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SVG SUBSET C++ API
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a60-svg-color.h
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1// svg color -*- mode: C++ -*-
2
3// Copyright (C) 2014-2025 Benjamin De Kosnik <b.dekosnik@gmail.com>
4
5// This file is part of the alpha60-MiL SVG library. This library is
6// free software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the Free
8// Software Foundation; either version 3, or (at your option) any
9// later version.
10
11// This library is distributed in the hope that it will be useful, but
12// WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14// General Public License for more details.
15
16#ifndef MiL_SVG_COLOR_H
17#define MiL_SVG_COLOR_H 1
18
19#include <map>
20#include <algorithm>
21#include <random>
22#include <iomanip>
23
24
25namespace svg {
26
27/**
28 HUE
29
30 color = color enum (and name string conversion)
31
32 color_qi = color quantified as RGB integral values 0-255
33 (similar to Scalar in OpenCV).
34
35 color_qf = color quantified as Hue Saturation Value (HSV) decimal values 0-1
36
37 spectrum = color spectrum as finite array of color enum values
38*/
39
40/// Color enumerated as types.
41enum class color
42{
43 none,
44
45 // 13 tints / shades
46 white,
47 black,
48 gray10,
49 gray20,
50 gray25, // gainsboro
51 gray30,
52 gray40,
53 gray50,
54 gray60,
55 gray75, // slategray
56 gray70,
57 gray80,
58 gray90,
59
60 wcag_lgray,
61 wcag_gray,
62 wcag_dgray,
63
64 // 15 yellow
65 kanzoiro, // daylily light orange
66 kohakuiro, // amber
67 kinsusutake, // golden-gray bamoo
68 daylily,
69 goldenyellow,
70 hellayellow,
71 antiquewhite,
72 lemonchiffon,
73 goldenrod,
74 navajowhite,
75 ivory,
76 gold,
77 duboisyellow1,
78 duboisyellow2,
79 duboisyellow3,
80
81 // 7 orange
82 orange,
83 darkorange,
84 asamaorange,
85 redorange,
86 orangered,
87 dutchorange,
88 internationalorange,
89
90 // 17 red
91 red,
92 foreigncrimson, // red
93 ginshu, // gray red
94 akabeni, // pure crimson
95 akebonoiro, // dawn color
96 ochre,
97 sohi,
98 benikaba, // red birch
99 benitobi, // red kite bird
100 ake, // scarlet/blood
101 crimson,
102 tomato,
103 coral,
104 salmon,
105 duboisred1,
106 duboisred2,
107 duboisred3,
108
109 // 4 brown
110 duboisbrown1,
111 duboisbrown2,
112 duboisbrown3,
113 duboisbrown4,
114 duboisbrown5,
115
116 // 20 green
117 byakuroku, // whitish green
118 usumoegi, // pale onion
119 moegi, // onion green
120 hiwamoegi, // siskin sprout
121 midori,
122 rokusho,
123 aotakeiro, // green bamboo
124 seiheki, // blue green
125 seijiiro, // celadon
126 yanagizome, // willow dye
127 green,
128 chartreuse,
129 greenyellow,
130 limegreen,
131 springgreen,
132 aquamarine,
133 duboisgreen1,
134 duboisgreen2,
135 duboisgreen3,
136 duboisgreen4,
137 duboisgreen5,
138
139 // 35 blue
140 blue,
141 ultramarine,
142 shinbashiiro,
143 hanada, // blue silk
144 ruriiro, // lapis
145 bellflower,
146 navy,
147 asagiiro, // light blue
148 indigo,
149 rurikon, // dark blue lapis
150 asamablue,
151 cyan,
152 lightcyan,
153 powderblue,
154 steelblue,
155 cornflowerblue,
156 deepskyblue,
157 dodgerblue,
158 lightblue,
159 skyblue,
160 lightskyblue,
161 midnightblue,
162 mediumblue,
163 royalblue,
164 darkslateblue,
165 slateblue,
166 azure,
167 crayolacerulean,
168 duboisblue1,
169 duboisblue2,
170 duboisblue3,
171 duboisblue4,
172 blueprintlight,
173 blueprint,
174 blueprintdark,
175
176 // 32 purple
177 wisteria,
178 murasaki, // purple
179 ayameiro,
180 peony,
181 futaai, // dark indigo
182 benimidori, // stained red/violet
183 redwisteria, // dusty rose
184 botan, // tree peony
185 kokimurasaki, // deep purple
186 usuiro, // thin
187 asamapink,
188 blueviolet,
189 darkmagenta,
190 darkviolet,
191 thistle,
192 plum,
193 violet,
194 magenta,
195 dfuschia,
196 deeppink,
197 hotpink,
198 pink,
199 kissmepink,
200 palevioletred,
201 mediumvioletred,
202 lavender,
203 orchid,
204 mediumorchid,
205 darkestmagenta,
206 mediumpurple,
207 purple,
208 dustyrose,
209 atmosphericp,
210
211 // STOS
212 command,
213 science,
214 engineering,
215
216 // Must be last, so can be cast to int for size.
