From Richard's C64 blog!
1st May – 26th May 2016
While things have looked very quiet on this project. It doesn’t mean that we are not continuing with the game project. In fact, the hardest part of the game code is practically out of the way. There are 16 alien formation tables set up so far, but there’s still more to go. For the time being I have decided to leave the additional alien group property tables for the time being and focus on trying to get the main game engine repaired.
The aliens were unable to shoot at the time, and I tried to re-install the alien firing. However because I had deleted a lot of the old code (as I assumed it wasn’t necessary) C64Studio processed loads of errors. I looked through the code, and tried to work a way round fixing the error result. Good news is that I managed to find the result. I re-created the enemy firing routine, selected the aliens to fire at random (via a pointer and value selector). If the alien was alive, the pointer and the bullet was out of the screen.
After fixing the alien firing I decided to fiddle about with the front end a little more. I added a flashing effect to the game’s title screen. Also a page flip routine was added in order to flip between the front end credits and also the high score table. The result turned out pretty good.
Next the main game. The aliens were originally spawning in sequence. However, I didn’t want the alien groups to spawn in order of the values 1 -17, so I setup the level pointers and some custom sequence tables to get the aliens spawning in a chosen value for that particular level. The video below shows you how the feature results during game play.