1 /* === S Y N F I G ========================================================= */
8 ** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
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.
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.
21 /* ========================================================================= */
23 /* === H E A D E R S ======================================================= */
40 using namespace synfig;
44 /* === M A C R O S ========================================================= */
46 #define COLOR_EPSILON (0.000001f)
48 /* === G L O B A L S ======================================================= */
50 /* === P R O C E D U R E S ================================================= */
52 /* === M E T H O D S ======================================================= */
57 Color::hex2real(String s)
59 std::istringstream i(s);
63 throw String("bad conversion from hex string \"") + s + String("\"");
68 Color::real2hex(ColorReal c)
75 o << hex << int(c*255.0f);
80 Color::set_hex(String& hex)
87 r = hex2real(hex.substr(0,1)+hex.substr(0,1));
90 else if (hex.size() == 3)
92 r = hex2real(hex.substr(0,1)+hex.substr(0,1));
93 g = hex2real(hex.substr(1,1)+hex.substr(1,1));
94 b = hex2real(hex.substr(2,1)+hex.substr(2,1));
95 r_ = r; g_ = g; b_ = b;
97 else if (hex.size() == 6)
99 r = hex2real(hex.substr(0,2));
100 g = hex2real(hex.substr(2,2));
101 b = hex2real(hex.substr(4,2));
102 r_ = r; g_ = g; b_ = b;
107 printf("caught <%s>\n", s.c_str());
114 Color::rotate_uv(const Angle& theta)const
118 ret.set_hue(ret.get_hue()+theta);
122 a(angle::sin(theta).get()),
123 b(angle::cos(theta).get());
128 return set_uv(b*u-a*v,a*u+b*v);
129 //return YUV(get_y(),b*u-a*v,a*u+b*v,get_a());
135 Color::clamped_negative()const
164 if(ret.r_>1) ret.r_=1;
165 if(ret.g_>1) ret.g_=1;
166 if(ret.b_>1) ret.b_=1;
167 if(ret.a_>1) ret.a_=1;
169 if(isnan(ret.get_r())) ret.r_=0.5;
170 if(isnan(ret.get_g())) ret.g_=0.5;
171 if(isnan(ret.get_b())) ret.b_=0.5;
172 if(isnan(ret.get_a())) ret.a_=1;
175 if(ret.r_>1) { ret.g_/=ret.r_; ret.b_/=ret.r_; ret.r_=1; }
176 if(ret.g_>1) { ret.r_/=ret.g_; ret.b_/=ret.g_; ret.g_=1; }
177 if(ret.b_>1) { ret.g_/=ret.b_; ret.r_/=ret.b_; ret.b_=1; }
178 if(ret.a_>1) ret.a_=1;
185 Color::clamped()const
197 if(ret.r_>1) ret.r_=1;
198 if(ret.g_>1) ret.g_=1;
199 if(ret.b_>1) ret.b_=1;
200 if(ret.a_>1) ret.a_=1;
202 if(isnan(ret.get_r())) ret.r_=0.5;
203 if(isnan(ret.get_g())) ret.g_=0.5;
204 if(isnan(ret.get_b())) ret.b_=0.5;
205 if(isnan(ret.get_a())) ret.a_=1;
210 typedef Color (*blendfunc)(Color &,Color &,float);
213 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
215 //c_dest'=c_src+(1.0-a_src)*c_dest
216 //a_dest'=a_src+(1.0-a_src)*a_dest
218 float a_src=src.get_a()*amount;
219 float a_dest=dest.get_a();
222 //if(fabsf(a_src)<COLOR_EPSILON) return dest;
224 // Scale the source and destination by their alpha values
228 dest=src + dest*(1.0f-a_src);
230 a_dest=a_src + a_dest*(1.0f-a_src);
233 if(fabsf(a_dest)>COLOR_EPSILON)
242 assert(dest.is_valid());
247 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
249 //a_out'=(a_src-a_bg)*amount+a_bg
250 //c_out'=(((c_src*a_src)-(c_bg*a_bg))*amount+(c_bg*a_bg))/a_out'
252 // ie: if(amount==1.0)
253 //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
257 float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
260 if(fabsf(a_out)>COLOR_EPSILON)
261 // if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
263 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
269 assert(out.is_valid());
274 blendfunc_ONTO(Color &a,Color &b,float amount)
276 float alpha(b.get_a());
277 return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
281 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
283 a.set_a(a.get_a()*b.get_a());
284 return blendfunc_STRAIGHT(a,b,amount);
288 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
290 const float alpha(a.get_a()*amount);
292 if(b.get_r()<a.get_r()*alpha)
293 b.set_r(a.get_r()*alpha);
295 if(b.get_g()<a.get_g()*alpha)
296 b.set_g(a.get_g()*alpha);
298 if(b.get_b()<a.get_b()*alpha)
299 b.set_b(a.get_b()*alpha);
305 blendfunc_DARKEN(Color &a,Color &b,float amount)
307 const float alpha(a.get_a()*amount);
309 if(b.get_r()>(a.get_r()-1.0f)*alpha+1.0f)
310 b.set_r((a.get_r()-1.0f)*alpha+1.0f);
312 if(b.get_g()>(a.get_g()-1.0f)*alpha+1.0f)
313 b.set_g((a.get_g()-1.0f)*alpha+1.0f);
315 if(b.get_b()>(a.get_b()-1.0f)*alpha+1.0f)
