synfig-core/tags/stable/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 String Color::hex_;
  51
  52 /* === P R O C E D U R E S ================================================= */
  53
  54 /* === M E T H O D S ======================================================= */
  55
  56
  57
  58 ColorReal
  59 Color::hex2real(String s)
  60 {
  61         std::istringstream i(s);
  62         int n;
  63         i.fill('0');
  64         if (!(i >> hex >> n))
  65                 throw String("bad conversion from hex string \"") + s + String("\"");
  66         return n / 255.0f;
  67 }
  68
  69 const String
  70 Color::real2hex(ColorReal c)
  71 {
  72         std::ostringstream o;
  73         o.width(2);
  74         o.fill('0');
  75         if (c<0) c = 0;
  76         if (c>1) c = 1;
  77         o << hex << int(c*255.0f);
  78         return o.str();
  79 }
  80
  81 void
  82 Color::set_hex(String& hex)
  83 {
  84         value_type r, g, b;
  85         try
  86         {
  87                 if (hex.size() == 1)
  88                 {
  89                         r = hex2real(hex.substr(0,1)+hex.substr(0,1));
  90                         r_ = g_ = b_ = r;
  91                 }
  92                 else if (hex.size() == 3)
  93                 {
  94                         r = hex2real(hex.substr(0,1)+hex.substr(0,1));
  95                         g = hex2real(hex.substr(1,1)+hex.substr(1,1));
  96                         b = hex2real(hex.substr(2,1)+hex.substr(2,1));
  97                         r_ = r; g_ = g; b_ = b;
  98                 }
  99                 else if (hex.size() == 6)
 100                 {
 101                         r = hex2real(hex.substr(0,2));
 102                         g = hex2real(hex.substr(2,2));
 103                         b = hex2real(hex.substr(4,2));
 104                         r_ = r; g_ = g; b_ = b;
 105                 }
 106         }
 107         catch (string s)
 108         {
 109                 printf("caught <%s>\n", s.c_str());
 110                 return;
 111         }
 112 }
 113
 114 #if 0
 115 Color&
 116 Color::rotate_uv(const Angle& theta)const
 117 {
 118 /*/
 119         Color ret(*this);
 120         ret.set_hue(ret.get_hue()+theta);
 121         return ret;
 122 /*/
 123         const float
 124                 a(angle::sin(theta).get()),
 125                 b(angle::cos(theta).get());
 126         const float
 127                 u(get_u()),
 128                 v(get_v());
 129
 130         return set_uv(b*u-a*v,a*u+b*v);
 131         //return YUV(get_y(),b*u-a*v,a*u+b*v,get_a());
 132 //*/
 133 }
 134 #endif
 135
 136 Color
 137 Color::clamped_negative()const
 138 {
 139         Color ret=*this;
 140
 141         if(ret.a_==0)
 142                 return alpha();
 143
 144         if(ret.a_<0)
 145                 ret=-ret;
 146
 147         if(ret.r_<0)
 148         {
 149                 ret.g_-=ret.r_;
 150                 ret.b_-=ret.r_;
 151                 ret.r_=0.0f;
 152         }
 153         if(ret.g_<0)
 154         {
 155                 ret.r_-=ret.g_;
 156                 ret.b_-=ret.g_;
 157                 ret.g_=0.0f;
 158         }
 159         if(ret.b_<0)
 160         {
 161                 ret.r_-=ret.b_;
 162                 ret.g_-=ret.b_;
 163                 ret.b_=0.0f;
 164         }
 165
 166         if(ret.r_>1) ret.r_=1;
 167         if(ret.g_>1) ret.g_=1;
 168         if(ret.b_>1) ret.b_=1;
 169         if(ret.a_>1) ret.a_=1;
 170
 171         if(isnan(ret.get_r())) ret.r_=0.5;
 172         if(isnan(ret.get_g())) ret.g_=0.5;
 173         if(isnan(ret.get_b())) ret.b_=0.5;
 174         if(isnan(ret.get_a())) ret.a_=1;
 175
 176 /*
 177         if(ret.r_>1) { ret.g_/=ret.r_; ret.b_/=ret.r_; ret.r_=1; }
 178         if(ret.g_>1) { ret.r_/=ret.g_; ret.b_/=ret.g_; ret.g_=1; }
 179         if(ret.b_>1) { ret.g_/=ret.b_; ret.r_/=ret.b_; ret.b_=1; }
 180         if(ret.a_>1) ret.a_=1;
 181 */
 182
 183         return ret;
 184 }
 185
 186 Color
 187 Color::clamped()const
