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__="http://www.uq.edu.au/esscc/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
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	__url__="http://www.uq.edu.au/esscc/escript-finley"
21
22	"""
23	@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	"""
30
31	__author__="John Ngui, john.ngui@uq.edu.au"
32
33
34	import vtk
35	from position import GlobalPosition
36	from constant import Viewport
37	from esys.escript import getMPISizeWorld
38
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	def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
48	"""
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	if getMPISizeWorld()>1:
57	raise ValueError,"pyvisi.Light is not running on more than one processor."
58
59	self.__viewport = viewport
60	self.__vtk_light = vtk.vtkLight()
61
62	# 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	scene._addVisualizationModules(self)
68
69	def __setupLight(self, scene):
70	"""
71	Set up the light and associate it with the renderer.
72
73	@type scene: L{Scene <scene.Scene>} object
74	@param scene: Scene in which objects are to be rendered on
75	"""
76
77	scene._addLight(self.__viewport, self.__vtk_light)
78
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	self.__modified = True
89
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	self.__modified = True
100
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	self.__modified = True
111
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	self.__modified = True
130
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	self.__modified = True
141
142	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	def _render(self, scene):
156	"""
157	Render the light.
158
159	@type scene: L{Scene <scene.Scene>} object
160	@param scene: Scene in which objects are to be rendered on
161	"""
162
163	if(self._isModified() == True):
164	# Will only be true once only when the light is instantiated.
165	if(self.__initialization == True):
166	self.__setupLight(scene)
167	self.__initialization == False
168
169	self.__modified = False
170
171