Trying to animate my title screen

[8bitPoet]

Hi all!

 

For the past week, I've been teaching myself batari Basic while creating my first game as a programmer. The online documentation has been absolutely invaluable. (Thanks @Random Terrain!)

 

After making a playable game, I thought I'd spend some time adding a bit of polish. I added sounds and a game over screen, but what it needs is a killer title screen!

 

Searching the AA forums, I discovered the bB Title Screen Kernel. EXACTLY WHAT I WAS LOOKING FOR! (Thanks @RevEng!) I downloaded it and consumed the accompanying PDF documentation and examples.

 

Then I followed the examples to generate my future killer title screen. I created the image assets, turned them into data using the recommended Image to Code utility, copied and edited the required files, and added the code to my game.

Compile -> Launch

LOOK! A title screen. But not a killer title screen. My animation isn't working.

 

Where's the bouncing spider? I made the image source file per the instructions. 

I even made this snazzy animated GIF for reference.

 

I'm currently trying to track down the issue. I created a test .bas that strips out every non-essential to eliminate any possible conflict, and it still doesn't animate.

 

So I'm gonna post the working files here, in hopes that someone can explain what I've done wrong.

TSK-anim-test.zip

 

 

 

[+Random Terrain]

You might end up needing to send RevEng a PM if he is too busy at the moment to keep an eye on this forum.

[glurk]

I don't know anything about bBASIC, (I'm a hardcore ASM guy) but I will say that it looks like you are wasting a large amount of ROM space with your animation frames.  All of the static stuff in the top part of the image frames should not be there, the animation frames should consist of only the areas that change (spider at bottom) to save space.

 

I saw in your other thread that it has a height of 56?  Looks like that could be reduced by half, at least...

 

[8bitPoet]

7 hours ago, glurk said:

All of the static stuff in the top part of the image frames should not be there, the animation frames should consist of only the areas that change (spider at bottom) to save space.

 

Hey @glurk! Yes, there are a lot of static pixels in that sprite.
 

Originally, I had the spider and web separate from the text, but that rendered with a gap of about 5 scanlines between them. 

 

I could probably half the ROM usage by redesigning that section to use the 48x2 mini kernel. (It draws 2 scanlines for every 1 line of data.)

 

[8bitPoet]

SOLVED!

 

I figured out what I did wrong. Turns out that the variable for tracking the animated sprite position has a specific naming convention and can't be changed.

 

I modified the variable name to _bmp_48x1_2_image to match the format of all of my other variables, but that leading underscore breaks the animation code in the kernel.