Panda3D
compassEffect.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 compassEffect.cxx
10  * @author drose
11  * @date 2002-07-16
12  */
13 
14 #include "compassEffect.h"
15 #include "cullTraverserData.h"
16 #include "config_pgraph.h"
17 #include "nodePath.h"
18 #include "bamReader.h"
19 #include "bamWriter.h"
20 #include "datagram.h"
21 #include "datagramIterator.h"
22 
23 TypeHandle CompassEffect::_type_handle;
24 
25 /**
26  * Constructs a new CompassEffect object. If the reference is an empty
27  * NodePath, it means the CompassEffect is relative to the root of the scene
28  * graph; otherwise, it's relative to the indicated node. The properties
29  * bitmask specifies the set of properties that the compass node inherits from
30  * the reference instead of from its parent.
31  */
32 CPT(RenderEffect) CompassEffect::
33 make(const NodePath &reference, int properties) {
34  CompassEffect *effect = new CompassEffect;
35  effect->_reference = reference;
36  effect->_properties = (properties & P_all);
37  return return_new(effect);
38 }
39 
40 /**
41  * Returns true if it is generally safe to transform this particular kind of
42  * RenderEffect by calling the xform() method, false otherwise.
43  */
45 safe_to_transform() const {
46  return false;
47 }
48 
49 /**
50  *
51  */
52 void CompassEffect::
53 output(std::ostream &out) const {
54  out << get_type() << ":";
55  if (_properties == 0) {
56  out << " none";
57  }
58  if ((_properties & P_pos) == P_pos) {
59  out << " xyz";
60  } else {
61  if ((_properties & P_x) != 0) {
62  out << " x";
63  }
64  if ((_properties & P_y) != 0) {
65  out << " y";
66  }
67  if ((_properties & P_z) != 0) {
68  out << " z";
69  }
70  }
71  if ((_properties & P_rot) != 0) {
72  out << " rot";
73  }
74  if ((_properties & P_scale) == P_scale) {
75  out << " scale";
76  } else {
77  if ((_properties & P_sx) != 0) {
78  out << " sx";
79  }
80  if ((_properties & P_sy) != 0) {
81  out << " sy";
82  }
83  if ((_properties & P_sz) != 0) {
84  out << " sz";
85  }
86  }
87  if (!_reference.is_empty()) {
88  out << " reference " << _reference;
89  }
90 }
91 
92 /**
93  * Should be overridden by derived classes to return true if cull_callback()
94  * has been defined. Otherwise, returns false to indicate cull_callback()
95  * does not need to be called for this effect during the cull traversal.
96  */
98 has_cull_callback() const {
99  return true;
100 }
101 
102 /**
103  * If has_cull_callback() returns true, this function will be called during
104  * the cull traversal to perform any additional operations that should be
105  * performed at cull time. This may include additional manipulation of render
106  * state or additional visible/invisible decisions, or any other arbitrary
107  * operation.
108  *
109  * At the time this function is called, the current node's transform and state
110  * have not yet been applied to the net_transform and net_state. This
111  * callback may modify the node_transform and node_state to apply an effective
112  * change to the render state at this level.
113  */
116  CPT(TransformState) &node_transform,
117  CPT(RenderState) &) const {
118  if (_properties == 0) {
119  // Nothing to do.
120  return;
121  }
122 
123  CPT(TransformState) true_net_transform = data.get_net_transform(trav);
124  CPT(TransformState) want_net_transform = true_net_transform;
125  adjust_transform(want_net_transform, node_transform, data.node());
126 
127  // Now compute the transform that will convert true_net_transform to
128  // want_transform. This is inv(true_net_transform) * want_transform.
129  CPT(TransformState) compass_transform =
130  true_net_transform->invert_compose(want_net_transform);
131 
132  // And modify our local node's apparent transform so that
133  // true_net_transform->compose(new_node_transform) produces the same result
134  // we would have gotten had we actually computed
135  // want_transform->compose(orig_node_transform).
136  node_transform = compass_transform->compose(node_transform);
137 }
138 
139 /**
140  * Should be overridden by derived classes to return true if
141  * adjust_transform() has been defined, and therefore the RenderEffect has
142  * some effect on the node's apparent local and net transforms.
143  */
145 has_adjust_transform() const {
146  return (_properties != 0);
147 }
148 
149 /**
150  * Performs some operation on the node's apparent net and/or local transforms.
151  * This will only be called if has_adjust_transform() is redefined to return
152  * true.
153  *
154  * Both parameters are in/out. The original transforms will be passed in, and
155  * they may (or may not) be modified in-place by the RenderEffect.
156  */
158 adjust_transform(CPT(TransformState) &net_transform,
159  CPT(TransformState) &node_transform,
160  const PandaNode *) const {
161  if (_properties == 0) {
162  // Nothing to do.
