Movement

[Unsurreal]

Hi...

 

I'm having difficulties on moving a sprite which was horizontally located by the RESP0 comand, it just doesn't move. Can somebody help me on this?

[Bad Panda Bear]

How are you trying to move it?

 

If you are trying to move it by setting the HMPx registery, then it won't move until you do a "STA HMOVE". (Note this should be done after an "STA WSYNC")

 

If you are using a full horizontal positioning scheme like described here, then it's simply a matter of changing the horizontal position variable between frames.

 

Hope this helps.

[Unsurreal]

Well, thanks anyway, but I discovered some other way to make it happen.

The problem was that at every frame I was saying to put the sprite in the same place by setting the RESP0, so it seemed that the moving routine was the problem.

I created a variable to make sure that I would locate the sprite in the place I want it to start just one time. I set it with 1 before the MainLoop (frame loop).

And then this is what I made, after the scanline loop:

 

; Check if I need to locate the Sprite at the center of the screen

 

ldy #82 ;this is the number of cycles I had to "waste"

 

lda rhpos ;load the variable responsable for the checking

beq hpos ;if it's 0 skip the code below and go to hpos

 

lda #0 ;A=0

sta rhpos ;rhpos=0, so it will never happen again

 

timeforhpos ;delay for right positioning

dey

bne timeforhpos

 

sta RESP0 ;and call the sprite right here

 

hpos ;label that the code goes when rhpos is 0

 

Thanks again.