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depthOffsetAttrib.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 depthOffsetAttrib.cxx
10 * @author drose
11 * @date 2002-03-14
12 */
13
14#include "depthOffsetAttrib.h"
16#include "dcast.h"
17#include "bamReader.h"
18#include "bamWriter.h"
19#include "datagram.h"
20#include "datagramIterator.h"
21
22TypeHandle DepthOffsetAttrib::_type_handle;
23int DepthOffsetAttrib::_attrib_slot;
24
25/**
26 * Constructs a new DepthOffsetAttrib object that indicates the relative
27 * amount of bias to write to the depth buffer for subsequent geometry.
28 */
29CPT(RenderAttrib) DepthOffsetAttrib::
30make(int offset) {
31 DepthOffsetAttrib *attrib = new DepthOffsetAttrib(offset, 0.0f, 1.0f);
32 return return_new(attrib);
33}
34
35/**
36 * Constructs a new DepthOffsetAttrib object that indicates the bias, and also
37 * specifies a minimum and maximum (or, more precisely, nearest and farthest)
38 * values to write to the depth buffer, in the range 0 .. 1. This range is 0,
39 * 1 by default; setting it to some other range can be used to create
40 * additional depth buffer effects.
41 */
42CPT(RenderAttrib) DepthOffsetAttrib::
43make(int offset, PN_stdfloat min_value, PN_stdfloat max_value) {
44 nassertr(min_value >= 0.0f && min_value <= 1.0f, nullptr);
45 nassertr(max_value >= 0.0f && max_value <= 1.0f, nullptr);
46 DepthOffsetAttrib *attrib = new DepthOffsetAttrib(offset, min_value, max_value);
47 return return_new(attrib);
48}
49
50/**
51 * Returns a RenderAttrib that corresponds to whatever the standard default
52 * properties for render attributes of this type ought to be.
53 */
54CPT(RenderAttrib) DepthOffsetAttrib::
55make_default() {
56 return return_new(new DepthOffsetAttrib(0, 0.0f, 1.0f));
57}
58
59/**
60 *
61 */
62void DepthOffsetAttrib::
63output(std::ostream &out) const {
64 out << get_type() << ":(" << get_offset() << ", " << get_min_value()
65 << ", " << get_max_value() << ")";
66}
67
68/**
69 * Intended to be overridden by derived DepthOffsetAttrib types to return a
70 * unique number indicating whether this DepthOffsetAttrib is equivalent to
71 * the other one.
72 *
73 * This should return 0 if the two DepthOffsetAttrib objects are equivalent, a
74 * number less than zero if this one should be sorted before the other one,
75 * and a number greater than zero otherwise.
76 *
77 * This will only be called with two DepthOffsetAttrib objects whose
78 * get_type() functions return the same.
79 */
80int DepthOffsetAttrib::
81compare_to_impl(const RenderAttrib *other) const {
82 const DepthOffsetAttrib *ta = (const DepthOffsetAttrib *)other;
83
84 if (_offset != ta->_offset) {
85 return _offset - ta->_offset;
86 }
87 if (_min_value != ta->_min_value) {
88 return _min_value < ta->_min_value ? -1 : 1;
89 }
90 if (_max_value != ta->_max_value) {
91 return _max_value < ta->_max_value ? -1 : 1;
92 }
93 return 0;
94}
95
96/**
97 * Intended to be overridden by derived RenderAttrib types to return a unique
98 * hash for these particular properties. RenderAttribs that compare the same
99 * with compare_to_impl(), above, should return the same hash; RenderAttribs
100 * that compare differently should return a different hash.
101 */
102size_t DepthOffsetAttrib::
103get_hash_impl() const {
104 size_t hash = 0;
105 hash = int_hash::add_hash(hash, _offset);
106 hash = float_hash().add_hash(hash, _min_value);
107 hash = float_hash().add_hash(hash, _max_value);
108 return hash;
109}
110
111/**
112 * Intended to be overridden by derived RenderAttrib types to specify how two
113 * consecutive RenderAttrib objects of the same type interact.
114 *
115 * This should return the result of applying the other RenderAttrib to a node
116 * in the scene graph below this RenderAttrib, which was already applied. In
117 * most cases, the result is the same as the other RenderAttrib (that is, a
118 * subsequent RenderAttrib completely replaces the preceding one). On the
119 * other hand, some kinds of RenderAttrib (for instance, ColorTransformAttrib)
120 * might combine in meaningful ways.
