Source code for soma.wip.aimsalgo.transform.bendingtransform

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

from soma import aims

class BendingTransform( object ) :

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

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

		alpha = self._coefficients[0]
		kapa = self._coefficients[1]

		if ( kapa != 0 ) :
			
			# Apply the bending transformation
			kapaInversed = kapa ** -1
			if (kapa > 0) :
				kapaSign = 1
			else :
				kapaSign = -1

			gamma = z * kapa
			r = x * math.cos(alpha) + y * math.sin(alpha)
			r1 = kapaInversed - math.cos(gamma) * (kapaInversed - r)
			
			X = x + math.cos( alpha ) * ( r1 - r )
			Y = y + math.sin( alpha ) * ( r1 - r )
			Z = math.sin(gamma) * (kapaInversed - r)

		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]

		alpha = self._coefficients[0]
		kapa = self._coefficients[1]

		if ( kapa != 0 ) :
			
			# Apply inverse of the bending transformation
			kapaInversed = kapa ** -1
			if (kapa > 0) :
				kapaSign = 1
			else :
				kapaSign = -1

			r1 = X * math.cos(alpha) + Y * math.sin(alpha)
			r = kapaInversed - ( kapaSign * math.sqrt( Z**2 + ( kapaInversed - r1 )**2 ) )
			gamma = math.atan2( Z * kapaSign, ( kapaInversed - r1 ) * kapaSign )
			x = X - math.cos( alpha ) * ( r1 - r )
			y = Y - math.sin( alpha ) * ( r1 - r )
			z = gamma * kapaInversed

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