 188 {
 189         Color ret(*this);
 190         if(ret.get_r()<0)
 191                 ret.set_r(0);
 192         if(ret.get_g()<0)
 193                 ret.set_g(0);
 194         if(ret.get_b()<0)
 195                 ret.set_b(0);
 196         if(ret.get_a()<0)
 197                 ret.set_a(0);
 198
 199         if(ret.r_>1) ret.r_=1;
 200         if(ret.g_>1) ret.g_=1;
 201         if(ret.b_>1) ret.b_=1;
 202         if(ret.a_>1) ret.a_=1;
 203
 204         if(isnan(ret.get_r())) ret.r_=0.5;
 205         if(isnan(ret.get_g())) ret.g_=0.5;
 206         if(isnan(ret.get_b())) ret.b_=0.5;
 207         if(isnan(ret.get_a())) ret.a_=1;
 208
 209         return(ret);
 210 }
 211
 212 typedef Color (*blendfunc)(Color &,Color &,float);
 213
 214 static Color
 215 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
 216 {
 217         //c_dest'=c_src+(1.0-a_src)*c_dest
 218         //a_dest'=a_src+(1.0-a_src)*a_dest
 219
 220         float a_src=src.get_a()*amount;
 221         float a_dest=dest.get_a();
 222
 223         // if a_arc==0.0
 224         //if(fabsf(a_src)<COLOR_EPSILON) return dest;
 225
 226         // Scale the source and destination by their alpha values
 227         src*=a_src;
 228         dest*=a_dest;
 229
 230         dest=src + dest*(1.0f-a_src);
 231
 232         a_dest=a_src + a_dest*(1.0f-a_src);
 233
 234         // if a_dest!=0.0
 235         if(fabsf(a_dest)>COLOR_EPSILON)
 236         {
 237                 dest/=a_dest;
 238                 dest.set_a(a_dest);
 239         }
 240         else
 241         {
 242                 dest=Color::alpha();
 243         }
 244         assert(dest.is_valid());
 245         return dest;
 246 }
 247
 248 static Color
 249 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
 250 {
 251         //a_out'=(a_src-a_bg)*amount+a_bg
 252         //c_out'=(((c_src*a_src)-(c_bg*a_bg))*amount+(c_bg*a_bg))/a_out'
 253
 254         // ie: if(amount==1.0)
 255         //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
 256
 257         Color out;
 258
 259         float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
 260
 261         // if a_out!=0.0
 262         if(fabsf(a_out)>COLOR_EPSILON)
 263 //      if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
 264         {
 265                 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
 266                 out.set_a(a_out);
 267         }
 268         else
 269                 out=Color::alpha();
 270
 271         assert(out.is_valid());
 272         return out;
 273 }
 274
 275 static Color
 276 blendfunc_ONTO(Color &a,Color &b,float amount)
 277 {
 278         float alpha(b.get_a());
 279         return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
 280 }
 281
 282 static Color
 283 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
 284 {
 285         a.set_a(a.get_a()*b.get_a());
 286         return blendfunc_STRAIGHT(a,b,amount);
 287 }
 288
 289 static Color
 290 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
 291 {
 292         const float alpha(a.get_a()*amount);
 293
 294         if(b.get_r()<a.get_r()*alpha)
 295                 b.set_r(a.get_r()*alpha);
 296
 297         if(b.get_g()<a.get_g()*alpha)
 298                 b.set_g(a.get_g()*alpha);
 299
 300         if(b.get_b()<a.get_b()*alpha)
 301                 b.set_b(a.get_b()*alpha);
 302
 303         return b;
 304 }
 305
 306 static Color
 307 blendfunc_DARKEN(Color &a,Color &b,float amount)
 308 {
 309         const float alpha(a.get_a()*amount);
 310
 311         if(b.get_r()>(a.get_r()-1.0f)*alpha+1.0f)
 312                 b.set_r((a.get_r()-1.0f)*alpha+1.0f);
 313
 314         if(b.get_g()>(a.get_g()-1.0f)*alpha+1.0f)
 315                 b.set_g((a.get_g()-1.0f)*alpha+1.0f);
 316
 317         if(b.get_b()>(a.get_b()-1.0f)*alpha+1.0f)
 318                 b.set_b((a.get_b()-1.0f)*alpha+1.0f);
 319
 320
 321         return b;
 322 }
 323
 324 static Color
 325 blendfunc_ADD(Color &a,Color &b,float amount)
 326 {
 327         const float alpha(a.get_a()*amount);
