New version of PacMan (PuckMan) for the BBC Micro

[tricky]

Latest version in post https://www.stardot.org.uk/forums/viewt ... 97#p410397.

New version of PacMan (PuckMan) for the BBC Micro.
I came to a standstill with MoonPatrol, so until the enthusiasm comes back, I thought I would try to keep busy.
I have started PacMan, as anyone who joins the ABUG dev nights will know.

screnshot.png (6.09 KiB) Viewed 10175 times

Here is the first demo, you can move and erase dots, but they aren't collected, so will be reprinted if a ghost goes over them.
The ghosts just head for the top-right corner and run in circles, but it allows you to see how the sprites work and that the ghosts can move at different speeds.

I have only just started adding Joystick support and it doesn't work correctly.
What I would like is feedback on moving PacMan, keys are Z, X, / and : and you can cut corners to gain a little on the ghosts.

[davidb]

Nice and smooth. I like the colours of the ghosts.

[tricky]

Thanks, there are only a few choices in MODE 1, and those were just the three that came out first
I was worried that the ghosts would look a little jerky, but then I had never noticed it in the arcades.

[tricky]

Minor update with fixed Joystick support
Press fire during game to enable joystick.

[leenew]

He he he fantastic so far!

Lee.

[0xC0DE]

Smooth! (didn't expect anything less from you actually )

[TobyLobster]

The controls work well, they are responsive and I don't miss corners or anything. I do slowly catch up with/pull away from the ghosts on the corners. Will later levels have faster ghosts? The animated mouth of Pacman is manic, but the original was too - do you have a policy of just duplicating and not trying to improve on the arcade experience? Anyway, very smooth. Nice progress.

[tricky]

I will be trying to match the arcade experience, but not exactly. Ghosts are different speeds on different levels and change speed with mode.
I used to write my games from memory and then play them to do final tweaks, but now I start by playing the original as my memory is very poor!
Having no creative ability beyond coding, I tend to stick with the original. I did not replicate the shield bug in Phoenix, nor the 2000000 scoring bug and I'm not planning on reproducing the path-finding target bug in Pacman.
I also don't give extra lives as I don't want my games to become endurance competitions.
I am open to suggestions, but reserve the right to pretend that I haven't seen them

[OneSwitch]

Very impressive. On my emulator and laptop I have to press SHIFT ; to go up, which is faffy.

Feels good though, compared to the original. Not 100% the same feel, but very close.

[tricky]

Thanks, the original cornering allows slightly faster cornering in two diagonals than the other two, mine is the same for all four.

It was actually trickier than I thought making it work well on what is effectively an eight way stick.

Depending on your emulator and OS, for games, you should be able to set the keyboard emulation so that the keys map to the same place on the keyboard, ignoring what is written on the laptop keyboard.

[dominicbeesley]

That looks really good - looking forward to giving it a try tonight. I've been playing Snapper quite a bit recently (it's one of my test-cases for hardware) but this looks super-smooth!

[tricky]

I think the others either use mode 2 to get the colours or don't hit 50fps.
It's only really the movement, nothing else is there yet.

[drfloyd]

Tricky is so hot !!!!!!!!

Lot of conversions these last weeks, it's really incredible !!!!!

[dbolli]

Nice. Look forward to the power pills

[tricky]

I've messed the timing up, you can see dots in the ghosts and the bottom line of pacman missing at the bottom.
I have also got a bug in ghost direction reversing, so disabled that for now too.
When you eat the last dot, you get the dying tune and the dots redraw apart from a couple that get hidden by pacmam; this won't happen when pacman is re-positioned.
The power dots don't do anything apart from mess the timing up!
I wasn't going to post another update as I was still feeling motivated, but maybe a little boost wouldn't hurt
I'm currently using the game gear sounds!

[Arcadian]

Goodness, this is a huge leap forward - I love it!!

[tricky]

The sound makes quite a difference. I can't remember if I allowed for the difference in sound chip clock frequencies. Anyway, it sounds a little high pitched to me - me with no audio skills!

I also feel that it is noticeably slow, which is probably because it is 50fps instead of 60. Pacman should start at 80% speed, but he is actually at 100. I can keep him there most of the time, but when the ghosts are supposed to got over 100,I would have to slow him down.
One option is to scale the graphics to 3/4, which would make it effectively 61.66'fps. I don't know which to pick, but I don't think my enthusiasm will run to both!

[0xC0DE]

Looking (and sounding) great tricky! Are you aiming to get as close as possible to the original game, or your own variation?

[tricky]

I'm trying to make it fell like pacman, but the ghost AI will not be bit identical. They should be just as predictable, but the old patterns will not work, however the old tactics should.
If you play the arcade game with an eight-way stick, you will find that you miss corners and it can be very frustrating. I have added eight-way support, which makes it more intuitive for beginner players, but behaves the same as the arcade game for experienced players. I did even out the corner cutting so it is the same in all directions, instead of biased.
The main idea is to have the game reward good players, but without meaning it is just a test of endurance.

