synfig-core/trunk/src/synfig/color.cpp

   1 /* === S Y N F I G ========================================================= */
   2 /*!     \file color.cpp
   3 **      \brief Color Class
   4 **
   5 **      $Id$
   6 **
   7 **      \legal
   8 **      Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
   9 **
  10 **      This package is free software; you can redistribute it and/or
  11 **      modify it under the terms of the GNU General Public License as
  12 **      published by the Free Software Foundation; either version 2 of
  13 **      the License, or (at your option) any later version.
  14 **
  15 **      This package is distributed in the hope that it will be useful,
  16 **      but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 **      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18 **      General Public License for more details.
  19 **      \endlegal
  20 */
  21 /* ========================================================================= */
  22
  23 /* === H E A D E R S ======================================================= */
  24
  25 #ifdef USING_PCH
  26 #       include "pch.h"
  27 #else
  28 #ifdef HAVE_CONFIG_H
  29 #       include <config.h>
  30 #endif
  31
  32 #include <ETL/angle>
  33 #include "color.h"
  34 #include <cstdio>
  35 #include <sstream>
  36 #include <iostream>
  37
  38 #endif
  39
  40 using namespace synfig;
  41 using namespace etl;
  42 using namespace std;
  43
  44 /* === M A C R O S ========================================================= */
  45
  46 #define COLOR_EPSILON   (0.000001f)
  47
  48 /* === G L O B A L S ======================================================= */
  49
  50 /* === P R O C E D U R E S ================================================= */
  51
  52 /* === M E T H O D S ======================================================= */
  53
  54
  55
  56 static ColorReal
  57 Color::hex2real(String s)
  58 {
  59         std::istringstream i(s);
  60         int n;
  61         i.fill('0');
  62         if (!(i >> hex >> n))
  63                 throw String("bad conversion from hex string \"") + s + String("\"");
  64         return n / 255.0f;
  65 }
  66
  67 static const String
  68 Color::real2hex(ColorReal c)
  69 {
  70         std::ostringstream o;
  71         o.width(2);
  72         o.fill('0');
  73         if (c<0) c = 0;
  74         if (c>1) c = 1;
  75         o << hex << int(c*255.0f);
  76         return o.str();
  77 }
  78
  79 void
  80 Color::set_hex(String& hex)
  81 {
  82         value_type r, g, b;
  83         try
  84         {
  85                 if (hex.size() == 3)
  86                 {
  87                         r = hex2real(hex.substr(0,1)+hex.substr(0,1));
  88                         g = hex2real(hex.substr(1,1)+hex.substr(1,1));
  89                         b = hex2real(hex.substr(2,1)+hex.substr(2,1));
  90                         r_ = r; g_ = g; b_ = b;
  91                 }
  92                 else if (hex.size() == 6)
  93                 {
  94                         r = hex2real(hex.substr(0,2));
  95                         g = hex2real(hex.substr(2,2));
  96                         b = hex2real(hex.substr(4,2));
  97                         r_ = r; g_ = g; b_ = b;
  98                 }
  99         }
 100         catch (string s)
 101         {
 102                 printf("caught <%s>\n", s.c_str());
 103                 return;
 104         }
 105 }
 106
 107 #if 0
 108 Color&
 109 Color::rotate_uv(const Angle& theta)const
 110 {
 111 /*/
 112         Color ret(*this);
 113         ret.set_hue(ret.get_hue()+theta);
 114         return ret;
 115 /*/
 116         const float
 117                 a(angle::sin(theta).get()),
 118                 b(angle::cos(theta).get());
 119         const float
 120                 u(get_u()),
 121                 v(get_v());
 122
 123         return set_uv(b*u-a*v,a*u+b*v);
 124         //return YUV(get_y(),b*u-a*v,a*u+b*v,get_a());
 125 //*/
 126 }
 127 #endif
 128
 129 Color
 130 Color::clamped_negative()const
 131 {
 132         Color ret=*this;
 133
 134         if(ret.a_==0)
 135                 return alpha();
 136
 137         if(ret.a_<0)
 138                 ret=-ret;
 139
 140         if(ret.r_<0)
 141         {
 142                 ret.g_-=ret.r_;
 143                 ret.b_-=ret.r_;
 144                 ret.r_=0.0f;
 145         }
