pyvisi/py_src/light.py

"""
@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"
__copyright__="""  Copyright (c) 2006 by ACcESS MNRF
                    http://www.access.edu.au
                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.iservo.edu.au/esys"
__version__="$Revision$"
__date__="$Date$"


import vtk
from position import GlobalPosition
from constant import Viewport

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
        """

        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	@var __author__: name of author
3	@var __copyright__: copyrights
4	@var __license__: licence agreement
5	@var __url__: url entry point on documentation
6	@var __version__: version
7	@var __date__: date of the version
8	"""
9
10	__author__="John Ngui, john.ngui@uq.edu.au"
11	__copyright__=""" Copyright (c) 2006 by ACcESS MNRF
12	http://www.access.edu.au
13	Primary Business: Queensland, Australia"""
14	__license__="""Licensed under the Open Software License version 3.0
15	http://www.opensource.org/licenses/osl-3.0.php"""
16	__url__="http://www.iservo.edu.au/esys"
17	__version__="$Revision$"
18	__date__="$Date$"
19
20
21	import vtk
22	from position import GlobalPosition
23	from constant import Viewport
24
25	class Light:
26	"""
27	Class that defines a light. A light controls the lighting for the
28	rendered object and works in a similar way to L{Camera <camera.Camera>}.
29	"""
30
31	# The SOUTH_WEST default viewport is used when there is only one viewport.
32	# This saves the user from specifying the viewport when there is only one.
33	def __init__(self, scene, viewport = Viewport.SOUTH_WEST):
34	"""
35	Initialise the light.
36
37	@type scene: L{Scene <scene.Scene>} object
38	@param scene: Scene in which components are to be added to
39	@type viewport: L{Viewport <constant.Viewport>} constant
40	@param viewport: Viewport in which objects are to be rendered on
41	"""
42
43	self.__viewport = viewport
44	self.__vtk_light = vtk.vtkLight()
45
46	# Keeps track whether light has been modified.
47	self.__modified = True
48	# Keeps track whether the modification to the light was due to the
49	# instantiation. If it is, then __setupLight() method is called.
50	self.__initialization = True
51	scene._addVisualizationModules(self)
52
53	def __setupLight(self, scene):
54	"""
55	Set up the light and associate it with the renderer.
56
57	@type scene: L{Scene <scene.Scene>} object
58	@param scene: Scene in which objects are to be rendered on
59	"""
60
61	scene._addLight(self.__viewport, self.__vtk_light)
62
63	def setColor(self, color):
64	"""
65	Set the light color.
66
67	@type color: L{Color <constant.Color>} constant
68	@param color: Light color
69	"""
70
71	self.__vtk_light.SetColor(color)
72	self.__modified = True
73
74	def setFocalPoint(self, position):
75	"""
76	Set the focal point of the light.
77
78	@type position: L{GlobalPosition <position.GlobalPosition>} object
79	@param position: Light focal point
80	"""
81
82	self.__vtk_light.SetFocalPoint(position._getGlobalPosition())
83	self.__modified = True
84
85	def setPosition(self, position):
86	"""
87	Set the position of the light.
88
89	@type position: L{GlobalPosition <position.GlobalPosition>} object
90	@param position: Light position
91	"""
92
93	self.__vtk_light.SetPosition(position._getGlobalPosition())
94	self.__modified = True
95
96	# Elevation and azimuth is set to zero so that users do not
97	# have to change both at the same time.
98	def setAngle(self, elevation = 0, azimuth = 0):
99	"""
100	An alternative to set the position and focal point of the light
101	by using the elevation and azimuth.
102
103	@type elevation: Number
104	@param elevation: Degree to rotate the light to the top and bottom
105	@type azimuth: Number
106	@param azimuth: Degree to rotate the light to the left and right
107	"""
108
109	# NOTE: The elevation angle of light does not appear to suffer the same
110	# constraint as the elevation angle of camera where the elevation
111	# angle is constraint between 90/-90.
112	self.__vtk_light.SetDirectionAngle(elevation, azimuth)
113	self.__modified = True
114
115	def setIntensity(self, intensity):
116	"""
117	Set the intensity (brightness) of the light.
118
119	@type intensity: Number
120	@param intensity: Intensity (brightness) of the light
121	"""
122
123	self.__vtk_light.SetIntensity(intensity)
124	self.__modified = True
125
126	def _isModified(self):
127	"""
128	Return whether the Light has been modified.
129
130	@rtype: Boolean
131	@return: True or False
132	"""
133
134	if (self.__modified == True):
135	return True
136	else:
137	return False
138
139	def _render(self, scene):
140	"""
141	Render the light.
142
143	@type scene: L{Scene <scene.Scene>} object
144	@param scene: Scene in which objects are to be rendered on
145	"""
146
147	if(self._isModified() == True):
148	# Will only be true once only when the light is instantiated.
149	if(self.__initialization == True):
150	self.__setupLight(scene)
151	self.__initialization == False
152
153	self.__modified = False
154
155