Catgirls Carrot Kingdom™ - Work in Progress 32K! - New Demo 10-16-2017

[OmegaPrime]

Thomas is correct this is quite easy in assembly

  ldx _JumpAccent
  beq +
  dec _JumpAccent
  lda _Joystick
  and #JoyStickPressedUp    ;adjust for atari 2600
  bne ++
  ldx #0
+:
  stx _JumpAccent
  lda #32                   ;adjust gravity as needed
  clc
  adc _ObjYVelocityL
  sta _ObjYVelocityL
  txa
  adc _ObjYVelcoityH
  sta _ObjYVelocityH
  bmi ++
  cmp #SomeLimit            ;Adjust as needed
  bcc ++
  stx _ObjYVelocityL
  lda #SomeLimit
  sta _ObjYVelocityH
++:
  rts

Good job on the game

Edited June 7, 2016 by OmegaPrime

[+SpiceWare]

Agree, the jumping is definitely "floaty". Had the same issue with early builds of Stay Frosty. I can send you the source to see how to implement gravity.

[Thomas Jentzsch]

If the math is too complicated, a precalculated table will do too.

[Jinroh]

Thanks for the feedback guys, the original jumping was by design due to my preference, but I coded up a more weighty implementation a little bit ago. I should be able to get it in the codebase later today and see how I like it.

[Paul Slocum]

The game looks cool. I use tables since it allows me to tune the physics in detail. Also worth considering running inertia. I think that perfectly tuned inertia, gravity, and jumping "physics" are a big part of what makes Super Mario the best series of platformers ever.

Edited June 7, 2016 by Paul Slocum

[Jinroh]

Thanks Paul, glad you're liking it.

 

Great suggestion, I agree. I'm hurting for 'RAM' as it is, so I dunno if I'll be able to squeeze that in after the few other things I need to squeeze in, but I'll keep it in mind if I can.

[+darryl1970]

Coming along well. If you like the jump, stick with your vision.

 

I really like the hearts for energy. Nice touch. birds are more forgiving too. I know cycles must to be getting tight with all you have going on in your kernel, since you're choosing to not use any help from dcp.

 

Impressive for a raw 2600 game.

[gauauu]

Thanks for the feedback guys, the original jumping was by design due to my preference,

 

 

If you like the jump, stick with your vision.

 

I concur. It's your game, make it work the way you want

[Iwantgames:)]

Hmm...yeah that's odd.

 

Here's a video recording with Stella 4.0, you should be able to make it all the way to the Bread Cat. We'll have to see what's going on for you guys.

 

https://youtu.be/Bplw2m74NPk

I played on a emulator on my phone. I'll have to get Stella 4.0 on PC so I can play the rest

[Jinroh]

Ah great I hope you enjoy it! :3

 

I'll have to try my phone emu too, though the only 'non-standard' thing it uses is F6 Bankswitching, so kinda strange it doesn't agree with it.

 

Tweaked the gravity and now I think it's a happy compromise for all of us.

 

Update, Tweaked Demo.

 

Edited July 16, 2016 by Jinroh

[Iwantgames:)]

Idk why the first demo didn't like my phone emulator, this new demo works fine. I made it to the bread cat and died

 

Awesome game, hard to believe the ol' 2600 could pull this off. Great job!!!

[Jinroh]

Awesome! Glad you enjoyed it!

 

I've been playing this evening too. Really tough to beat the bread cat, but satisfying when you do it!

 

Started on designing the next level as well. ^^

Edited June 8, 2016 by Jinroh

[Iwantgames:)]

WAHOO!!! I BEAT THE BREAD CAT!!!!!!

 

I did notice one thing, if I run backwards away from the flying enemy until I hit the left side of the screen the enemy disappears when it reaches me without inflicting any damage.

[Jinroh]

Right on man, congrats! He's a tough cat.

 

Oh thanks, I'll check out the bat disappearing before inflicting damage.

He's a tough cat.

[CrazyChris]

Thanks man, I was trying to channel early 80s arcade feel when I re-booted the title screen.

