One way platform collision?

[AmonParticipant]

Can anyone offer some code? I just can’t get it right.

Basically a one-way jump from beneath the platform on to it. I’m still hacking away at a method. Code below. I’m using tiles 64×64 pixels that I place using an array.

Monkey

Method Update(delta:Float) If Keyboard.KeyHit(Key.Space) And canJump = 1 'direction = 3 'frame = 4 isJumping = 1 canJump = 0 Endif If isJumping = 1 y = y - jumpHeight jumpHeight = jumpHeight - gravity * delta If jumpHeight <= -1.4 isFalling = 1 isJumping = 0 Endif If isFalling = 1 If GameScreen.LevelArray[ x / 64, y / 64] = 1 Endif Endif If GameScreen.LevelArray[x / 64, y / 64] <> 1 And isFalling = 1 y += jumpHeight Endif Endif

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Method Update(delta:Float) If Keyboard.KeyHit(Key.Space) And canJump = 1 'direction = 3 'frame = 4 isJumping = 1 canJump = 0 Endif If isJumping = 1 y = y - jumpHeight jumpHeight = jumpHeight - gravity * delta   If jumpHeight <= -1.4 isFalling = 1 isJumping = 0 Endif If isFalling = 1 If GameScreen.LevelArray[ x / 64, y / 64] = 1   Endif Endif If GameScreen.LevelArray[x / 64, y / 64] <> 1 And isFalling = 1 y += jumpHeight Endif Endif

[DruggedBunnyParticipant]

Don’t know if any good, but the Monkey1 code at the very bottom of this page seems to work…

I didn’t understand Nate’s comment about ceilings here (different thread — second post from bottom), but the gist of his method sounds good.

[PakzParticipant]

I am watching soccer atm so no time to prepare some code. But the way I always look at things like this is by thinking in states.

When the playing is in his jump and going up I set a new variable called jumpingup=true. Another variable like jumpingdown=true if he is falling down. With variables like this I can see when to check for or not check for collision. (if jumpingup=true and myuptilecollision() then …)

I will try to remember to look after the match and make some code.

[PakzParticipant]

I hope this can help a bit. It is not a short piece of code but I did try to add comment.

 

