Test of preliminary routines that open the center pod and show the "energy field" that can be hit to destroy the station in one shot.
The energy field is drawn using a missile. If the station is drawn with player0, the energy field is drawn with missile1. Likewise missile0 is used for stations drawn with player1. I did this as we can't control the color of the missiles, so this gives us a chance for the energy field to be a color other than green.
At the time the stations are drawn, the "draw shots" routine has yet to run, so the energy field has a higher priority than shots. I think this will be OK most of the time, though for levels like 4 this might cause a problem as shots could be invisible when they cross the horizontal zone (boxed in red in the screenshot) with the energy fields. It depends on whether or not other sprites are flickering in that section - in this screenshot the player's ship is part of the flicker with the stations, so a station shot does show up in the zone on the left.
This also shows a minor issue with these preliminary routines - the energy field is only drawn if the sprite is drawn, and which of the two energy field shapes is selected by bit 1 of the FRAME counter, so at certain sprite flicker rates the energy field doesn't appear to alternate between its two shapes. To fix this I'll just keep track of which energy field was shown last for each station.
I've turned off collision detection for the station shots to make it easier to view the changes. Right Difficulty=A will stop your ship from moving, which also helps to see what's happening.
I think it works out quite well, though will probably change it so that each station can have a different energy field shape as the current shape doesn't look quite right with the Vertical Station.
There are some quirks that I've not yet looked into
I've ordered a Treadmill Desk that will be delivered on the 5th. Starting tomorrow I'm going to move everything out of my office. I figure it'll take a few days, but I want to shampoo the carpet next weekend before the new desk is delivered. Over the course of the week of the 5th I'll be setting up the Treadmill Desk and figuring out how to arrange everything (except the old desk) back into my office.
Due to all this, I suspect it'll be a few weeks before the next Draconian build is posted.