getting the tile that was hit

[RaverDave]

Hi @ll..

Ok I am fiddling around finally with playbasic!
Now then I changed the code of the basic collision example to read in data to build the level, what i want now is to find out which tile within the map the player has collided with,and to delete that tile from the map level( think arknoid! )..here is the code i have so far

PlayBASIC Code: [Select]

  OpenScreen 640,480,32,2 
   SetFPS 0
   Mouse Off
   ScreenVsync On
 
 PlayerX=50
 PlayerY=430
 PlayerWidth   =10
 PlayerHeight   =10
 Speed=4
 MyMap = GetFreeMap()
 CreateMap MyMap, 1

  TileWidth=32
  TileHeight=16
  Number_of_tiles = 5
  
 ; Loop through and draw a series of randomly coloured Boxes to the screen
  For lp=1 To Number_of_tiles
     xpos=lp*tileWidth  
     BoxC Xpos,0,Xpos+TileWidth,TileHeight,1,RndRGB()     
  Next 

 ; Grab the box graphics that we've just drawn as image.
  TempImage=GetFreeImage()
  GetImage TempImage,0,0,xpos+TIleWidth,Tileheight
  
  
  
RemStart
     So far, we've created our Map and Manually Created an image containing some
    coloured blocks. Now it's time to import this image into our Map for use.
    
      When we have map block graphics stored in an image, we import them using
    the MakeMapGFX command.  This command requires the Map you wish to store these
    blocks in, the source Image to import, the Tile Width, the Tile Height, number
    of tiles to import and finally the transparent colour (if any) to use for
    these tiles.
RemEnd

 ; Import this image into our previously defined Map.  
  MakeMapGFX MyMAP,TempImage,TileWidth,TileHeight,Number_Of_Tiles,RGB(0,0,0)



RemStart
    Now we have a Map that has a set of tiles ready for use in it, so the next
    thing we need to is create a level.  This is done with the CREATELEVEL command.
    Which requires two things, it needs the know within what MAP this level should
    be created, and what Level Index it should for this level. 
    

RemEnd

   ; Create level 1 in MyMAP, 100 tile across and 200 tiles down.
    CreateLevel MyMap,1, 100,200
    
    

RemStart
    We're just about ready now to start drawing, but first we need to fill the level
    with what tiles it should draw.  In this example, the following code will randomly fill
    the level.  Normally you would use a level editing program like PLAY MAPPER for
    such things.  But your welcome to do it manually if you like.  
RemEnd

    For Ylp=0 To 12
     For Xlp=0 To 19
      t=ReadData()
      If t>0
    PokeLevelTile MyMap,1,Xlp,ylp,t
  EndIf
     Next xlp
    Next ylp
    
    Data 1,1,1,0,1,0,0,0,1,1,1,0,1,0,1,0,0,0,0,0
    Data 1,0,1,0,1,0,0,0,1,0,1,0,1,0,1,0,0,0,0,0
    Data 1,1,1,0,1,0,0,0,1,1,1,0,0,1,0,0,0,0,0,0
    Data 1,0,0,0,1,0,0,0,1,0,1,0,0,1,0,0,0,0,0,0
    Data 1,0,0,0,1,1,1,0,1,0,1,0,0,1,0,0,0,0,0,0
    Data 0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0
    Data 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
    Data 1,1,0,0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0
    Data 1,0,1,0,1,0,1,0,1,0,0,0,0,1,0,0,1,0,0,0
    Data 1,1,0,0,1,1,1,0,1,1,1,0,0,1,0,0,1,0,0,0
    Data 1,0,1,0,1,0,1,0,0,0,1,0,0,1,0,0,1,0,0,0
  Data 1,0,1,0,1,0,1,0,0,0,1,0,0,1,0,0,1,0,0,0
  Data 1,1,0,0,1,0,1,0,1,1,1,0,1,1,1,0,1,1,1,0
; Draw the Level to the screen at Xpos 0 and Ypos 50
   
  
; Show the user te screen and wait for a key to be pressed
   Repeat
   
  
  
  DrawMap MyMap,1,0,0
  ; Store the players possible new position
    PLayerNewX=PlayerX
    PLayerNewY=PlayerY

   ;  Handle the players Movement
    If UpKey() Then PlayerNewY=PLayerY-Speed
    If DownKey() Then PlayerNewY=PLayerY+Speed
    If LeftKey() Then PlayerNewX=PLayerX-Speed
    If RightKey() Then PlayerNewX=PLayerX+Speed

   
     
  ; ==========================
  ; Handle Collision
  ; ===========================
   