Monkey

#Import "<std>" #Import "<mojo>" Using std.. Using mojo.. Class map Field map:Int[][] Field mapwidth:Int Field mapheight:Int Field tilewidth:Int Field tileheight:Int Field screenwidth:Int Field screenheight:Int Method New(screenwidth:Int,screenheight:Int) Self.screenwidth = screenwidth Self.screenheight = screenheight setlevel1() End Method Method setlevel1() map = New Int[][] ( New Int[]( 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 1, 1, 1, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 1, 1, 1, 1, 0, 0, 0, 0, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 1, 1, 1, 1, 0, 0, 0, 0, 2 ), New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ), New Int[]( 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ) ) mapwidth = map[0].Length mapheight = map.Length End Method End Class Class player ' player x and y Field px:Float Field py:Float ' player widht and heigth Field pw:Int Field ph:Int ' How fast left move and right Field horspeed:Int=3 ' gravity variables Field incy:Float=0 Field falling:Bool=False Field jumping:Bool=False Method New(x:Int,y:Int,w:Int,h:Int) px = x py = y pw = w ph = h End Method ' Player controls Method controls() ' Left and right movement (horspeed is the speed left and right) For Local i:Int=0 Until horspeed ' If we are jumping or falling then we only want to be ' stopped by tile number 2 If jumping=True Or falling = True If Keyboard.KeyDown(Key.Right) And playertc(1,0,2) = False px += 1 End If If Keyboard.KeyDown(Key.Left) And playertc(-1,0,2) = False px -= 1 End If Else 'Here we are not jumping or falling so we want the ' collision with movement left and right to stop when ' hitting any tile number. If Keyboard.KeyDown(Key.Right) And playertc(1,0,99) = False px += 1 End If If Keyboard.KeyDown(Key.Left) And playertc(-1,0,99) = False px -= 1 End If End if Next ' Player jump when press space. We are not jumping or falling right now. If jumping=False And falling=False And Keyboard.KeyHit(Key.Space) jumping=True incy = 5 End If End Method ' ' This method takes care of the falling and jumping for the player Method gravity() ' First check if we have something beneach us ' and if not then fall down. Be sure we are ' not falling or jumping right now. If falling = False And jumping=False If playertc(0,1,99) = False falling=True incy = 0 End If End If ' Code for when jumping state = true If jumping = True incy-=.1 For Local i:Int = 0 Until Ceil(incy) ' If we are not jumping into a solid non jump through tile ' then keep jumping If playertc(0,-1,2) = False py -= 1 Else 'if we touched a tile we can not jump through then init ' falling incy=0 jumping = False falling = True Exit End If Next ' If we run out of jump force(incy) then set to falling If incy<=0 Then jumping=false falling=True incy=0 End If End If ' Code for when the falling state is true If falling=True Then incy+=.05 For Local i:Int=0 Until Ceil(incy) ' If we have nothing beneath us or are not inside anything ' then keep falling If playertc(0,1,99) = False Or playertc(0,0,99) = True py+=1 Else 'if we hit solid bottom falling = False Exit End If Next End If End Method ' Player versus tile collision (uses offsets x1 and y1) ' Here we check if the player is inside any nearby tile around him. ' x1 and y1 is the offset. This way we can check the player position ' and a little bit around him. Method playertc:Bool(x1:Int=0,y1:Int=0,tile:Int) Local cx:Int = (px + x1) / mymap.tilewidth Local cy:Int = (py + y1) / mymap.tileheight For Local y2:Int=cy-1 Until cy+2 For Local x2:Int=cx-1 Until cx+2 If x2>=0 And x2<mymap.mapwidth And y2>=0 And y2<mymap.mapheight ' If we check for tile = 99 then we check for any tile above value 0 If tile=99 Then If mymap.map[y2][x2] > 0 If rectsoverlap(px+x1,py+y1,pw,ph,x2*mymap.tilewidth,y2*mymap.tileheight,mymap.tilewidth,mymap.tileheight) = True Return True End If End If Else 'Here we check the map we are inside of with the inputted tile number If mymap.map[y2][x2] = tile If rectsoverlap(px+x1,py+y1,pw,ph,x2*mymap.tilewidth,y2*mymap.tileheight,mymap.tilewidth,mymap.tileheight) = True Return True End If End If End If End If Next Next Return False End Method ' Draw the player on the screen Method draw(canvas:Canvas) canvas.Color = Color.Blue canvas.DrawRect(px,py,pw,ph) End Method ' Helper function Function rectsoverlap:Bool(x1:Int, y1:Int, w1:Int, h1:Int, x2:Int, y2:Int, w2:Int, h2:Int) If x1 >= (x2 + w2) Or (x1 + w1) <= x2 Then Return False If y1 >= (y2 + h2) Or (y1 + h1) <= y2 Then Return False Return True End Function End Class Global myplayer:player Global mymap:map Class MyWindow Extends Window Method New() ' Set The title of the window... Title="Tilemap example Array of Arrays....." mymap = New map(Width,Height) mymap.tilewidth = Width/mymap.map[0].Length mymap.tileheight = Height/mymap.map.Length myplayer = New player(4*mymap.tilewidth,4*mymap.tileheight,mymap.tilewidth/2,mymap.tileheight/2) End Method Method OnRender( canvas:Canvas ) Override App.RequestRender() ' Activate this method ' Clear with black color canvas.Clear(Color.Black) canvas.Color = Color.White 'Draw the tilemap For Local y:Int=0 Until mymap.map.Length For Local x:Int=0 Until mymap.map[0].Length If mymap.map[y][x] > 0 canvas.DrawRect(x*mymap.tilewidth,y*mymap.tileheight,mymap.tilewidth,mymap.tileheight) End If Next Next ' Do the player controls and draw myplayer.controls() myplayer.gravity() myplayer.draw(canvas) ' if key escape then quit If Keyboard.KeyReleased(Key.Escape) Then App.Terminate() End Method End Class Function Main() New AppInstance New MyWindow App.Run() End Function

