Monkey-X - Topdown Tilemap with player movement code example

Here a short example on how to do topdown tilemaps with player movement. Use the cursor keys to move the player through the map. The player can not go through solid tiles.

Code below :

Import mojo

    Global playerx:Float = 6*32
    Global playery:Float = 11*32
    Const playerwidth:Int = 32
    Const playerheight:Int = 32
    Const screenwidth = 640
    Const screenheight = 480
    Const tilewidth = 32
    Const tileheight = 32
    Const mapwidth:Int=20
    Const mapheight:Int=15
    Global map:Int[][] = [      [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1],
                                [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1],
                                [1,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,1,0,0,1],
                                [1,0,0,0,0,0,0,0,1,1,1,1,1,0,0,0,1,0,0,1],
                                [1,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1],
                                [1,0,1,1,1,1,1,1,1,0,0,0,1,1,0,0,1,1,1,1],
                                [1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1],
                                  [1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1],                       
                                  [1,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,1,0,0,1],
                                  [1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,1],
                                  [1,0,1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1],
                                  [1,0,0,0,0,0,0,0,0,1,1,0,1,1,1,0,0,0,0,1],
                                 [1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1],
                                [1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1],
                                [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1] ]

Class MyGame Extends App

    Method OnCreate()
        SetUpdateRate(60)
    End Method
    Method OnUpdate()  
        For Local i=0 Until 2      
        If KeyDown(KEY_UP)
            If playertc(0,-1) = False
                playery-=1
            End If
        End If
        If KeyDown(KEY_DOWN)
            If playertc(0,1) = False
                playery+=1
            End If
        End If
        If KeyDown(KEY_LEFT)
            If playertc(-1,0) = False
                playerx-=1
            End If
        End If
        If KeyDown(KEY_RIGHT)
            If playertc(1,0) = False
                playerx+=1
            End If
        End If
        Next
    End Method
    Method OnRender()
        Cls 0,0,0 
        drawmap
        drawplayer
        SetColor 255,255,255
        DrawText "Topdown tilemap and player movement - Use Cursor Keys to move",10,10
    End Method
End Class

Function drawplayer:Void()
    SetColor 255,255,0
    DrawOval playerx,playery,playerwidth,playerheight
End Function

Function drawmap:Void()
    SetColor 255,255,255
    For Local y=0 Until mapheight
    For Local x=0 Until mapwidth
        If map[y][x] = 1
            DrawRect x*tilewidth,y*tileheight,tilewidth,tileheight
        End If
    Next
    Next
End Function

' This function returns true if the player coordinates are inside a tile on the map.
Function playertc:Bool(x1:Int=0,y1:Int=0)
    Local cx = (playerx + x1) / tilewidth
    Local cy = (playery + y1) / tileheight
    For Local y2=cy-1 Until cy+2
    For Local x2=cx-1 Until cx+2
        If x2>=0 And x2<mapwidth And y2>=0 And y2<mapheight
            If map[y2][x2] > 0
                If rectsoverlap(playerx+x1,playery+y1,playerwidth,playerheight,x2*tilewidth,y2*tileheight,tilewidth,tileheight) = True
                    Return True
                End If
            End If
        End If
    Next
    Next
    Return False
End 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 Main()
    New MyGame()
End Function