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lightRampAttrib.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 lightRampAttrib.cxx
10 * @author drose
11 * @date 2002-03-04
12 */
13
14#include "lightRampAttrib.h"
16#include "dcast.h"
17#include "bamReader.h"
18#include "bamWriter.h"
19#include "datagram.h"
20#include "datagramIterator.h"
21
22TypeHandle LightRampAttrib::_type_handle;
23int LightRampAttrib::_attrib_slot;
24CPT(RenderAttrib) LightRampAttrib::_default;
25
26/**
27 * Constructs a new LightRampAttrib object. This is the standard OpenGL
28 * lighting ramp, which clamps the final light total to the 0-1 range.
29 */
30CPT(RenderAttrib) LightRampAttrib::
31make_default() {
32 if (_default == nullptr) {
33 LightRampAttrib *attrib = new LightRampAttrib();
34 _default = return_new(attrib);
35 }
36 return _default;
37}
38
39/**
40 * Constructs a new LightRampAttrib object. This differs from the usual
41 * OpenGL lighting model in that it does not clamp the final lighting total to
42 * (0,1).
43 */
44CPT(RenderAttrib) LightRampAttrib::
45make_identity() {
46 LightRampAttrib *attrib = new LightRampAttrib();
47 attrib->_mode = LRT_identity;
48 return return_new(attrib);
49}
50
51/**
52 * Constructs a new LightRampAttrib object. This causes the luminance of the
53 * diffuse lighting contribution to be quantized using a single threshold:
54 *
55 * @code
56 * if (original_luminance > threshold0) {
57 * luminance = level0;
58 * } else {
59 * luminance = 0.0;
60 * }
61 * @endcode
62 */
63CPT(RenderAttrib) LightRampAttrib::
64make_single_threshold(PN_stdfloat thresh0, PN_stdfloat val0) {
65 LightRampAttrib *attrib = new LightRampAttrib();
66 attrib->_mode = LRT_single_threshold;
67 attrib->_threshold[0] = thresh0;
68 attrib->_level[0] = val0;
69 return return_new(attrib);
70}
71
72/**
73 * Constructs a new LightRampAttrib object. This causes the luminance of the
74 * diffuse lighting contribution to be quantized using two thresholds:
75 *
76 * @code
77 * if (original_luminance > threshold1) {
78 * luminance = level1;
79 * } else if (original_luminance > threshold0) {
80 * luminance = level0;
81 * } else {
82 * luminance = 0.0;
83 * }
84 * @endcode
85 */
86CPT(RenderAttrib) LightRampAttrib::
87make_double_threshold(PN_stdfloat thresh0, PN_stdfloat val0, PN_stdfloat thresh1, PN_stdfloat val1) {
88 LightRampAttrib *attrib = new LightRampAttrib();
89 attrib->_mode = LRT_double_threshold;
90 attrib->_threshold[0] = thresh0;
91 attrib->_level[0] = val0;
92 attrib->_threshold[1] = thresh1;
93 attrib->_level[1] = val1;
94 return return_new(attrib);
95}
96
97/**
98 * Constructs a new LightRampAttrib object. This causes an HDR tone mapping
99 * operation to be applied.
100 *
101 * Normally, brightness values greater than 1 cannot be distinguished from
102 * each other, causing very brightly lit objects to wash out white and all
103 * detail to be erased. HDR tone mapping remaps brightness values in the
104 * range 0-infinity into the range (0,1), making it possible to distinguish
105 * detail in scenes whose brightness exceeds 1.
106 *
107 * However, the monitor has finite contrast. Normally, all of that contrast
108 * is used to represent brightnesses in the range 0-1. The HDR0 tone mapping
109 * operator 'steals' one quarter of that contrast to represent brightnesses in
110 * the range 1-infinity.
111 *
112 * @code
113 * FINAL_RGB = (RGB^3 + RGB^2 + RGB) / (RGB^3 + RGB^2 + RGB + 1)
114 * @endcode
115 */
116CPT(RenderAttrib) LightRampAttrib::
117make_hdr0() {
118 LightRampAttrib *attrib = new LightRampAttrib();
119 attrib->_mode = LRT_hdr0;
120 return return_new(attrib);
121}
122
123/**
124 * Constructs a new LightRampAttrib object. This causes an HDR tone mapping
125 * operation to be applied.
126 *
127 * Normally, brightness values greater than 1 cannot be distinguished from
128 * each other, causing very brightly lit objects to wash out white and all
129 * detail to be erased. HDR tone mapping remaps brightness values in the
130 * range 0-infinity into the range (0,1), making it possible to distinguish
131 * detail in scenes whose brightness exceeds 1.
132 *
133 * However, the monitor has finite contrast. Normally, all of that contrast
134 * is used to represent brightnesses in the range 0-1. The HDR1 tone mapping
135 * operator 'steals' one third of that contrast to represent brightnesses in
136 * the range 1-infinity.
137 *
138 * @code
139 * FINAL_RGB = (RGB^2 + RGB) / (RGB^2 + RGB + 1)
140 * @endcode
141 */
142CPT(RenderAttrib) LightRampAttrib::
143make_hdr1() {
144 LightRampAttrib *attrib = new LightRampAttrib();
145 attrib->_mode = LRT_hdr1;
146 return return_new(attrib);
147}
148
149/**
150 * Constructs a new LightRampAttrib object. This causes an HDR tone mapping
151 * operation to be applied.
152 *
153 * Normally, brightness values greater than 1 cannot be distinguished from
154 * each other, causing very brightly lit objects to wash out white and all
155 * detail to be erased. HDR tone mapping remaps brightness values in the
156 * range 0-infinity into the range (0,1), making it possible to distinguish
157 * detail in scenes whose brightness exceeds 1.
