Wednesday, 19 July 2017

IIGS Take 2

The experimental work I'd done on the IIGS port prior to starting on the port proper has certainly paid off; as of tonight it's rendering the characters, lives, copyright, asteroids and player ship (and the latter only when it should be). I should note that I'm yet to generate or code for the bit-shifted graphics.

It may look no different to the previous version, but the display list is greatly simplified - effectively tokenised - and all the dead code has been removed from the 6502 core, giving me more headroom on the IIGS. And I've still got a little more optimisation to do in my rendering routines.

IIGS Asteroids Take 2 - optimal display list

When I next get the chance I'll continue with the saucer, the shots and the shrapnel which should be as straightforward as the other objects have been until now.  That'll just leave the exploding ship, which I am yet to work on at all.

I think that'll be a good point to research reading the IIGS keyboard; I've been encouraged by reading vague suggestions that it's possible to read the IIGS keyboard directly from the ADB. If that pans out I'll be able to make the game playable, if slow.

Then it'll be time to work on the bit-shifted graphics and erase logic (right now it's clearing the entire screen every frame). That should bring the game back up to speed and I'm hoping it'll actually then be too fast!

I'll be happy if I get to this point by the weekend for WOzFest Slot 7!

Beyond that, there'll be the addition of the exploding ship, sound (samples), support for variable beam brightness, and spit & polish and bells & whistles, such as a title screen, joystick/paddle support etc etc.

1 comment:

  1. I see quite a difference between the two games, the latter one had a bit of displaced graphics while this more advanced version looks more proper and graphically clear. Cant wait to try this one as well. Bravo for the efforts.