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222

#Import "<std>" #Import "<mojo>"   Using std.. Using mojo..     Class map     Field map:Int[][]     Field mapwidth:Int     Field mapheight:Int Field tilewidth:Int Field tileheight:Int     Field screenwidth:Int     Field screenheight:Int Method New(screenwidth:Int,screenheight:Int) Self.screenwidth = screenwidth Self.screenheight = screenheight setlevel1() End Method Method setlevel1()      map = New Int[][] (         New Int[]( 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 1, 1, 1, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 1, 1, 1, 1, 0, 0, 0, 0, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 1, 1, 1, 1, 0, 0, 0, 0, 2 ),         New Int[]( 2, 0, 0, 0, 0, 0, 0, 0, 0, 2 ),         New Int[]( 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 ) )         mapwidth = map[0].Length         mapheight = map.Length End Method End Class   Class player ' player x and y Field px:Float Field py:Float ' player widht and heigth Field pw:Int Field ph:Int ' How fast left move and right Field horspeed:Int=3 ' gravity variables Field incy:Float=0 Field falling:Bool=False Field jumping:Bool=False Method New(x:Int,y:Int,w:Int,h:Int) px = x py = y pw = w ph = h End Method ' Player controls Method controls() ' Left and right movement (horspeed is the speed left and right) For Local i:Int=0 Until horspeed ' If we are jumping or falling then we only want to be ' stopped by tile number 2 If jumping=True Or falling = True If Keyboard.KeyDown(Key.Right) And playertc(1,0,2) = False px += 1 End If If Keyboard.KeyDown(Key.Left) And playertc(-1,0,2) = False px -= 1 End If Else 'Here we are not jumping or falling so we want the ' collision with movement left and right to stop when ' hitting any tile number. If Keyboard.KeyDown(Key.Right) And playertc(1,0,99) = False px += 1 End If If Keyboard.KeyDown(Key.Left) And playertc(-1,0,99) = False px -= 1 End If End if Next ' Player jump when press space. We are not jumping or falling right now. If jumping=False And falling=False And Keyboard.KeyHit(Key.Space) jumping=True incy = 5 End If End Method ' ' This method takes care of the falling and jumping for the player Method gravity() ' First check if we have something beneach us ' and if not then fall down. Be sure we are ' not falling or jumping right now. If falling = False And jumping=False If playertc(0,1,99) = False falling=True incy = 0 End If End If ' Code for when jumping state = true If jumping = True incy-=.1 For Local i:Int = 0 Until Ceil(incy) ' If we are not jumping into a solid non jump through tile ' then keep jumping If playertc(0,-1,2) = False py -= 1 Else 'if we touched a tile we can not jump through then init ' falling incy=0 jumping = False falling = True Exit End If Next ' If we run out of jump force(incy) then set to falling If incy<=0 Then jumping=false falling=True incy=0 End If End If ' Code for when the falling state is true If falling=True Then incy+=.05 For Local i:Int=0 Until Ceil(incy) ' If we have nothing beneath us or are not inside anything ' then keep falling If playertc(0,1,99) = False Or playertc(0,0,99) = True py+=1 Else 'if we hit solid bottom falling = False Exit End If Next End If End Method ' Player versus tile collision (uses offsets x1 and y1) ' Here we check if the player is inside any nearby tile around him. ' x1 and y1 is the offset. This way we can check the player position ' and a little bit around him. Method playertc:Bool(x1:Int=0,y1:Int=0,tile:Int)     Local cx:Int = (px + x1) / mymap.tilewidth     Local cy:Int = (py + y1) / mymap.tileheight     For Local y2:Int=cy-1 Until cy+2     For Local x2:Int=cx-1 Until cx+2         If x2>=0 And x2<mymap.mapwidth And y2>=0 And y2<mymap.mapheight         ' If we check for tile = 99 then we check for any tile above value 0         If tile=99 Then             If mymap.map[y2][x2] > 0                 If rectsoverlap(px+x1,py+y1,pw,ph,x2*mymap.tilewidth,y2*mymap.tileheight,mymap.tilewidth,mymap.tileheight) = True                     Return True                 End If             End If Else 'Here we check the map we are inside of with the inputted tile number             If mymap.map[y2][x2] = tile                 If rectsoverlap(px+x1,py+y1,pw,ph,x2*mymap.tilewidth,y2*mymap.tileheight,mymap.tilewidth,mymap.tileheight) = True                     Return True                 End If             End If End If         End If     Next     Next     Return False End Method ' Draw the player on the screen Method draw(canvas:Canvas) canvas.Color = Color.Blue canvas.DrawRect(px,py,pw,ph) End Method ' Helper function Function rectsoverlap:Bool(x1:Int, y1:Int, w1:Int, h1:Int, x2:Int, y2:Int, w2:Int, h2:Int)      If x1 >= (x2 + w2) Or (x1 + w1) <= x2 Then Return False      If y1 >= (y2 + h2) Or (y1 + h1) <= y2 Then Return False      Return True End Function   End Class   Global myplayer:player Global mymap:map   Class MyWindow Extends Window Method New() ' Set The title of the window... Title="Tilemap example Array of Arrays....." mymap = New map(Width,Height) mymap.tilewidth = Width/mymap.map[0].Length mymap.tileheight = Height/mymap.map.Length myplayer = New player(4*mymap.tilewidth,4*mymap.tileheight,mymap.tilewidth/2,mymap.tileheight/2) End Method Method OnRender( canvas:Canvas ) Override App.RequestRender() ' Activate this method ' Clear with black color canvas.Clear(Color.Black) canvas.Color = Color.White 'Draw the tilemap For Local y:Int=0 Until mymap.map.Length For Local x:Int=0 Until mymap.map[0].Length If mymap.map[y][x] > 0 canvas.DrawRect(x*mymap.tilewidth,y*mymap.tileheight,mymap.tilewidth,mymap.tileheight) End If Next Next ' Do the player controls and draw myplayer.controls() myplayer.gravity() myplayer.draw(canvas) ' if key escape then quit If Keyboard.KeyReleased(Key.Escape) Then App.Terminate() End Method End Class   Function Main() New AppInstance New MyWindow App.Run() End Function

[AmonParticipant]

Thank you. That’s very good of you.

[nerobotParticipant]

I saw link to example of one side platform on Chipmunk homepage…

[coconParticipant]

Thanks Pakz for posting it, this will worth the study.

 

Nerobot, perhaps for full physics capabilities the chipmunk will be better. Or perhaps a combination of custom arcade physics and real physics, would produce very interesting results. There is something weird in arcade physics that are very useful and efficient. I had tried many tests in Processing Box2D with hacks and tuning to achieve that arcade feeling, and not even close enough to the result needed.

 

Also I have seen earlier that Diddy2 framework has a platform example in the works, check it out or ask TheRevils for more information.

[therevillsParticipant]

Basically dont check for any collisions when moving upwards should do it…

[Author]

Posts