Kid Grid play mechanics

[NIKON]

I am soo noob to this ... how do you confine the Player object to the grid?

[RevEng]

There are 2 steps...

 

1. start the player off on the grid

2. only allow joystick moves that keep him on the grid

 

How you tackle step 2 is a bit dependent on the game. In Salvo, I do step 2 something like this...

 

    temp1=playerx&15
    temp2=playery&31
    if temp1 then goto skipvertical
    if joy0down && playery<160 then playerdir=0:goto joydone
    if joy0up && playery>32   then playerdir=1:goto joydone
skipvertical
    if temp2 then goto skiphorizontal
    if joy0left  && playerx>16 then playerdir=2:goto joydone
    if joy0right && playerx<96 then playerdir=3:goto joydone
skiphorizontal
joydone

In your case the grid isn't always a grid, so this probably isn't enough on it's own. You also need to peek at the character underneath the player and make sure it's not a blank space character. There's an example of this in the "ramcharmap" sample - the character check there is done to make sure there's ground under the player's feet, but it's conceptually the same thing.

[NIKON]

There are 2 steps...

 

1. start the player off on the grid

2. only allow joystick moves that keep him on the grid

 

How you tackle step 2 is a bit dependent on the game. In Salvo, I do step 2 something like this...

 

    temp1=playerx&15
    temp2=playery&31
    if temp1 then goto skipvertical
    if joy0down && playery<160 then playerdir=0:goto joydone
    if joy0up && playery>32   then playerdir=1:goto joydone
skipvertical
    if temp2 then goto skiphorizontal
    if joy0left  && playerx>16 then playerdir=2:goto joydone
    if joy0right && playerx<96 then playerdir=3:goto joydone
skiphorizontal
joydone

In your case the grid isn't always a grid, so this probably isn't enough on it's own. You also need to peek at the character underneath the player and make sure it's not a blank space character. There's an example of this in the "ramcharmap" sample - the character check there is done to make sure there's ground under the player's feet, but it's conceptually the same thing.

 

Thank you .. this gives me some insight as to go about it.