I put a poll up, but haven't checked it to see how close to the original the speed the game should feel.
If I go with full res, which is my current preference, I will not start packman at 80% speed, but probably 88%so that he will still have the same relative speed to the ghosts, but not feel so slow.
The other option is to go with 3/4 res, which would approximate 61.66' fps and all the timing should be as per the arcade, but possibly with Elroy2 capped to 100% or maybe all speeds slowed by 5%. Something to think about later (but not too late!).

[Zuffle]

love it Rich. just had a little blast on it and it's coming along nicely

your retro projects are always inspirational

[tricky]

Thanks, I'm quite pleased with the way it is coming along, although I need to tidy up as there are only 400 contiguous bytes free and a lot to add!
One more update for the weekend.
I have introduced a "tunnel" bug and occasional flicker on the top scan line of pacman
The ghosts vaguely do what they are supposed to, but still start in their test positions.

[tricky]

Here is another small update.
You can now eat ghosts, but the end of level is still, just carry on.
There are two known bugs that I would love to know how to reproduce:
1. A dot is occasionally draw on the maze walls. It isn't really there, so doesn't affect game play other than there may be an invisible dot.
2. A gap is made in the wall of the maze, but again this doesn't affect game play.
If you notice either of these happen, I would love to know how to reproduce them.

[0xC0DE]

Excellent tricky! Plays very well.

I think the power pill is temporarily corrupted when ghosts pass through them. Not sure if only in power pill mode.

Also, I somehow managed to stay in power pill mode indefinitely. 3 of 4 ghosts were blue but I couldn't eat them.
Until I got another power pill.

[tricky]

I have a little fifo of dots that need redrawing once the ghost has moved off them. To avoid flicker, I redraw the dots after redrawing the power pills, so the dot overwrites the middle of the pill until the dot drops off the end of the fifo. I will add a test and not add those dots to the fifo as the power pil is always draw. - thanks for the reminder, I had forgotten!

I don't know how you managed to end with blue ghosts as that was the last bug that I thought I had fixed.
Thanks for the report, I'll put it on the list.

It is great when people spot these things as I spend very little time actually playing the game and most of my limited time coding.

[tricky]

A little more progress this morning, now the ghosts can get you, but you have infinite lives.
I fixed the ghosts immediately coming out of their home after being eaten.
When you complete a level, things reset, but pacman leaves a bit of his crust - it doesn't affect gameplay.

After a massive tidy up, I now have nearly 1.5KB free in a single chunk, although there are many things still to go in and much to tidy up!
There is a place holder dying animation, as the real one is a few hundred bytes that there may not be room for.
I don't think that there will be room for the eyes going home without their body (probably a few hundred bytes), but we'll see.
I would like to get some form of intermission in, but again, I think it will be a couple of hundred bytes plus the music, which I will probably put in anyway just as an extended breather.

I am starting to like this no interrupt handler for games that don't need multiple interrupts per frame as it gives you 0..&7FFF without any gaps, unless you want a stack or treat ZP as being special

Apart from pacman's crust, I would love to hear about any graphical glitches and if possible, how to reproduce them.
Same for sound or any other faults.
There is so much missing gameplay, that it probably isn't worth mentioning it!

If anyone feels like making new sound effects that would be great, but if not, I will try to find better ones and if not, go with what I have.
Currently apart from the start music, everything is only single channel, but some could be two channel.

[fwibbler]

I managed to get it to crash on Beebem.
I've put a screen shot of the moment.
I'll try and capture a video tomorrow (hope I remember)

[oss003]

Hi Tricky, game looks great ... got that arcade feeling for a moment ..
Shouldn't the ghosts slow down when they are blue?

Greetings
Kees

[fwibbler]

Made a video of it (only a short one)

[tricky]

Thanks both of you.

That looks more like a beebem bug!

The ghosts should slow down - I miss-read a different version of this table:

Code: Select all

	PAC-MAN SPEED			GHOST SPEED		
LEVEL	NORM	DOTS	FRIGHT	DOTS	NORM	FRIGHT	TUNNEL
1	80%	~71%	90%	~79%	75%	50%	40%
2 – 4	90%	~79%	95%	~83%	85%	55%	45%
5 – 20	100%	~87%	100%	~87%	95%	60%	50%
21+	90%	~79%	–	–	95%	–	50%

I had missed that there were two fright speeds, one for you and one for the ghosts, the ghosts go to 90, while you stay on 80!
I'm going to have to redo the table as I had scaled everything to keep pacman as fast as possible - 80% feels too slow (50 vs 60 fps)!
You basically miss a frame when you eat a dot but can gain 3 when turning a corner.
Scaled to maximise pacman speed:

Code: Select all

NORM	FRIGHT	NORM	FRIGHT	TUNNEL
89%	100%	83%	56%	44%
95%	100%	89%	58%	47%
100%	100%	95%	60%	50%
95%	-	100%	-	53%

[tricky]

Made a video of it (only a short one)

Which version of beebem are you using?

I suspect it has a bug in the BIT zp instruction and the AND part.