How do you limit joystick to 4-way movement?

[+Random Terrain]

I used to know how to do this stuff on the VIC-20 and Commodore 64, but I cannot remember how to limit the joystick to 4-way movement. I'm almost done with my test program with the random mazes and a little sprite you can move around, but the little thing can sneak diagonally sometimes and go over little bits of the wall.

 

How do you stop the player from moving diagonally?

 

Thanks.

[vdub_bobby]

I used to know how to do this stuff on the VIC-20 and Commodore 64, but I cannot remember how to limit the joystick to 4-way movement. I'm almost done with my test program with the random mazes and a little sprite you can move around, but the little thing can sneak diagonally sometimes and go over little bits of the wall.

 

How do you stop the player from moving diagonally?

 

Thanks.

938370[/snapback]

If you stop reading the joystick once you have you've detected movement in a single direction then you won't get diagonals.

Edited September 26, 2005 by vdub_bobby

[+Random Terrain]

If you stop reading the joystick once you have you've detected movement in a single direction then you won't get diagonals.

Thanks.

 

Does it matter that the little sprite moves like Pac-Man? It doesn't stop until it comes to a wall.

 

Oh yeah, and about what you said, is this the best way to do that?

 

  if joy0up then do some stuff : goto skipstick
 if joy0down then do some stuff : goto skipstick
 if joy0left then do some stuff : goto skipstick
 if joy0right then do some stuff
skipstick

Edited September 26, 2005 by Random Terrain

[vdub_bobby]

Oh yeah, and about what you said, is this the best way to do that?

 

  if joy0up then do some stuff : goto skipstick
 if joy0down then do some stuff : goto skipstick
 if joy0left then do some stuff : goto skipstick
 if joy0right then do some stuff
skipstick

938396[/snapback]

I dunno about "best," but that looks like it will certainly work. That's how I'd do it, anyway.

 

Or put it in a subroutine and:

   if joy0up then do some stuff : return
  if joy0down then do some stuff : return
  if joy0left then do some stuff : return
  if joy0right then do some stuff : return
  return

[+Random Terrain]

I dunno about "best," but that looks like it will certainly work.  That's how I'd do it, anyway.

 

Or put it in a subroutine and:

   if joy0up then do some stuff : return
  if joy0down then do some stuff : return
  if joy0left then do some stuff : return
  if joy0right then do some stuff : return
  return

938407[/snapback]

Thanks. That's a good alternative to remember. I'd have to have a label for either one, so I guess the goto version will work OK for now unless something changes. Maybe I should check to see which one takes up more bytes.

[+Random Terrain]

After trying and failing many times, I found a different way to stop the diagonal movement and stop the player from passing through bits of the wall. I had to jump to the same movement related gosubs twice and make the x and y negative/positive variables equal zero at the right time.

Edited September 27, 2005 by Random Terrain