cVec.tbasicu

' cVec a math vector class
' by kryton9 - Kent Sarikaya 2017
' some functions derived from processing code at
' https://github.com/processing/processing/blob/master/core/src/processing/core/PVector.java
' thanks to Petr Schreiber for contributions to this code

' methods of this class 
' cpy2   : copies this vector to the passed in vector
' cpyFrm : copies to this vector from the passed in vector 
' eqls   : assigns all values x, y, z at one time
' inc    : adds the passed in vector to this vector
' dec    : subtracts the passed in vector from this vector
' scl    : scales this vector by the value passed in 
' div    : divides this vector by the value passed in
' dot    : returns the dot product of this vector and the passed in vector
' dstnc  : returns the distance between this vector and the passed in vector
' cross  : assigns the cross product between this vector and the passed in vector
' limit  : limits the magnitude of this vector
' mag    : returns the magnitude ( length ) of this vector
' nrmlz  : normalize this vector 
' rndmz  : randomizes this vector to random unit vector
' hdng   : returns the heading angle of this vector
' angle  : returns the angle between this vector and the passed in vector
' rot    : rotates this vector by the angle passed in
' txt    : returns formatted string values of this vector
' out    : prints formatted values of this vector
' setMag : set the magnitude of this vector 
' frmAngle : set this vector to this angle
 
Uses "math"

Type cVec
    Public
        x As Single
        y As Single
        z As Single 
    Private 
        vec2 As Boolean ' is this a Vec2 or Vec3, default vec2 is false, auto set when created   

    Public  
        Function _Create ( Optional x As Single = 0, y As Single = 0, z As Single = 0) 
            Me.vec2 = (Function_CParams = 2)
            If Function_CParams = 0 Then Return

            Me.x = x
            Me.y = y 
            Me.z = z
        End Function
         
        ' copies this vector to the passed in vector  
        Function cpy2 ( ByRef vecToCopyTo As cVec )   
            vecToCopyTo.x = Me.x
            vecToCopyTo.y = Me.y 
            vecToCopyTo.z = Me.z   
        End Function 
        
        ' copies to this vector from the passed in vector  
        Function cpyFrm ( copyFromVec As cVec )   
            Me.x = copyFromVec.x
            Me.y = copyFromVec.y
            Me.z = copyFromVec.z   
        End Function
        
        ' assigns all values x, y, z at one time, set is a keyword so used eqls
        Function eqls ( x As Single, y As Single, Optional z As Single = 0)
            Me.vec2 = (Function_CParams = 2)
            Me.x = x
            Me.y = y 
            Me.z = z
        End Function
        
        ' adds the passed in vector to this vector
        ' add is a keyword can't use, so used inc 
        Function inc ( vecToAdd As cVec )   
            Me.x += vecToAdd.x
            Me.y += vecToAdd.y 
            Me.z += vecToAdd.z   
        End Function
        
        ' subtracts the passed in vector from this vector 
        ' sub is a keyword can't use, so used dec
        Function dec ( vecToSub As cVec )   
            Me.x -= vecToSub.x
            Me.y -= vecToSub.y 
            Me.z -= vecToSub.z   
        End Function
        
        ' scales this vector by the value passed in
         Function scl ( scaleByThis As Single )   
            Me.x *= scaleByThis
            Me.y *= scaleByThis 
            Me.z *= scaleByThis   
        End Function
        
        ' divides this vector by the value passed in
        Function div ( divideByThis As Single )
            If divideByThis <> 0 Then   
                Me.x /= divideByThis
                Me.y /= divideByThis 
                Me.z /= divideByThis
            End If   
        End Function
        
        ' returns the dot product of this vector and the passed in vector
        Function dot (otherVec As cVec) As Single
            Return Me.x * otherVec.x + Me.y * otherVec.y + Me.z * otherVec.z
        End Function 
        
