Admittedly, most of my built-in functions are quite hacky. I originally wanted to use general implementations of functions in a way that would allow them to be used for multiple programs, but I quickly ran into performance issues with that that I worked around by making the functions less general.

For example, the map() function, which draws a tilemap to the screen, but only the tiles that match a bitmask, originally just looped through a grid of sprites and drew them if they matched the bitmask. Now, I instead draw the tilemap into an unused portion of the screen, turn it into an RLET sprite, and then store the RLET sprite in a cache based on its position and bitmask. That works great for Celeste Classic (even faster than regular tilemaps), since it uses map() in a very predictable way that's good for caching. But for a game that uses map() differently, it could give performance that's much worse than just drawing the sprites one at a time.

Fantastic work - while a general lib would be good, I can fully understand why this would really need to be implementation specific for critical things.

Does it still happen in the latest version or just the original one? I fixed a bug that behaves like that in yesterday's release.

[s]whoa that was fast[/s]

I actually don't know -- I downloaded this about a month or two ago, and haven't updated literally anything on my calculator since then

Somehow I am just now seeing this- and I must say, it looks absolutely incredible! Seriously, I didn't know the CE could do such amazing graphics.

Oh, really? Prepare to be absolutely flabbergasted (by someone who is not me)

I've released an update today with a few bug fixes:

• Fixed an issue where the timer ran at half speed in practice mode.
  
• Player now correctly jumps in from slightly below the edge of the screen, rather than starting the jump from the spawn point.
  
• Practice mode timer now counts from the start of the spawn animation rather than the point where control is handed to the player.

Thanks to Orlando and superboi0119 from the Celeste Classic Discord for reporting and helping debug these issues.

I've also set up a test branch that's able to load TAS files, which should make it easier to identify behavior that differs from the original game in the future by comparing it against another implementation that's using the same inputs.

This is really cool. I have another version of this but for PSP it’s a fun game that took me like 30 minutes to do. It’s just interesting they took a game that runs on a 64mb ram system to a 48kb ram system

Is there a link to the branch? I'm interested in trying that out!

I just pushed it: https://github.com/commandblockguy/CEleste/tree/tas

It isn't too useful at the moment, since it can only replay TAS files, not record them. TAS files for the real game desynchronize pretty quickly, which I assume is due to numeric precision differences in my port.

Celeste Classic 2 when?

What other games do you think are possible to port?