Panda3D
scissorAttrib.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 scissorAttrib.cxx
10  * @author drose
11  * @date 2008-07-29
12  */
13 
14 #include "scissorAttrib.h"
16 #include "dcast.h"
17 #include "bamReader.h"
18 #include "bamWriter.h"
19 #include "datagram.h"
20 #include "datagramIterator.h"
21 
22 using std::max;
23 using std::min;
24 
25 TypeHandle ScissorAttrib::_type_handle;
26 int ScissorAttrib::_attrib_slot;
27 CPT(RenderAttrib) ScissorAttrib::_off_attrib;
28 
29 /**
30  * Use ScissorAttrib::make() to construct a new ScissorAttrib object.
31  */
32 ScissorAttrib::
33 ScissorAttrib(const LVecBase4 &frame) :
34  _frame(frame),
35  _off(false)
36 {
37  // Impose sensible bounds.
38  _frame[0] = max(min(_frame[0], (PN_stdfloat)1.0), (PN_stdfloat)0.0);
39  _frame[1] = max(min(_frame[1], (PN_stdfloat)1.0), _frame[0]);
40  _frame[2] = max(min(_frame[2], (PN_stdfloat)1.0), (PN_stdfloat)0.0);
41  _frame[3] = max(min(_frame[3], (PN_stdfloat)1.0), _frame[2]);
42 }
43 
44 /**
45  * Constructs a new ScissorAttrib object that removes the scissor region and
46  * fills the DisplayRegion.
47  */
48 CPT(RenderAttrib) ScissorAttrib::
49 make_off() {
50  if (_off_attrib != nullptr) {
51  return _off_attrib;
52  }
53  ScissorAttrib *attrib = new ScissorAttrib(LVecBase4(0.0f, 1.0f, 0.0f, 1.0f));
54  attrib->_off = true;
55  _off_attrib = return_new(attrib);
56  return _off_attrib;
57 }
58 
59 /**
60  * Constructs a ScissorAttrib that restricts rendering to the indicated frame
61  * within the current DisplayRegion. (0,0) is the lower-left corner of the
62  * DisplayRegion, and (1,1) is the upper-right corner.
63  */
64 CPT(RenderAttrib) ScissorAttrib::
65 make(const LVecBase4 &frame) {
66  ScissorAttrib *attrib = new ScissorAttrib(frame);
67  return return_new(attrib);
68 }
69 
70 /**
71  * Returns a RenderAttrib that corresponds to whatever the standard default
72  * properties for render attributes of this type ought to be.
73  */
74 CPT(RenderAttrib) ScissorAttrib::
75 make_default() {
76  return make_off();
77  // return return_new(new ScissorAttrib(LVecBase4(0.0f, 1.0f, 0.0f, 1.0f)));
78 }
79 
80 /**
81  *
82  */
83 void ScissorAttrib::
84 output(std::ostream &out) const {
85  out << get_type() << ":[" << _frame << "]";
86 }
87 
88 /**
89  * Intended to be overridden by derived ScissorAttrib types to return a unique
90  * number indicating whether this ScissorAttrib is equivalent to the other
91  * one.
92  *
93  * This should return 0 if the two ScissorAttrib objects are equivalent, a
94  * number less than zero if this one should be sorted before the other one,
95  * and a number greater than zero otherwise.
96  *
97  * This will only be called with two ScissorAttrib objects whose get_type()
98  * functions return the same.
99  */
100 int ScissorAttrib::
101 compare_to_impl(const RenderAttrib *other) const {
102  const ScissorAttrib *ta = (const ScissorAttrib *)other;
103 
104  if (_off && ta->_off) {
105  return 0;
106  }
107 
108  if (_off && !ta->_off) {
109  return -1;
110  }
111 
112  if (!_off && ta->_off) {
113  return 1;
114  }
115 
116  return _frame.compare_to(ta->_frame);
117 }
118 
119 /**
120  * Intended to be overridden by derived RenderAttrib types to return a unique
121  * hash for these particular properties. RenderAttribs that compare the same
122  * with compare_to_impl(), above, should return the same hash; RenderAttribs
123  * that compare differently should return a different hash.