 328
 329         b.set_r(b.get_r()+a.get_r()*alpha);
 330         b.set_g(b.get_g()+a.get_g()*alpha);
 331         b.set_b(b.get_b()+a.get_b()*alpha);
 332
 333         return b;
 334 }
 335
 336 static Color
 337 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
 338 {
 339         const float alpha(a.get_a()*amount);
 340
 341         b.set_r(b.get_r()-a.get_r()*alpha);
 342         b.set_g(b.get_g()-a.get_g()*alpha);
 343         b.set_b(b.get_b()-a.get_b()*alpha);
 344
 345         return b;
 346 }
 347
 348 static Color
 349 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
 350 {
 351         const float alpha(a.get_a()*amount);
 352
 353         b.set_r(abs(b.get_r()-a.get_r()*alpha));
 354         b.set_g(abs(b.get_g()-a.get_g()*alpha));
 355         b.set_b(abs(b.get_b()-a.get_b()*alpha));
 356
 357         return b;
 358 }
 359
 360 static Color
 361 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
 362 {
 363         if(amount<0) a=~a, amount=-amount;
 364
 365         amount*=a.get_a();
 366         b.set_r(((b.get_r()*a.get_r())-b.get_r())*(amount)+b.get_r());
 367         b.set_g(((b.get_g()*a.get_g())-b.get_g())*(amount)+b.get_g());
 368         b.set_b(((b.get_b()*a.get_b())-b.get_b())*(amount)+b.get_b());
 369         return b;
 370 }
 371
 372 static Color
 373 blendfunc_DIVIDE(Color &a,Color &b,float amount)
 374 {
 375         amount*=a.get_a();
 376
 377         // We add COLOR_EPSILON in order to avoid a divide-by-zero condition.
 378         // This causes DIVIDE to bias toward positive values, but the effect is
 379         // really neglegable. There is a reason why we use COLOR_EPSILON--we
 380         // want the change to be imperceptable.
 381
 382         b.set_r(((b.get_r()/(a.get_r()+COLOR_EPSILON))-b.get_r())*(amount)+b.get_r());
 383         b.set_g(((b.get_g()/(a.get_g()+COLOR_EPSILON))-b.get_g())*(amount)+b.get_g());
 384         b.set_b(((b.get_b()/(a.get_b()+COLOR_EPSILON))-b.get_b())*(amount)+b.get_b());
 385
 386         return b;
 387 }
 388
 389 static Color
 390 blendfunc_COLOR(Color &a,Color &b,float amount)
 391 {
 392         Color temp(b);
 393         temp.set_uv(a.get_u(),a.get_v());
 394         return (temp-b)*amount*a.get_a()+b;
 395 }
 396
 397 static Color
 398 blendfunc_HUE(Color &a,Color &b,float amount)
 399 {
 400         Color temp(b);
 401         temp.set_hue(a.get_hue());
 402         return (temp-b)*amount*a.get_a()+b;
 403 }
 404
 405 static Color
 406 blendfunc_SATURATION(Color &a,Color &b,float amount)
 407 {
 408         Color temp(b);
 409         temp.set_s(a.get_s());
 410         return (temp-b)*amount*a.get_a()+b;
 411 }
 412
 413 static Color
 414 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
 415 {
 416         Color temp(b);
 417         temp.set_y(a.get_y());
 418         return (temp-b)*amount*a.get_a()+b;
 419 }
 420
 421 static Color
 422 blendfunc_BEHIND(Color &a,Color &b,float amount)
 423 {
 424         if(a.get_a()==0)a.set_a(COLOR_EPSILON);         //!< \hack
 425         a.set_a(a.get_a()*amount);
 426         return blendfunc_COMPOSITE(b,a,1.0);
 427 }
 428
 429 static Color
 430 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
 431 {
 432         if(a.get_a()<b.get_a()*amount)
 433                 return a.set_a(a.get_a()*amount);
 434         return b;
 435 }
 436
 437 static Color
 438 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
 439 {
 440         if(a.get_a()*amount>b.get_a())
 441                 return a.set_a(a.get_a()*amount);
 442         return b;
 443 }
 444
 445 static Color
 446 blendfunc_SCREEN(Color &a,Color &b,float amount)
 447 {
 448         if(amount<0) a=~a, amount=-amount;
 449
 450         a.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
 451         a.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
 452         a.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
 453
 454         return blendfunc_ONTO(a,b,amount);
 455 }
 456
 457 static Color
 458 blendfunc_OVERLAY(Color &a,Color &b,float amount)
