Panda3D
sequenceNode.cxx
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1/**
2 * PANDA 3D SOFTWARE
3 * Copyright (c) Carnegie Mellon University. All rights reserved.
4 *
5 * All use of this software is subject to the terms of the revised BSD
6 * license. You should have received a copy of this license along
7 * with this source code in a file named "LICENSE."
8 *
9 * @file sequenceNode.cxx
10 * @author drose
11 * @date 2002-03-06
12 */
13
14#include "pandabase.h"
15#include "sequenceNode.h"
16#include "cullTraverser.h"
17
18TypeHandle SequenceNode::_type_handle;
19
20/**
21 *
22 */
23SequenceNode::
24SequenceNode(const SequenceNode &copy) :
26 AnimInterface(copy)
27{
28}
29
30/**
31 * Returns the number of frames in the animation. This is a property of the
32 * animation and may not be directly adjusted by the user (although it may
33 * change without warning with certain kinds of animations, since this is a
34 * virtual method that may be overridden).
35 */
37get_num_frames() const {
38 return get_num_children();
39}
40
41/**
42 * Returns true if it is generally safe to combine this particular kind of
43 * PandaNode with other kinds of PandaNodes of compatible type, adding
44 * children or whatever. For instance, an LODNode should not be combined with
45 * any other PandaNode, because its set of children is meaningful.
46 */
48safe_to_combine() const {
49 return false;
50}
51
52/**
53 * Returns true if it is generally safe to combine the children of this
54 * PandaNode with each other. For instance, an LODNode's children should not
55 * be combined with each other, because the set of children is meaningful.
56 */
59 return false;
60}
61
62/**
63 * Returns a newly-allocated Node that is a shallow copy of this one. It will
64 * be a different Node pointer, but its internal data may or may not be shared
65 * with that of the original Node.
66 */
68make_copy() const {
69 return new SequenceNode(*this);
70}
71
72/**
73 * This function will be called during the cull traversal to perform any
74 * additional operations that should be performed at cull time. This may
75 * include additional manipulation of render state or additional
76 * visible/invisible decisions, or any other arbitrary operation.
77 *
78 * Note that this function will *not* be called unless set_cull_callback() is
79 * called in the constructor of the derived class. It is necessary to call
80 * set_cull_callback() to indicated that we require cull_callback() to be
81 * called.
82 *
83 * By the time this function is called, the node has already passed the
84 * bounding-volume test for the viewing frustum, and the node's transform and
85 * state have already been applied to the indicated CullTraverserData object.
86 *
87 * The return value is true if this node should be visible, or false if it
88 * should be culled.
89 */
92 select_child(get_frame());
93 return true;
94}
95
96/**
97 * Returns the index number of the first visible child of this node, or a
98 * number >= get_num_children() if there are no visible children of this node.
99 * This is called during the cull traversal, but only if
100 * has_selective_visibility() has already returned true. See
101 * has_selective_visibility().
102 */
105 return get_frame();
106}
107
108/**
109 * Should be overridden by derived classes to return true if this kind of node
110 * has the special property that just one of its children is visible at any
111 * given time, and furthermore that the particular visible child can be
112 * determined without reference to any external information (such as a
113 * camera). At present, only SequenceNodes and SwitchNodes fall into this
114 * category.
115 *
116 * If this function returns true, get_visible_child() can be called to return
117 * the index of the currently-visible child.
118 */
121 return true;
122}
123
124/**
125 * Returns the index number of the currently visible child of this node. This
126 * is only meaningful if has_single_child_visibility() has returned true.
127 */
129get_visible_child() const {
130 return get_frame();
131}
132
133/**
134 *
135 */
136void SequenceNode::
137output(std::ostream &out) const {
138 out << get_type() << " " << get_name() << ": ";
139 AnimInterface::output(out);
140}
141
142/**
143 * Tells the BamReader how to create objects of type SequenceNode.
144 */
147 BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
148}
149
150/**
151 * Writes the contents of this object to the datagram for shipping out to a
152 * Bam file.