217 last
218};
219
220/// Total number of enumerated colors.
221constexpr uint color_max_size = static_cast<uint>(color::last);
222
223/// Convert color to RGB color value string.
224const std::string&
225to_string(const color e)
226{
227 using enum_map_type = std::map<color, std::string>;
228
229 static enum_map_type enum_map;
230 if (enum_map.empty())
231 {
232 enum_map[color::white] = "rgb(255, 255, 255)";
233 enum_map[color::black] = "rgb(0, 0, 0)";
234 enum_map[color::gray90] = "rgb(25, 25, 25)";
235 enum_map[color::gray80] = "rgb(50, 50, 50)";
236 enum_map[color::gray75] = "rgb(64, 64, 64)";
237 enum_map[color::gray70] = "rgb(77, 77, 77)";
238 enum_map[color::gray60] = "rgb(100, 100, 100)";
239 enum_map[color::gray50] = "rgb(128, 128, 128)";
240 enum_map[color::gray40] = "rgb(150, 150, 150)";
241 enum_map[color::gray30] = "rgb(180, 180, 180)";
242 enum_map[color::gray25] = "rgb(191, 191, 191)";
243 enum_map[color::gray20] = "rgb(200, 200, 200)";
244 enum_map[color::gray10] = "rgb(230, 230, 230)";
245
246 enum_map[color::wcag_lgray] = "rgb(148, 148, 148)"; // LG TXT on white 3:1
247 enum_map[color::wcag_gray] = "rgb(118, 118, 118)"; // min on white 4.5:1
248 enum_map[color::wcag_dgray] = "rgb(46, 46, 46)"; // on white 13.6:1
249
250 enum_map[color::command] = "rgb(255, 0, 171)";
251 enum_map[color::science] = "rgb(150, 230, 191)";
252 enum_map[color::engineering] = "rgb(161, 158, 178)";
253
254 enum_map[color::kissmepink] = "rgb(255, 59, 241)";
255
256 enum_map[color::red] = "rgb(255, 0, 0)";
257 enum_map[color::green] = "rgb(0, 255, 0)";
258 enum_map[color::blue] = "rgb(0, 0, 255)";
259
260 enum_map[color::asamablue] = "rgb(1, 137, 255)";
261 enum_map[color::asamaorange] = "rgb(236, 75, 37)";
262 enum_map[color::asamapink] = "rgb(200, 56, 81)";
263
264 // Yellows
265 enum_map[color::kanzoiro] = "rgb(255, 137, 54)";
266 enum_map[color::kohakuiro] = "rgb(202, 105, 36)";
267 enum_map[color::kinsusutake] = "rgb(125, 78, 45)";
268 enum_map[color::daylily] = "rgb(255, 137, 54)";
269 enum_map[color::goldenyellow] = "rgb(255, 164, 0)";
270 enum_map[color::hellayellow] = "rgb(255, 255, 0)";
271 enum_map[color::antiquewhite] = "rgb(250, 235, 215)";
272 enum_map[color::lemonchiffon] = "rgb(255, 250, 205)";
273 enum_map[color::goldenrod] = "rgb(250, 250, 210)";
274 enum_map[color::navajowhite] = "rgb(255, 222, 173)";
275
276 enum_map[color::ivory] = "rgb(255, 255, 240)";
277 enum_map[color::gold] = "rgb(255, 215, 0)";
278
279 enum_map[color::duboisyellow1] = "rgb(255, 255, 5)";
280 enum_map[color::duboisyellow2] = "rgb(255, 234, 18)";
281 enum_map[color::duboisyellow3] = "rgb(255, 215, 1)";
282
283 // Orange
284 enum_map[color::orange] = "rgb(255, 165, 0)";
285 enum_map[color::orangered] = "rgb(255, 69, 0)";
286 enum_map[color::redorange] = "rgb(220, 48, 35)";
287 enum_map[color::darkorange] = "rgb(255, 140, 17)";
288 enum_map[color::dutchorange] = "rgb(250, 155, 30)";
289 enum_map[color::internationalorange] = "rgb(255, 79, 0)";
