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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
22using std::max;
23using std::min;
24
25TypeHandle ScissorAttrib::_type_handle;
26int ScissorAttrib::_attrib_slot;
27CPT(RenderAttrib) ScissorAttrib::_off_attrib;
28
29/**
30 * Use ScissorAttrib::make() to construct a new ScissorAttrib object.
31 */
32ScissorAttrib::
33ScissorAttrib(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 */
48CPT(RenderAttrib) ScissorAttrib::
49make_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 */
64CPT(RenderAttrib) ScissorAttrib::
65make(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 */
74CPT(RenderAttrib) ScissorAttrib::
75make_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 */
83void ScissorAttrib::
84output(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 */
100int ScissorAttrib::
101compare_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 */
125size_t ScissorAttrib::
126get_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 */
145CPT(RenderAttrib) ScissorAttrib::
146compose_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 */
169void ScissorAttrib::
170register_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 */
179write_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 */
193TypedWritable *ScissorAttrib::
194make_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 */
209void ScissorAttrib::
210fillin(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...
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...
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...
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.
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.