 459 {
 460         if(amount<0) a=~a, amount=-amount;
 461
 462         Color rm;
 463         rm.set_r(b.get_r()*a.get_r());
 464         rm.set_g(b.get_g()*a.get_g());
 465         rm.set_b(b.get_b()*a.get_b());
 466
 467         Color rs;
 468         rs.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
 469         rs.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
 470         rs.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
 471
 472         Color& ret(a);
 473
 474         ret.set_r(a.get_r()*rs.get_r() + (1.0-a.get_r())*rm.get_r());
 475         ret.set_g(a.get_g()*rs.get_g() + (1.0-a.get_g())*rm.get_g());
 476         ret.set_b(a.get_b()*rs.get_b() + (1.0-a.get_b())*rm.get_b());
 477
 478         return blendfunc_ONTO(ret,b,amount);
 479 }
 480
 481 static Color
 482 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
 483 {
 484         if(amount<0) a=~a, amount=-amount;
 485
 486         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()));
 487         else                            a.set_r(b.get_r()*(a.get_r()*2.0f));
 488         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()));
 489         else                            a.set_g(b.get_g()*(a.get_g()*2.0f));
 490         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()));
 491         else                            a.set_b(b.get_b()*(a.get_b()*2.0f));
 492
 493         return blendfunc_ONTO(a,b,amount);
 494 }
 495
 496 static Color
 497 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
 498 {
 499         Color rm(b);
 500
 501         //multiply the inverse alpha channel with the one below us
 502         rm.set_a((1-a.get_a())*b.get_a());
 503
 504         return blendfunc_STRAIGHT(rm,b,amount);
 505 }
 506
 507
 508 Color
 509 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
 510 {
 511 #if 0
 512         if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
 513         {
 514 #ifdef _DEBUG
 515                 a=magenta().set_a(a.get_a());
 516 #else
 517                 a=black().set_a(a.get_a());
 518 #endif
 519         }
 520
 521         if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
 522         {
 523 #ifdef _DEBUG
 524                 b=magenta().set_a(b.get_a());
 525 #else
 526                 b=black().set_a(b.get_a());
 527 #endif
 528         }
 529 #endif
 530
 531 /*
 532         if(!a.is_valid()&&b.is_valid())
 533                 return b;
 534
 535         if(a.is_valid()&&!b.is_valid())
 536                 return a;
 537
 538         if(!a.is_valid()||!b.is_valid())
 539         {
 540 #ifdef _DEBUG
 541                 return magenta();
 542 #else
 543                 return black();
 544 #endif
 545         }
 546 */
 547
 548         // No matter what blend method is being used,
 549         // if the amount is equal to zero, then only B
 550         // will shine through
 551         if(fabsf(amount)<=COLOR_EPSILON)return b;
 552
 553         assert(type<BLEND_END);
 554
 555         const static blendfunc vtable[BLEND_END]=
 556         {
 557                 blendfunc_COMPOSITE,
 558                 blendfunc_STRAIGHT,
 559                 blendfunc_BRIGHTEN,
 560                 blendfunc_DARKEN,
 561                 blendfunc_ADD,
 562                 blendfunc_SUBTRACT,
 563                 blendfunc_MULTIPLY,
 564                 blendfunc_DIVIDE,
 565                 blendfunc_COLOR,
 566                 blendfunc_HUE,
 567                 blendfunc_SATURATION,
 568                 blendfunc_LUMINANCE,
 569                 blendfunc_BEHIND,
 570                 blendfunc_ONTO,
 571                 blendfunc_ALPHA_BRIGHTEN,
 572                 blendfunc_ALPHA_DARKEN,
 573                 blendfunc_SCREEN,
 574                 blendfunc_HARD_LIGHT,
 575                 blendfunc_DIFFERENCE,
 576                 blendfunc_ALPHA_OVER,
 577                 blendfunc_OVERLAY,
 578                 blendfunc_STRAIGHT_ONTO,
 579         };
 580
 581         return vtable[type](a,b,amount);
 582 }