!Munchy A clone of a classic maze game

Like most people at the moment I am working from home. I have been writing
some PIC assembler software for work which involves encoding and decoding
data for transmission over a RF link. As I am writing both ends it can be
difficult to debug which end is going wrong the Receiver or Transmitter
software.

Anyway this was making my head hurt :-) so I thought I need a distraction as
I had some success writing !Stargate I thought I would have another go.

Rather than thinking up a new game I will make a clone of a classic that
will be easy :-) boy how wrong I was?.

I started creating the maze and then started thinking about the operation of
the game not only do the ghosts have to follow the maze they also have to
patrol their quarter of the screen?.

They also have to know where the centre box is and also have to be able to
track you when needed. I take my hat off the the author of !Snapper anyway I
think I got there but ended up with a bigger head pain than I started with
:-)

Operation and Clues

Ghosts will randomly move around their quarter of the screen I have
added a bit more of a random walk around their own areas they do not always
take the same path.

On level 1 the ghosts make no attempt to track you they are all just
on random paths.

Above Level 1 Ghosts start to track this can be caused by going to
near a ghost, even the other side of a barrier is close enough to
possibly start the tracking, this tracking will continue until you
die or make the ghosts edible by eating one of the 4 power pills.

Also at random intervals a ghost will be told to track you, the ghost
can be anywhere on the screen. Ghosts are told to track in order so
they will be assigned as follows:-

Magenta
Red
Green
Cyan

So look out for the Magenta ghost leaving its area it is probably
looking for you!. If the ghost is busy (edible or displaying eyes)
then the next in the list will be assigned to track you.

On lower levels only 1 ghost at a time can track you as you go to
higher levels more ghosts track, up to a maximum of 4.

I have tested the game on:-
Titanium
Raspberry PI 400
Raspberry PI 2B+
Iyonix

I have tried to balance the level so that it not impossible but
still challenging.

I tried to crunch the program using !crunchie but after crunching it failed
when saving the scores? So I have left the program as is but I suspect it would
run a bit faster if it was crunched.

The games uses its own internal timer so should run at the same speed on different hardware
on the Iyonix it can look a bit blurred as it tries to run at the correct speed.

Let me know what you think and how it works for you.

You can Download from :-
www.mbelect.co.uk/RISCOS

Ooh another game. :-)

Let 2021 be the year of lots of new RISC OS games – big and small. I believe a new one from AMCOG is imminent.

I’ll give !Munchy a proper play/play-testing later on today (right now I’m bogged down with my own game dev project).

Yes another game this working from home is proving to be productive not just in games but in real work as well :-)
It must be because I’m not getting interrupted by phone calls all the time.

Interestingly I have removed the WAIT for vsync in the program and tested the game on all four computers here
and it draws perfectly fine no tearing of graphics.

I’m using the draw to a sprite and then plot the sprite to the screen. Which is using a single graphics screen bank but you would think that at some point the sprite would be drawn at the wrong time and produce a corrupted screen but no?. I wonder why?

I have used the TimerMod to regulate the update speed of the graphics but still can’t believe that there is no tearing
of graphics?

As I have had few replies I am assuming:-

1: no one downloaded Munchy
2: it works OK on most systems :-)

I’m assuming option 2 :-)

I have made Munchy Multitask it seeems to work quite well on most systems.

If your interested you can download from :-
www.mbelect.co.uk/RISCOS

Some text from the help file below:-

Desktop Display Mode:-

The game should adapt to any desktop display mode.

MultiTasking :-

Once !Munchy is started it will place an icon on the iconbar.

If you press select on the Iconbar icon a window will open displaying
the !munchy high score table. See this window for details of which keys to use.

If this window has the desktop focus a high volume of wimp polls will be used to
enable smooth animation.

If the desktop window focus is moved to another application the wimp polling will
be reduced so that the system can multitask in a more efficient way.

If the main game is being displayed when the focus is in the main window a high volume
of wimp polls will be used, the game will be paused if you move the focus to another
window this is good for coffee breaks :-)

Most of the computers I have tried the game on can multitask only the Iyonix needs
to run in full screen to operate at a reasonable speed.

Iconbar Menu Options:-

The main iconbar menu has the following options.
Info (Program information window)
Full Screen (uses MODE 28 (640 × 480) this single tasks.
Scale 1.5 : 1 (960 × 720) size window
Scale 1:1 (640 × 480) size window
Quit quit the program

Window Menu Option:-
Quit quit the program

It works very well for me so far; I really enjoy the scaled window option; I think this is a really nicely done version of a classic game.
With respect to tearing (lack of it) thats a great point; I just took the vsynch out of a text window I have that used to flicker like crazy; and it still seems smooth on a PI400, some GPU magic perhaps.
Cheers for creating and sharing this; it is great fun, its only weakness is that unlike the original pub version you cant sit a couple of pints on it.

Thanks for the feedback I’m glad your enjoying the game, sorry can’t help with the beers though :-)

With regards to the vsync all four computer work here without using vsync even the iyonix
It’s seems that outputting all graphics to a sprite and then plotting the sprite to the screen is very efficient.

Hi Terry,

Thanks for the game it runs well on my ARMX6 and provides another distraction to getting on and doing other things :-)

Great games Terry. Nice to see RDSP in use within them.

