Deconstructing Mario Bros

casualsax3 · Post by **casualsax3** » Tue Nov 28, 2006 9:23 pm

http://acg.media.mit.edu/people/fry/deconstructulator/

snkcube · Post by **snkcube** » Wed Nov 29, 2006 1:55 am

casualsax3 wrote:http://acg.media.mit.edu/people/fry/deconstructulator/

Hey, that's pretty cool.

Nightcrawler · Post by **Nightcrawler** » Wed Nov 29, 2006 2:33 pm

That is pretty cool. Thanks for that link. I'll pass that one to the guys over at ROMhacking.net as I'm sure they'd be interested in this if it hasn't been posted there already by somebody else.

neoblaze · Post by **neoblaze** » Wed Nov 29, 2006 3:21 pm

wow

shiny

whicker · Post by **whicker** » Thu Nov 30, 2006 1:56 am

For extra credit points:

Why are the sprite indexes for the enemies (and thus the images on the right) constantly being rotated every frame?

funkyass · Post by **funkyass** » Thu Nov 30, 2006 3:01 am

because they take up more than one frame?

whicker · Post by **whicker** » Thu Nov 30, 2006 4:26 am

funkyass wrote:because they take up more than one frame?

Hmm. nope.

Even the 100 points that rises appears in multiple sprite slots, and it's not animated.

Maybe my grammar is unclear (sorry)... the sprite order is being shuffled around, if you look closely, when there is a sprite besides Mario onscreen.

Also notice how Mario isn't shuffled, yet is animated ...

Joe Camacho · Post by **Joe Camacho** » Thu Nov 30, 2006 4:28 am

Kind of neat, I would really hope to understand what is really happening.

AntoineWG · Post by **AntoineWG** » Thu Nov 30, 2006 9:44 am

It probably has to do with the motion of the Goombas' feet, since the Koopas don't do it. Rather than loading 2 more sprites for their feet every frame, they get mirrored and the indecies get swapped, making it look like their feet are going up and down. It's probably less memory intensive than loading 4 sprites just for their feet and faster than loading 2 sprites from the cartridge every frame.

casualsax3 · Post by **casualsax3** » Fri Dec 01, 2006 9:33 pm

Here is something along the same lines, with a very detailed description of what is going on - this one deals with Metroid.
http://mdb.classicgaming.gamespy.com/m1/lvldata.htm

whicker · Post by **whicker** » Sun Dec 03, 2006 5:15 am

Well, anyway, the shuffling is going on to avoid having a given sprite completely disappear. There can only be 8 8-pixel wide sprites on a given scanline. Since most enemies in the game are 16 pixels wide, more than 3 enemies or other sprites will cause flashing if Mario is on the same horizontal line.

To everyone's benefit, flashing is better than an invisible sprite. The sprites take turns being invisible for one frame due to the shuffling.

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Deconstructing Mario Bros

Deconstructing Mario Bros

Re: Deconstructing Mario Bros