 

I really like it, also kinda looks like a Christmas sweater design.

How about an AtariAge Christmas sweater?

 

Kidding aside, love the demo!

[Jinroh]

Haha, maybe that'll be the pack-in with the special edition Carrot Kingdom™. A nice Christmas Sweater. xD

Edited July 29, 2018 by Jinroh

[TheHoboInYourRoom]

Um... the demo is almost unplayably jittery. The framerate is not stable at all. Every screen transition jumps to a new number of scanlines. The picture jitters everytime the screen scrolls, very slightly when the fireball in the castle flies up, and also very slightly whenever Jinny's shots are on screen. Using the scanline counter in Stella, I see the demo never settles on 262 lines per frame. All of this also happens on real hardware.

[+darryl1970]

Um... the demo is almost unplayably jittery. The framerate is not stable at all. Every screen transition jumps to a new number of scanlines. The picture jitters everytime the screen scrolls, very slightly when the fireball in the castle flies up, and also very slightly whenever Jinny's shots are on screen. Using the scanline counter in Stella, I see the demo never settles on 262 lines per frame. All of this also happens on real hardware.

I never really noticed any major imperfection that made it unplayable, but you seem to have experience with counting scanline and the Stella debugger.

Did you post this because you have a suggestion to fix these things you have noticed?

I thought it was a pretty decent homebrew for being pure VCS.

[TheHoboInYourRoom]

Did you post this because you have a suggestion to fix these things you have noticed?

No, I don't. I'm not very skilled at programming the VCS, plus Jinroh is the only one who has access to the source code. I'm just bringing the framerate issues (which are quite hard on the eyes) to his attention.

[Jinroh]

Thanks for bringing this up THIYR, because I have honestly not had this problem on hardware or emulation.

 

Do you have a video or something, I'm curious. In Stella 4.5+ during scrolling and stationary scenes I get an unmoving 250 lines.

[+SpiceWare]

Thanks for bringing this up THIYR, because I have honestly not had this problem on hardware or emulation.

 

Do you have a video or something, I'm curious. In Stella 4.5+ during scrolling and stationary scenes I get an unmoving 250 lines.

You need to be running the current version of Stella (or at least 4.7.1), I added screen jitter/roll emulation to it as documented in these three blog posts: Overscan Jitter, Overscan Jitter 2, DPC+ Jitter, and Jitter 3, Recovery Time.

 

The CARROT KINGDOM screen is 280 scanlines:

 

The ENTERING CASTLE screen is 279 scanlines - this small change in count can cause minor jitter:

 

The game screen is 250 scanlines - this drastic change in count causes the screen to roll:

 

When I get to here in Stella the scanline count starts to rapidly change, causing screen jitter:

 

On my real Atari this is the point the game crashes and resets back to the CARROT KINGDOM screen. You can see that, and the screen roll/jitter, in this video:

IMG_7344.m4v.zip

 

To fix the jitter/roll problems you need to make it so every screen is 262 scanlines. That crash is going to be hard to track down and fix. Most likely it's hitting a BRK instruction, I had that occur in Medieval Mayhem.

[Jinroh]

Oh wow, thanks so much Spiceware. I appreciate the info, I'm going to look into.

[+SpiceWare]

To see that scanline count in Stella hit COMMAND-L (on Mac) or ALT-L (on Linux or Windows).

[Jinroh]

Thanks Spiceware. Should be an easy enough fix.

[+Propane13]

One other piece of advice-- after fixing the screens, I'd suggest going back over your code to check to make sure the screen size is holding between different screen transitions (i.e. character falls to next screen). When developing Mean Santa, I had my "did we complete the objectives on Screen One" check way down in the logic. It was so far down that I had done all of the previous logic, then had the check, and then started working on the new screen logic. This took my calculations over the VBLANK period. It was a simple fix of moving this check further up. I'd highly suggest testing these edge cases as well, as they can cause the screen to roll between scenes. You may even need to have a "black static screen" for 1/60 of a second, just to keep things steady.

 

-John