Sega Saturn Widescreen hacks (Panzer dragoon Saga POC)

Discussion in 'Sega Saturn Programming and Development' started by Esppiral, Aug 30, 2016.

  1. corvusd

    corvusd Member

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    Very well seen!

    Possibly one of the few 2D games, which are completely made (stage, backgrounds, objects and characters) with the VDP1. The Shadows are Scaled sprites without redrawing or distortion, here the transparency of VDP1 can be used perfectly here without any penalty. :) The VDP2 only is used for the UI. Thank you!!
     
  2. Yakumo

    Yakumo Pillar of the Community *****

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    It may also be the reason why the game sucks. The animation and movement of the sprites is so wrong on this port. Easily the worst SNK to Saturn port.
     
  3. XL2

    XL2 Rising Member

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    I have a special request : would you be able to find the code to turn on wireframe and remove user clipping calls in Quake and Duke Nukem?
    I would like to see how much/little overdraw these games have to see if it's worth writing a portal based engine vs "simple" pvs (I got portals/pvs working in my own engine, not sure if having portals do extra clipping is worth the cpu cost).
    Thanks a lot!
     
    Last edited: Nov 1, 2018
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  4. jollyroger

    jollyroger Gutsy Member

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    FYI: if all goes well, this winter I am planning to make some modifications to Yabause and/or Mednafen to enable a number of debugging/profiling features, including a custom render pass specifically to display and measure overdraw...
     
  5. XL2

    XL2 Rising Member

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    That would be awesome!
    Right now I use wireframe and half transparency to get a rough idea of the overdraw, but having per pixel global info would be amazing.
    Any ways to make the emulated vdp1 more on par with real hardware (ie slower fillrate) as an option?
     
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  6. jollyroger

    jollyroger Gutsy Member

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    Not sure what you mean by emulate "slower fillrate". The actual rendering method used by the hardware vdp1 to draw polygons can be emulated precisely to correctly account for overdraw, but as you know the fillrate does not become "slower", only the pixels are written to multiple times.
     
  7. XL2

    XL2 Rising Member

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    No, I meant something else completely.
    The vdp1 is emulated way faster than what the real hardware can do.
    I don't think I ever managed to make it slow down in Yabause.
    Llike 1000 quads, gouraud and half transparency on everything, yet it stays at 30 fps while it runs at 3 or 6 on real hardware.
    But it can be useful to know when the cpu is the bottleneck, but it's always a suprise when I test on real hardware.
     
  8. corvusd

    corvusd Member

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    Hi @jollyroger and @XL2

    Thank you both for your developments to keep alive and maximize the SS.

    Honestly, I think you're both right, because deep down you're dealing with the same goal. I explain.

    The PSone Profiler does not show you the slowdowns or FPS the game is going through. One of the things it shows is the cost of each drawing each pixel in a frame. And the % of total use of each instruction on its maximum capacity in the BUS.

    Extrapolate this to an emulator I think it's possible. And it would help development at least 50%. It would indicate many issues to correct or improve. It is clear that we will have to go through the Real Hard in a final process or final adjustment.

    For my analysis I have created a table with the "cost" by primitive and effect applied in the SS. To quantify how much the total theoretical Fillrate of the VDP1 is reduced. It is "a first shot" on my part, but it has helped me enormously to understand the machine and the games that I am analyzing.

    On the other hand YabaSanshiro since its version 1.8.x shows the FPS in the VDP1, and I have to say that I trust a lot. Well, it gives real data of known games. That's how I'm analyzing Frame Rate in a lot of them.

    Putting all the pieces together I think you can estimate a final performance in 1 frame and set of frames.

    With respect to having a wireframe on hand, and the use of User Local Clipping, I think it can be a before and after to really see how it helps to lower the redraw in these Lobotomy games. Because I've only really seen it in these 3D games.

    Thanks community! Regards!
     
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  9. jollyroger

    jollyroger Gutsy Member

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    I see, that makes total sense. In that respect, the emulation is not very accurate in terms of timing. At a first glance, Mednafen seems to have a much more reasonable approach to timing and emulation than Yabause (and most of its forks), which is much more oriented towards emulation performance.
    Perfect emulation of the VDP1 timing is certainly not impossible, and the Mednafen developers have done a substantial amount of work to that extent already, so I would recommend using that emulator for profiling/measurement purposes. I will probably use it too to develop the additional performance profiling features I want to add.
     
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  10. Esppiral

    Esppiral Gutsy Member

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    Any request? I ran out of ideas.
     
  11. Esppiral

    Esppiral Gutsy Member

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    @paul_met I've only found zoom modifiers for several games, do you think they could be useful to you to find a horizontal modifier

    Form the top of my head
    Burning rangers
    Independence day
    Nippen nammaru
    Wipeout
    And several more
     
  12. paul_met

    paul_met Rising Member

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    Maybe. You should post these values.
     

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