My game development thread

[Mr_Navigator]

Hmmn I seem to remember coding a a graphical program with a whole load of lines (of say 250 to 1210) that were in a repeat - loop and doing all the algorithm changes so that line 1200 would switch the cross hair graphic off and the next line 1210 (containing the new position of the graphic) would switch it back on. With no calculations going in the switch I thought this would be smooth flicker free changing as quickly as much as possible, however the result was far from it and more like you describe. The other thing I was doing was EXORing to the screen and this done at speed is what I believe was causing the disappearing act. Sadly, you don't have a programming solution to overcome only its execution.

[RWAP]

Did you try Slowgold - an old Dilwyn Jones Computing title - http://www.dilwyn.me.uk/utils/slowgold.zip

[vanpeebles]

Yes It was strange as making it slower, actually made it worse and in some cases the pointer vanished completely. It does seem like a weird refresh issue.

[dilwyn]

Does your set up have access to the second screen (i.e. Minerva ROM)? that may be a possible problem, perhaps it could be switched off.

It could be original programming taking in to account the one speed of the QL and that speeding the process up meant the graphic routines couldn't keep up the refresh rates.

That's a possibility. Of course if the program is drawing its own cursor off and on (rather than the normal system cursor), it's possible that the drawing and undrawing happens within the same frame - if the system is fast enough - so that it ends up not being seen, or being seen for a while and missed in some frames.

Would be interesting to see if it behaves differently on original QL speed, or whether this just happens onfaster systems like Gold Card. If the program was written in SuperBASIC, you could try putting a delay in the keyboard read/cursor drawing routine, something like LET a$=INKEY$(1) (the 1 could be a slightly larger value, experiment a little) so that the small delay causes less flicker.

Whereas Slowgold uses interrupts to slow down a program, SLUG on a Gold Cardworks IIRC by introducing a delay in the keyboard reads, so the program tends to speed up when not reading the keyboard, although in a game for example you would pretty well always be checking the keyboard for user input anyway, so you may not notice the speedup effect when playing a game.

Dilwyn

[vanpeebles]

Well after much thought and pondering I think I've got my gameplay mechanics and puzzles sorted. I can see how it's going to play out as a game and also fit into a text adventure. I maybe need to think up a few more bits but it's starting to take shape. Next step is planning my rooms and all details.

[dilwyn]

Well after much thought and pondering I think I've got my gameplay mechanics and puzzles sorted. I can see how it's going to play out as a game and also fit into a text adventure. I maybe need to think up a few more bits but it's starting to take shape. Next step is planning my rooms and all details.

Look forward to seeing the finished game, you've obviously put a lot of time and effort into this!

Dilwyn

[Mr_Navigator]

There are several prograns - probably the best is bmp2pic by Phoebus Dokos (that is what we used for QWord) - it only converts from BMP files, but that should do!.

Having downloaded the QL Service Manual, it is two parts, text and pictures in PIC format (from Dilwyn's site), so what I would like to do is look at the images, however PhotoShop doesn't recognise the extension. Does anyone know a way to convert from QL PIC to something that can be displayed in PhotoShop?

[twellys]

Have you tried wunpic (From Dilwyn's site)?

Cheers,

Tim

[dilwyn]

There are several prograns - probably the best is bmp2pic by Phoebus Dokos (that is what we used for QWord) - it only converts from BMP files, but that should do!.

Having downloaded the QL Service Manual, it is two parts, text and pictures in PIC format (from Dilwyn's site), so what I would like to do is look at the images, however PhotoShop doesn't recognise the extension. Does anyone know a way to convert from QL PIC to something that can be displayed in PhotoShop?

Try the BMP program from my website's graphics page at http://www.dilwyn.me.uk/graphics/index.html - it runs on QL and can convert QL screens, QL PIC files, QL PSA files to Windows BMP format, which should be viewable (albeit large files) in most programs on the PC at least (don't know about Macs).

Dilwyn

[vanpeebles]

What other QL art programs are recommended? ACT can make live screen grabs from other QL programs so it would be possible to draw the graphics in something else and screen grab. The graphic style of the game willl be line drawn with perspective so maybe some kind of CAD/Vector program instead of bitmap?