163  return;
164  }
165 
166  // The reference transform: where we are acting as if we inherit from.
167  // Either the root node (identity) or the specified reference node.
168  CPT(TransformState) ref_transform;
169  if (_reference.is_empty()) {
170  ref_transform = TransformState::make_identity();
171  } else {
172  ref_transform = _reference.get_net_transform();
173  }
174 
175  // Now compute the net transform we actually want to achieve. This is all
176  // of the components from the net transform we want to inherit normally from
177  // our parent, with all of the components from the ref transform we want to
178  // inherit from our reference.
179  CPT(TransformState) want_net_transform;
180  if (_properties == P_all) {
181  // If we want to steal the whole transform, that's easy.
182  want_net_transform = ref_transform;
183 
184  } else {
185  // How much of the pos do we want to steal? We can always determine a
186  // transform's pos, even if it's nondecomposable.
187  LVecBase3 want_pos = net_transform->get_pos();
188  const LVecBase3 &ref_pos = ref_transform->get_pos();
189  if ((_properties & P_x) != 0) {
190  want_pos[0] = ref_pos[0];
191  }
192  if ((_properties & P_y) != 0) {
193  want_pos[1] = ref_pos[1];
194  }
195  if ((_properties & P_z) != 0) {
196  want_pos[2] = ref_pos[2];
197  }
198 
199  if ((_properties & ~P_pos) == 0) {
200  // If we only want to steal the pos, that's pretty easy.
201  want_net_transform = net_transform->set_pos(want_pos);
202 
203  } else if ((_properties & (P_rot | P_scale)) == (P_rot | P_scale)) {
204  // If we want to steal everything *but* the pos, also easy.
205  want_net_transform = ref_transform->set_pos(want_pos);
206 
207  } else {
208  // For any other combination, we have to be able to decompose both
209  // transforms.
210  if (!net_transform->has_components() ||
211  !ref_transform->has_components()) {
212  // If we can't decompose, just do the best we can: steal everything
213  // but the pos.
214  want_net_transform = ref_transform->set_pos(want_pos);
215 
216  } else {
217  // If we can decompose, then take only the components we want.
218  LQuaternion want_quat = net_transform->get_quat();
219  if ((_properties & P_rot) != 0) {
220  want_quat = ref_transform->get_quat();
221  }
222 
223  LVecBase3 want_scale = net_transform->get_scale();
224  const LVecBase3 &ref_scale = ref_transform->get_scale();
225  if ((_properties & P_sx) != 0) {
226  want_scale[0] = ref_scale[0];
227  }
228  if ((_properties & P_sy) != 0) {
229  want_scale[1] = ref_scale[1];
230  }
231  if ((_properties & P_sz) != 0) {
232  want_scale[2] = ref_scale[2];
233  }
234 
235  want_net_transform =
236  TransformState::make_pos_quat_scale(want_pos, want_quat, want_scale);
237  }
238  }
239  }
240 
241  net_transform = want_net_transform;
242 }
243 
244 /**
245  * Intended to be overridden by derived CompassEffect types to return a unique
246  * number indicating whether this CompassEffect is equivalent to the other
247  * one.
248  *
249  * This should return 0 if the two CompassEffect objects are equivalent, a
250  * number less than zero if this one should be sorted before the other one,
251  * and a number greater than zero otherwise.
252  *
253  * This will only be called with two CompassEffect objects whose get_type()
254  * functions return the same.
255  */
256 int CompassEffect::
257 compare_to_impl(const RenderEffect *other) const {
258  const CompassEffect *ta;
259  DCAST_INTO_R(ta, other, 0);
260 
261  if (_properties != ta->_properties) {
262  return _properties - ta->_properties;
263  }
264  int compare = _reference.compare_to(ta->_reference);
265  if (compare != 0) {
266  return compare;
267  }
268  return 0;
269 }
270 
271 /**
272  * Tells the BamReader how to create objects of type CompassEffect.
273  */
276  BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
277 }
278 
279 /**
280  * Writes the contents of this object to the datagram for shipping out to a
281  * Bam file.
282  */
284 write_datagram(BamWriter *manager, Datagram &dg) {
285  RenderEffect::write_datagram(manager, dg);
286  dg.add_uint16(_properties);
287 
288  if (manager->get_file_minor_ver() >= 43) {
289  _reference.write_datagram(manager, dg);
290  }
291 }
292 
293 /**
294  * Receives an array of pointers, one for each time manager->read_pointer()
295  * was called in fillin(). Returns the number of pointers processed.
