Pete's QBASIC Site

Aha!

2009-06-08T21:24:47-05:00

I found an answer; I didn't need to make a copy (Actually, I tried it the wrong way). Sorry about that; but it is a good idea!

Here is my updated code:

Code:

for a = 0 to columns-1    for b = 0 to rows-1      if spritemode(map(a,b)) = 1 then       cmin = (a*16)-15: cmax = (a*16)+15       rmin = (b*16)-15: rmax = (b*16)+15       if r >= rmin and r = cmin and c <= cmax then         if r = rmin then r = r -1        if r = rmax then r = r +1        if c = cmin then c = c -1        if c = cmax then c = c +1        end if      end if    next bnext a

This deals with each row and column collision as it occurs.

Sorry that I didn't try out your idea fully.

BTW, remember the pseudo-code post (the wasn't part of the original code)

Statistics: Posted by BluescreenODeff — Mon Jun 08, 2009 9:24 pm

Collision Detection in FB Game

2009-06-08T20:54:07-05:00

Sorry, the clipboard did something silly.
I'll explain it in pseudo-code:

if r is greater than or equal to rmin and r is less than or equal to rmax and c is greater than or equal to cmin and c is less than or equal to cmax then

r and c is my way of saying y and x. It's easier for me to think "row, column".

Anyway, thanks for the idea; I'll try it.

Statistics: Posted by BluescreenODeff — Mon Jun 08, 2009 8:54 pm

Collision Detection in FB Game

2009-06-08T20:39:42-05:00

I'm having a little trouble following the code (specifically, what does "if r >= rmin and r = cmin and c <= cmax then " do?).

What about moving a copy of coordinates, then check collision detection? If no collision, then update the original coordinates with the updated copy, otherwise ignore the copy. I found that to help me out sometimes when weird things happen.

Statistics: Posted by Mentat — Mon Jun 08, 2009 8:39 pm

Collision Detection in FB Game

2009-06-08T19:54:34-05:00

Hello everyone. I'm working on an RPG and I've nearly got the colission detection right. My problem is when you hit the object that is specified as a wall, you are blocked, but you also can't move in any other direction until you let go of the key. I use MULTIKEY to get the character moving. This is the collision detection code:

Code:

for a = 0 to columns-1    for b = 0 to rows-1      if spritemode(map(a,b)) = 1 then       cmin = (a*16)-15: cmax = (a*16)+15       rmin = (b*16)-15: rmax = (b*16)+15       if r >= rmin and r = cmin and c <= cmax then        if MULTIKEY(&h48) then r = r + 1       if MULTIKEY(&h4D) then c = c - 1       if MULTIKEY(&h50) then r = r - 1       if MULTIKEY(&h4B) then c = c + 1               end if      end if    next bnext a

columns and rows are the number of columns and rows in the current map.
spritemode is the status of each tile (whether or not you can go through them)
map(a,b) is the map, of course.
the cmin, cmax, rmin, and rmax es specify the boundaries the character has to cross before any collision action is taken.

If there is a collision, the game will move the character in the opposite direction 1 pixel, according to what button was pushed.

Any suggestions? Thanks and God Bless!

Statistics: Posted by BluescreenODeff — Mon Jun 08, 2009 7:54 pm