GBJAM 14

Hosted by Polyducks, chasehunter, DL, poltergasm, timconceivable, tatltuae, Traslo, arknano, batfeula · #GBJAM

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GBJAM 14 community

Question: Do blinking/flickering effects count as a 5th color?

A topic by Fuzzy created 41 days ago Views: 181 Replies: 5

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Fuzzy41 days ago (3 edits)

Let's assume that I am making a game with the jam's restrictions in mind. I decide to use flickering effects. There is no palette swapping. Does it still count as a 5th color?
Visualisation displayed below.

As you can see in the gif, the portrait of the robot gets covered by a set of oscillating lines. They move up and down every frame, to the point that it creates an optical illusion of a 5th (well, in this case 4th) color, specifically for the purpose of simulating translucency.

50 fps gif

However, as demonstrated by the photo below (or by looking at the gif's individual frames), there is absolutely no additional color beyond the black, white and red displayed.

static screenshot

This flickering is something you could do on the game boy's display.

But your explanation of the color palette rules make me worried that I'd be disqualified for using this technique, despite respecting the hardware's limitations.

So, would a game using flickering for the optical illusion of transparency be disqualified?

poltergasmJam Host41 days ago(+1)

Unfortunately we can't allow it, unless you achieve it on a genuine gb rom of course. The gameboy had notoriously slower response times so the effect would look different on modern hardware. To make the rules simple we chose to disallow any kind of "illusion" that attempts to break the 4 color rule, and this would be one of them. Otherwise there'd be hundreds of branching conditions on what you can and can't do.

Deleted post41 days ago

Deleted 41 days ago

Fuzzy41 days ago (3 edits)

I'd argue that the game boy LCD's response time would actually help to sell the effect better. The flickering would look even bore like an in-between color thanks to that screen's ghosting.

In fact, here's an example of it being used in castlevania II. Real gameboy hardware.

When belmont goes ino the water, or in fact, when any item goes into the water, they start flickeing in a manner not too dissimilar to what I did.

The only difference being that i flicker alternating lines instead of the whole part of the sprite that is submerged.

Part of why I love the game boy is how the devs essentially "cheated" the limitations by essentially turning them against each other.

Intentionally using ghosting as a pseudo teansparency effect or for motion blur, or layering sprites to get more details, all those small tricks that make you wonder how they did it.

If you want, I can try to collect more footage of examples.

poltergasmJam Host41 days ago(+1)

I agree the delayed response time would probably make it look better than on modern hardware. As I said, if you want to crack open GB Studio, use GBSDK or write it from scratch in assembly and produce a gb rom, then go nuts. Just because it's a similar technique doesn't mean you get the same effect. If your question starts with "Can I do this to give the illusion of a fifth color" then the answer is strictly no, as per the rules. You may not like (and I don't in some cases), but it keeps things simple and reduces headaches from answering the same questions over and over again.

timconceivableJam HostSubmitted41 days ago (3 edits)

just in case you missed the 4-color rant :)

FAQ > Questions about GBJam entries >

I have a question about the four colour limitation:

You can only have four colours on the screen at once. Black is a colour. The four colours include all shades, all tones, all hues. Gameboy does not support semi-opacity. The four colours apply to the whole screen, including sprites. You cannot have one four colour palette for your background and another for sprites. This jam does not allow for a fifth experimental colour like ‘default screen background’. Four is the total amount of colours you are allowed. You may use three or two. Five is right out.
The four colours you choose do not have to be the default palette you’ve found on Wikipedia. Lospec.com has loads of four colour palettes you could try. You can even make your own.
➡️ You can change your palette mid-game so long as the new palette is four colours. You cannot change your colours mid-scan-line or any other sneaky trickery. If you have more than four colours on the screen at any one time it is not obeying the rules.
Yes, the gameboy had three colours plus transparency on sprites. No, this is not a restriction you need to obey in your competition entry.
You can change the palette with a light switch or when it’s night time so long as there are only four colours on the screen at one time. Are there four colours on the screen? Yes? Congratulations, you abide by the rules. Are there five colours? Do two of the colours blend with opacity to make a new colour? Wow buddy, looks like you’re in more than four colour territory!
‘Four colours maximum’ means ‘four unique colours’. A colour is a unit measured by its unique properties such as hue, saturation and value (or whatever other colour system you subscribe to). You could have red, blue, green and yellow on your screen, but ‘a slightly darker shade of red’ would count as a new colour. You could not have fifty shades of blue and argue that you’re only using ‘one colour’.
➡️ Yes, the illusion of a fifth colour counts as a fifth colour. Do you quickly flip the palettes to make an extra colour? Does it have an extra colour on the screen? Welcome to five coloursville friendo, population: you.
No, dithering does not count as an illusion of a fifth colour, as long as you are sticking to the 160x144 resolution.
If you want to argue how your five colours are special, do it in your game jam submission. I’m sure the reviewers (your fellow game jammers) will understand… 👀
If your next question starts with “but what if” the answer is no. No, you can’t do your special idea. It breaks the rules.
“Can I use shaders?”
Does your game have four colours? Is the resolution 160x144? Does your game art adhere to the spirit of the jam - i.e. does it look and feel like it’s on a gameboy? Yes? Go ahead.
“But-”
Then no.

Fuzzy41 days ago (1 edit) (+1)

It's specifically the rant that caused me to be confused and worried.

Because while you allow dithering, the rant made it sound like flickering as a whole was completely banned if it made it look like the palette had more colors than were ever displayed, even if there was no palette swapping or "true" 5th color involved.

Hence why I included visual examples explaining how flickering tricks the eye into seeing more colors than there are. I just wanted to clear up confusion.

Thankfully your co-host clarified that sprite flickering was completely off the table, so now I won't waste time making a game that would auto fail the jam's rules.

itch.io

GBJAM 14

Question: Do blinking/flickering effects count as a 5th color?

FAQ > Questions about GBJam entries >

I have a question about the four colour limitation: