Alright. I've asked this question before, Collision Detection.

[Apollo]

I have been trying to get collison detection in my programs, and each time I think I have it I don't. So, if one of you knows how to achieve this with an object that moves around a screen and bumps into other objects in the middle of the room, please tell me. Or, if someone has a program that already does this, I would equally appreciate it. Please help me, this is the only thing standing in the way of me, and making a game.

End.

[MrShickadance]

Collision Detection.

Fun!

well first you have to keep track of all your objects on the screen. Most likely you have a structure (Type) which represents an object on the screen. so, all you have to do is get the object in question and compare it's coord's with all other objects.

this is on the fly so it's not going to be 100% accurate nor is it the most eff. way.

Public Type BALL_OBJECT
  X  as Long    '' center
  Y  As Long    '' center
  DX as Long    '' movement on the X axis
  DY As Long    '' movement on the Y axis
  R  as Long    '' radius
  D  as Boolean '' is the object displayed
  N  as Long    '' object number
End Type

Global GBO(0 To 99) as BALL_OBJECT

Public Function DetectCollision(bo as BALL_OBJECT) as Boolean
  
  Dim lLoop as Long
  Dim dist  as Long
  
  For lLoop = 0 To Ubound(GBO)
    '' check for not the same object # and the object is being displayed
    If (GBO(lLoop).N <> bo.N) And (GBO(lLoop).D) Then
      

      '' get the est. distance
      dist = (abs(bo.X - GBO(lLoop).X) + _
              abs(bo.Y - GBO(lLoop).Y)) - 
             (Int((abs(bo.X - GBO(lLoop).X) + _
              abs(bo.Y - GBO(lLoop).Y))/2)
      
      '' check for a collision
      If (dist <= (GBO(lLoop).R + bo.R)) Then
        DetectCollision = True
        Exit Function
      End If
    End If
  Next lLoop
  
End Function

remember, this may not work correctly but it's a step in the right direction.

Good Luck

[Apollo]

For counter = 1 To 8
    If collider.Top >= wall(counter).Top And collider.Top <= wall(counter).Top + wall(counter).Height Or collider.Top + collider.Height >= wall(counter).Top And collider.Top + collider.Height <= wall(counter).Top + wall(counter).Height Then
        If collider.Left >= wall(counter).Left And collider.Left <= wall(counter).Left + wall(counter).Width Or collider.Left + collider.Width >= wall(counter).Left And collider.Left + collider.Width <= wall(counter).Left + wall(counter).Width Then
            collide = True
        End If
    End If
Next

This is what I have come up with. It checks for all of the objects on the screen, which are in a control array. But, when the picture of my character hits the top of an object (when their tops are the same) he will go right through it. I'm currently checking for something though. The key to this may lie in whether or not he's bigger than the object on the screen. A certain occurance my code doesn't cover..

[Apollo]

I figured it out.

Ok. There are 3 types of 2D collison.

1.) The user's top is greater than the top of an object, but less than it's bottom. We have a hit.

2.) The user's bottom is less than the object's bottom, but greater than it's top. More collison.

3 (the one that screwed me up.) The user's top is less than the objects top, and the user's bottom is greater than the object's bottom, in other words, the user is bigger than the object itself. Which was the problem I had.

, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , !!!!!!!!!!!!!!!!!

[MrShickadance]

Congrats!!

heh, hey if you highlight those smiley faces at the bottom of your message some look mad and some look said. wierd