Merry Christmas from Bitshifters!

[kieranhj]

A festive greeting from Bitshifters for your BBC Micro!
https://bitshifters.github.io/posts/pro ... as-19.html

[roland]

Very impressive, like all your demo's

IIRC many of the effects are done by changing the palette at the right moment. Can this be done on a FPGAtom, now that we have 64 colours and an eight MHz cpu core?

And of course a merry Chrisrmas to you also

[lurkio]

A festive greeting from Bitshifters for your BBC Micro! ...

Absolutely nuts! Such smooth animation. Brilliant!

Btw, unlike the older version on the Bitshifters website, the latest version of JSBeeb enables sound on iOS:

• https://bbc.godbolt.org/?disc=https://b ... del=Master

[kieranhj]

Absolutely nuts! Such smooth animation. Brilliant!

Btw, unlike the older version on the Bitshifters website, the latest version of JSBeeb enables sound on iOS:

• https://bbc.godbolt.org/?disc=https://b ... del=Master

Thank you! I’ve had my phone on silent setting for so long I didn’t realise sound was working now. I’ll ask Simon if he can update it.

[0xC0DE]

Excellent demo!!

[kieranhj]

IIRC many of the effects are done by changing the palette at the right moment. Can this be done on a FPGAtom, now that we have 64 colours and an eight MHz cpu core?

This one has no fancy palette switching or CRTC tricks - at 2MHz there’s just enough time to move 64 3x3 pixel blocks independently. So that’s 2x EOR plots to the screen and 2x 16-bit adds (x & y) for each. I didn’t spend much time optimising so could probably squeeze a few more in if I really tried.

There’s a ‘screen buffer’ of chunky pixels that gets visited line-by-line at a random X position each frame. If there’s a pixel there we set up a lerp from a random position on the edge of the screen that takes 64 frames to reach its correct destination.

I got lucky with the music - simonm found and converted it from YM for me. The timing almost exactly matched up for filling and removing the screens already, so I just tweaked until I was happy.

[oss003]

Nice demo Kieran .... looks great and very smooth movements ....

Greetings
Kees

[billcarr2005]

A festive greeting from Bitshifters for your BBC Micro!

[Diminished]

Beautiful stuff.

[jms2]

That's superb! I love the way it looks like the "snow" is swirling about, but actually everything is moving in straight lines.

If you pick pixels to move randomly, how do you make certain you've cleared everything on that line?

[Arcadian]

Aw, this is wonderful - thanks guys!!