Congo Bongo POC

[+splendidnut]

So... over the summer I rewrote my Congo Bongo POC/demo in C.  This was done to help with testing out the C-like language/compiler I'm working on.  Also, I'm hoping this will help with handling the two (or more) planned ports of the game (2600 and 7800).

 

So far, I've got:

-- The player in full color - He can move around, jump, and climb.  Movement is still a bit rough as it doesn't compensate properly for the "diagonals".  And there are a couple of quirks with jumping.  So still a bit rough, probably even a bit more rough than before in the previous POC releases.

-- The monkey in full color - I copied the code from my 7800 demo and rewrote it in C.  The monkey has a simple path he follows.  He moves between grid spots, pausing after each move, and jumps up/down when necessary.... The jumping is still quite rough, but it suffices for now.

-- The coconut - Just bounces up and down... This is something I've just started working on.  Just ignore the tail...

-- Bongo... well, some of his data is in the ROM, but there's no code for him yet.

The cool thing is this demo is currently clocking in around 3k of code/data.  Which leads me to believe I might be able to end up with a playable one-level demo that fits within 4k.   But, that all depends on how much more game logic is needed, and what kind of craziness the drawing kernel will turn into.

At this point, I haven't gone thru the trouble of figuring out exactly how I want to do the kernel to get multiple sprites on the screen.  I am currently using a 2 line, doDraw-based kernel.  I'm basically out of cycles (save for a single NOP), but was able to have the 4pf colored background (single line) with 2 full color sprites (double line) and a missile (for the coconut(s)).

 

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For me this demo serves as a POC.  Being able to see the player in multi-color on the alternating line-color background gives me confidence that this is worth doing.  With the previous POCs, I was a little worried that it wasn't going to look good enough.  Now, the only thing I'm worried about is how well flickering sprites will look.  I've got an idea of how to display a decent looking Bongo, but it involves flicker, so we'll have to wait and see how that looks.

 

------

 

So, with all that said, here are the ROMs for NTSC, PAL50, and PAL60.

 

For NTSC, I chose the colors specifically to somewhat match those I've already chosen for the 7800 version.

 

For PAL, I've provided both PAL50 and PAL60.  I've chosen different palettes for each of those, with the PAL60 being the one trying to match NTSC.  My Stella settings for PAL are a bit out of whack, so let me know if I've made some grave error in color selection.  I know PAL might be somewhat of a pain to get right, since I don't have access to PAL hardware.

Anyways,  Enjoy!

 

congo_20210909_NTSC.bin

congo_20210909_PAL50.bin

congo_20210909_PAL60.bin

 

=============================================

 

Latest (as of April 30, 2022):

congo_20220430_NTSC.bin

congo_20220430_PAL60.bin

congo_20220430_PAL50.bin

 

congo_20211112_NTSC.bin congo_20211112_PAL50.bin congo_20211112_PAL60.bin

[+atari2600land]

Looks great so far!

I became stuck here:

[Bomberman94]

I played the PAL60 version: graphics looks strange regarding colors (miscolored) but movement of man feels already „natural“ (movement, jumps, climbing and diagonal going…). I made it to the top but often get stuck on the right, too. Man appears a bit too big/high but looks good in general (arcade man has a thicker belly and a red nose ?). The „older“ interlaced PAL60 screens looked better (I know you’re working on this or better say: decide what mechanism you choose for it). 

Edited September 19, 2021 by Bomberman94

[+splendidnut]

Here's an update.  This has been sitting around on my computer for a bit as I got a bit bogged down with compiler changes while working on it.

 

If I remember correctly:

 

  - I did quite a bit of rework on the player logic, so that should be relatively bug free.

 

  - The drawing kernel has been split into two (as can be seen by the background color change).  It will probably be split a couple of more times (1) to handle Bongo at the top, (2) give at least one or two more zones in preparation for handling more sprites.

 

  - Some more work has been done on the coconut logic.  It now bounces down the steps, and attempts to bounce towards the player a bit (if on the steps).  Still needs quite a bit of work though.

 

So gameplay wise, not much, but something 

 

Enjoy.

 

congo_20211112_NTSC.bin

congo_20211112_PAL60.bin

congo_20211112_PAL50.bin

 

 

I've also played around with the colors a bit (first image is the new version).  I found that the original colors (second image) were too red on an actual CRT.

[+splendidnut]

As for getting stuck:  If you've fallen off the waterfall on the right side, currently there is a way to walk back around to the starting area.  It's a little tricky due to the background graphics being a bit deceptive around that waterfall.  When the game is playable, it will become a non-issue as the player will die if he falls off the cliff.

[SearsRoebuck]

Looks great! I was going to hold out more for the 7800 version, but I also like homebrews for the 2600 where the limits of its hardware are pushed. I might get both versions. 

