Sunday, July 9, 2017

Monkey-X - Beginners - 2D Vector Rotation - code example

Import mojo

Class vector
    ' A vector has a origin of 0,0. The length and direction
    ' is the x and y variables. 
    Field x:Float
    Field y:Float
    Method New(x:Float=0.0,y:Float=0.0)
        ' Fill in the x and y
        Self.x = x
        Self.y = y
    End Method
    ' This method rotates the input vector by a value(degrees)
    Method rotate:vector(v:vector,val:Int)
        ' create a temporary vector
        Local u:vector = New vector()
        ' rotate the inputted vector and put the data in u.
        u.x = v.x * Cos(val) - v.y * Sin(val)
        u.y = v.x * Sin(val) + v.y * Cos(val)
        ' return the new vector
        Return u
    End Method
End Class

Class MyGame Extends App
    ' some local variables.
    Field alienx:Float=100,alieny:Float=100
    Field myvec:vector
    Method OnCreate()
        ' create the new vector (2,2)
        myvec = New vector(2,2)
    End Method
    Method OnUpdate()        
    End Method
    Method OnRender()
        Cls 0,0,0 
        SetColor 255,255,255
        ' Move the alien based on the vector's x,y
        ' rotate the vector.
        myvec = myvec.rotate(myvec,10)
        ' draw the alien.
        DrawText "2D Vector Rotation",0,0
    End Method
End Class

Function Main()
    New MyGame()
End Function

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