Map generation

BlitzMax Forums/BlitzMax Beginners Area/Map generation

qim	(Posted 2010) [#1]

I'm working on a map generator based on this blog. So far I have the following code.


SuperStrict

Graphics 800, 600

Global max_x:Int = 512
Global max_y:Int = 512

Global start_x:Int = 0, start_y:Int = 0

Global map:Int[max_x, max_y]

Global grass:Int = 8
Global water:Int = 1

Global tile:Int = 0

Function ClearMap()
	For Local x:Int = 0 To max_x - 1
		For Local y:Int = 0 To max_y - 1
			map[x, y] = 0
		Next
	Next
End Function


Function CreateMap()
	For Local i:Int = 3 To 7 Step 1
		Local grid_size:Int = max_x Shr i
		
		Local grids:Int = max_x / grid_size
		
		For Local x:Int = 0 To grids - 1
			For Local y:Int = 0 To grids - 1
				
				tile = Rand(0, 1)
				
				FillMap(x * grid_size, y * grid_size, grid_size, tile)
			Next
		Next
	Next
End Function


Function FillMap(_x:Int, _y:Int, _size:Int, _tile:Int)
	Local c:Int = CheckSurroundings(_x, _y)

	Select _tile
		Case 0
			If c > water Then _tile = 0
		Case 1
			If c > grass Then _tile = 1
		Default
			_tile = _tile
	End Select
	
	For Local x:Int = _x To _x + _size - 1
		For Local y:Int = _y To _y + _size - 1
			map[x, y] = _tile
		Next
	Next
End Function

Function CheckSurroundings:Int(x:Int, y:Int)
	Local chance:Int = 0
	Local xc:Int, yc:Int
	Local _tile:Int = map[x, y]
	
	xc = x - 1
	yc = y - 1
	If yc < 0 Then yc = max_y - 1
	If xc < 0 Then xc = max_x - 1

	'left 
	If map[xc, y] = _tile Then chance = chance + 1
	'top left
	If map[xc, yc] = _tile Then chance = chance + 1
	'top
	If map[x, yc] = _tile Then chance = chance + 1
	
	xc = x + 1
	If xc > max_x - 1 Then xc = 0

	'top right
	If map[xc, yc] = _tile Then chance = chance + 1
	'right
	If map[xc, y] = _tile Then chance = chance + 1
	
	yc = y + 1
	If yc > max_y - 1 Then yc = 0
	
	'bottom right
	If map[xc, yc] = _tile Then chance = chance + 1
	'bottom
	If map[x, yc] = _tile Then chance = chance + 1
	
	xc = x - 1
	If xc < 0 Then xc = max_x - 1
	'bottom left
	If map[xc, yc] = _tile Then chance = chance + 1
	
	Return chance
			
End Function


Function DrawMap()
	For Local x:Int = 0 To max_x - 1
		For Local y:Int = 0 To max_y - 1
			Select map[x, y]
				Case 0
					SetColor (0, 255, 0)
				Default
					SetColor (0, 0, 255)
			End Select
			Plot (x, y)
		Next
	Next
End Function

CreateMap
DrawMap

While Not KeyDown(KEY_ESCAPE)
		Flip
		
		If KeyHit(KEY_ENTER) Then
			ClearMap
			CreateMap
			DrawMap
		EndIf
Wend

I guess I'm pretty close to a working generator, but at the moment it all ends up in a green and blue noise. :-( Does anyone know, where to fix this?

Last edited 2010