PacMan

[Oak]

Hi!
I'm bulding a PacMan game(it works good at this point). I went into a dilem. What kind of processing should I use about PacMan eating stuff? There's 2 hypothesis that begs me for attention.
Pixel Detection:
detect% = POINT(pac.x, pac.y)
IF detect% = 0 THEN ...
and so on...
Coordination:
IF pac.x = 12 AND pac.y = 20 THEN ...
and so on...

What should I do for my craving PacMan?

 

[Nyaj2k1]

Set up some collision detection to see if any of PacMan's borders are touching any dots. Like this:

' Ok, lets assume you have a type array that contains
' the dots coordinates. Dot(60).X, and Dot(60).Y. We
' also have the variables PacMan.X and PacMan.Y

' Loop through all the dots and see if any borders of
' PacMan are touching them. PacMan's width is 20 pixels
' and his height is 18 pixels.

For Looper = 0 to 60 step 1
DidCollide = 1
If PacMan.X > Dot(Looper).X then
DidCollide = 0
Elseif PacMan.Y > Dot(Looper).Y then
DidCollide = 0
Elseif PacMan.X + 20 < Dot(Looper).X then
DidCollide = 0
Elseif PacMan.Y + 18 < Dot(Looper).Y then
DidCollide = 0
Endif
If DidCollide = 1 then
' Take care of anything that happens when
' PacMan hits a dot.
Endif
Next

 

[Nyaj2k1]

How's that working for you?

 

[Oak]

I've been gone for the week end. I'll try it!
I presume that phantom collision detection should be implemented the same way. Is it correct?
Thanks

 

[Nyaj2k1]

Please define what you mean by 'Phantom'... There is a million ways to say the same thing when it comes to programming!

 

[Nyaj2k1]

If by phantom you are reffering to the fact that you are checking allready-dissapeared dots, you could make another object in the Dot array: Dot.Active(0-60), then alter the above code so you're never checking the same dot twice:

For Looper = 0 to 60 step 1
If Dot.Active(Looper) = 1 then
DidCollide = 1
If PacMan.X > Dot(Looper).X then
DidCollide = 0
Elseif PacMan.Y > Dot(Looper).Y then
DidCollide = 0
Elseif PacMan.X + 20 < Dot(Looper).X then
DidCollide = 0
Elseif PacMan.Y + 18 < Dot(Looper).Y then
DidCollide = 0
Endif
If DidCollide = 1 then
Dot.Active(Looper) = 0
' Take care of anything that happens when
' PacMan hits a dot.
Endif
Endif
Next

 

[Nyaj2k1]

Lol... It took me this long to figure out that when you said &quot;Phantom&quot; collision detection, you ment collision detection width those Blue, Red, and White &quot;Ghosts&quot; that run around the screen in the hopes of killing Pac-Man...

   .-------.
   |  .-.  |
   | | OO| |
   | |   | |
   | '^^^'.--------.
   '------|  .--.  |
          | / _.-' |
          | \  '-. |
          |  '--'  |
          '--------'

You should be able to use that collision detection code, except insted of just using the X and Y values of the dot, we must compare the Width and Height of the 'Phantom'. The width and height of the Phantom is 20, 18.

For Looper = 0 to 4 step 1
If Phantom(Looper).Alive = 1 then
DidCollide = 1
If PacMan.X > Phantom(Looper).X + 20 then
DidCollide = 0
Elseif PacMan.Y > Phantom(Looper).Y + 18 then
DidCollide = 0
Elseif PacMan.X + 20 < Phantom(Looper).X then
DidCollide = 0
Elseif PacMan.Y + 18 < Phantom(Looper).Y then
DidCollide = 0
Endif
If DidCollide = 1 then
' Take care of anything that happens when
' PacMan hits a Phantom.
Endif
Endif
Next

 

[Oak]

Thanks. It should help!