Search found 1133 matches

by 93143
Wed May 27, 2020 11:46 pm
Forum: General Stuff
Topic: SNES Doom development, Randy Linden
Replies: 12
Views: 618

Re: SNES Doom development, Randy Linden

I re-read coto's earlier post, and it gave me an idea. If it turns out that the wall drawing code is in fact heavily bottlenecked by pixel cache stall (as I suspect), and drawing four or more wall columns at a time is too complicated to fit in the register set (as I suspect), it might actually be re...
by 93143
Tue May 26, 2020 12:36 am
Forum: General Stuff
Topic: SNES Doom development, Randy Linden
Replies: 12
Views: 618

Re: SNES Doom development, Randy Linden

Not in hardware. The whole PLOT arrangement was designed exclusively for CHR bitplane graphics. And even if it hadn't been, Mode 7 is a tiled bytemap format, so there would be no access penalty for any particular drawing pattern - just write the byte (or not) and you're done. You could draw in Mode ...
by 93143
Tue May 26, 2020 12:08 am
Forum: SNESdev
Topic: Design guidance for 3D Engine on SuperFX
Replies: 24
Views: 931

Re: Design guidance for 3D Engine on SuperFX

Okay, after a bit more searching elsewhere on the web, it appears Wikipedia was wrong (!!!) and decent modern bob deinterlacers do not in fact bob after all. Good to know...
by 93143
Mon May 25, 2020 8:54 pm
Forum: SNESdev
Topic: Design guidance for 3D Engine on SuperFX
Replies: 24
Views: 931

Re: Design guidance for 3D Engine on SuperFX

I guess what I'm complaining about is that the "deinterlacing" part is completely unnecessary and for some reason tends to take forever, causing a huge increase in perceived input lag. ...I'm reading the Wikipedia article on deinterlacing and I can't see anything about filling in the blank lines in ...
by 93143
Mon May 25, 2020 6:25 pm
Forum: SNESdev
Topic: Design guidance for 3D Engine on SuperFX
Replies: 24
Views: 931

Re: Design guidance for 3D Engine on SuperFX

You'll have (227 - 160)*165.5 = 11088 bytes of VRAM upload bandwidth per frame. wat An NTSC frame is 262 lines, no? That should give you nearly 16.5 KB per frame. More than adequate in the context of 248x160 (which is almost exactly 16:9) or even 256x168 (which is still closer than 240x160). Person...
by 93143
Mon May 25, 2020 1:49 am
Forum: SNESdev
Topic: Writing to VRAM during HBlank
Replies: 9
Views: 1318

Re: Writing to VRAM during HBlank

Awesome. I tested it on my SD2SNES on my RetroDuo, and it seems to work fine. I'll even post a photo. Thanks! More verification is always good. Now how compressed is BRR? Not to rain on your parade, but we know the format and it's fixed-rate. It's 9 bytes for 16 samples. So 16-bit audio compresses ...
by 93143
Sat May 23, 2020 10:05 pm
Forum: General Stuff
Topic: SNES Doom development, Randy Linden
Replies: 12
Views: 618

Re: SNES Doom development, Randy Linden

Well GSU is blit-based drawing, the framebuffer then translates to planar format. I was (mis?)using the term "blit" to mean a bitwise combination of the new and old graphics data, without prejudice as to format. The framebuffer doesn't "translate" anything; it's just data in RAM, and it is in plana...
by 93143
Sat May 23, 2020 5:24 pm
Forum: SNESdev
Topic: Design guidance for 3D Engine on SuperFX
Replies: 24
Views: 931

Re: Design guidance for 3D Engine on SuperFX

I think the SNES DMA limits are ~6K per VBlank assuming you have nothing else to DMA, say updating sprites for example. That's only if you don't use force blank to trim the top and/or bottom of the screen. You gain 165.5 bytes worth of extra DMA time for every line the PPU doesn't render (assuming ...
by 93143
Sat May 23, 2020 3:52 pm
Forum: General Stuff
Topic: SNES Doom development, Randy Linden
Replies: 12
Views: 618

Re: SNES Doom development, Randy Linden

The GSU chip has per dot drawing opcodes. Yes, and the way it works is each pixel plotted goes into a primary pixel cache representing a horizontal sliver of 8 pixels from a particular tile in the framebuffer, with flag bits denoting plotted pixels. Once it's full, or you plot to coordinates outsid...
by 93143
Sat May 23, 2020 12:05 am
Forum: General Stuff
Topic: SNES Doom development, Randy Linden
Replies: 12
Views: 618

Re: SNES Doom development, Randy Linden

Hopefully more fascinating stuff to come: https://github.com/RandalLinden/DOOM-FX Not much there yet but the GPL... I kinda want to take a look at the wall rendering code. Rendering vertical lines one by one (as I believe the original Doom did) is pretty much the most pessimum way to use the Super F...
by 93143
Tue May 05, 2020 7:08 pm
Forum: General Stuff
Topic: Nintendo legacy console leak
Replies: 5
Views: 770

Re: Nintendo legacy console leak

Dolphin has made a statement. They're afraid to even look at it, because it would break the legal basis for their project.
by 93143
Wed Apr 22, 2020 3:51 pm
Forum: SNESdev
Topic: New SNES game: Yo-Yo Shuriken [Cartridge+ROM]
Replies: 5
Views: 5945

Re: New SNES game: Yo-Yo Shuriken [Cartridge+ROM]

It wasn't a boss. It was during a level. Two of the little orange shields that bounce your shuriken off at an angle just happened to be in exactly the right relative positioning to keep bouncing it between them indefinitely. As it happens there were a couple of options for breaking out of it: (a) wa...
by 93143
Tue Apr 21, 2020 5:55 am
Forum: SNESdev
Topic: Writing to VRAM during HBlank
Replies: 9
Views: 1318

Re: Writing to VRAM during HBlank

I wonder how much bandwidth per line you can get away with if you use IRQ instead of HDMA. So do I. It depends on the S-PPU's BG data access pattern, but not in a complicated way. It shouldn't be especially hard to test, so I figure I'll take a look once I get another chance. Has there been any pro...
by 93143
Thu Apr 16, 2020 5:37 am
Forum: SNESdev
Topic: New SNES game: Yo-Yo Shuriken [Cartridge+ROM]
Replies: 5
Views: 5945

Re: New SNES game: Yo-Yo Shuriken [Cartridge+ROM]

I beat it! It's pretty simple, but surprisingly absorbing. I did soft-lock it once, though. My shuriken got in between two orange shields at an angle to each other and wouldn't stop bouncing between them. Considering how much is onscreen, it seems fairly robust. Thank you for this. I don't buy thing...
by 93143
Tue Mar 31, 2020 7:19 pm
Forum: SNESdev
Topic: Writing to VRAM during HBlank
Replies: 9
Views: 1318

Writing to VRAM during HBlank

TmEE had a trick where he turned off the screen during hblank that allowed him to transfer more per scanline. He turned the display back on right before the screen went active. But yeah otherwise it just stalls the cpu. Didn't cause any artifacting from what I remember. But I don't remember the exa...