124  */
125 size_t ScissorAttrib::
126 get_hash_impl() const {
127  size_t hash = 0;
128  if (!_off) {
129  hash = _frame.add_hash(hash);
130  }
131  return hash;
132 }
133 
134 /**
135  * Intended to be overridden by derived RenderAttrib types to specify how two
136  * consecutive RenderAttrib objects of the same type interact.
137  *
138  * This should return the result of applying the other RenderAttrib to a node
139  * in the scene graph below this RenderAttrib, which was already applied. In
140  * most cases, the result is the same as the other RenderAttrib (that is, a
141  * subsequent RenderAttrib completely replaces the preceding one). On the
142  * other hand, some kinds of RenderAttrib (for instance, ColorTransformAttrib)
143  * might combine in meaningful ways.
144  */
145 CPT(RenderAttrib) ScissorAttrib::
146 compose_impl(const RenderAttrib *other) const {
147  if (_off) {
148  return other;
149  }
150 
151  const ScissorAttrib *ta = (const ScissorAttrib *)other;
152 
153  if (ta->_off) {
154  return this;
155  }
156 
157  LVecBase4 new_frame(max(ta->_frame[0], _frame[0]),
158  min(ta->_frame[1], _frame[1]),
159  max(ta->_frame[2], _frame[2]),
160  min(ta->_frame[3], _frame[3]));
161 
162  ScissorAttrib *attrib = new ScissorAttrib(new_frame);
163  return return_new(attrib);
164 }
165 
166 /**
167  * Tells the BamReader how to create objects of type ScissorAttrib.
168  */
169 void ScissorAttrib::
170 register_with_read_factory() {
171  BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
172 }
173 
174 /**
175  * Writes the contents of this object to the datagram for shipping out to a
176  * Bam file.
177  */
179 write_datagram(BamWriter *manager, Datagram &dg) {
180  RenderAttrib::write_datagram(manager, dg);
181 
182  _frame.write_datagram(dg);
183  if (manager->get_file_minor_ver() >= 34) {
184  dg.add_bool(_off);
185  }
186 }
187 
188 /**
189  * This function is called by the BamReader's factory when a new object of
190  * type ScissorAttrib is encountered in the Bam file. It should create the
191  * ScissorAttrib and extract its information from the file.
192  */
193 TypedWritable *ScissorAttrib::
194 make_from_bam(const FactoryParams &params) {
195  ScissorAttrib *attrib = new ScissorAttrib(LVecBase4(0.0f, 1.0f, 0.0f, 1.0f));
196  DatagramIterator scan;
197  BamReader *manager;
198 
199  parse_params(params, scan, manager);
200  attrib->fillin(scan, manager);
201 
202  return attrib;
203 }
204 
205 /**
206  * This internal function is called by make_from_bam to read in all of the
207  * relevant data from the BamFile for the new ScissorAttrib.
208  */
209 void ScissorAttrib::
210 fillin(DatagramIterator &scan, BamReader *manager) {
211  RenderAttrib::fillin(scan, manager);
212 
213  _frame.read_datagram(scan);
214  _off = false;
215 
216  if (manager->get_file_minor_ver() >= 34) {
217  _off = scan.get_bool();
218  }
219 }
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 class to retrieve the individual data elements previously stored in a Datagram.
bool get_bool()
Extracts a boolean value.
An ordered list of data elements, formatted in memory for transmission over a socket or writing to a ...
Definition: datagram.h:38
void add_bool(bool value)
Adds a boolean value to the datagram.
Definition: datagram.I:34
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
This is the base class for a number of render attributes (other than transform) that may be set on sc...
Definition: renderAttrib.h:51
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 restricts rendering to within a rectangular region of the scene, without otherwise affecting the...
Definition: scissorAttrib.h:36
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
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.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.
CPT(RenderAttrib) ScissorAttrib
Constructs a new ScissorAttrib object that removes the scissor region and fills the DisplayRegion.
PANDA 3D SOFTWARE Copyright (c) Carnegie Mellon University.