 146         if(ret.g_<0)
 147         {
 148                 ret.r_-=ret.g_;
 149                 ret.b_-=ret.g_;
 150                 ret.g_=0.0f;
 151         }
 152         if(ret.b_<0)
 153         {
 154                 ret.r_-=ret.b_;
 155                 ret.g_-=ret.b_;
 156                 ret.b_=0.0f;
 157         }
 158
 159         if(ret.r_>1) ret.r_=1;
 160         if(ret.g_>1) ret.g_=1;
 161         if(ret.b_>1) ret.b_=1;
 162         if(ret.a_>1) ret.a_=1;
 163
 164         if(isnan(ret.get_r())) ret.r_=0.5;
 165         if(isnan(ret.get_g())) ret.g_=0.5;
 166         if(isnan(ret.get_b())) ret.b_=0.5;
 167         if(isnan(ret.get_a())) ret.a_=1;
 168
 169 /*
 170         if(ret.r_>1) { ret.g_/=ret.r_; ret.b_/=ret.r_; ret.r_=1; }
 171         if(ret.g_>1) { ret.r_/=ret.g_; ret.b_/=ret.g_; ret.g_=1; }
 172         if(ret.b_>1) { ret.g_/=ret.b_; ret.r_/=ret.b_; ret.b_=1; }
 173         if(ret.a_>1) ret.a_=1;
 174 */
 175
 176         return ret;
 177 }
 178
 179 Color
 180 Color::clamped()const
 181 {
 182         Color ret(*this);
 183         if(ret.get_r()<0)
 184                 ret.set_r(0);
 185         if(ret.get_g()<0)
 186                 ret.set_g(0);
 187         if(ret.get_b()<0)
 188                 ret.set_b(0);
 189         if(ret.get_a()<0)
 190                 ret.set_a(0);
 191
 192         if(ret.r_>1) ret.r_=1;
 193         if(ret.g_>1) ret.g_=1;
 194         if(ret.b_>1) ret.b_=1;
 195         if(ret.a_>1) ret.a_=1;
 196
 197         if(isnan(ret.get_r())) ret.r_=0.5;
 198         if(isnan(ret.get_g())) ret.g_=0.5;
 199         if(isnan(ret.get_b())) ret.b_=0.5;
 200         if(isnan(ret.get_a())) ret.a_=1;
 201
 202         return(ret);
 203 }
 204
 205 typedef Color (*blendfunc)(Color &,Color &,float);
 206
 207 static Color
 208 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
 209 {
 210         //c_dest'=c_src+(1.0-a_src)*c_dest
 211         //a_dest'=a_src+(1.0-a_src)*a_dest
 212
 213         float a_src=src.get_a()*amount;
 214         float a_dest=dest.get_a();
 215
 216         // if a_arc==0.0
 217         //if(fabsf(a_src)<COLOR_EPSILON) return dest;
 218
 219         // Scale the source and destination by their alpha values
 220         src*=a_src;
 221         dest*=a_dest;
 222
 223         dest=src + dest*(1.0f-a_src);
 224
 225         a_dest=a_src + a_dest*(1.0f-a_src);
 226
 227         // if a_dest!=0.0
 228         if(fabsf(a_dest)>COLOR_EPSILON)
 229         {
 230                 dest/=a_dest;
 231                 dest.set_a(a_dest);
 232         }
 233         else
 234         {
 235                 dest=Color::alpha();
 236         }
 237         assert(dest.is_valid());
 238         return dest;
 239 }
 240
 241 static Color
 242 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
 243 {
 244         //a_out'=(a_src-a_bg)*amount+a_bg
 245         //c_out'=(((c_src*a_src)-(c_bg*a_bg))*amount+(c_bg*a_bg))/a_out'
 246
 247         // ie: if(amount==1.0)
 248         //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
 249
 250         Color out;
 251
 252         float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
 253
 254         // if a_out!=0.0
 255         if(fabsf(a_out)>COLOR_EPSILON)
 256 //      if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
 257         {
 258                 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
 259                 out.set_a(a_out);
 260         }
 261         else
 262                 out=Color::alpha();
 263
 264         assert(out.is_valid());
 265         return out;
 266 }
 267
 268 static Color
 269 blendfunc_ONTO(Color &a,Color &b,float amount)
 270 {
 271         float alpha(b.get_a());
 272         return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
 273 }
 274
 275 static Color
 276 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
 277 {
 278         a.set_a(a.get_a()*b.get_a());
 279         return blendfunc_STRAIGHT(a,b,amount);
 280 }
 281
 282 static Color
 283 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
 284 {
 285         const float alpha(a.get_a()*amount);
 286
 287         if(b.get_r()<a.get_r()*alpha)
 288                 b.set_r(a.get_r()*alpha);
 289
 290         if(b.get_g()<a.get_g()*alpha)
 291                 b.set_g(a.get_g()*alpha);
 292
 293         if(b.get_b()<a.get_b()*alpha)
 294                 b.set_b(a.get_b()*alpha);
 295
 296         return b;