290
291 // Brown
292 enum_map[color::duboisbrown1] = "rgb(128, 5, 5)";
293 enum_map[color::duboisbrown2] = "rgb(134, 90, 61)";
294 enum_map[color::duboisbrown3] = "rgb(81, 55, 42)";
295 enum_map[color::duboisbrown4] = "rgb(197, 146, 37)";
296 enum_map[color::duboisbrown5] ="rgb(255, 240, 200)";
297
298 // Reds
299 enum_map[color::foreigncrimson] = "rgb(201, 31, 55)";
300 enum_map[color::ginshu] = "rgb(188, 45, 41)";
301 enum_map[color::akabeni] = "rgb(195, 39,43)";
302 enum_map[color::akebonoiro] = "rgb(250, 123, 98)";
303
304 enum_map[color::ochre] = "rgb(255, 78, 32)";
305 enum_map[color::sohi] = "rgb(227, 92, 56)";
306 enum_map[color::benikaba] = "rgb(157, 43, 34)";
307 enum_map[color::benitobi] = "rgb(145, 50, 40)";
308 enum_map[color::ake] = "rgb(207, 58, 36)";
309
310 enum_map[color::crimson] = "rgb(220, 20, 60)";
311 enum_map[color::tomato] = "rgb(255, 99, 71)";
312 enum_map[color::coral] = "rgb(255, 127, 80)";
313 enum_map[color::salmon] = "rgb(250, 128, 114)";
314
315 enum_map[color::duboisred1] = "rgb(255, 29, 16)";
316 enum_map[color::duboisred2] = "rgb(249,110, 11)";
317 enum_map[color::duboisred3] = "rgb(215, 25, 50)";
318
319 // Greens
320 enum_map[color::byakuroku] = "rgb(165, 186, 147)";
321 enum_map[color::usumoegi] = "rgb(141, 178, 85)";
322 enum_map[color::moegi] = "rgb(91, 137, 48)";
323 enum_map[color::hiwamoegi] = "rgb(122, 148, 46)";
324 enum_map[color::midori] = "rgb(42, 96, 59)";
325 enum_map[color::rokusho] = "rgb(64, 122, 82)";
326 enum_map[color::aotakeiro] = "rgb(0, 100, 66)";
327 enum_map[color::seiheki] = "rgb(58, 105, 96)";
328 enum_map[color::seijiiro] = "rgb(129, 156, 139)";
329 enum_map[color::yanagizome] = "rgb(140, 158, 94)";
330
331 enum_map[color::chartreuse] = "rgb(127, 255, 0)";
332 enum_map[color::greenyellow] = "rgb(173, 255, 47)";
333 enum_map[color::limegreen] = "rgb(50, 205, 50)";
334 enum_map[color::springgreen] = "rgb(0, 255, 127)";
335 enum_map[color::aquamarine] = "rgb(127, 255, 212)";
336
337 enum_map[color::duboisgreen1] = "rgb(5, 255, 5)";
338 enum_map[color::duboisgreen2] = "rgb(127, 225, 15)";
339 enum_map[color::duboisgreen3] = "rgb(16, 114, 9)";
340 enum_map[color::duboisgreen4] = "rgb(0, 148, 16)";
341 enum_map[color::duboisgreen5] = "rgb(24, 57, 30)";
342
343 // Blues
344 enum_map[color::ultramarine] = "rgb(93, 140, 174)";
345 enum_map[color::shinbashiiro] = "rgb(0, 108, 127)";
346 enum_map[color::hanada] = "rgb(4, 79, 103)";
347 enum_map[color::ruriiro] = "rgb(31, 71, 136)";
348 enum_map[color::bellflower] = "rgb(25, 31, 69)";
349 enum_map[color::navy] = "rgb(0, 49, 113)";
350 enum_map[color::asagiiro] = "rgb(72, 146, 155)";
351 enum_map[color::indigo] = "rgb(38, 67, 72)";
352 enum_map[color::rurikon] = "rgb(27, 41, 75)";
353 enum_map[color::cyan] = "rgb(0, 255, 255)";
354
355 enum_map[color::lightcyan] = "rgb(224, 255, 255)";
356 enum_map[color::powderblue] = "rgb(176, 224, 230)";
357 enum_map[color::steelblue] = "rgb(70, 130, 237)";
358 enum_map[color::cornflowerblue] = "rgb(100, 149, 237)";
359 enum_map[color::deepskyblue] = "rgb(0, 191, 255)";
360 enum_map[color::dodgerblue] = "rgb(30, 144, 255)";
361 enum_map[color::lightblue] = "rgb(173, 216, 230)";
362 enum_map[color::skyblue] = "rgb(135, 206, 235)";
363 enum_map[color::lightskyblue] = "rgb(173, 206, 250)";
364 enum_map[color::midnightblue] = "rgb(25, 25, 112)";
365
366 enum_map[color::mediumblue] = "rgb(0, 0, 205)";
367 enum_map[color::royalblue] = "rgb(65, 105, 225)";
368 enum_map[color::darkslateblue] = "rgb(72, 61, 139)";
369 enum_map[color::slateblue] = "rgb(106, 90, 205)";
370 enum_map[color::azure] = "rgb(240, 255, 255)";
371 enum_map[color::crayolacerulean] = "rgb(29, 172, 214)";
372
373 enum_map[color::duboisblue1] = "rgb(37, 42, 255)";
374 enum_map[color::duboisblue2] = "rgb(100, 150, 245)";
375 enum_map[color::duboisblue3] = "rgb(74, 87, 129)";
376 enum_map[color::duboisblue4] = "rgb(49, 64, 103)";
377
378 enum_map[color::blueprintlight] = "rgb(0, 25, 166)";
379 enum_map[color::blueprint] = "rgb(0, 20, 132)";
380 enum_map[color::blueprintdark] = "rgb(0, 16, 106)";
381
382 // Purples
383 enum_map[color::wisteria] = "rgb(135, 95, 154)";
384 enum_map[color::murasaki] = "rgb(79, 40, 75)";
385 enum_map[color::ayameiro] = "rgb(118, 53, 104)";
386 enum_map[color::peony] = "rgb(164, 52, 93)";
387 enum_map[color::futaai] = "rgb(97, 78, 110)";
388 enum_map[color::benimidori] = "rgb(120, 119, 155)";
389 enum_map[color::redwisteria] = "rgb(187, 119, 150)";
390 enum_map[color::botan] = "rgb(164, 52, 93)";
391 enum_map[color::kokimurasaki] = "rgb(58, 36, 59)";
392 enum_map[color::usuiro] = "rgb(168, 124, 160)";
393
394 enum_map[color::blueviolet] = "rgb(138, 43, 226)";
395 enum_map[color::darkmagenta] = "rgb(139, 0, 139)";
396 enum_map[color::darkviolet] = "rgb(148, 0, 211)";
397 enum_map[color::thistle] = "rgb(216, 191, 216)";
398 enum_map[color::plum] = "rgb(221, 160, 221)";
399 enum_map[color::violet] = "rgb(238, 130, 238)";
400 enum_map[color::magenta] = "rgb(255, 0, 255)";
401 enum_map[color::dfuschia] = "rgb(255, 35, 255)";
402 enum_map[color::deeppink] = "rgb(255, 20, 147)";
403 enum_map[color::hotpink] = "rgb(255, 105, 180)";
404 enum_map[color::pink] = "rgb(255, 192, 203)";
405
406 enum_map[color::palevioletred] = "rgb(219, 112, 147)";
407 enum_map[color::mediumvioletred] = "rgb(199, 21, 133)";
408 enum_map[color::lavender] = "rgb(230, 230, 250)";
409 enum_map[color::orchid] = "rgb(218, 112, 214)";
410 enum_map[color::mediumorchid] = "rgb(186, 85, 211)";
411 enum_map[color::darkestmagenta] = "rgb(180, 0, 180)";
412 enum_map[color::mediumpurple] = "rgb(147, 112, 219)";
413 enum_map[color::purple] = "rgb(128, 0, 128)";
414 enum_map[color::dustyrose] = "rgb(191, 136, 187)";
415 enum_map[color::atmosphericp] = "rgb(228, 210, 231)";
416
417 enum_map[color::none] = "rgb(1, 0, 0)";
418 enum_map[color::last] = "rgb(0, 0, 1)";
419
420 // Error check to make sure all the colors have names/values.
