ME: Alright. By the end of yesterday I'd solved the blockers, so today I can make some good progress on my work project.
MY BRAIN: You should drop everything and design a set of hypothetical color palettes for a 16-bit-color version of https://wasm4.org/
ME: Oh snap that's a really good idea
SOME HOURS LATER:
(In order:
1 (top left): 5 bits red, 5 bits green, 5 bits blue, 1 bit alpha
2 (top right): 5 bits blue, 6 bits green, 5 bits blue
3 (bottom left): 4 bits red, 4 bits green, 4 bits blue, 4 bits alpha
4 (bottom right): 5 bits red, 5 bits blue, 4 bits green, 2 bits alpha
I'm doing something unusual with "0 alpha", since it seems wasteful to devote half the color space to an identical full-invisible color. There are many problems I haven't considered yet but the work so far was enlightening.)
Things I have not yet considered:
- Is a linear map of the color space the best possible approach for the WASM16 use case? What about "SRGB"?
- When colors combine (via alpha), should they combine back into the 16-bit color space, or should they be composed in a higher-bit space such as the graphics card native?
- Assuming "full transparent" is done by a key color, could alpha combinations of colors result in accidentally mapping to the keycolor? What does alpha-blending WITH the keycolor mean?
Also, there's this interesting post:
https://mastodon.social/@TomF@mastodon.gamedev.place/110029989349970818
Saying when 565 was tried in video cards it lead to bad results because this is bad at displaying "pure" grays, and suggesting a 5-5-5-1 where the final bit is a shared brightness rather than alpha (!), a fascinating idea I'd never thought of. Did any retro consoles have a 16-bit color space (eg that their smaller palettes draw from)? How did they handle this? Wikipedia says the SNES underlying colorspace was 24-bit… hm.
@mcc reminded again of my experiences with 16-bit color on Windows 95 back in the mists of prehistory, how when switching modes sometimes it would (apparently?) attempt to display 5-5-5 RGB as 5-6-5 RGB resulting in purplish grays, or that's what i assume was going on
idk if that was a Windows 95 problem or just a problem with my graphics card/driver in retrospect, though
