 3D for Tube2020. It is very limited (only moves in x,y,z not rotations), which allowed to take all kind of shortcuts. The Jag can do gouraud shading without much performance issue (I think) but I will experiment with this later, not on Tube2020. @KevinMos3 OK I'll add an option in the title screen for gravity!
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