    If CheckMapImpact(MyMap,1,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWidth,PlayerHeight)   
   ; If there was impact with the map, then read our
   ; new position back. 
     PlayerX=GetMapImpactX()
     PlayerY=GetMapImpactY()
     
     ; Check what side the impact occured upon
      ; and display a message
         
    If GetMapImpactLeft()
       Print "Impact occured on the LEFT side"   
    EndIf
           
    If GetMapImpactRight()
         Print "Impact occured on the RIGHT side"   
    EndIf

    If GetMapImpactTop()
       Print "Impact occured on the TOP side"   
    EndIf

    If GetMapImpactBot()
       Print "Impact occured on the Bottom side"   
    EndIf
     
        
  Else
     ; No Collision, Then set the current players
     ; position to it's new position
       PlayerX=PlayerNewX
    PlayerY=PlayerNewY  
    EndIf

    
     X2=playerX+PlayerWidth

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[stef]

Hi!

Interesting and good idea!

(In your code you should use "Cls 0" after "repeat"or "text 0,0" instead of "print")

Greetings
stef

[RaverDave]

yeh,well thats no big deal,in fact that print code is coming out,its of no use really,i just want this collision working,then i will get the ball(square ball!!) bouncing around by itself destroying the tiles

[kevin]

When a collision occurs you just peek out the block(s as there might be more than 1 impact)  

Which is pretty much what the bellow changes do.  Although there's a little error with it.  I'll give you hint, it's the logic when the tile is to be deleted..  currently were deleting the tile on the same level as the block.  but that's not always going to be the case.

PlayBASIC Code: [Select]

; OpenScreen 640,480,32,2
;SetFPS 0
;Mouse Off
;ScreenVsync On

PlayerX=50
PlayerY=430
PlayerWidth =10
PlayerHeight =10
Speed=4
MyMap = GetFreeMap()
CreateMap MyMap, 1

 TileWidth=32
 TileHeight=16
 Number_of_tiles = 5
 
; Loop through and draw a series of randomly coloured Boxes to the screen
 For lp=1 To Number_of_tiles
    xpos=lp*tileWidth  
    BoxC Xpos,0,Xpos+TileWidth,TileHeight,1,RndRGB()    
 Next

; Grab the box graphics that we've just drawn as image.
 TempImage=GetFreeImage()
 GetImage TempImage,0,0,xpos+TIleWidth,Tileheight
 
 
 
RemStart
    So far, we've created our Map and Manually Created an image containing some
   coloured blocks. Now it's time to import this image into our Map for use.
   
     When we have map block graphics stored in an image, we import them using
   the MakeMapGFX command.  This command requires the Map you wish to store these
   blocks in, the source Image to import, the Tile Width, the Tile Height, number
   of tiles to import and finally the transparent colour (if any) to use for
   these tiles.
RemEnd

; Import this image into our previously defined Map.  
 MakeMapGFX MyMAP,TempImage,TileWidth,TileHeight,Number_Of_Tiles,RGB(0,0,0)



RemStart
   Now we have a Map that has a set of tiles ready for use in it, so the next
   thing we need to is create a level.  This is done with the CREATELEVEL command.
   Which requires two things, it needs the know within what MAP this level should
   be created, and what Level Index it should for this level.
   

RemEnd

; Create level 1 in MyMAP, 100 tile across and 200 tiles down.
   CreateLevel MyMap,1, 100,200
   
   
   
   For Ylp=0 To 12
    For Xlp=0 To 19
     t=ReadData()
      If t>0
     PokeLevelTile MyMap,1,Xlp,ylp,t
   EndIf
    Next xlp
   Next ylp
   
   Data 1,1,1,0,1,0,0,0,1,1,1,0,1,0,1,0,0,0,0,0
   Data 1,0,1,0,1,0,0,0,1,0,1,0,1,0,1,0,0,0,0,0
   Data 1,1,1,0,1,0,0,0,1,1,1,0,0,1,0,0,0,0,0,0
   Data 1,0,0,0,1,0,0,0,1,0,1,0,0,1,0,0,0,0,0,0
   Data 1,0,0,0,1,1,1,0,1,0,1,0,0,1,0,0,0,0,0,0
   Data 0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0
   Data 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
   Data 1,1,0,0,1,1,1,0,1,1,1,0,1,1,1,0,1,1,1,0
   Data 1,0,1,0,1,0,1,0,1,0,0,0,0,1,0,0,1,0,0,0
   Data 1,1,0,0,1,1,1,0,1,1,1,0,0,1,0,0,1,0,0,0
   Data 1,0,1,0,1,0,1,0,0,0,1,0,0,1,0,0,1,0,0,0
   Data 1,0,1,0,1,0,1,0,0,0,1,0,0,1,0,0,1,0,0,0
   Data 1,1,0,0,1,0,1,0,1,1,1,0,1,1,1,0,1,1,1,0
; Draw the Level to the screen at Xpos 0 and Ypos 50