421 if (enum_map.size() != color_max_size + 1)
422 {
423 string m("to_string(color)::color map size fail ");
424 m += k::newline;
425 m += std::to_string(enum_map.size());
426 m += " not equal to named colors of size ";
427 m += k::newline;
428 m += std::to_string(color_max_size);
429 throw std::runtime_error(m);
430 }
431 }
432 return enum_map[e];
433}
434
435
436/// Color quantified as integral RGB components in the range [0,255].
437/// aka like Scalar in OpenCV.
438struct color_qi
439{
440 using itype = unsigned short;
441
442 itype r;
443 itype g;
444 itype b;
445
446 // Return "rgb(64, 64, 64)";
447
448 static string
449 to_string(color_qi s)
450 {
451 std::ostringstream oss;
452 oss << "rgb(" << s.r << ',' << s.g << ',' << s.b << ")";
453 return oss.str();
454 }
455
456 // From "rgb(64, 64, 64)";
457 static color_qi
458 from_string(string s)
459 {
460 // Kill rgb() enclosing, if be.
461 if (s.empty() || s.size() < 5 || s[0] != 'r')
462 {
463 string m("color_qi::from_string input is not in rbg form: ");
464 m += s;
465 m += k::newline;
466 throw std::runtime_error(m);
467 }
468 else
469 {
470 s.pop_back();
471 s = s.substr(4);
472 }
473
474 // String stream which eats whitespace and knows number separation.
475 std::istringstream iss(s);
476 iss >> std::skipws;
477
478 char c(0);
479
480 ushort rs(0);
481 iss >> rs;
482 itype r = static_cast<itype>(rs);
483 iss >> c;
484
485 ushort gs(0);
486 iss >> gs;
487 itype g = static_cast<itype>(gs);
488 iss >> c;
489
490 ushort bs(0);
491 iss >> bs;
492 itype b = static_cast<itype>(bs);
493
494 return color_qi(r, g, b);
495 }
496
497 color_qi() = default;
498 color_qi(const color_qi&) = default;
499 color_qi& operator=(const color_qi&) = default;
500
501 // auto operator<=>(const color_qi&) const = default;
502
503 color_qi(itype ra, itype ga, itype ba) : r(ra), g(ga), b(ba) { }
504
505 color_qi(const color e)
506 {
507 color_qi klr = from_string(svg::to_string(e));
508 r = klr.r;
509 b = klr.b;
510 g = klr.g;
511 }
512};
513
514inline bool
515operator==(const color_qi& c1, const color_qi& c2)
516{
517 const bool t1 = c1.r == c2.r;
518 const bool t2 = c1.g == c2.g;
519 const bool t3 = c1.b == c2.b;
520 return t1 && t2 && t3;
521}
522
523
524/// Convert color_qi to string.
525const std::string
526to_string(const color_qi klr)
527{ return color_qi::to_string(klr); }
528
529
530/**
531 Color quantified as floating point HSV components in the range [0,1].
532
533 https://web.archive.org/web/20150303174723/
534 http://en.literateprograms.org/RGB_to_HSV_color_space_conversion_(C)
535*/
536struct color_qf
537{
538 using ftype = float;
539
540 ftype h; /// Hue degree between 0.0 and 360.0
541 ftype s; /// Saturation between 0.0 (gray) and 1.0
542 ftype v; /// Value between 0.0 (black) and 1.0
543
544 color_qf() = default;
545 color_qf(const color_qf&) = default;
546 color_qf& operator=(const color_qf&) = default;
547
548 // auto operator<=>(const color_qf&) const = default;
549
550 color_qf(ftype vh, ftype vs, ftype vv) : h(vh), s(vs), v(vv) { }
551
552 // Conversion constructor, convert from RGB to HSV.
553 color_qf(const color_qi& cqi)
554 {
555 // Start by converting rgb to decimal range.
556 // color_qi assumes [0,255], color_qf converts to range [0,1]
557 auto [r, g, b] = cqi;
558 double rf = scale_value_on_range(r, 0, 255, 0, 1);
559 double gf = scale_value_on_range(g, 0, 255, 0, 1);
560 double bf = scale_value_on_range(b, 0, 255, 0, 1);
561 std::initializer_list<double> l1 = { rf, gf, bf };
562 double rgb_max = std::max(l1);
563
564 // Value first.
