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"Platformer with ladders", by nebula

Single screen platformer with ladders

Code

;
; Platformer with ladders
;
; Type : single screen
;
;
; The collision used is done by scanning the 9 tiles ontop and around the
; player. In this example the outside of the map is checked and the block
; tiles. The collision was therefore done with rectsoverlap.
;

;
; A system checks flags whenever a player is ontop of a ladder and changes
; the player onladder states. Also it sets the nearest top and nearest 
; bottom coordinates which we can use to exit the ladder climbing state.
; When the player presses up or down he climbs until the ladderbound is
; reached and then sets the usingladder state to false.
;

;
; Graphics used : 
; Created in the program
; Level size : 
; 9*9 squares
; Special :
; Mouse left places player anywhere on the map

Graphics 500,400,32,2
SetBuffer BackBuffer()

Dim map(9,9)

Type fps
     Field fps,counter,timer
End Type
Global fps.fps = New fps

Type player
     Field x#,y#
     Field jump,fall,grav#
     Field onladder,ladderbottom,laddertop,usingladder
End Type
Global player.player = New player

Type mymap
     Field nothing
     Field block
End Type

Type gfx
     Field tiles[5]
     Field player
End Type
Global gfx.gfx = New gfx

player\grav = 0.1

; Initiate the system
inigfx
readlevel
player\fall = True

Color 255,255,255

While KeyDown(1) = False
     Cls
     drawlevel
     drawplayer
     playercontrol
     levelactive
     gravity
     
     If MouseDown(1) = True Then          player\x = MouseX():          player\y = MouseY()
     updatefps
     Text 0,0,fps\fps
     Flip True
Wend
End

Function playeronladder(x,y)
     px = ((player\x+x) / 32) - 1
     py = ((player\y+y) / 32) - 1
     If RectsOverlap(px,py,1,1,0,0,10,10) = False Then Return
     If map(px,py) = 2 Then Return True
     If map(px,py) = 3 Then Return True
End Function

Function levelactive()
     px = (player\x / 32) - 1
     py = (player\y / 32) - 1
     player\onladder = False
     If RectsOverlap(px,py,1,1,0,0,10,10) = False Then Return
     If map(px,py) = 2 Then player\onladder = True
     If map(px,py) = 3 Then player\onladder = True
     If map(px,py) = 2 Then player\laddertop = py*32 : Line 0,py*32,320,py*32
     If py-1 > 0 
          If map(px,py-1) = 3 Then player\laddertop = py*32
     EndIf
     If py < 9 Then
          If map(px,py+1) = 3 Then player\ladderbottom = py*32+32 : Line 0,py*32+96,320,py*32+96
          If map(px,py+1) = 2 Then player\ladderbottom = py*32+32 : Line 0,py*32+96,320,py*32+96
End If

If player\onladder = False Then player\usingladder = False

End Function

Function gravity()

If player\fall = True Then
          For i=0 To player\grav
          player\y = player\y + .1;player\grav
          If playertilecollision(0,2) = True Or playeronladder(0,2) = True
               player\fall = False
               player\grav = False
               player\y = player\y/32*32     
               player\jump = False     
          End If
          Next
          player\grav = player\grav + .1
     End If

If playertilecollision(0,2) = False And playeronladder(0,2) = False
          If player\usingladder = False
               player\fall = True

End If
     End If
     
     If player\jump = True Then
          player\y=player\y + player\grav
          player\grav = player\grav + .1
          If player\grav > 0 Then player\jump = False : player\fall = True
     End If

End Function

Function playercontrol()
     If KeyDown(200) = True Then ; cursor up jump
          If player\jump = False And player\fall = False
          If player\onladder = False Then
          If playertilecollision(0,0) = False Then
               player\jump = True
               player\grav = -1.55
          End If
          End If
          If player\onladder = True Then
               If playertilecollision(0,-4) = False Then
                    player\y = player\y - 1
                    player\usingladder = True
                    If player\y+16 < player\laddertop Then 
                    player\onladder = False
                    player\usingladder = False
                    End If
               End If
          End If
          End If
     End If
     If KeyDown(205) = True Then ; cursor right ; right
          If playertilecollision(1,0) = False Then
               player\x = player\x + 1
          End If
     End If
     If KeyDown(203) = True Then ; cursor left ; left
          If playertilecollision(-1,0) = False Then
               player\x = player\x - 1
          End If
     End If
     If KeyDown(208) = True Then
          If playeronladder(0,2) = True Then
               If playertilecollision(0,0) = False
               player\onladder = True
               player\usingladder = True     
               player\y = player\y + 1
               If player\y > player\ladderbottom Then 
               player\onladder = False
               player\usingladder = False
               End If
               End If
          End If
     End If
End Function

