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#########################################################################
#
# Project : Pyaimsalgo
# Module : aimsalgo.transform
# Create date : 2007-07-19
#
# Description :
# 	This file contains TaperingTransform class
#
#########################################################################
import sys, math

from soma import aims

class TaperingTransform :

	def __init__( self, coefficients) :
		self._coefficients = coefficients

	def transform( self, point ) :
		
		x = point[0]
		y = point[1]
		z = point[2]

		zlimit = self._coefficients[0]
		k1 = self._coefficients[1]
		k2 = self._coefficients[2]
		k3 = self._coefficients[3]

		if ( zlimit != 0 ) :
			
			# Apply the tapering transformation
			X = ( ( k1 * z + k3 ) / zlimit + 1) * x
			Y = ( ( k2 * z + k3 )  / zlimit + 1) * y
			Z = z

		else :
			X = x
			Y = y
			Z = z
		
		return aims.Point3df(X, Y, Z)
		
	def inverseTransform( self, point ) :
		
		X = point[0]
		Y = point[1]
		Z = point[2]

		zlimit = self._coefficients[0]
		k1 = self._coefficients[1]
		k2 = self._coefficients[2]
		k3 = self._coefficients[3]

		coef1 = ( ( k1 * Z + k3 ) / zlimit + 1)
		coef2 = ( ( k2 * Z + k3 )  / zlimit + 1)
		
		if ( ( coef1 != 0 ) and ( coef2 != 0 ) ) :
			
			# Apply inverse of the tapering transformation
			x = X / coef1
			y = Y / coef2
			z = Z

		else :
			x = X
			y = Y
			z = Z
		
		return aims.Point3df(x, y, z)