pyvisi/py_src/light.py


########################################################
#
# Copyright (c) 2003-2008 by University of Queensland
# Earth Systems Science Computational Center (ESSCC)
# http://www.uq.edu.au/esscc
#
# Primary Business: Queensland, Australia
# Licensed under the Open Software License version 3.0
# http://www.opensource.org/licenses/osl-3.0.php
#
########################################################

__copyright__="""Copyright (c) 2003-2008 by University of Queensland
Earth Systems Science Computational Center (ESSCC)
http://www.uq.edu.au/esscc
Primary Business: Queensland, Australia"""
__license__="""Licensed under the Open Software License version 3.0
http://www.opensource.org/licenses/osl-3.0.php"""
__url__="https://launchpad.net/escript-finley"

"""
@var __author__: name of author
@var __copyright__: copyrights
@var __license__: licence agreement
@var __url__: url entry point on documentation
@var __version__: version
@var __date__: date of the version
"""

__author__="John Ngui, john.ngui@uq.edu.au"


import vtk
from position import GlobalPosition
from constant import Viewport
from esys.escript import getMPISizeWorld

class Light:
    """
    Class that defines a light. A light controls the lighting for the
    rendered object and works in a similar way to L{Camera <camera.Camera>}.
    """

    # The SOUTH_WEST default viewport is used when there is only one viewport.
    # This saves the user from specifying the viewport when there is only one.
    def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
        """
        Initialise the light.

        @type scene: L{Scene <scene.Scene>} object
        @param scene: Scene in which components are to be added to  
        @type viewport: L{Viewport <constant.Viewport>} constant
        @param viewport: Viewport in which objects are to be rendered on
        """
                if getMPISizeWorld()>1:
                     raise ValueError,"pyvisi.Light is not running on more than one processor."

        self.__viewport = viewport
        self.__vtk_light = vtk.vtkLight()

        # Keeps track whether light has been modified.
        self.__modified = True
        # Keeps track whether the modification to the light was due to the
        # instantiation. If it is, then __setupLight() method is called.
        self.__initialization = True
        scene._addVisualizationModules(self)

    def __setupLight(self, scene):
        """
        Set up the light and associate it with the renderer.

        @type scene: L{Scene <scene.Scene>} object
        @param scene: Scene in which objects are to be rendered on
        """

        scene._addLight(self.__viewport, self.__vtk_light)

    def setColor(self, color):
        """
        Set the light color.

        @type color: L{Color <constant.Color>} constant
        @param color: Light color
        """

        self.__vtk_light.SetColor(color)
        self.__modified = True

    def setFocalPoint(self, position):
        """
        Set the focal point of the light.

        @type position: L{GlobalPosition <position.GlobalPosition>} object
        @param position: Light focal point
        """

        self.__vtk_light.SetFocalPoint(position._getGlobalPosition())
        self.__modified = True

    def setPosition(self, position):
        """
        Set the position of the light.

        @type position: L{GlobalPosition <position.GlobalPosition>} object
        @param position: Light position
        """

        self.__vtk_light.SetPosition(position._getGlobalPosition())
        self.__modified = True

    # Elevation and azimuth is set to zero so that users do not 
    # have to change both at the same time.
    def setAngle(self, elevation = 0, azimuth = 0):
        """
        An alternative to set the position and focal point of the light 
        by using the elevation and azimuth. 

        @type elevation: Number
        @param elevation: Degree to rotate the light to the top and bottom
        @type azimuth: Number
        @param azimuth: Degree to rotate the light to the left and right
        """

        # NOTE: The elevation angle of light does not appear to suffer the same
        # constraint as the elevation angle of camera where the elevation
        # angle is constraint between 90/-90.
        self.__vtk_light.SetDirectionAngle(elevation, azimuth)
        self.__modified = True

    def setIntensity(self, intensity):
        """
        Set the intensity (brightness) of the light.

        @type intensity: Number
        @param intensity: Intensity (brightness) of the light
        """

        self.__vtk_light.SetIntensity(intensity)
        self.__modified = True

    def _isModified(self):
        """
        Return whether the Light has been modified.

        @rtype: Boolean
        @return: True or False
        """

        if (self.__modified == True):
            return True
        else:
            return False

    def _render(self, scene):
        """
        Render the light.

        @type scene: L{Scene <scene.Scene>} object
        @param scene: Scene in which objects are to be rendered on
        """

        if(self._isModified() == True):
            # Will only be true once only when the light is instantiated.
            if(self.__initialization == True): 
                self.__setupLight(scene)
                self.__initialization == False

