[WIP] Moon Patrol conversion

[PascalDe73]

Originally Posted by jotd

I thought again about dual playfield and I think I can pull this off by using it for blue mountains & ground strip, with different scroll values (they never are on the same Y, it's close but still separated), allowing to NOT blit them (a bit like JoeJoe did with Frogger).

If I can get enough colors / hack them (this is one of the main issues for not using DPF) then I can reduce the number of blits drastically, restore the blue mountains for slow machines and enhance other layers, even go 50Hz, reducing the compromises a lot.

Hi JOTD,

I test Your latest version.

On my A1200 all works correctly

on my A500 Rev.6A (Agnus 6372A) (512+512k) not enough memory to start (Error 103)

On my A500 Rev 6A(Agnus 8372A) (512K+512K) equipped with an ACA500Plus :

On Standard A500 Menu KS 1.3 + 1.0M Chip (emulated from Agnus 8372A), Your ADF works correctly with a nice picture)

But under WB 3.1.4.1 and under WHDLoad I have the same problem about a bad picture (as You can see in my video Youtube Posted Yesturday).

[ Show youtube player ]

[jotd]

that looks like program is believing that AGA is set...

thanks for testing.

[Cimmerian]

Plays great on aga,appreciate the work you've done Jotd,thank you

[tomcat666]

Working perfectly fine and VERY smooth (as buttah) on A1200 with pistorm32

[Marconelly]

Originally Posted by jotd

I thought again about dual playfield and I think I can pull this off by using it for blue mountains & ground strip, with different scroll values (they never are on the same Y, it's close but still separated), allowing to NOT blit them (a bit like JoeJoe did with Frogger).

If I can get enough colors / hack them (this is one of the main issues for not using DPF) then I can reduce the number of blits drastically, restore the blue mountains for slow machines and enhance other layers, even go 50Hz, reducing the compromises a lot.

Thank you so much for all the effort you're putting into this. Reading your posts, it sounds like a lot of the time these ports are like a puzzle to be solved. Sometimes it can feel like you found the ideal mix of solutions and parameters, but it's still not working quite right. I know all too well how frustrating that can be. I'd say do what you feel is fun and don't stress over it. For the colors in the DPF mode, to me it seems that even if you use just one color for the mountains and one for the road - if that lets you achieve 50Hz, that's still better than more colors at 25Hz, or not having one mountain layer at all.

[jotd]

Tried many things tonight, and all failed

- using CIA interrupt => fail, unexpected crashes. The game is enabling interrupts within the interrupt (to wait for tick or something). This is stupid but removing that locks up. And works from vblank. But not from copper screen or CIA...

- reducing to 8 colors for green mountain + bobs: just too hard, too many colors, even with sprite overbooking.

So I think that this will remain as is for 68000/ECS. AGA version could have 50 fps full without blitting with 16+16 colors. Maybe I'll do it, but not now. Will try to fix the remaining bugs and will move on for now

[Don_Adan]

Are You using $78 vector or ciab.resource? I never have problems with high priority timer interrupts. Of course used by me for Amiga music players only.

[jotd]

hooking on $78 vector. It should work, copper screen interrupt should work too, but the game irq requires borderline stuff. Not investigating further.

@PascalDe73: bad night but I think I fixed the corrupt display on ECS for you check new version.

[Bren McGuire]

jotd sir you are unstoppable

[lmimmfn]

Originally Posted by jotd

Tried many things tonight, and all failed

- using CIA interrupt => fail, unexpected crashes. The game is enabling interrupts within the interrupt (to wait for tick or something). This is stupid but removing that locks up. And works from vblank. But not from copper screen or CIA...

- reducing to 8 colors for green mountain + bobs: just too hard, too many colors, even with sprite overbooking.

So I think that this will remain as is for 68000/ECS. AGA version could have 50 fps full without blitting with 16+16 colors. Maybe I'll do it, but not now. Will try to fix the remaining bugs and will move on for now

Tbh I think you're trying too hard with trying to have both the OCS/ECS and AGA versions. Pick one(the easiest one) finish it as best you can and come back whenever with the other version.

[jotd]

yeah, I thought it was possible but there was always something to contradict my hypotheses.

ECS version is okay (could not make it 512K either, other than removing the sfx+music which I'm not going to do...), I'm starting a full fledged AGA version which should run 50Hz even on bare A1200, with all layers, and moon city (which was missing from the ECS version due to lack of colors).

I'll create a startup shell for the floppy version to select the best version for the current machine.

[acidbottle]

A dedicated 50Hz AGA version is awesome, great job on this port so far.

I hope this shows that despite how incredibly simple and ancient these games may appear, it is still a very huge challenge, even for expert coders, squeezing everything into an OCS machine, even with ram upgrades.

[jotd]

I'd love that someone proves me wrong. I'm not an expert coder, but I'm doing the bare minimum of blits, with assembly, so it's probably very close to what a wizard coder could do, unless the color constraints are discarded (merging colors which would be a problem on this colorful game, but AGA dual playfield will do the job).

[DanyPPC]

You make a great job, not all coders today use assembler.

Your games are arcade perfect !

[zzbylu]

A wonderful conversion!
[ Show youtube player ]

[tomcat666]

Originally Posted by zzbylu

A wonderful conversion!
[ Show youtube player ]

What's with the rasterbars in the "border" ? Don't get those here ....

[jotd]

It's supposed to be hidden (ECS/AGA have BORDERBLANK) except that I can't seem to make it work with ECS.

If someone has a clue...

Working on AGA version right now. I expect 1:1 pixel perfect or almost with all layers. Time to work on the hardware scrolling.

[vulture]

@jotd

Not a coder, just a quick question tho, are the green and blue mountains both true intersecting parallax layers? I was thinking maybe the green ones could be done as sliced parallax (which, I believe, is cheaper), ditto for blue mountains if they're placed a bit higher or their details overlapping the green mountains are erased.
Again, not a coder, don't know if it's possible or if it helps at all, just an idea.

[PascalDe73]

Originally Posted by jotd

@PascalDe73: bad night but I think I fixed the corrupt display on ECS for you check new version.

Hi JOTD,

Sorry for Your Bad night...

But You are a GENIUS.... It full works NOW on my A500 ACA500PLUS under WHDLoad version... and with Full both Montains (Green & Blue)

Many thanks for that... and the time to resolve that problem.

Your latest ADF version was tested too without any problems IN MY A500ACA500Plus In mode emulation 1MB CHIP (ECS 1MB)

On my A1200 all works too (ADF & WHDLoad).

Best Regards,

Pascal

[jotd]

Originally Posted by vulture

@jotd

Not a coder, just a quick question tho, are the green and blue mountains both true intersecting parallax layers? I was thinking maybe the green ones could be done as sliced parallax (which, I believe, is cheaper), ditto for blue mountains if they're placed a bit higher or their details overlapping the green mountains are erased.
Again, not a coder, don't know if it's possible or if it helps at all, just an idea.

The blue & green mountains Y position varies depending on levels. I have used tricks to avoid erasing top of green because blue is already erasing. Also blue uses 2 bitplanes, and green uses 3, so blitting is (I think) minimal. But green has to use mask to preserve blue.



When the colors become uniformly blue/green I'm changing color 0 to avoid filling the screen... Much faster.



AGA changes that: blue mountain can be in 1 playfield, hardware scrolled, and green mountain is blitted in another playfield, no need to mask, just brutal blit. And moon city will probably be possible (it has more colors).


Ground strip will benefit from hardware scrolling too.