 
; Show the user te screen and wait for a key to be pressed
Repeat

 
 
   DrawMap MyMap,1,0,0



   PLayerX,PLayerY=Handle_player(PLayerX,PLayerY,PLayerWIdth,PlayerHeight,Speed,MyMap,1)


   
  X2=playerX+PlayerWidth
  Y2=playerY+PlayerHeight
  Box playerX,playerY,x2,y2,1
 
  Rem Circle playerX,playerY,10,1
 v=ScanCode()
 If v=16
    quit=1 
 endif
   
Sync
Until quit=1






Function Handle_player(PLayerX,PLayerY,PLayerWIdth,PlayerHeight,Speed,ThisMap,ThisLevel)
   
; Store the players possible new position
   PLayerNewX=PlayerX
   PLayerNewY=PlayerY

;  Handle the players Movement
   If UpKey() Then PlayerNewY=PLayerY-Speed
   If DownKey() Then PlayerNewY=PLayerY+Speed
   If LeftKey() Then PlayerNewX=PLayerX-Speed
   If RightKey() Then PlayerNewX=PLayerX+Speed
 
; ==========================
; Handle Collision
; ===========================
   If CheckMapImpact(thisMap,ThisLevel,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWidth,PlayerHeight)  

; If there was impact with the map, then read our
; new position back.
    PlayerX=GetMapImpactX()
    PlayerY=GetMapImpactY()
   
  TileWidth=GetMapBlockWidth(ThisMap)
  TileHeight=GetMapBlockHeight(ThisMap)

  TileX=PlayerX/TileWidth  
  TileY=PlayerY/Tileheight
  
  ; Check what side the impact occured upon
   ; and display a message
       
    If GetMapImpactLeft()

Login required to view complete source code

[RaverDave]

If CheckMapImpact& #40;thisMap,ThisLevel,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWidth,PlayerHe
ight)  

this line errors,is it coz you are using 'thismap' instead of 'mymap'??

[RaverDave]

errr.in fact it errors all over that line :)
could you do me a favour Kev and get the collisions going for me with some nice comments to learn from?

[stef]

hi!

 If CheckMapImpact(thisMap,ThisLevel,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWidth,PlayerHeight)

this works better (but crashes on left window border=

stef

[RaverDave]

hmmm,all i get is a compile error...

Error number 23

Irregular brackets : missing closing


Very strange as checking the syntax it seems correct

[stef]

hi!

If CheckMapImpact(thisMap,ThisLevel,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWid
th,PlayerHeight)

do all in one line!!



that's a strange copy and paste or whatever error!!

Code Select Expand


If CheckMapImpact(thisMap,ThisLevel,PlayerX,playerY,PlayerNewX,PlayerNewY,PLayerWidth,PlayerHeight)


it replaced " (" with "&  #40;" !!!!!


stef

[RaverDave]

This is getting weird,I still get the same error with the brackets still in place..


I have:

If Checkmapimpact(thismap,thislevel,playerX,playerY,playernewX,playernewY,Playerwidth,playerheight)



Surely this should be ok??

[RaverDave]

Ah!! sussed it out,It didnt like the command splitting up onto another line!
Ok thanks Alot, there is a slight problem in that it doesnt delete a tile at a certain point on the tile,but i think thats coz the block is much smaller than the tile,least I presume!

[stef]

hi

your line works on my computer with PB v1.89m

[RaverDave]

Actually this is odd,and some point it stops the ball but doesnt delete the tile nearest to the ball,but one above it..how do i get around this?
If you mess around long enough you will see..

In fact an easy way to see the problem is approach a tile from the bottom upwards,but offset the block(ball) from the tile to the left so only half the block approaches it..errrr...like this..

Code Select Expand


          |----------------|
          |                    |
          |----------------|

      |-----|
      |-----|    <============== Move Upwards!



[RaverDave]

My Oh My! My artistic example ruined by weird phantom tabs!! Anyhow you get the idea!

[kevin]

I mentioned this above with the original post,  I was hoping once i'd shown the method you could correct the logic to handle mis-aligned cases.

Rather than just dump the working solution, i'll post a little something about why it occurs and how to fix it later.