Monkey-X - Flood Fill (seed fill) and Distance - code example

Import mojo

Global screenwidth:Int=640
Global screenheight:Int=480
Global mapwidth:Int=20
Global mapheight:Int=20
Global tilewidth:Float=Float(screenwidth)/Float(mapwidth)
Global tileheight:Float=Float(screenheight)/Float(mapheight)

Class MyGame Extends App
    Field flood:Bool=False
    Field fillval:Int=1
    Field delay:Int
    Field map:Int[][]
    Field mapd:Int[][] 'map containing the distance (distance map)
    Field floodx:Stack<Int> = New Stack<Int> 'flood 
    Field floody:Stack<Int> = New Stack<Int>
    Field floodv:Stack<Int> = New Stack<Int> 'distance
    Field mx:Int[] = [0,1,0,-1] 'expand up/right/down/left
    Field my:Int[] = [-1,0,1,0]
    Method OnCreate()
        SetUpdateRate(60)
        map = New Int[mapwidth][]
        For Local i=0 Until mapwidth
            map[i] = New Int[mapheight]
        Next
        mapd = New Int[mapwidth][]
        For Local i=0 Until mapwidth
            mapd[i] = New Int[mapheight]
        Next
        For Local x=0 Until mapwidth/2
            map[x][mapheight/2] = 6
        Next
    End Method
    Method OnUpdate()
        Local tx:Int=MouseX()/tilewidth
        Local ty:Int=MouseY()/tileheight
        If MouseDown(MOUSE_LEFT) And flood=False And map[tx][ty] <> 6
            Print "Flooding - "+Millisecs()
            floodx.Clear
            floody.Clear
            map[tx][ty] = fillval
            floodx.Push(tx)
            floody.Push(ty)
            floodv.Push(1)
            flood = True
            fillval+=1
            If fillval > 5 Then fillval = 0
        End If
        If flood = True
            If floodx.Length > 0
            Local x1:Int=floodx.Top
            Local y1:Int=floody.Top
            Local v1:Int=floodv.Top
            floodx.Pop
            floody.Pop
            floodv.Pop
            For Local i=0 Until 4
                Local x2:Int=x1+mx[i]
                Local y2:Int=y1+my[i]
                If x2>=0 And x2<mapwidth And y2>=0 And y2<mapheight
                If Not (map[x2][y2] = fillval) And Not (map[x2][y2] = 6)
                    map[x2][y2] = fillval
                    ' if you insert the new locations at the bottom
                    ' of the list then you will get correct distance values (flooding)
                    floodx.Insert(0,x2)
                    floody.Insert(0,y2)
                    floodv.Insert(0,v1+1)
                    'store the distance in the map
                    mapd[x2][y2] = v1+1
                End If
                End If
            Next
            Else
            flood=False
            Print "Flooding done"
            End If
        End If
    End Method
    Method OnRender()
        For Local y=0 Until mapheight
        For Local x=0 Until mapwidth
            Local col:Int=map[x][y]
            SetColor col*30,col*30,col*30
            DrawRect x*tilewidth,y*tileheight,tilewidth+1,tileheight+1
        Next
        Next
        For Local i=0 Until floodx.Length
                SetColor 255,255,0
            DrawCircle floodx.Get(i)*tilewidth+tilewidth/2,floody.Get(i)*tileheight+tileheight/2,tilewidth/2
        Next
        SetColor 255,255,255
        For Local y=0 Until mapheight
        For Local x=0 Until mapwidth
            DrawText mapd[x][y],x*tilewidth+tilewidth-10,y*tileheight+tileheight-10
        Next
        Next
        SetColor 255,255,255
        DrawText "Press Left Mouse to flood map..",0,0
    End Method

End Class

Function Main()
    New MyGame()
End Function