Function playertilecollision(x1,y1)
;
; This collision checks a segment of the map against the player
;

; collide with walls
px = (player\x-32)/32
py = (player\y-32)/32
For y=-1 To 1
For x=-1 To 1
     If RectsOverlap(px+x,py+y,1,1,0,0,10,10) Then
     ;Rect (px*32)+(x*32),(py*32)+(y*32),32,32,False
     If map(px+x,py+y) = 1 Then
          If RectsOverlap((player\x)+x1,(player\y)+y1,16,18,(px*32)+(x*32)+32,(py*32)+(y*32)+32,32,32) = True Then
               Return True
          End If
     End If
     End If
Next:Next

; out of level
If RectsOverlap(player\x+x1-16,player\y+16+y1,16,16,32,32,9*32,10*32) = False Then Return True

End Function

Function drawplayer()
     DrawImage gfx\player,player\x,player\y
End Function

Function drawlevel()
     For x=0 To 11
          DrawImage gfx\tiles[1],x*32,y*32
          DrawImage gfx\tiles[1],x*32,y*32+11*32
     Next
     For y=0 To 11
          DrawImage gfx\tiles[1],0*32,y*32
          DrawImage gfx\tiles[1],11*32,y*32
     Next
     For y=0 To 9
     For x=0 To 9
          tmp = map(x,y)
          DrawImage gfx\tiles[map(x,y)],x*32+32,y*32+32
     Next:Next
End Function

Function readlevel()
     Restore level1
     For y=0 To 9
     For x=0 To 9
          Read a
          If a = 8 Then player\x = 32*x+32+1 : player\y = 32*y+32+1
          Select a
               Case 0     
               map(x,y) = a
               Case 1
               map(x,y) = a
               Case 2
               map(x,y) = a
               Case 3
               map(x,y) = a
          End Select
     Next:Next
End Function

.level1
Data 9,0,0,0,0,0,0,0,0,0
Data 1,1,3,1,1,1,1,1,1,1
Data 0,0,2,0,0,0,0,0,0,0
Data 1,1,1,1,1,1,1,3,1,1
Data 0,0,0,0,0,0,0,2,0,0
Data 1,3,1,1,1,1,1,1,1,1
Data 0,2,0,0,0,0,0,0,0,0
Data 0,2,0,0,0,0,0,0,0,0
Data 1,1,1,1,1,1,1,1,3,1
Data 8,0,0,0,0,0,0,0,2,0

Function inigfx()
     gfx\tiles[0] = makeblacktile()
     gfx\tiles[1] = makeblocktile()
     gfx\tiles[2] = makeladdertile()
     gfx\tiles[3] = makeladdertile2()
     gfx\player = makeplayer()
End Function

Function makeplayer()
     Local tmpim = CreateImage(16,16)
     SetBuffer ImageBuffer(tmpim)
     ;
     Color 0,255,0
     Oval 0,0,16,16
     Color 255,0,0
     Rect 0,0,16,16,False
     ;
     SetBuffer BackBuffer()
     Return tmpim
End Function

Function makeladdertile2() ; with block behind it
     Local tmpim = CreateImage(32,32)
     SetBuffer ImageBuffer(tmpim)
     ;
     For y=0 To 32 Step 9
          Color 200,200,0
          Rect 2,2+y,30,5
          Color 255,255,255
          For x1=0 To 1
          For y1=0 To 1
          Rect 4+x1*20,2+y,4,4
          Next:Next
     Next
     ;
     SetBuffer BackBuffer()
     Return tmpim
End Function

Function makeladdertile()
     Local tmpim = CreateImage(32,32)
     SetBuffer ImageBuffer(tmpim)
     ;
     ClsColor 0,0,0
     Cls
     For y=0 To 32 Step 9
          Color 200,200,0
          Rect 2,2+y,30,5
          Color 255,255,255
          For x1=0 To 1
          For y1=0 To 1
          Rect 4+x1*20,2+y,4,4
          Next:Next
     Next
     ;
     SetBuffer BackBuffer()
     Return tmpim
End Function

Function makeblocktile()
     Local tmpim = CreateImage(32,32)
     SetBuffer ImageBuffer(tmpim)
     ClsColor 100,100,100
     Cls
     Color 150,150,150
     Rect 0,0,32,32,False
     SetBuffer BackBuffer()
     Return tmpim
End Function

Function makeblacktile()
     Local tmpim = CreateImage(32,32)
     SetBuffer ImageBuffer(tmpim)
     ClsColor 5,5,5
     Cls
     SetBuffer BackBuffer()
     Return tmpim
End Function

Function updatefps()
     fps\counter = fps\counter + 1
     If fps\timer < MilliSecs() Then
          fps\fps = fps\counter
          fps\counter = 0
          fps\timer = MilliSecs() + 1000
     End If
End Function

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