153 */
155write_datagram(BamWriter *manager, Datagram &dg) {
157 AnimInterface::write_datagram(manager, dg);
158}
159
160/**
161 * This function is called by the BamReader's factory when a new object of
162 * type SequenceNode is encountered in the Bam file. It should create the
163 * SequenceNode and extract its information from the file.
164 */
165TypedWritable *SequenceNode::
166make_from_bam(const FactoryParams &params) {
167 SequenceNode *node = new SequenceNode("");
168 DatagramIterator scan;
169 BamReader *manager;
170
171 parse_params(params, scan, manager);
172 node->fillin(scan, manager);
173
174 return node;
175}
176
177/**
178 * This internal function is called by make_from_bam to read in all of the
179 * relevant data from the BamFile for the new SequenceNode.
180 */
181void SequenceNode::
182fillin(DatagramIterator &scan, BamReader *manager) {
183 SelectiveChildNode::fillin(scan, manager);
184 AnimInterface::fillin(scan, manager);
185}
void parse_params(const FactoryParams &params, DatagramIterator &scan, BamReader *&manager)
Takes in a FactoryParams, passed from a WritableFactory into any TypedWritable's make function,...
Definition: bamReader.I:275
This is the fundamental interface for things that have a play/loop/stop type interface for frame-base...
Definition: animInterface.h:35
get_frame
Returns the current integer frame number.
Definition: animInterface.h:70
This is the fundamental interface for extracting binary objects from a Bam file, as generated by a Ba...
Definition: bamReader.h:110
static WritableFactory * get_factory()
Returns the global WritableFactory for generating TypedWritable objects.
Definition: bamReader.I:177
This is the fundamental interface for writing binary objects to a Bam file, to be extracted later by ...
Definition: bamWriter.h:63
This collects together the pieces of data that are accumulated for each node while walking the scene ...
This object performs a depth-first traversal of the scene graph, with optional view-frustum culling,...
Definition: cullTraverser.h:45
A class to retrieve the individual data elements previously stored in a Datagram.
An ordered list of data elements, formatted in memory for transmission over a socket or writing to a ...
Definition: datagram.h:38
An instance of this class is passed to the Factory when requesting it to do its business and construc...
Definition: factoryParams.h:36
void register_factory(TypeHandle handle, CreateFunc *func, void *user_data=nullptr)
Registers a new kind of thing the Factory will be able to create.
Definition: factory.I:73
A basic node of the scene graph or data graph.
Definition: pandaNode.h:65
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
Definition: pandaNode.cxx:3583
get_num_children
Returns the number of child nodes this node has.
Definition: pandaNode.h:124
A base class for nodes like LODNode and SequenceNode that select only one visible child at a time.
A node that automatically cycles through rendering each one of its children according to its frame ra...
Definition: sequenceNode.h:27
virtual int get_num_frames() const
Returns the number of frames in the animation.
virtual bool safe_to_combine_children() const
Returns true if it is generally safe to combine the children of this PandaNode with each other.
virtual bool has_single_child_visibility() const
Should be overridden by derived classes to return true if this kind of node has the special property ...
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
virtual int get_first_visible_child() const
Returns the index number of the first visible child of this node, or a number >= get_num_children() i...
virtual int get_visible_child() const
Returns the index number of the currently visible child of this node.
virtual bool cull_callback(CullTraverser *trav, CullTraverserData &data)
This function will be called during the cull traversal to perform any additional operations that shou...
virtual bool safe_to_combine() const
Returns true if it is generally safe to combine this particular kind of PandaNode with other kinds of...
virtual PandaNode * make_copy() const
Returns a newly-allocated Node that is a shallow copy of this one.
static void register_with_read_factory()
Tells the BamReader how to create objects of type SequenceNode.
TypeHandle is the identifier used to differentiate C++ class types.
Definition: typeHandle.h:81
Base class for objects that can be written to and read from Bam files.
Definition: typedWritable.h:35
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.