565 v = rgb_max;
566 if (v != 0)
567 {
568 double nrf(rf / v);
569 double ngf(gf / v);
570 double nbf(bf / v);
571 std::initializer_list<double> l2 = { nrf, ngf, nbf };
572 double nrgb_min = std::min(l2);
573 double nrgb_max = std::max(l2);
574
575 // Saturation second.
576 s = nrgb_max - nrgb_min;
577 if (s != 0)
578 {
579 // Hue third.
580 double srf((nrf - nrgb_min) / s);
581 double sgf((ngf - nrgb_min) / s);
582 double sbf((nbf - nrgb_min) / s);
583 std::initializer_list<double> l3 = { srf, sgf, sbf };
584 double srgb_max = std::max(l3);
585
586 if (srgb_max == srf)
587 {
588 h = 0.0 + 60.0 * (sgf - sbf);
589 if (h < 0.0)
590 h += 360.0;
591 }
592 else if (srgb_max == sgf)
593 {
594 h = 120.0 + (60.0 * (sbf - srf));
595 }
596 else
597 {
598 // srgb_max == sbf
599 h = 240.0 + (60.0 * (srf - sgf));
600 }
601 }
602 else
603 h = 0;
604 }
605 else
606 {
607 h = 0;
608 s = 0;
609 }
610 }
611
612 color_qf(const color e)
613 {
614 color_qi klr(e);
615 *this = color_qf(klr);
616 }
617
618 static string
619 to_string(color_qf s)
620 {
621 std::ostringstream oss;
622 oss << std::fixed << std::setprecision(2);
623 oss << "hsv(" << s.h << ',' << s.s << ',' << s.v << ")";
624 return oss.str();
625 }
626
627 /// Back to RGB
628 /// https://www.rapidtables.com/convert/color/hsv-to-rgb.html
629 const color_qi
630 to_color_qi()
631 {
632 const ftype c = v * s;
633 const ftype x = c * (1.0 - std::fabs(std::fmod(h / 60.0, 2) - 1.0));
634 const ftype m = v - c;
635
636 float r, g, b;
637 if (h >= 0 && h < 60)
638 {
639 r = c, g = c, b = 0;
640 }
641 else if (h >= 60 && h < 120)
642 {
643 r = x, g = c, b = 0;
644 }
645 else if (h >= 120 && h < 180)
646 {
647 r = 0, g = c, b = x;
648 }
649 else if (h >= 180 && h < 240)
650 {
651 r = 0, g = x, b = c;
652 }
653 else if (h >= 240 && h < 300)
654 {
655 r = x, g = 0, b = c;
656 }
657 else
658 {
659 r = c, g = 0, b = x;
660 }
661
662 auto lpixel = [m] (float ff) { return color_qi::itype((ff + m) * 255); };
663
664 return color_qi(lpixel(r), lpixel(g), lpixel(b));
665 }
666};
667
668
669/// Convert color_qf to string.
670const std::string
671to_string(const color_qf klr)
672{ return color_qf::to_string(klr); }
673
674
675/// Less than compare for color_qf
676bool
677color_qf_lt_hue_v1(const color_qf& k1, const color_qf& k2)
678{
679 const bool eqh = k1.h == k2.h;
680 const bool lth = k1.h < k2.h;
681 const bool lts = k1.v < k2.v;
682
683 if (eqh)
684 return lts;
685 else
686 return lth;
687};
688
689bool
690color_qf_lt_hue_v2(const color_qf& k1, const color_qf& k2)
691{
692 const bool eqh = k1.h == k2.h;
693 const bool lth = k1.h < k2.h;
694
695 if (eqh)
696 {
697 const color_qf::ftype k1hyp = std::sqrt((k1.s * k1.s) + (k1.v * k1.v));
698 const color_qf::ftype k2hyp = std::sqrt((k2.s * k2.s) + (k2.v * k2.v));
699 const bool ltothers = k1hyp < k2hyp;
700 return ltothers;
701 }
702 else
703 return lth;
704};
705
706color_qf::ftype
707color_qf_distance(const color_qf& k1, const color_qf& k2)
708{
709 using ftype = color_qf::ftype;
710 const ftype sdist = std::abs(k1.s - k2.s);
711 const ftype vdist = std::abs(k1.v - k2.v);
712
713 const ftype habs = std::abs(k1.h - k2.h);
714 const ftype hdist = habs > 180 ? 360 - habs : habs;
715
716 // Euclidean distance.
