LN sprite clipping

While trying to collect unused bytes here and there in the LN2 disassembled source, I figured out an optimization that shortens the code and makes one of two lookup tables unnecessary. If I were able to consolidate all the unused fragments before $2000 (where the bitmap starts) I would probably be able to gain a 512 byte slot for some additional code. In there I would move a few routines so that I could extend the sprite clipping routine to work 100% of the times.

The sprite clipping problem is quite complex to explain so I will try to put together a few images of where the tricky bit is and why John Twiddy’s simplification saved him big time.
As I commented before, this problem seems to have been solved properly in LN3 (well done Stan!).

About Luigi Di Fraia

I am a Senior DevOps Engineer so I get to work with the latest technologies and open-source software. However, in my private time I enjoy retro-computing.
This entry was posted in Retrocomputing, Technical and tagged , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s