Excel 2D Terrain Generation by Sancarn

'The following code is by sancarn:
'www.youtube.com/sancarn

'Excel Terrain Generator using Noise Map
'LARGELY seed dependant


Function GenerateColumnTopDown(MaxHeight, TopGrass, Y_startcell, X_startcell)
a = Now()

'This function generates a single column of "terrain values". We are basically giving the
'cells ID values which will be used later in the game.

'Range(Cells(Y_1,X_1),Cells(Y_2,X_2)) = ID - sets the value of all cells in the array between Cells (X_1,Y_1) and (X_2,Y_2) to ID.
'Cells(Y,X) = ID - sets the value of cell (X,Y) to ID.

'a = Now() and b = Now() and the "Debug.Print "ColumnGen operation took: "; (b - a)" are
'merely used to find out how long the function takes to execute. This prints to the
'immediate window!

Range(Cells(Y_startcell, X_startcell), Cells(Y_startcell + TopGrass, X_startcell)) = 0
Cells(Y_startcell + TopGrass + 1, X_startcell) = 2
Range(Cells(Y_startcell + TopGrass + 2, X_startcell), Cells(Y_startcell + TopGrass + 3, X_startcell)) = 3
Range(Cells(Y_startcell + TopGrass + 4, X_startcell), Cells(Y_startcell + MaxHeight - 1, X_startcell)) = 1
Cells(Y_startcell + MaxHeight, X_startcell) = 7

‘GenerateColumnTopDown = 0

b = Now()

Debug.Print "ColumnGen operation took: "; (b - a)
End Function






Function NewInternalSeed(seed)

'This function takes the old seed and provides a new seed. We find this new seed by multiplying the
'old seed by Pi.
    'InternalSeed = InternalSeed * π
    Pi = 3.14159265358979

'Finally we take the floor of this value, to make it an integer. Then we take the rightmost 10 characters with the Right() function.
'And finally we take the value depicted by the string from the Right() function with the Val() function.

    NewInternalSeed = Val(Right(Int(seed * Pi), 10))

End Function






Function NewTopGrass(seed, AmpCoefficient, prevTopGrass)

'This function generates the new height of the grass.

'This uses a noise map I created given by certain AmplificationCoefficients between 0 and 5
'AmpCoef| Rand#	0	1	2	3	4	5	6	7	8	9
'0	|	0	-1	0	0	0	0	0	0	0	1
'1	|	0	-1	-1	0	0	0	0	0	1	1
'2	|	0	-2	-1	-1	0	0	0	1	1	2
'3	|	0	-3	-2	-1	0	0	0	1	2	3
'4	|	0	-6	-4	-2	0	0	0	2	4	6
'5	|	0	-8	-6	-4	-2	0	2	4	6	8

'First we change the amp coefficient to the modified amp coefficient which helps with the calculations (instead of having
' to use a look up table)

ModifiedAmpCoefficient = Abs(AmpCoefficient - 5)
If ModifiedAmpCoefficient = 0 Then ModifiedAmpCoefficient = 0.5

'Now we find the Rand# from the newly generated seed.

RandNo = Val(Right(seed, 1))

'Printing off some debug code to the immediate window.

Debug.Print "RandNo = "; RandNo
Debug.Print "ModifiedAmpCoefficient = "; ModifiedAmpCoefficient

'Finally we use the case function to select certain rules to map the Rand# to the correct value in the noise map
'relative to the modified amp coefficient

Select Case RandNo
    Case 0
        NewTopGrass = prevTopGrass
    Case 1, 2, 3, 4
        RandNo = RandNo - 5
            'x = RandNo / ModifiedAmpCoefficient  'Old buggy code
            'RandNo = Int(x) + (x - Int(x) > 0)   'Old buggy code
        RandNo = -1 * Int(Abs(RandNo) / ModifiedAmpCoefficient)
    Case 5, 6, 7, 8, 9
        RandNo = RandNo - 5
        RandNo = Int(RandNo / ModifiedAmpCoefficient)
End Select

'Finally the NewTopGrass is equal to the old top grass + the random number defined by the noise map.
NewTopGrass = prevTopGrass + RandNo
End Function






Sub generateWorld()

'This generates the start of a world in excel.

MaxHeight = 35 'Max Height of world
Y_startcell = 1 'Verticle starting cell position
X_startcell = 50 'Horrizontal starting cell position
seed = 1234967899 'The maps seed
AmpCoefficient = 2 'Amplification Coefficient - From 0 to 5, 0 being flat and 5 being mountainous. 3 suggested
MaxGenCollumns = 60 'Max number of columns to be generated

prevTopGrass = 15 'initial default topgrass (from the top)

 'prevTopGrass = Abs(prevTopGrass - MaxHeight) 'attempt to make top grass from the bottom instead of from the top

For x = 0 To MaxGenCollumns
    Debug.Print "Trial"; x
    Xval = X_startcell + x
    seed = NewInternalSeed(seed)
    prevTopGrass = NewTopGrass(seed, AmpCoefficient, prevTopGrass)

    GenColFunctVariable = GenerateColumnTopDown(MaxHeight, prevTopGrass, Y_startcell, Xval)
Next x

'Finally we do some cursor positioning to try and aid the player into the rendered terrain zone.

    Columns.ColumnWidth = 2
    Rows.RowHeight = 15
    Columns.Select
    Cells(Y_startcell + MaxHeight, X_startcell + MaxGenCollumns).Select
    'Cells(Y_startcell, X_startcell).Select
    Cells(Y_startcell + MaxHeight / 2, X_startcell + MaxGenCollumns / 2).Select
End Sub