Final Version preview/review on the Zeropage Homebrew Show!

[Andrew Davie]

Heads-up on a presentation/review of the demo binary on Zeropage Homebrew's show!
Tue May 21, 2024 | LIVE @ 6PM PT | 9PM ET | 1AM GMT+1Day

Zeropage Homebrew twitch stream

[Andrew Davie]

Well, that was interesting.  Thank you to James and Tanya for the excellent demo!
It's the end of my day now; the show was 11am my time and it's now 9pm. I believe I have fixed nearly all the bugs - the only unknown is I don't have hardware setup at the moment to test - all my dev has been done on the excellent Gopher emulator.

To address some of the "issues" (not bugs, surely!) that we saw in the stream (and remember that none of these show up on the emulator)...

1) at the start of each level you should see a fade-in circle-swipe - but all we saw was a black screen. Bug found/fixed. It's a tad complex, but essentially the circle looks at how many cycles are available in the overscan (OS) or vertical blank (VB) in which it is running. When testing yesterday I put in a silly "make sure there are at least 80000 cycles" - which is fine on the emulator. But unfortunately the timings on the emulator/hardware vary slightly and to put a long story short the circle code was going "I need 80000 cycles to do this guys... how many cycles are there spare....how many.....??!!  Nah, fuck that!!"  and that was that. No circle. We're lucky the game managed to continue after the (not-visible) circle was finished.  So, a definite fix. I rewrote it to instead of requiring X cycles FREE, it always happens at the start of VB or OS when there are the most cycles available - and limit it to taking at most 20K cycles. I think this might solve a lot of issues with circle swipe overtime.

2) On review of the stream, it looks like ALL of the crashes were when "GAME OVER" is displayed and circle is swiping. I moved the GAME OVER draw to early on, too. Because the circle swipe is now limited to 20k this gives an awful lot of cycles spare for GAME OVER draw. I have yet to test on hardware but this is the way to go. Hopefully already fixed.

3) I discovered today in my testing that Gopher's reported timings are "best effort" - providing actual ARM cycle counts for code is not the simplest of things so when I was relying on profiled timings, they were actually a little out. I discovered this by wrapping some timing code around a routine; Gopher reported it about 13% faster than it really was. This has since been mitigated by a change to Gopher to scale the timings. But it also explains why when I was trying to be cycle-accurate in "how much free time?" calculations it was working on emulators and not on hardware. For now, I'm adding 25% to the times to give me a little safety margin.

That just about covers the issues shown in the stream. Although I was cringing while watching these things happen - they all appear to be the one major problem; time overflow when GAME OVER and circle swipe are happening.  So other than that, it all held up pretty well really.

On review of the stream I see James throw his arms up in celebration a few times when he successfully completed a level.  And towards the end, just making heaps of not-thinking errors as his brain got tired and worn out.  To me, this body language says that there's good playability there.

Thanks to everyone who joined us. 


Just one small note about Minesweeper - although not the most exciting of games I did note how quickly both Tanya and James were able to play, with the single-button control system. It seemed intuitive when I designed it and seemed to me that it worked well for them during play.  I was rooting along with some of the "moves" and when James made that last error "1" marking I wanted to yell out "Noooooooooo!".

[markzilla1985]

It was really nice timing to honor their cat Sprite in the demo on ZPH. Can't wait til June 1st annoucement list !

[Andrew Davie]

This is what I like to see - someone excited to complete a level I designed!

[Andrew Davie]

Maybe I should have cropped the picture. It gives the impression James is a bit too excited