        ' returns the distance between this vector and the passed in vector
        ' dist is s keyword so used dstnc
        Function dstnc ( otherVec As cVec ) As Single  
            Single dx = Me.x - otherVec.x
            Single dy = Me.y - otherVec.y
            Single dz = Me.z - otherVec.z
            Return Sqr ( dx * dx + dy * dy + dz * dz)
        End Function
        
        ' the vector: result contains the cross product between this vector
        ' And the passed in vector: otherVec
        Function cross( otherVec As cVec, ByRef result As cVec )
            result.x = Me.y * otherVec.z - otherVec.y * Me.z
            result.y = Me.z * otherVec.x - otherVec.z * Me.x
            result.z = Me.x * otherVec.y - otherVec.x * Me.y
        End Function
        
        ' limits the magnitude of this vector
         Function limit ( limitMax As Single )
            If ( Me.mag > limitMax) Then
                Me.nrmlz
                Me.scl limitMax
            End If
         End Function
         
        ' returns the magnitude ( length ) of this vector 
        Function mag ( ) As Single   
            Return Sqr ( Me.x * Me.x + Me.y * Me.y + Me.z * Me.z )    
        End Function
        
        ' normalize this vector
        Function nrmlz ( )
            Single mag = Me.mag 
            If mag = 0 Then Return  
            Me.x /= mag
            Me.y /= mag
            Me.z /= mag
        End Function 
        
        ' randomizes this vector to random unit vector
        Function rndmz ( )
            Single angle = Rnd() * Pi * 2
            Me.z = Rnd * 2 - 1 
            Me.x = Sqr ( 1 - Me.z * Me.z ) * Cos ( angle )
            Me.y = Sqr ( 1 - Me.z * Me.z ) * Sin ( angle )
        End Function   
        
        ' meant for 2d vectors, returns the heading angle of this vector, ignores z in 3d vectors
        Function hdng ( ) As Single 
            If Me.z = 0 Then
                Return DegToRad ( ATAN2 ( Me.y, Me.x ) )
            Else
                Return 0
            End If
        End Function

        ' returns the angle between this vector and the passed in vector
        Function angle ( v2 As cVec ) As Single
            If ( Me.x = 0 And Me.y = 0 And Me.z = 0 ) Then Return 0.0
            If ( v2.x = 0 And v2.y = 0 And v2.z = 0 ) Then Return 0.0            
            Double dot = Me.x * v2.x + Me.y * v2.y + Me.z * v2.z
            Double v1mag = Me.mag
            Double v2mag = v2.mag
            Double amt = dot / ( v1mag * v2mag )
            If (amt <= -1) Then
                Return Pi
            ElseIf amt >= 1 Then
              Return 0
            End If 

            Return RadToDeg ArcCos amt  
        End Function
    
        ' meant for 2d vectors, rotates this vector, ignores z in 3d vectors
        Function rot (angle As Single)
            Single temp = Me.x
            Me.x = Me.x * Cos ( angle ) - Me.y * Sin ( angle )
            Me.y = temp * Sin ( angle ) + Me.y * Cos ( angle )
        End Function

        ' returns formatted string values of this vector
        Function txt ( Optional numDecimals As Byte ) As String
            If numDecimals = 0 Then numDecimals = 6
            string mask = "#." + repeat$(numDecimals, "0")
             
            If Me.vec2 Then
              Return Format$(Me.x, mask) + ", " + Format$(Me.y, mask)
            Else
              Return Format$(Me.x, mask) + ", " + Format$(Me.y, mask) + ", " + Format$(Me.z, mask)
            End If
        End Function
        
        ' prints formatted values of this vector
        Function out ( Optional numDecimals As Byte ) As Boolean
            If numDecimals = 0 Then numDecimals = 6
            
            PrintL me.txt(numDecimals)
            
            Return TRUE
        End Function 
        
        ' set the magnitude of this vector
        Function setMag ( length As Single ) 
            Me.nrmlz
            Me.scl( length )   
        End Function 
        
        ' set this vector to this angle
        Function frmAngle ( angle As Single ) 
            Me.eqls( Cos ( angle ), Sin ( angle ), 0 )  
        End Function  
End Type