SMK minor gfx bug

Stifu · Post by **Stifu** » Sat Feb 05, 2005 9:06 am

(Sorry if this is an already known bug...)
There's a little graphic bug in Super Mario Kart...

---------------------Internal ROM Info----------------------
File: smk.smc
Name: SUPER MARIO KART Company: Nintendo
Header: None Bank: HiROM
Interleaved: No SRAM: 16 Kb
Type: DSP-1 + Batt ROM: 4 Mb
Country: USA Video: NTSC
ROM Speed: 120ns (FastROM) Revision: 1.0
Checksum: Good 0xEB44 CRC32: CD80DB86
--------------------------Database--------------------------
Name: Super Mario Kart
Country: USA Revision: 1.0
Port 1: Gamepad Port 2: Gamepad
Genre 1: Racing Genre 2: Battle

First, the bug is kinda random. It doesn't always happen... You may need to reset the game and try again to get it to happen.
Sometime, when you "strongly" turn to a side while pressing L or R (thus raising dust around your kart), the bottom pixel raw of the dust is a bit buggy.

Screenshot

It's the blue parts on this screen... Depending on the track, it can get red and maybe other colors, too.
It seems to be a pretty old bug, too. I don't know if it ever worked right with ZSNES. It does with Snes9x, by the way.

-_pentium5.1_- · Post by **-_pentium5.1_-** » Sat Feb 05, 2005 9:09 pm

I think that might be an intentional feature of the game. Can you post an unedited screenshot of the entire game screen?

Do you have high-resolution mode 7 on in the video settings?

FitzRoy · Post by **FitzRoy** » Sat Feb 05, 2005 9:25 pm

IIRC, snes9x doesn't even render the map grass correctly, so I wouldn't be too quick to assume that what it's doing is right. I'd look at the actual cart, or perhaps super sleuth.

Stifu · Post by **Stifu** » Sat Feb 05, 2005 9:58 pm

I don't remember this happening on a real console... I can't check, though.

-_pentium5.1_- wrote:Do you have high-resolution mode 7 on in the video settings?

Nope.

By the way, I just realized it never works right. Sometime it adds inappropriate pixel colors to the bottom pixel raw of the dust, and sometime there's missing dust pixels at the bottom... that's why it looked normal to me at first sight.

More screenshots:

Blue pixels at the bottom of the dust
Missing pixels at the bottom of the dust
Brown pixels at the bottom of the dust
Blue pixels at the bottom of the dust

creaothceann · Post by **creaothceann** » Mon Feb 07, 2005 10:31 am

This might be related to the "Metroid" bug: HDMA timing.
Does it happen with the 2nd player in two-player mode?

Stifu · Post by **Stifu** » Mon Feb 07, 2005 11:00 am

The 2nd player (so, at the bottom half of the screen) isn't affected by this bug at all... Thanks for having suggested to try that.

That proves the bug with the 1st player is definitely NOT an intentional feature...

Stifu · Post by **Stifu** » Tue Feb 08, 2005 8:17 am

The bug also happens if you simply drive through sand and stuff like that, as long as you raise a cloud of smoke / dust... Not just when you hold L/R while turning.

Post by **pagefault** » Tue Feb 08, 2005 6:46 pm

It's a bug in the transparency code when I am currently working on right now to fix FF3, so I may be able to fix this while I am at it.

Stifu · Post by **Stifu** » Tue Feb 08, 2005 6:51 pm

That's cool... Thanks for having answered.

Good luck.