717 //return std::sqrt(hdist*hdist + sdist*sdist + vdist*vdist);
718
719 // Weighted.
720 //return hdist*hweight + sdist*sweight + vdist*vweight;
721 return hdist*1.2 + sdist*2 + vdist*3;
722}
723
724
725/// Default compare distances from k1,k2 to black
726bool
727color_qf_lt_v(const color_qf& k1, const color_qf& k2)
728{
729 using ftype = color_qf::ftype;
730
731 const color_qf originklr = color::black;
732
733 // Compute distance from both arguments to compare color.
734 ftype d1 = color_qf_distance(k1, originklr);
735 ftype d2 = color_qf_distance(k2, originklr);
736 const bool ret = d1 < d2;
737 return ret;
738};
739
740
741/// Forwarding function.
742inline bool
743color_qf_lt(const color_qf& k1, const color_qf& k2)
744{ return color_qf_lt_v(k1, k2); };
745
746
747inline bool
748operator==(const color_qf& c1, const color_qf& c2)
749{
750 const bool t1 = c1.h == c2.h;
751 const bool t2 = c1.s == c2.s;
752 const bool t3 = c1.v == c2.v;
753 return t1 && t2 && t3;
754}
755
756inline bool
757operator<(const color_qf& c1, const color_qf& c2)
758{ return color_qf_lt(c1, c2); }
759
760
761/// Return a variant on saturation/value only.
762color_qf
763mutate_color_qf(const color_qf& k)
764{
765 color_qf ret(k);
766 static std::mt19937_64 rg(std::random_device{}());
767 auto distr = std::uniform_real_distribution<>(0.5, 1);
768
769 // saturation 0.5 to 1, aka more saturated.
770 double stry = distr(rg);
771 if (ret.s < stry)
772 ret.s = stry;
773
774 // value 0.5 to 1, aka less dark
775 double vtry = distr(rg);
776 if (ret.v < vtry)
777 ret.v = vtry;
778
779 return ret;
780}
781
782
783/**
784 Combine color a with color b in percentages ad and ab, respectively.
785
786 To average, constrain paramters ad and ab such that: ad + ab == 2.
787
788 Like so:
789 ushort ur = (a.r + b.r) / 2;
790 ushort ug = (a.g + b.g) / 2;
791 ushort ub = (a.b + b.b) / 2;
792*/
793color_qi
794combine_color_qi(const color_qi& a, const double ad,
795 const color_qi& b, const double bd)
796{
797 double denom = ad + bd;
798 double ur = ((a.r * ad) + (b.r * bd)) / denom;
799 double ug = ((a.g * ad) + (b.g * bd)) / denom;
800 double ub = ((a.b * ad) + (b.b * bd)) / denom;
801
802 using itype = color_qi::itype;
803 itype cr = static_cast<itype>(ur);
804 itype cg = static_cast<itype>(ug);
805 itype cb = static_cast<itype>(ub);
806 return color_qi { cr, cg, cb };
807}
808
809/// Average two colors, return the result.
810color_qi
811average_color_qi(const color_qi& a, const color_qi& b)
812{ return combine_color_qi(a, 1.0, b, 1.0); }
813
814
815/// Types for Color iteration and combinatorics.
816using color_qis = std::vector<color_qi>;
817using color_qfs = std::vector<color_qf>;
818
819} // namespace svg
820
821#endif
svg::color_max_size
constexpr uint color_max_size
Total number of enumerated colors.
Definition a60-svg-color.h:221
svg::color
color
Color enumerated as types.
Definition a60-svg-color.h:42
svg::ushort
unsigned short ushort
Base integer type: positive and negative, signed integral value.
Definition a60-svg.h:56
svg::scale_value_on_range
double scale_value_on_range(const ssize_type value, const ssize_type min, const ssize_type max, const ssize_type nfloor, const ssize_type nceil)
Scale value from min to max on range (nfloor, nceil).
