Commander X16

 

There is one thing that bothered me just a bit about sprites in this demo: selecting the RAM window for the image sort-of requires a VPOKE to *TWO* addresses.  Here's why.

A 256 color 64x64 sprite takes up 2K RAM.  So a list of them starting at $04000 would be at these nice even addresses:

$4000

$5000

$6000

$7000

... and so on.

But, the way the sprite window is split between two memory registers, you'd have to VPOKE to two addresses to do this.

So for the demo, I aligned these images on $2000 byte boundaries:

$4000

$6000

$8000

$A000

$C000

Leaving 2K gaps between each.

It's not a major big deal, but every little odd corner adds up.

As for the sprites themselves, I think they look just a little too jaggy.  I have a set of greyscale images that I'll try next.

...yes, greyscale looks a bit better, but perhaps the jaggies are mainly from the "flashier" ships like the Genoese Galley and the Xebec.

 

Now the greyscale looks like it's constrainable into a 4 bit scheme, which means these sprite images could shrink from 4K down to 2K, which would be nice.

 

SHIPS-BW.PRG

Updated the demo.

* removed user control; ship wanders aimlessly

* added 7 more ships

* added some mild flocking behavior in the additional ships

1 hour ago, Fenner Machine said:

Is this correct?

A 64x64 sprite at 8 bits per pixel (256 colour) would take 4K RAM?

Or am I missing something?

You're right.  It's my brain.