            self.__modified = False
            

1	ksteube	1809
2			########################################################
3			#
4			# Copyright (c) 2003-2008 by University of Queensland
5			# Earth Systems Science Computational Center (ESSCC)
6			# http://www.uq.edu.au/esscc
7			#
8			# Primary Business: Queensland, Australia
9			# Licensed under the Open Software License version 3.0
10			# http://www.opensource.org/licenses/osl-3.0.php
11			#
12			########################################################
13
14			__copyright__="""Copyright (c) 2003-2008 by University of Queensland
15			Earth Systems Science Computational Center (ESSCC)
16			http://www.uq.edu.au/esscc
17			Primary Business: Queensland, Australia"""
18			__license__="""Licensed under the Open Software License version 3.0
19			http://www.opensource.org/licenses/osl-3.0.php"""
20	jfenwick	2344	__url__="https://launchpad.net/escript-finley"
21	ksteube	1809
22	ksteube	1147	"""
23	jongui	1197	@var __author__: name of author
24			@var __copyright__: copyrights
25			@var __license__: licence agreement
26			@var __url__: url entry point on documentation
27			@var __version__: version
28			@var __date__: date of the version
29	ksteube	1147	"""
30
31	jongui	1197	__author__="John Ngui, john.ngui@uq.edu.au"
32
33
34	ksteube	1147	import vtk
35			from position import GlobalPosition
36			from constant import Viewport
37	gross	2313	from esys.escript import getMPISizeWorld
38	ksteube	1147
39			class Light:
40			"""
41			Class that defines a light. A light controls the lighting for the
42			rendered object and works in a similar way to L{Camera <camera.Camera>}.
43			"""
44
45			# The SOUTH_WEST default viewport is used when there is only one viewport.
46			# This saves the user from specifying the viewport when there is only one.
47	jongui	1148	def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
48	ksteube	1147	"""
49			Initialise the light.
50
51			@type scene: L{Scene <scene.Scene>} object
52			@param scene: Scene in which components are to be added to
53			@type viewport: L{Viewport <constant.Viewport>} constant
54			@param viewport: Viewport in which objects are to be rendered on
55			"""
56	gross	2313	if getMPISizeWorld()>1:
57			raise ValueError,"pyvisi.Light is not running on more than one processor."
58	ksteube	1147
59			self.__viewport = viewport
60			self.__vtk_light = vtk.vtkLight()
61
62	jongui	1148	# Keeps track whether light has been modified.
63			self.__modified = True
64			# Keeps track whether the modification to the light was due to the
65			# instantiation. If it is, then __setupLight() method is called.
66			self.__initialization = True
67	jongui	1158	scene._addVisualizationModules(self)
68	ksteube	1147
69	jongui	1158	def __setupLight(self, scene):
70	ksteube	1147	"""
71			Set up the light and associate it with the renderer.
72	jongui	1158
73			@type scene: L{Scene <scene.Scene>} object
74			@param scene: Scene in which objects are to be rendered on
75	ksteube	1147	"""
76
77	jongui	1158	scene._addLight(self.__viewport, self.__vtk_light)
78	ksteube	1147
79			def setColor(self, color):
80			"""
81			Set the light color.
82
83			@type color: L{Color <constant.Color>} constant
84			@param color: Light color
85			"""
86
87			self.__vtk_light.SetColor(color)
88	jongui	1148	self.__modified = True
89	ksteube	1147
90			def setFocalPoint(self, position):
91			"""
92			Set the focal point of the light.
93
94			@type position: L{GlobalPosition <position.GlobalPosition>} object
95			@param position: Light focal point
96			"""
97
98			self.__vtk_light.SetFocalPoint(position._getGlobalPosition())
99	jongui	1148	self.__modified = True
100	ksteube	1147
101			def setPosition(self, position):
102			"""
103			Set the position of the light.
104
105			@type position: L{GlobalPosition <position.GlobalPosition>} object
106			@param position: Light position
107			"""
108
109			self.__vtk_light.SetPosition(position._getGlobalPosition())
110	jongui	1148	self.__modified = True
111	ksteube	1147
112			# Elevation and azimuth is set to zero so that users do not
113			# have to change both at the same time.
114			def setAngle(self, elevation = 0, azimuth = 0):
115			"""
116			An alternative to set the position and focal point of the light
117			by using the elevation and azimuth.
118
119			@type elevation: Number
120			@param elevation: Degree to rotate the light to the top and bottom
121			@type azimuth: Number
122			@param azimuth: Degree to rotate the light to the left and right
123			"""
124
125			# NOTE: The elevation angle of light does not appear to suffer the same
126			# constraint as the elevation angle of camera where the elevation
127			# angle is constraint between 90/-90.
128			self.__vtk_light.SetDirectionAngle(elevation, azimuth)
129	jongui	1148	self.__modified = True
130	ksteube	1147
131			def setIntensity(self, intensity):
132			"""
133			Set the intensity (brightness) of the light.
134
135			@type intensity: Number
136			@param intensity: Intensity (brightness) of the light
137			"""
138
139			self.__vtk_light.SetIntensity(intensity)
140	jongui	1148	self.__modified = True
141	ksteube	1147
142	jongui	1148	def _isModified(self):
143			"""
144			Return whether the Light has been modified.
145
146			@rtype: Boolean
147			@return: True or False
148			"""
149
150			if (self.__modified == True):
151			return True
152			else:
153			return False
154
155	jongui	1158	def _render(self, scene):
156	jongui	1148	"""
157			Render the light.
158	jongui	1158
159			@type scene: L{Scene <scene.Scene>} object
160			@param scene: Scene in which objects are to be rendered on
161	jongui	1148	"""
162
163			if(self._isModified() == True):
164			# Will only be true once only when the light is instantiated.
165			if(self.__initialization == True):
166	jongui	1158	self.__setupLight(scene)
167	jongui	1148	self.__initialization == False
168
169	jongui	1194	self.__modified = False
170	jongui	1148
171