Definition a60-svg.h:216
svg::color_qfs
std::vector< color_qf > color_qfs
Definition a60-svg-color.h:817
svg::to_string
const string to_string(const unit e)
Definition a60-svg-base-types.h:41
svg::color_qis
std::vector< color_qi > color_qis
Types for Color iteration and combinatorics.
Definition a60-svg-color.h:816
svg::operator<
bool operator<(const color_qf &c1, const color_qf &c2)
Definition a60-svg-color.h:757
svg::average_color_qi
color_qi average_color_qi(const color_qi &a, const color_qi &b)
Average two colors, return the result.
Definition a60-svg-color.h:811
svg::mutate_color_qf
color_qf mutate_color_qf(const color_qf &k)
Return a variant on saturation/value only.
Definition a60-svg-color.h:763
svg::color_qf_lt_hue_v2
bool color_qf_lt_hue_v2(const color_qf &k1, const color_qf &k2)
Definition a60-svg-color.h:690
svg::operator==
bool operator==(const color_qi &c1, const color_qi &c2)
Definition a60-svg-color.h:515
svg::combine_color_qi
color_qi combine_color_qi(const color_qi &a, const double ad, const color_qi &b, const double bd)
Definition a60-svg-color.h:794
svg::color_qf_distance
color_qf::ftype color_qf_distance(const color_qf &k1, const color_qf &k2)
Definition a60-svg-color.h:707
svg::color_qf_lt_v
bool color_qf_lt_v(const color_qf &k1, const color_qf &k2)
Default compare distances from k1,k2 to black.
Definition a60-svg-color.h:727
svg::color_qf_lt
bool color_qf_lt(const color_qf &k1, const color_qf &k2)
Forwarding function.
Definition a60-svg-color.h:743
svg::uint
unsigned int uint
Definition a60-svg.h:57
svg::color_qf_lt_hue_v1
bool color_qf_lt_hue_v1(const color_qf &k1, const color_qf &k2)
Less than compare for color_qf.
Definition a60-svg-color.h:677
svg::color_qf
Definition a60-svg-color.h:537
svg::color_qf::v
ftype v
Saturation between 0.0 (gray) and 1.0.
Definition a60-svg-color.h:542
svg::color_qf::to_color_qi
const color_qi to_color_qi()
Back to RGB https://www.rapidtables.com/convert/color/hsv-to-rgb.html.
Definition a60-svg-color.h:630
svg::color_qf::h
ftype h
Definition a60-svg-color.h:540
svg::color_qf::color_qf
color_qf(const color e)
Definition a60-svg-color.h:612
svg::color_qf::color_qf
color_qf(ftype vh, ftype vs, ftype vv)
Definition a60-svg-color.h:550
svg::color_qf::color_qf
color_qf()=default
Value between 0.0 (black) and 1.0.
svg::color_qf::ftype
float ftype
Definition a60-svg-color.h:538
svg::color_qf::s
ftype s
Hue degree between 0.0 and 360.0.
Definition a60-svg-color.h:541
svg::color_qf::operator=
color_qf & operator=(const color_qf &)=default
svg::color_qf::color_qf
color_qf(const color_qf &)=default
svg::color_qf::to_string
static string to_string(color_qf s)
Definition a60-svg-color.h:619
svg::color_qf::color_qf
color_qf(const color_qi &cqi)
Definition a60-svg-color.h:553
svg::color_qi
Color quantified as integral RGB components in the range [0,255]. aka like Scalar in OpenCV.
Definition a60-svg-color.h:439
svg::color_qi::color_qi
color_qi(const color_qi &)=default
svg::color_qi::operator=
color_qi & operator=(const color_qi &)=default
svg::color_qi::color_qi
color_qi()=default
svg::color_qi::to_string
static string to_string(color_qi s)
Definition a60-svg-color.h:449
svg::color_qi::b
itype b
Definition a60-svg-color.h:444
svg::color_qi::g
itype g
Definition a60-svg-color.h:443
svg::color_qi::color_qi
color_qi(itype ra, itype ga, itype ba)
Definition a60-svg-color.h:503
svg::color_qi::itype
unsigned short itype
Definition a60-svg-color.h:440
svg::color_qi::from_string
static color_qi from_string(string s)
Definition a60-svg-color.h:458
svg::color_qi::r
itype r
Definition a60-svg-color.h:442
svg::color_qi::color_qi
color_qi(const color e)
Definition a60-svg-color.h:505
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