Positron5

OK I'll bite. If you are after the Ballblazer playfield effect then a method like the one I used on the atari 8bit would do.. Take a sprite like this one for a space harrier background: harr_playf_1.pcx With the tilt capability of the lynx you could tilt this image through 2 "segments" then switchback to original image. That takes care of horizontal parallax. To simulate forward and backward movement you would need to use line interrupts to animate bands of colour down the screen.?

I would like to report on my attempts to compile @42BS's poly_mmu_68k source from: https://github.com/42Bastian/new_bjl/tree/main/exp/poly_mmu with further advice from Bastian his code needs his modified rmac( that provides option -4) and rln and his latest lyxass that can be obtained from his github repository. The variable BJL_ROOT needs to be declared( see export command) I have to say that I'm a user of cygwin64 under Windows8.1 and this causes an "can't find file or directory" error that breaks the build. If anyone wants to try this I would be interested to hear your results.

pm sent

That's good, it is probably a problem with my tool chain.

As an experiment I tried to compile poly_mmu from the makefile and lyxass2022( also rmac) and I got a load of errors. One such warning was file poly_mmu equ is missing. ??

The clipping concept is good but I think that the blitter triangle way looks the winner.

For anyone that is interested, you can find Bastian's source code from his topic here: New bjl_update: Polygon

That's great, this makes a valuable contribution to the subject. I have had a look and the gpu source for poly_mmu is there -it is the file listed as poly_mmu.js.

@42bs. I will try and have a go at producing some triangles and get to know the blitter instruction set.☺️

Thanks @Cyprian for replying, I searched through the forum and I found this- In it Luigi301 gives a good account of a method of using the blitter etc to create a functional 3d renderer. GPU and blitter looks like the way to go.??

I want to investigate how you would draw a triangle on the jaguar display. Would this be possible by using the scaled bitmapped object and controlling the HSCALE and VSCALE (independently?), xpos and ypos values, similar to @42bs's atari lynx method. Can anyone explain the process? Andrew

I think this thread is great. The technical analysis is really fertile and with coders like BS42, Cubanismo, Cyprian , CyranoJ, Zerosquare, laoo and others the Jag scene looks like some great things are happening. Cheers

Thanks, sometimes a simple technique can be all that's needed to get the right effect.?

Hi @Karri, I'm intrigued- Are you drawing EOR sprites and tricking out the palette??? Andrew

hi Karri, Also, Shakespeare wrote some of his plays to gain favour with royalty like Queen Elizabeth 1.

Just a thought?. You could arrange the palette into 2 * 2bit blocks of a 4 bit color sprite so that both images - the original and one shifted 90degrees- are together in the sprite data. Then you just turn on the relevant palette pens to display either representations. Of course it will only work for 4 color sprites.

Hi, I have solved the problem with creating a working lynxcart of Spacecube/ contacts demo. Basically I was adding two headers to the .o file ?. I include the fixed .lnx file and the amended.cfg and makefile here. Also I have made the changes on bitbucket(see earlier post). Greetings Andrew contact2.zip

Hi Igor, Ideas for the name of this years game jam. Lynxtastic or Lynxtastica. Or on an Abba theme Arrival, Supertrouper,Voulez-vous.... Or even Lynxotica (from exotica). You did ask ??. Cheers Andrew

I made the changes, thanx @42bs. a See http:// https://ANDREW-PROGS@bitbucket.org/ANDREW-PROGS/contacts.git for source. If anyone has noticed a distortion in the shape of the cube, it is because the transformed cooordinates of the cube corners are re -used for the next spacial calculation. Also the sine/cosine table is at a resolution of 8 bits and this contributes to the effect of lossy maths. Cheers.

Maybe because it is quirky it keeps some appeal. I think the weather feature was a nice addition.

Hello Bastian, thank you for the corrections. I will make the changes ?☺. I blame it on my assembler roots.

Hi All, I have made some updates to the spacecube project and I want to share them with you. This demo I've called CubeContact and displays a rotating cube with a simple hidden surface removal technnique. Also the cube coordinate system is much improved giving the possibility of other 3d object design handling. The code is available here: https://ANDREW-PROGS@bitbucket.org/ANDREW-PROGS/contacts.git game.O (will run in handy)

Hi Igor, My package of Raspberry pi programmer and 10 shells arrived today.??? Do have a great new year. Cheers Andrew

XOR A, B AND A, #$0F XOR A, B In this example you keep the bottom nybble in A and replace the top nybble in A with the one from B. This technique is useful because it reduces memory access cycles. I saw it in atextbook about 3o years ago.?

All good. The tool chain I use is cc65 for windows, cygwin64 for win, gimp2, mednafen and a lot of head scratching ???☺