121 */
122CPT(RenderAttrib) DepthOffsetAttrib::
123compose_impl(const RenderAttrib *other) const {
124 const DepthOffsetAttrib *ta = (const DepthOffsetAttrib *)other;
125
126 int new_offset = ta->_offset + _offset;
127
128 DepthOffsetAttrib *attrib = new DepthOffsetAttrib(new_offset, ta->_min_value, ta->_max_value);
129 return return_new(attrib);
130}
131
132/**
133 * Intended to be overridden by derived RenderAttrib types to specify how two
134 * consecutive RenderAttrib objects of the same type interact.
135 *
136 * See invert_compose() and compose_impl().
137 */
138CPT(RenderAttrib) DepthOffsetAttrib::
139invert_compose_impl(const RenderAttrib *other) const {
140 const DepthOffsetAttrib *ta = (const DepthOffsetAttrib *)other;
141
142 int new_offset = ta->_offset - _offset;
143
144 DepthOffsetAttrib *attrib = new DepthOffsetAttrib(new_offset, ta->_min_value, ta->_max_value);
145 return return_new(attrib);
146}
147
148/**
149 * Tells the BamReader how to create objects of type DepthOffsetAttrib.
150 */
151void DepthOffsetAttrib::
152register_with_read_factory() {
153 BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
154}
155
156/**
157 * Writes the contents of this object to the datagram for shipping out to a
158 * Bam file.
159 */
161write_datagram(BamWriter *manager, Datagram &dg) {
162 RenderAttrib::write_datagram(manager, dg);
163
164 dg.add_int32(_offset);
165 if (manager->get_file_minor_ver() >= 31) {
166 dg.add_stdfloat(_min_value);
167 dg.add_stdfloat(_max_value);
168 }
169}
170
171/**
172 * This function is called by the BamReader's factory when a new object of
173 * type DepthOffsetAttrib is encountered in the Bam file. It should create
174 * the DepthOffsetAttrib and extract its information from the file.
175 */
176TypedWritable *DepthOffsetAttrib::
177make_from_bam(const FactoryParams &params) {
178 DepthOffsetAttrib *attrib = new DepthOffsetAttrib(0, 0.0f, 1.0f);
179 DatagramIterator scan;
180 BamReader *manager;
181
182 parse_params(params, scan, manager);
183 attrib->fillin(scan, manager);
184
185 return attrib;
186}
187
188/**
189 * This internal function is called by make_from_bam to read in all of the
190 * relevant data from the BamFile for the new DepthOffsetAttrib.
191 */
192void DepthOffsetAttrib::
193fillin(DatagramIterator &scan, BamReader *manager) {
194 RenderAttrib::fillin(scan, manager);
195
196 _offset = scan.get_int32();
197 _min_value = 0.0f;
198 _max_value = 1.0f;
199 if (manager->get_file_minor_ver() >= 31) {
200 _min_value = scan.get_stdfloat();
201 _max_value = scan.get_stdfloat();
202 }
203}
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.
PN_stdfloat get_stdfloat()
Extracts either a 32-bit or a 64-bit floating-point number, according to Datagram::set_stdfloat_doubl...
int32_t get_int32()
Extracts a signed 32-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_int32(int32_t value)
Adds a signed 32-bit integer to the datagram.
Definition datagram.I:67
void add_stdfloat(PN_stdfloat value)
Adds either a 32-bit or a 64-bit floating-point number, according to set_stdfloat_double().
Definition datagram.I:133
This is a special kind of attribute that instructs the graphics driver to apply an offset or bias to ...
get_offset
Returns the depth offset represented by this attrib.
get_min_value
Returns the value for the minimum (closest) depth value to be stored in the buffer,...
get_max_value
Returns the value for the maximum (farthest) depth value to be stored in the buffer,...
virtual void write_datagram(BamWriter *manager, Datagram &dg)
Writes the contents of this object to the datagram for shipping out to a Bam file.
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.
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.
This hash_compare class hashes a float or a double.
size_t add_hash(size_t start, const Key &key) const
Adds the indicated key into a running hash.
static size_t add_hash(size_t start, const Key &key)
Adds the indicated key into a running hash.
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.