296  */
298 complete_pointers(TypedWritable **p_list, BamReader *manager) {
299  int pi = RenderEffect::complete_pointers(p_list, manager);
300 
301  if (manager->get_file_minor_ver() >= 43) {
302  pi += _reference.complete_pointers(p_list + pi, manager);
303  }
304 
305  return pi;
306 }
307 
308 /**
309  * This function is called by the BamReader's factory when a new object of
310  * type CompassEffect is encountered in the Bam file. It should create the
311  * CompassEffect and extract its information from the file.
312  */
313 TypedWritable *CompassEffect::
314 make_from_bam(const FactoryParams &params) {
315  CompassEffect *effect = new CompassEffect;
316  DatagramIterator scan;
317  BamReader *manager;
318 
319  parse_params(params, scan, manager);
320  effect->fillin(scan, manager);
321 
322  return effect;
323 }
324 
325 /**
326  * This internal function is called by make_from_bam to read in all of the
327  * relevant data from the BamFile for the new CompassEffect.
328  */
329 void CompassEffect::
330 fillin(DatagramIterator &scan, BamReader *manager) {
331  RenderEffect::fillin(scan, manager);
332  _properties = scan.get_uint16();
333 
334  if (manager->get_file_minor_ver() >= 43) {
335  _reference.fillin(scan, manager);
336  }
337 }
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
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
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
This is the fundamental interface for extracting binary objects from a Bam file, as generated by a Ba...
Definition: bamReader.h:110
int get_file_minor_ver() const
Returns the minor version number of the Bam file currently being read.
Definition: bamReader.I:83
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
int get_file_minor_ver() const
Returns the minor version number of the Bam file currently being written.
Definition: bamWriter.I:59
A CompassEffect causes a node to inherit its rotation (or pos or scale, if specified) from some other...
Definition: compassEffect.h:46
virtual void cull_callback(CullTraverser *trav, CullTraverserData &data, CPT(TransformState) &node_transform, CPT(RenderState) &node_state) const
If has_cull_callback() returns true, this function will be called during the cull traversal to perfor...
virtual bool has_adjust_transform() const
Should be overridden by derived classes to return true if adjust_transform() has been defined,...
virtual void adjust_transform(CPT(TransformState) &net_transform, CPT(TransformState) &node_transform, const PandaNode *node) const
Performs some operation on the node's apparent net and/or local transforms.
virtual int complete_pointers(TypedWritable **plist, BamReader *manager)
Receives an array of pointers, one for each time manager->read_pointer() was called in fillin().
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
static void register_with_read_factory()
Tells the BamReader how to create objects of type CompassEffect.
virtual bool has_cull_callback() const
Should be overridden by derived classes to return true if cull_callback() has been defined.
virtual bool safe_to_transform() const
Returns true if it is generally safe to transform this particular kind of RenderEffect by calling the...
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.
uint16_t get_uint16()
Extracts an unsigned 16-bit integer.
An ordered list of data elements, formatted in memory for transmission over a socket or writing to a ...
Definition: datagram.h:38
void add_uint16(uint16_t value)
Adds an unsigned 16-bit integer to the datagram.
Definition: datagram.I:85
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
NodePath is the fundamental system for disambiguating instances, and also provides a higher-level int...
Definition: nodePath.h:159
void fillin(DatagramIterator &scan, BamReader *manager)
This internal function is called by make_from_bam to read in all of the relevant data from the BamFil...
Definition: nodePath.cxx:6994
bool is_empty() const
Returns true if the NodePath contains no nodes.
Definition: nodePath.I:188
int complete_pointers(TypedWritable **plist, BamReader *manager)
Receives an array of pointers, one for each time manager->read_pointer() was called in fillin().
Definition: nodePath.cxx:6934
int compare_to(const NodePath &other) const
Returns a number less than zero if this NodePath sorts before the other one, greater than zero if it ...
Definition: nodePath.I:1965
void write_datagram(BamWriter *manager, Datagram &dg) const
Writes the contents of this object to the datagram for shipping out to a Bam file.
Definition: nodePath.cxx:6883
A basic node of the scene graph or data graph.
Definition: pandaNode.h:65
This is the base class for a number of special render effects that may be set on scene graph nodes to...
Definition: renderEffect.h:48
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
This represents a unique collection of RenderAttrib objects that correspond to a particular renderabl...
Definition: renderState.h:47
Indicates a coordinate-system transform on vertices.
get_quat
Returns the rotation component of the transform as a quaternion.
get_scale
Returns the scale component of the transform.
bool has_components() const
Returns true if the transform can be described by separate pos, hpr, and scale components.
get_pos
Returns the pos component of the transform.
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
virtual int complete_pointers(TypedWritable **p_list, BamReader *manager)
Receives an array of pointers, one for each time manager->read_pointer() was called in fillin().
CPT(RenderEffect) CompassEffect
Constructs a new CompassEffect object.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.