AuthorTopic: SNES Sprite Restrictions?  (Read 23144 times)

Offline straypixels

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SNES Sprite Restrictions?

on: November 03, 2008, 03:03:45 pm
I may be dense, but I can't find this information anywhere. Here or on google. I found a plethra of "OMG! CHANGE THE PALETTE IN YOUR SNES ROMS! OMG!" stuff, but no where that really outlined the restrictions. I want to really push myself to get better at this, so I want to work with some restrictions. I'm working on some sprites done with NES restrictions, but I'd like to upgrade :)

Does anyone know what the SNES palette restrictions are? Is it just like NES, but doubled, or what?

Thanks!

stray...  .
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Offline PypeBros

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Re: SNES Sprite Restrictions?

Reply #1 on: November 03, 2008, 03:32:04 pm
the best source of information i've found so far was http://en.wikibooks.org/wiki/Super_NES_Programming. (courtesy of http://snesdev.antihero.org/).
Afaik, each palette is now 15 colors + a common "backdrop" color, as usual with nintendo hardware, though early games (SMW and ZLTTP) preferred to encode only 3 bits per pixel and have smaller ROM.

Sorry for not being more precise, but the specs for the SNES PPU (picture processing uint ?) are surprisingly cryptic, so i prefer saying only a few than saying something completely wrong.

Offline ptoing

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Re: SNES Sprite Restrictions?

Reply #2 on: November 03, 2008, 03:35:11 pm
Colourdepth on the SNES is 15 bit, 5 bit per channel.
There are no ugly colours, only ugly combinations of colours.

Offline straypixels

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Re: SNES Sprite Restrictions?

Reply #3 on: November 03, 2008, 08:04:41 pm
Forgive my lack of knowledge here, ptoing, but what defines a channel? I'm assuming a bit would be a single color? So essentially, 15 colors... 5 bit per scan line?
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Offline ptoing

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Re: SNES Sprite Restrictions?

Reply #4 on: November 03, 2008, 08:15:12 pm
Channel as in Red Green Blue. So you have 5 bit per channel, which means 32 settings for each Red, Green and Blue, which makes a total of 32768 colours to choose from.
There are no ugly colours, only ugly combinations of colours.

Offline straypixels

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Re: SNES Sprite Restrictions?

Reply #5 on: November 03, 2008, 09:01:42 pm
Okay, so the most pertinent restrictions to pixel art according to this http://en.wikibooks.org/wiki/Super_NES_Programming/SNES_Specs are:

  • Maximum colors per layer per scanline: 256.
  • Maximum colors on-screen: 32,768 (using color arithmetic for transparency effects).
  • Resolution: between 256x224 and 512x448.
  • Maximum onscreen objects (sprites): 128 (32 per line, up to 34 8x8 tiles per line).
  • Maximum number of sprite pixels on one scanline: 256.

So, allow me to make sure I understand this... You don't have to worry about this as much when you're working on a modern PC lol

assuming 256x224 resolution, you've got 224 scan lines, but I think that's about all I get here lol. Once we  get to onscreen objects and sprite pixels on a scan line, I'm confused.

Also, who do you determine what an acceptable color is? Ptoing, you and that wiki agree that you can use 32,768 colors on screen at a time... is that ANY combination of colors, or a specific combination?

Am I over complicating it? ^_^
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Offline AlexHW

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Re: SNES Sprite Restrictions?

Reply #6 on: November 03, 2008, 09:23:56 pm
if a game exceeds the maximum sprites on one scanline, then the extra sprites get clipped or aren't drawn I think.
as far as i understand, its all about how the tech handles/stores the data. the tech can only do so much based upon how it was designed.

Offline Akira

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Re: SNES Sprite Restrictions?

Reply #7 on: November 04, 2008, 02:02:54 am
Ptoing, you and that wiki agree that you can use 32,768 colors on screen at a time... is that ANY combination of colors, or a specific combination?
I'm not Ptoing but I might be able to help. As mentioned earlier you have 32 settings for each channel. That's like having 0-255 (256 settings) for each RGB channel we use commonly today. The settings will be set equally apart from full off to full on (black to full green for example). Basically if you can only use todays 256 setting RGB channels with values of multiples of 8 (256/32=8) so you could have 0,0,0 - 8,8,8 - 16,16,16 - 24,24,24 - 32,32,32 - 40,40,40 and so on up to 256 and any combination of these (0,16,40 for example).
I hope this makes sense.
thanks Dogmeat!

Offline straypixels

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Re: SNES Sprite Restrictions?

Reply #8 on: November 04, 2008, 03:28:43 am
Akira! You rock :) That's exactly what I was trying to figure out.

Next question... what's a scanline? I mean, I know what it does in a TV, but does it basically equal a 1px line?
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Offline ptoing

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Re: SNES Sprite Restrictions?

Reply #9 on: November 04, 2008, 10:14:09 am
Cheers Akira.

Yes a scanline is always a single pixel line afaik.
There are no ugly colours, only ugly combinations of colours.