Definitely one of the best Pac-Man style games I’ve played for a long time. The ghost logic seems like a good solution (an explanation of the original Pac-Man’s ghost logic is here: Pac-Man Ghost logic)
I’ve downloaded Stargate too.

Playing both on my Pi 3+ on RISC OS Direct (Doing development kit updates and a couple of new games at the moment. Lots of late night coding)…

Fab!

Some suggestions for your next version…

Well done on getting it run in a window. I can change between scales while the game is running, but if I select full screen it goes back to the beginning. Can it switch between fullscreen and window while carrying on the game? Or pause fullscreen and return to desktop temporarily?

I really liked the intro screen with the relaxing music, but in the game the retro sound fx were different volumes, in particular is it possible to make the loud lose game sound at the same level as the others?

@ Doug
Thanks for the feedback.

@Tony
Thank you for making RDSP available, it certainly made my life a bit easier.
With regards to the game in general and ghost logic it is much more complicated than
first appears it was quite a challenge to write , I think the current logic of my game is a good compromise. keep up the good work one of the reasons I considered writing these games was looking at what you have achieved using BASIC, Interestingly I have a version of Munchy written in C and there is very little difference in speed between the two I think these games spend so much time in the system os_sprite routines that the game logic makes very little difference to the overal speed, of course having much faster hardware does help as well.

@Julie
Damm I knew someone was going to spot that :-) Munchy started off life as a single tasking program
I kind of shoe horned the original version into the multitasking version, in the single tasking version there is a tight loop that controls the game,keyboard input etc. When moving to the desktop you have to release control every frame to get reasonable multitasking. I will have a think about your suggestions if I was writing it as a multitasking application from the start well hindsight is a wonderful thing …

To be honest I am amazed I got to finish these games you definitely suffer from the 90/10 rule the last 10% takes a lot of effort I mean who needs a high score table anyway :-)

munchy multitask seems to work fine on my ARMv7 Pi2, RISC OS 5.28

A feature request: support normal arrow keys and/or joystick? pls?

I get ‘unknown or missing variable’ at line 2990.

I get ‘unknown or missing variable’ at line 2990.

Hi Chris,

A bit more indepth reporting may help Terry , like is this on start up or when does it happen, what system, what OS version etc. :-)

VRPC Adjust RISC OS 4.39. On start up. The BASIC is cruched so I don’t know what it is trying to do.

@Chris
Thats strange you would expect others to have had such a severe error?
No one else has reported this yet?

I have just uploaded a new version of Munchy you can get it from the usual place
www.mbelect.co.uk/RISCOS

I have made a lot of changes so keep your eyes open for errors.

The main changes are :-

You can press F12 at any time to exit back to the desktop even when playing the main game.
I have also reduced the volume of the dying sound.
Added arrow keys as well as the standard keys for movement.
Added joystick control.

When you make any kind of mode change there is a short delay before the game starts to animate
on my Titanium it can take a few seconds to get to full screen and by then your dead :-(

see below for other stuff:-

V 1.00 Initial release
V 1.01 Fixed graphic pointer error in Loadpacmangraphics
added remapping of maze and fruit graphics to
new pointer values on mode change, only an error
if playing a game and then changing screen mode.

Added menu options in main menu for mode
and scale changes.

Game now uses the same main and score procdedures
for both desktop and single tasking
This allows you to move back and forth between
the two without effecting the game

When going to full screen the desktop window is
closed and set to 1:1 this has the effect of
pausing the game an reducing wimp poll

Put pauses in game before mode change or opening
window in desktop. stops you dying :-)

Added arrow keys for direction.

Lowered volume of dying sound.

Added Joystick control

Oh! Thank you! Very nice!

New version works fine on ARMv7 Pi2, with RISC OS 5.28, usbjoystick 0.20 + cheap SNES clone joypad!

It now says USBStick requires USBDriver. On VRPC there is no USBDriver module.

Try
www.mbelect.co.uk/RISCOS/progs/MunchyNJ.zip

I have removed the USB joystick interface.

It now says unknown variable at line 2300.

I have no idea why it does that I am using it on 4 different computers here?

You Could try increasing the wimpslot in the !run but Im just guessing I can’t believe there is a unknown variable as no one else has reported the problem?

Its works on:-
Titanium
Iyonix
Pi2B+
PI400

Im stumped?.

It now says unknown variable at line 2300.

Im stumped?.

I can confirm the fault on OS4.39 RPCEmu with MunchyNJ. The BASIC is StrongBS’d so I can’t get any further. Increasing WimpSlot did not help. (It is OK on OS5.27 RPCEmu.)

If you download again I have placed an uncrunched
version of MunchyNJ so we can find out whats going on.

I have no problem releasing the code I was just making it more readable to the rest of the world:-) before I released it.

Working fine on BeagleBoard -xM, ROS 5.29.

If you download again I have placed an uncrunched version of MunchyNJ so we can find out whats going on.

DIM var LOCAL num on OS4.39 is the problem. Seven of them. Delete the LOCALs and Munchy munches OK.

Thanks for identifying the problem I wonder why its different was DIM LOCAL
added to BASIC later?.

I Can remove them it will just use a bit more memory but as It allocates about 5M
for the graphics when converting to 16M colours I cant see it making much difference.

I make some changes and then upload a new version of MunchyNJ as in my haste I forgot to remove the joystick in the uncrunched version and also update the toolbox resource file.

Thanks again.