Hi-res Mode 7

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creaothceann
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Hi-res Mode 7

Post by creaothceann » Thu Jul 05, 2018 6:39 am

Has anybody tried this?
  1. Mode 7 + pseudo hi-res + mainscreen=BG1 + subscreen=sprites
  2. Mode 7 + pseudo hi-res + mainscreen=BG1 + subscreen=BG1
Option 1 should blend Mode 7 and sprites on a real non-RGB CRT or an emulator with blurring / NTSC filter.
Option 2 probably looks the same as regular Mode 7, unless the SNES somehow has a very well hidden hardware feature...
My current setup:
Super Famicom ("2/1/3" SNS-CPU-GPM-02) → SCART → OSSC → StarTech USB3HDCAP → AmaRecTV 3.10

tepples
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Re: Hi-res Mode 7

Post by tepples » Thu Jul 05, 2018 7:58 am

The "hires mode 7" is an emulator-only hack that the authentic S-PPU cannot reproduce.

Interlaced mode 7 should be a slightly more useful way to increase usable resolution even on hardware. Create your HDMA table half a pixel down every other frame.

byuu
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Re: Hi-res Mode 7

Post by byuu » Thu Jul 05, 2018 8:05 am

creaothceann, the whole point of mode 7 is to do rather extreme calculations (affine texture mapping) on a 128x128 base image. There is no way you're going to be able to meaningfully recreate those transformations on sprite data to feed into the alternating columns. If you could do that, then at that point you might as well use a regular or hires BG mode.

I explained how the trick worked in bsnes a bit more at the link you provided, which should show better to others why this is impossible on real hardware.

creaothceann
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Re: Hi-res Mode 7

Post by creaothceann » Thu Jul 05, 2018 9:21 am

Yes, the sprite data would of course be in 2D. I was just thinking that maybe pseudo hi-res wouldn't work for some reason in Mode 7. (Although it really should.)

Interlaced Mode 7 sounds very interesting though, even if one field would lag behind. Maybe useful for static screens that still need a variable perspective.
My current setup:
Super Famicom ("2/1/3" SNS-CPU-GPM-02) → SCART → OSSC → StarTech USB3HDCAP → AmaRecTV 3.10

tepples
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Re: Hi-res Mode 7

Post by tepples » Thu Jul 05, 2018 9:55 am

If you're recalculating an entire HDMA table every frame for mode 7, it shouldn't take any longer to calculate it for interlaced display than for progressive display.

creaothceann
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Re: Hi-res Mode 7

Post by creaothceann » Thu Jul 05, 2018 10:59 am

Yes, but due to the nature of interlaced mode it wouldn't look that good with movement.
My current setup:
Super Famicom ("2/1/3" SNS-CPU-GPM-02) → SCART → OSSC → StarTech USB3HDCAP → AmaRecTV 3.10

lidnariq
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Re: Hi-res Mode 7

Post by lidnariq » Thu Jul 05, 2018 11:14 am

Artifacts from a weave (aka "terrible") deinterlacer are NOT a realistic representation of what interlaced video looks like, especially when shown as a single merged frame.

byuu
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Re: Hi-res Mode 7

Post by byuu » Thu Jul 05, 2018 12:31 pm

Yes, both EXTBG and pseudo-hires can work in every mode. Whether it's useful is another story.

There's nothing stopping a 480p60 fake mode 7, but ... ugh.

nocash
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Re: Hi-res Mode 7

Post by nocash » Fri Jul 06, 2018 11:09 am

Interlace might look good with moving or blurred images (eg. photos/videos). But for static images with high contrast (eg. text/graphics), it's causing ugly flimmering. And, PAL/SNES is additionally having a hardware flaw, causing distorted horizontal position of the upper some scanlines in interlace mode.

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