Moving Platforms

[kevin]

 
 Moving Platforms

  This example creates a fairly simple moving platform as found in many a classic 2d game.  The platform moves between a the origin point and the destination, to make it little more interesting, it pauses for a second upon reaching either the origin or target.  

PlayBASIC Code: [Select]

  Setfps 60

   OriginX#=100
   OriginY#=100
   
   TargetX#=600
   TargetY#=400

   Mode=0

   CurrentDist#=0

      DistToTarget#=GetDistance2D(OriginX#,OriginY#,TargetX#,TargetY#)
   AngleToTarget#=GetAngle2D(OriginX#,OriginY#,TargetX#,TargetY#)


   Do
      cls $4080a0

      line OriginX#,OriginY#,TargetX#,TargetY#


      Select Mode

            // -----------------------------------------
            case 0   // Platform moving from Original Point to Target
            // -----------------------------------------
               CurrentDist#=   CurrentDist#+2
               if CurrentDist#>=DistToTarget#
                     CurrentDist#=DistToTarget#
                     PauseTime=Timer()+1000
                     inc mode
               endif

               x#=OriginX#+CosRadius(AngleToTarget#,CurrentDist#)
               y#=OriginY#+SinRadius(AngleToTarget#,CurrentDist#)

            // -----------------------------------------
            case 1   // Pausing while at this point
            // -----------------------------------------
               if PauseTime<Timer()
                  inc mode
               endif
            
            // -----------------------------------------
            case 2  // Platform moving from target back to oring
            // -----------------------------------------

               CurrentDist#=   CurrentDist#-2
               if CurrentDist#<0
                     CurrentDist#=0
                     PauseTime=Timer()+1000
                     inc mode
               endif

               x#=OriginX#+CosRadius(AngleToTarget#,CurrentDist#)
               y#=OriginY#+SinRadius(AngleToTarget#,CurrentDist#)
      
            // -----------------------------------------
            case 3
            // -----------------------------------------
               if PauseTime<Timer()
                  mode =0
               endif
            
      Endselect
      

       DrawPLatform(X#,y#,50,20)
                  
       Sync
   loop

    



Function DrawPLatform(X,y,width,Height)

    x1=x-(Width/2)
    x2=X+width
    
    y1=y-(Height/2)
    y2=y+Height

   c1=$a04050
   c2=$5060760   

   shadebox x1,y1,x2,y2,c1,c1,c2,c2

EndFunction

[kevin]

 This one uses sinus to make the platform appear to accelerate while moving between the points.

PlayBASIC Code: [Select]

  Setfps 60

   OriginX#=100
   OriginY#=100
   
   TargetX#=600
   TargetY#=400


   CenterX#=(OriginX#+TargetX#)/2
   CenterY#=(OriginY#+TargetY#)/2


   Mode=0

   DistToTarget#=GetDistance2D(OriginX#,OriginY#,TargetX#,TargetY#)/2
   AngleToTarget#=GetAngle2D(OriginX#,OriginY#,TargetX#,TargetY#)




   Do
      cls $4080a0

      line OriginX#,OriginY#,TargetX#,TargetY#


      Select Mode

            // -----------------------------------------
            case 0   // Platform moving from Original Point to Target
            // -----------------------------------------

               CurrentDistAngle#= CurrentDistAngle#+1

               if CurrentDistAngle#>=180
                     CurrentDistAngle#=180
                     PauseTime=Timer()+1000
                     inc mode
               endif


               CurrentDist#=cos(180+CurrentDistAngle#)*(DistToTarget#)

               x#=CenterX#+CosRadius(AngleToTarget#,CurrentDist#)
               y#=CenterY#+SinRadius(AngleToTarget#,CurrentDist#)

            // -----------------------------------------
            case 1   // Pausing while at this point
            // -----------------------------------------
               if PauseTime<Timer()
                  inc mode
               endif
            
            // -----------------------------------------
            case 2  // Platform moving from target back to oring
            // -----------------------------------------

               CurrentDistAngle#= CurrentDistAngle#+1

               if CurrentDistAngle#>=360
                     CurrentDistAngle#=360
                     PauseTime=Timer()+1000
                     inc mode
               endif
               CurrentDist#=cos(180+CurrentDistAngle#)*(DistToTarget#)
               x#=CenterX#+CosRadius(AngleToTarget#,CurrentDist#)
               y#=CenterY#+SinRadius(AngleToTarget#,CurrentDist#)
      
            // -----------------------------------------
            case 3
            // -----------------------------------------
               if PauseTime<Timer()
                  mode =0
                  CurrentDistAngle#=0
               endif
            
      Endselect
      

       DrawPLatform(X#,y#,50,20)

                  
       Sync
   loop

    



Function DrawPLatform(X,y,width,Height)

    x1=x-(Width/2)
    x2=X+width
    
    y1=y-(Height/2)
    y2=y+Height

   c1=$a04050
   c2=$5060760   

   shadebox x1,y1,x2,y2,c1,c1,c2,c2

EndFunction

[micky4fun]

Hi all

hope its ok to post just a little snippet using Kevins code ,
think its very worthwhile if you have spare time to go through all the old source codes,

this is 8 moving platforms as in mario sonic etc , could use more or less
thought it might be usefull , see if my latest game requires this !

mick

[ATLUS]

Very useful code, thanks!