Bob's Blog

So do you like the stateless fractional movement trick now that you understand it?

So do you like the stateless fractional movement trick now that you understand it?

Heck yes I do! Saved me some RAM - plus, I've never really liked fractional positioning: it is great when your velocity is < 1 pixel per frame but kind of a pain when your velocity is >= 1 pixel per frame. My fractional positioning code usually looks something like this:

   lda FractionalPosition
  clc
  adc Velocity
  sta FractionalPosition
  lda IntegerPosition
  adc #0
  sta IntegerPosition

All very neat and tidy, but you cannot move faster than 255/256 pixels per frame with this method. Annoying!

 

So I usually end up calling the fractional position routine several times per frame, which works just fine but is a bit of a time waster.

 

With this routine I call it once and it works great. Thanks again.

 

 

Too bad it won't work for situations (most of them) where the speed changes in mid-"air."

   lda FractionalPosition
  clc
  adc FractionalVelocity
  sta FractionalPosition
  lda IntegerPosition
  adc IntegerVelocity
  sta IntegerPosition

IMHO, the elevators are moving too fast. I liked the speed they were going before.

IMHO, the elevators are moving too fast. I liked the speed they were going before.

 

There fast but I get through fairly often.

   lda FractionalPosition
  clc
  adc FractionalVelocity
  sta FractionalPosition
  lda IntegerPosition
  adc IntegerVelocity
  sta IntegerPosition

Thanks; I'll keep that in mind.

IMHO, the elevators are moving too fast. I liked the speed they were going before.

 

A little faster than before indeed, although not too difficult. The bigger problem is there's no delay between when you get hit and it lets you try running to the side again. In my case, if I got hit by the first elevator, I wouldn't be able to stop pushing to the side fast enough and before I knew it I was missing 5 lives.

 

I'd find it amusing if the maid fell off the screen similar to how mario would when he got hit in Mario Brothers. (It would certainly take care of the needed delay. )

I'd find it amusing if the maid fell off the screen similar to how mario would when he got hit in Mario Brothers. (It would certainly take care of the needed delay. )

That's not a bad idea...