Version 0.018 is complete. This upgrades the rom to 16k. And the amount of space available in each bank is awesome.

 

I've spliced up the code as detailed in the previous post. The rom plays essentially the same as the previous version/beta as far as anyone were to tell by playing it. There's just a lot more space available to add things now.

 

As I mentioned, I took a stab at trying to modify the Random Number generator. After reading it over and actually understanding what it was doing this is what I've changed it to:

 

NextRandom SUBROUTINE
 lda random
 beq .doEor
 lsr
 bcc .skipEor
.doEor:
 lda SWCHA
 adc Incrementer
 sbc PlayerCnt
 ora #%10000000
.skipEor:
 sta random
 rts

 

This means I got rid of the constant. I make sure I set the top bit to 1 when reseting the value to make sure we get the maximum number of bits and to ensure it can go to the top range now and then. Swcha is usually mostly high values to begin with, but Incrementer goes through the full range (not that it'll see the entire range, but most of it) and PlayerCnt ... I'm not entirely sure what it's valued at by the time it gets checked. Probably 0 if I decrement that in the display. If I don't then it's set to the top scanline of the player.

 

I also call it once per game-tick, in frame 3 of 6. So it runs through it's values and recalculates new ones even if it isn't required. It will also recalculate values during either the AI or Collision Managers as it gets called by individual routines. The only one that really uses it right now is hte HeartPlacer demo routine which fills up available object slots with hearts if they're empty.

 

I'm not entirely sure what I'll do for the next version, but I'm leaning towards allowing for object animation. For instance I may redo the heart so that it's smaller but pulsates a little (A 5 frame sequence with 3 unique frames)

 

A test run for when I do more complicated animations with monsters.

 

 

Oh. You'll notice the screen bumps in the castle room when you move around the castle gate's scanlines. A glitch, but just one made from laziness for this version. The graphics data for the gate crosses a page boundary. That's generating an extra cycle which causes the glitch in some situations. I'll be correcting it with the next version - thought I'd leave it til the next version since I'll be looking at sprite layout more closely then.