 297 }
 298
 299 static Color
 300 blendfunc_DARKEN(Color &a,Color &b,float amount)
 301 {
 302         const float alpha(a.get_a()*amount);
 303
 304         if(b.get_r()>(a.get_r()-1.0f)*alpha+1.0f)
 305                 b.set_r((a.get_r()-1.0f)*alpha+1.0f);
 306
 307         if(b.get_g()>(a.get_g()-1.0f)*alpha+1.0f)
 308                 b.set_g((a.get_g()-1.0f)*alpha+1.0f);
 309
 310         if(b.get_b()>(a.get_b()-1.0f)*alpha+1.0f)
 311                 b.set_b((a.get_b()-1.0f)*alpha+1.0f);
 312
 313
 314         return b;
 315 }
 316
 317 static Color
 318 blendfunc_ADD(Color &a,Color &b,float amount)
 319 {
 320         const float alpha(a.get_a()*amount);
 321
 322         b.set_r(b.get_r()+a.get_r()*alpha);
 323         b.set_g(b.get_g()+a.get_g()*alpha);
 324         b.set_b(b.get_b()+a.get_b()*alpha);
 325
 326         return b;
 327 }
 328
 329 static Color
 330 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
 331 {
 332         const float alpha(a.get_a()*amount);
 333
 334         b.set_r(b.get_r()-a.get_r()*alpha);
 335         b.set_g(b.get_g()-a.get_g()*alpha);
 336         b.set_b(b.get_b()-a.get_b()*alpha);
 337
 338         return b;
 339 }
 340
 341 static Color
 342 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
 343 {
 344         const float alpha(a.get_a()*amount);
 345
 346         b.set_r(abs(b.get_r()-a.get_r()*alpha));
 347         b.set_g(abs(b.get_g()-a.get_g()*alpha));
 348         b.set_b(abs(b.get_b()-a.get_b()*alpha));
 349
 350         return b;
 351 }
 352
 353 static Color
 354 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
 355 {
 356         if(amount<0) a=~a, amount=-amount;
 357
 358         amount*=a.get_a();
 359         b.set_r(((b.get_r()*a.get_r())-b.get_r())*(amount)+b.get_r());
 360         b.set_g(((b.get_g()*a.get_g())-b.get_g())*(amount)+b.get_g());
 361         b.set_b(((b.get_b()*a.get_b())-b.get_b())*(amount)+b.get_b());
 362         return b;
 363 }
 364
 365 static Color
 366 blendfunc_DIVIDE(Color &a,Color &b,float amount)
 367 {
 368         amount*=a.get_a();
 369
 370         // We add COLOR_EPSILON in order to avoid a divide-by-zero condition.
 371         // This causes DIVIDE to bias toward positive values, but the effect is
 372         // really neglegable. There is a reason why we use COLOR_EPSILON--we
 373         // want the change to be imperceptable.
 374
 375         b.set_r(((b.get_r()/(a.get_r()+COLOR_EPSILON))-b.get_r())*(amount)+b.get_r());
 376         b.set_g(((b.get_g()/(a.get_g()+COLOR_EPSILON))-b.get_g())*(amount)+b.get_g());
 377         b.set_b(((b.get_b()/(a.get_b()+COLOR_EPSILON))-b.get_b())*(amount)+b.get_b());
 378
 379         return b;
 380 }
 381
 382 static Color
 383 blendfunc_COLOR(Color &a,Color &b,float amount)
 384 {
 385         Color temp(b);
 386         temp.set_uv(a.get_u(),a.get_v());
 387         return (temp-b)*amount*a.get_a()+b;
 388 }
 389
 390 static Color
 391 blendfunc_HUE(Color &a,Color &b,float amount)
 392 {
 393         Color temp(b);
 394         temp.set_hue(a.get_hue());
 395         return (temp-b)*amount*a.get_a()+b;
 396 }
 397
 398 static Color
 399 blendfunc_SATURATION(Color &a,Color &b,float amount)
 400 {
 401         Color temp(b);
 402         temp.set_s(a.get_s());
 403         return (temp-b)*amount*a.get_a()+b;
 404 }
 405
 406 static Color
 407 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
 408 {
 409         Color temp(b);
 410         temp.set_y(a.get_y());
 411         return (temp-b)*amount*a.get_a()+b;
 412 }
 413
 414 static Color
 415 blendfunc_BEHIND(Color &a,Color &b,float amount)
 416 {
 417         if(a.get_a()==0)a.set_a(COLOR_EPSILON);         //!< \hack
 418         a.set_a(a.get_a()*amount);
 419         return blendfunc_COMPOSITE(b,a,1.0);
 420 }
 421
 422 static Color
 423 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
 424 {
 425         if(a.get_a()<b.get_a()*amount)
 426                 return a.set_a(a.get_a()*amount);
 427         return b;
 428 }
 429
 430 static Color
 431 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
 432 {
 433         if(a.get_a()*amount>b.get_a())
 434                 return a.set_a(a.get_a()*amount);
 435         return b;
 436 }
 437
 438 static Color
 439 blendfunc_SCREEN(Color &a,Color &b,float amount)
 440 {
 441         if(amount<0) a=~a, amount=-amount;
 442
 443         a.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
