8 replies to this topic

[cd-w]

Hi Folks,

I have now spent a ridiculous amount of time refining my scrolling
maze demo, and I thought it was time to post an update. Apologies for
starting a new thread, but the old one had got a bit off topic. The
new version should be attached to this message, and as usual the full
source code is included.



I have now decided on a game concept, which will be a cross between
Atari Adventure and PacMan (thanks to JoustPong/FlapPing for the
inspiration). Basically, you will control a PacMan-like character who
will wander around the maze, avoiding ghosts (instead of dragons), and
collecting keys to open doors. To kill the ghosts, you will collect
power pills in the usual PacMan way.

The demo attached to this message has the basic PacMan movement, and
scrolling maze stuff working. The ghosts and objects have yet to be
implemented, though some of the basic code is already in place. In
particular, every second screen line is reserved for displaying the
objects/ghosts, which will allow them to be displayed in a different
colour. The code has also been completely overhauled since the last
scrolling maze demo.

Anyway, before I go any further with the coding, I thought I would ask
for a bit of help:

1) Do you think the basic game concept will be interesting enough? Any
suggestions for improvement would be appreciated.

2) Any suggestions for a game name? I need something a bit better
than PacAdv, and that won't generate any lawsuits!

3) My artistic skills are practically non-existent. If anyone can
design a better 6x6 PacMan sprite, then I would be very grateful.

4) The kernel is about as tight as I can make it, but there are not
quite enough cycles to set the border colour to black on every line.
Any suggestions for improvements to the DRAWOBJ and DRAWPAC macros
at the beginning of the code would be welcome. Also, any other
suggestions for code improvements will be welcome.

Well, that is all for now. As usual, feel free to take the code and
use it in your own projects.

Chris

Attached Files

•  pacadv.zip   16.03K   103 downloads

[vdub_bobby]

Looks pretty fantastic right now. Thumbs up!

[cd-w]

Hi Folks,

I have attached a new version of my Pac Adventure demo to this message. The maze now contains objects, some of which can be collected (see screenshot). All that really remains now is to get the ghosts moving around the maze, and add some polish.



The demo works well in both Stella and Z26, and displays a constant 60fps/262 lines. However, for some reason the graphics are garbled when I try it on real hardware with my supercharger. Does anyone know why this might be the case? The source code is included in the ZIP file.

Many thanks,
Chris

Attached Files

•  pacadv02.zip   20.04K   87 downloads

[Thomas Jentzsch]

I like the idea of a scrolling maze, but I think the resolution is a bit too low. You almost have no idea about what is happening in front of you.

Some suggestions:
1. higher resoulution (~2x)
2. position Pac Man closer to the opposite side of the current movement direction
3. a radar screen

[cd-w]

Thomas Jentzsch said:

I like the idea of a scrolling maze, but I think the resolution is a bit too low. You almost have no idea about what is happening in front of you.

Some suggestions:
1. higher resoulution (~2x)
2. position Pac Man closer to the opposite side of the current movement direction
3. a radar screen

I agree that the resolution is a little low, but I don't think I have the space cycles for any of these suggestions. As I see it, the only feasible options are:
1 - reduce the speed to give more reaction time
2 - play a sound when a ghost is nearby to warn the player
3 - redesign to use sprites instead of a purely PF-based approach

Chris

[Thomas Jentzsch]

cd-w said:

I agree that the resolution is a little low, but I don't think I have the space cycles for any of these suggestions.

I haven't looked at the code yet. Where exactly is the problem?

[Thomas Jentzsch]

Ok, I could not resist and had a look at the code now.

You are alternating between Pac-Man and object lines. Each of those lines is created from scratch. Maybe you could save some results for the next repeated lines? Of course, this would break you nice and clean code.

But it probably would be MUCH easier if you just draw Pac-Man by using a sprite.

[cd-w]

Thomas Jentzsch said:

I haven't looked at the code yet. Where exactly is the problem?

To elaborate, the problems are as follows:
1) Higher resoulution: the 6x6 pacman character is generated using the PF, so the size can't really be reduced without making it unrecognisable (e.g. 4x4).
2) Position Pac Man closer to the opposite side of the current movement direction: The yellow colour of the PacMan character is accomplished by changing COLUPF at exactly the right time in the kernel. If we move the
character to the left or right then the timings will get very complex!
3) A Radar Screen: not enough spare cycles to display this (only 10 free cycles over 8 scanlines).
All of these problems could be solved by moving over to a prite-based approach, but that would essentially mean starting again from scratch ...

Thomas Jentzsch said:

... but it probably would be MUCH easier if you just draw Pac-Man by using a sprite.

My original idea was to create a game that had much larger characters than could be accomplished using the regular sprite hardware. Also, I wanted to see how far the PF hardware could be strecthed. However, I can see now that this isn't such a great after all! I think I might abandon this first game attempt and start on something a bit different using real sprites ...

Thanks for the feedback.

Chris

[Thomas Jentzsch]

cd-w said:

[My original idea was to create a game that had much larger characters than could be accomplished using the regular sprite hardware.

By using a quad sized sprite, your Pac-Man will still have the same size as now.