[KevKelley]

This looks wonderful. I always thought it was an interesting game. I never really played the arcade but this is very ambitious and impressive.

[alfredtdk]

Impressive to be just a 4kb alpha demo, I think there will be an expansion beyond that. Will it use DPC+ features?

[Bomberman94]

Plays and feels really good - man might be a bit smaller for my taste. Please make the „interlaced“ graphics available (again) and please make this game come true ?

[+splendidnut]

Before I post an update, I'll address a couple of things mentioned above:

 

On 11/16/2021 at 11:05 PM, alfredtdk said:

Impressive to be just a 4kb alpha demo, I think there will be an expansion beyond that. Will it use DPC+ features?

 

On 11/22/2021 at 4:00 PM, Bomberman94 said:

Plays and feels really good - man might be a bit smaller for my taste. Please make the „interlaced“ graphics available (again) and please make this game come true ?

 

Thanks!

 

I was hoping to be able to have a 4k playable version of level 1... but after making the necessary changes for the next update, I've run out of room.... so using bank-switching is now a necessity.  Currently the Graphics data fits in 1K and the display kernel is around 0.75k.  The other 2.25k is game logic, mainly character movement (player, monkeys, coconuts).  The code to handle player movement is just over 0.5k.

 

I'm currently debating which scheme to use.  As of right now:

 

 - E7 (M-Network) could be used... but, I have a feeling that I would need to split up the display kernel to run across separate banks.... because, after the everything I had to do to add the updates, I'm afraid it might grow beyond 1k of code... and with the need of +1k of graphics to go with it, would not fit within a single 2k bank of E7.

 

 - The typical Atari schemes (F8,F4,F0)... would work nicely, but I would probably end up going with the 32k scheme (16k probably wouldn't be enough given the current situation I'm in)

 

 - DPC+ is probably overkill being as the kernel works very nicely now and doesn't even need extra RAM.  But at the same time, it would make it easy to fix some of the current display kernel issues.... Probably the biggest benefit would be the ability to have single-line sprites instead of double-line sprites.. would definitely help with making the explorer guy a more reasonable size.  BUT, I think with the alternating line kernel, might not work out too well.    Though, it might make it easier to have the "alternating line/alternating frame blending" feature that @Bomberman94 wants back.

 

If I were to go down the DPC+ route, I would probably make up my own bank-switching scheme instead...  something that would help alleviate the sprite switching situation (ChaoticGrill would greatly benefit from this), and also make it easier to load things into the Display Data RAM from the 6507.

 

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The other thing I'm debating is whether I continue using my Neolithic "C" compiler or take the assembly code that's been generated and just work towards finishing the game in assembly.  At this point, one of the harder things, "the player movement logic", is probably done or very close to being done.  The jumping and the platform following are all working great and they were the harder things to get working right (I'm in the middle of copying that code into the 7800 version).  The big issue with the compiler is that it still needs quite a bit of work... it currently doesn't support banking or relocating code... and there's a couple of bugs that caught me off guard this morning.  Other than that, it's been a great tool... and made prototyping Bongo relatively easy.

 

[+splendidnut]

Anyways... time for an update:

 

+  Added Bongo to the top of the screen.

-  Sound effects had to be removed to make room... boooo.

-  Coconut is now broken.  Wait, what?

+  But, there's now two monkeys, following a path.... ok....

 

Wait, what kind of update is this?  Two things added, two things broken removed... jeez. 

 

The 4k is now full... there might be a free byte or two here and there.... but pretty much full.

 

Enjoy!

 

congo_20220430_NTSC.bin

 

congo_20220430_PAL60.bin

 

congo_20220430_PAL50.bin

 

 

And the Bongo prototype:

bongo_test.bin

 

And might as well post a screenshot:

 

[Bomberman94]

On 4/30/2022 at 8:28 PM, splendidnut said:

Anyways... time for an update:

 

+  Added Bongo to the top of the screen.

-  Sound effects had to be removed to make room... boooo.

-  Coconut is now broken.  Wait, what?

+  But, there's now two monkeys, following a path.... ok....

 

Wait, what kind of update is this?  Two things added, two things broken removed... jeez. 

 

The 4k is now full... there might be a free byte or two here and there.... but pretty much full.

 

Enjoy!

 

congo_20220430_NTSC.bin 4 kB · 55 downloads

 

congo_20220430_PAL60.bin 4 kB · 15 downloads

 

congo_20220430_PAL50.bin 4 kB · 11 downloads

 

 

And the Bongo prototype:

bongo_test.bin 4 kB · 18 downloads

 

And might as well post a screenshot:

 

I really like your Bongo - nice Face expression (the belly is a bit „empty“ but personally I can’t say how to make it better ?). The bongo_test.bin gives only a square with Bongo on top right (I have PAL console)?

 

I‘m very excited to see more - I have the feeling that our Atari‘s will get the Congo Bongo they deserve ☺️