 444         a.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
 445         a.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
 446
 447         return blendfunc_ONTO(a,b,amount);
 448 }
 449
 450 static Color
 451 blendfunc_OVERLAY(Color &a,Color &b,float amount)
 452 {
 453         if(amount<0) a=~a, amount=-amount;
 454
 455         Color rm;
 456         rm.set_r(b.get_r()*a.get_r());
 457         rm.set_g(b.get_g()*a.get_g());
 458         rm.set_b(b.get_b()*a.get_b());
 459
 460         Color rs;
 461         rs.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
 462         rs.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
 463         rs.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
 464
 465         Color& ret(a);
 466
 467         ret.set_r(a.get_r()*rs.get_r() + (1.0-a.get_r())*rm.get_r());
 468         ret.set_g(a.get_g()*rs.get_g() + (1.0-a.get_g())*rm.get_g());
 469         ret.set_b(a.get_b()*rs.get_b() + (1.0-a.get_b())*rm.get_b());
 470
 471         return blendfunc_ONTO(ret,b,amount);
 472 }
 473
 474 static Color
 475 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
 476 {
 477         if(amount<0) a=~a, amount=-amount;
 478
 479         if(a.get_r()>0.5f)      a.set_r(1.0-(1.0f-(a.get_r()*2.0f-1.0f))*(1.0f-b.get_r()));
 480         else                            a.set_r(b.get_r()*(a.get_r()*2.0f));
 481         if(a.get_g()>0.5f)      a.set_g(1.0-(1.0f-(a.get_g()*2.0f-1.0f))*(1.0f-b.get_g()));
 482         else                            a.set_g(b.get_g()*(a.get_g()*2.0f));
 483         if(a.get_b()>0.5f)      a.set_b(1.0-(1.0f-(a.get_b()*2.0f-1.0f))*(1.0f-b.get_b()));
 484         else                            a.set_b(b.get_b()*(a.get_b()*2.0f));
 485
 486         return blendfunc_ONTO(a,b,amount);
 487 }
 488
 489 static Color
 490 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
 491 {
 492         Color rm(b);
 493
 494         //multiply the inverse alpha channel with the one below us
 495         rm.set_a((1-a.get_a())*b.get_a());
 496
 497         return blendfunc_STRAIGHT(rm,b,amount);
 498 }
 499
 500
 501 Color
 502 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
 503 {
 504 #if 0
 505         if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
 506         {
 507 #ifdef _DEBUG
 508                 a=magenta().set_a(a.get_a());
 509 #else
 510                 a=black().set_a(a.get_a());
 511 #endif
 512         }
 513
 514         if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
 515         {
 516 #ifdef _DEBUG
 517                 b=magenta().set_a(b.get_a());
 518 #else
 519                 b=black().set_a(b.get_a());
 520 #endif
 521         }
 522 #endif
 523
 524 /*
 525         if(!a.is_valid()&&b.is_valid())
 526                 return b;
 527
 528         if(a.is_valid()&&!b.is_valid())
 529                 return a;
 530
 531         if(!a.is_valid()||!b.is_valid())
 532         {
 533 #ifdef _DEBUG
 534                 return magenta();
 535 #else
 536                 return black();
 537 #endif
 538         }
 539 */
 540
 541         // No matter what blend method is being used,
 542         // if the amount is equal to zero, then only B
 543         // will shine through
 544         if(fabsf(amount)<=COLOR_EPSILON)return b;
 545
 546         assert(type<BLEND_END);
 547
 548         const static blendfunc vtable[BLEND_END]=
 549         {
 550                 blendfunc_COMPOSITE,
 551                 blendfunc_STRAIGHT,
 552                 blendfunc_BRIGHTEN,
 553                 blendfunc_DARKEN,
 554                 blendfunc_ADD,
 555                 blendfunc_SUBTRACT,
 556                 blendfunc_MULTIPLY,
 557                 blendfunc_DIVIDE,
 558                 blendfunc_COLOR,
 559                 blendfunc_HUE,
 560                 blendfunc_SATURATION,
 561                 blendfunc_LUMINANCE,
 562                 blendfunc_BEHIND,
 563                 blendfunc_ONTO,
 564                 blendfunc_ALPHA_BRIGHTEN,
 565                 blendfunc_ALPHA_DARKEN,
 566                 blendfunc_SCREEN,
 567                 blendfunc_HARD_LIGHT,
 568                 blendfunc_DIFFERENCE,
 569                 blendfunc_ALPHA_OVER,
 570                 blendfunc_OVERLAY,
 571                 blendfunc_STRAIGHT_ONTO,
 572         };
 573
 574         return vtable[type](a,b,amount);
 575 }