158 *
159 * However, the monitor has finite contrast. Normally, all of that contrast
160 * is used to represent brightnesses in the range 0-1. The HDR2 tone mapping
161 * operator 'steals' one half of that contrast to represent brightnesses in
162 * the range 1-infinity.
163 *
164 * @code
165 * FINAL_RGB = (RGB) / (RGB + 1)
166 * @endcode
167 */
168CPT(RenderAttrib) LightRampAttrib::
169make_hdr2() {
170 LightRampAttrib *attrib = new LightRampAttrib();
171 attrib->_mode = LRT_hdr2;
172 return return_new(attrib);
173}
174
175/**
176 *
177 */
178void LightRampAttrib::
179output(std::ostream &out) const {
180 out << get_type() << ":";
181 switch (_mode) {
182 case LRT_default:
183 out << "default()";
184 break;
185 case LRT_identity:
186 out << "identity()";
187 break;
188 case LRT_single_threshold:
189 out << "single_threshold(" << _level[0] << "," << _level[1] << "," << _threshold[0] << ")";
190 break;
191 case LRT_double_threshold:
192 out << "double_threshold(" << _level[0] << "," << _level[1] << "," << _threshold[0] << "," << _threshold[1] << ")";
193 break;
194 case LRT_hdr0:
195 out << "hdr0()";
196 break;
197 case LRT_hdr1:
198 out << "hdr1()";
199 break;
200 case LRT_hdr2:
201 out << "hdr2()";
202 break;
203 }
204}
205
206/**
207 * Intended to be overridden by derived LightRampAttrib types to return a
208 * unique number indicating whether this LightRampAttrib is equivalent to the
209 * other one.
210 *
211 * This should return 0 if the two LightRampAttrib objects are equivalent, a
212 * number less than zero if this one should be sorted before the other one,
213 * and a number greater than zero otherwise.
214 *
215 * This will only be called with two LightRampAttrib objects whose get_type()
216 * functions return the same.
217 */
218int LightRampAttrib::
219compare_to_impl(const RenderAttrib *other) const {
220 const LightRampAttrib *ta = (const LightRampAttrib *)other;
221
222 int compare_result = ((int)_mode - (int)ta->_mode) ;
223 if (compare_result != 0) {
224 return compare_result;
225 }
226 for (int i = 0; i < 2; i++) {
227 if (_level[i] != ta->_level[i]) {
228 return (_level[i] < ta->_level[i]) ? -1 : 1;
229 }
230 }
231 for (int i = 0; i < 2; i++) {
232 if (_threshold[i] != ta->_threshold[i]) {
233 return (_threshold[i] < ta->_threshold[i]) ? -1 : 1;
234 }
235 }
236 return 0;
237}
238
239/**
240 * Intended to be overridden by derived RenderAttrib types to return a unique
241 * hash for these particular properties. RenderAttribs that compare the same
242 * with compare_to_impl(), above, should return the same hash; RenderAttribs
243 * that compare differently should return a different hash.
244 */
245size_t LightRampAttrib::
246get_hash_impl() const {
247 size_t hash = 0;
248 hash = int_hash::add_hash(hash, (int)_mode);
249 float_hash fh;
250 for (int i = 0; i < 2; i++) {
251 hash = fh.add_hash(hash, _level[i]);
252 hash = fh.add_hash(hash, _threshold[i]);
253 }
254 return hash;
255}
256
257/**
258 * Tells the BamReader how to create objects of type LightRampAttrib.
259 */
262 BamReader::get_factory()->register_factory(get_class_type(), make_from_bam);
263}
264
265/**
266 * Writes the contents of this object to the datagram for shipping out to a
267 * Bam file.
268 */
270write_datagram(BamWriter *manager, Datagram &dg) {
271 RenderAttrib::write_datagram(manager, dg);
272
273 dg.add_int8(_mode);
274 for (int i=0; i<2; i++) {
275 dg.add_stdfloat(_level[i]);
276 }
277 for (int i=0; i<2; i++) {
278 dg.add_stdfloat(_threshold[i]);
279 }
280}
281
282/**
283 * This function is called by the BamReader's factory when a new object of
284 * type LightRampAttrib is encountered in the Bam file. It should create the
285 * LightRampAttrib and extract its information from the file.
286 */
287TypedWritable *LightRampAttrib::
288make_from_bam(const FactoryParams &params) {
289 LightRampAttrib *attrib = new LightRampAttrib;
290 DatagramIterator scan;
291 BamReader *manager;
292
293 parse_params(params, scan, manager);
294 attrib->fillin(scan, manager);
295
296 return attrib;
297}
298
299/**
300 * This internal function is called by make_from_bam to read in all of the
301 * relevant data from the BamFile for the new LightRampAttrib.
302 */
303void LightRampAttrib::
304fillin(DatagramIterator &scan, BamReader *manager) {
305 RenderAttrib::fillin(scan, manager);
306
307 _mode = (LightRampMode)scan.get_int8();
308 for (int i=0; i<2; i++) {
309 _level[i] = scan.get_stdfloat();
310 }
311 for (int i=0; i<2; i++) {
312 _threshold[i] = scan.get_stdfloat();
313 }
314}
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
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
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...
int8_t get_int8()
Extracts a signed 8-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_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
void add_int8(int8_t value)
Adds a signed 8-bit integer to the datagram.
Definition datagram.I:42
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
A Light Ramp is any unary operator that takes a rendered pixel as input, and adjusts the brightness o...
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 LightRampAttrib.
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.