316 b.set_b((a.get_b()-1.0f)*alpha+1.0f);
323 blendfunc_ADD(Color &a,Color &b,float amount)
325 const float alpha(a.get_a()*amount);
327 b.set_r(b.get_r()+a.get_r()*alpha);
328 b.set_g(b.get_g()+a.get_g()*alpha);
329 b.set_b(b.get_b()+a.get_b()*alpha);
335 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
337 const float alpha(a.get_a()*amount);
339 b.set_r(b.get_r()-a.get_r()*alpha);
340 b.set_g(b.get_g()-a.get_g()*alpha);
341 b.set_b(b.get_b()-a.get_b()*alpha);
347 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
349 const float alpha(a.get_a()*amount);
351 b.set_r(abs(b.get_r()-a.get_r()*alpha));
352 b.set_g(abs(b.get_g()-a.get_g()*alpha));
353 b.set_b(abs(b.get_b()-a.get_b()*alpha));
359 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
361 if(amount<0) a=~a, amount=-amount;
364 b.set_r(((b.get_r()*a.get_r())-b.get_r())*(amount)+b.get_r());
365 b.set_g(((b.get_g()*a.get_g())-b.get_g())*(amount)+b.get_g());
366 b.set_b(((b.get_b()*a.get_b())-b.get_b())*(amount)+b.get_b());
371 blendfunc_DIVIDE(Color &a,Color &b,float amount)
375 // We add COLOR_EPSILON in order to avoid a divide-by-zero condition.
376 // This causes DIVIDE to bias toward positive values, but the effect is
377 // really negligible. There is a reason why we use COLOR_EPSILON--we
378 // want the change to be imperceptable.
380 b.set_r(((b.get_r()/(a.get_r()+COLOR_EPSILON))-b.get_r())*(amount)+b.get_r());
381 b.set_g(((b.get_g()/(a.get_g()+COLOR_EPSILON))-b.get_g())*(amount)+b.get_g());
382 b.set_b(((b.get_b()/(a.get_b()+COLOR_EPSILON))-b.get_b())*(amount)+b.get_b());
388 blendfunc_COLOR(Color &a,Color &b,float amount)
391 temp.set_uv(a.get_u(),a.get_v());
392 return (temp-b)*amount*a.get_a()+b;
396 blendfunc_HUE(Color &a,Color &b,float amount)
399 temp.set_hue(a.get_hue());
400 return (temp-b)*amount*a.get_a()+b;
404 blendfunc_SATURATION(Color &a,Color &b,float amount)
407 temp.set_s(a.get_s());
408 return (temp-b)*amount*a.get_a()+b;
412 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
415 temp.set_y(a.get_y());
416 return (temp-b)*amount*a.get_a()+b;
420 blendfunc_BEHIND(Color &a,Color &b,float amount)
422 if(a.get_a()==0)a.set_a(COLOR_EPSILON); //!< \hack
423 a.set_a(a.get_a()*amount);
424 return blendfunc_COMPOSITE(b,a,1.0);
428 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
430 if(a.get_a()<b.get_a()*amount)
431 return a.set_a(a.get_a()*amount);
436 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
438 if(a.get_a()*amount>b.get_a())
439 return a.set_a(a.get_a()*amount);
444 blendfunc_SCREEN(Color &a,Color &b,float amount)
446 if(amount<0) a=~a, amount=-amount;
448 a.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
449 a.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
450 a.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
452 return blendfunc_ONTO(a,b,amount);
456 blendfunc_OVERLAY(Color &a,Color &b,float amount)
458 if(amount<0) a=~a, amount=-amount;
461 rm.set_r(b.get_r()*a.get_r());
462 rm.set_g(b.get_g()*a.get_g());
463 rm.set_b(b.get_b()*a.get_b());
466 rs.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
467 rs.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
468 rs.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
472 ret.set_r(a.get_r()*rs.get_r() + (1.0-a.get_r())*rm.get_r());
473 ret.set_g(a.get_g()*rs.get_g() + (1.0-a.get_g())*rm.get_g());
474 ret.set_b(a.get_b()*rs.get_b() + (1.0-a.get_b())*rm.get_b());
476 return blendfunc_ONTO(ret,b,amount);
480 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
482 if(amount<0) a=~a, amount=-amount;
484 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()));
485 else a.set_r(b.get_r()*(a.get_r()*2.0f));
486 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()));
487 else a.set_g(b.get_g()*(a.get_g()*2.0f));
488 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()));
489 else a.set_b(b.get_b()*(a.get_b()*2.0f));
491 return blendfunc_ONTO(a,b,amount);
495 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
499 //multiply the inverse alpha channel with the one below us
500 rm.set_a((1-a.get_a())*b.get_a());
502 return blendfunc_STRAIGHT(rm,b,amount);
507 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
510 if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
513 a=magenta().set_a(a.get_a());
515 a=black().set_a(a.get_a());
519 if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
522 b=magenta().set_a(b.get_a());
524 b=black().set_a(b.get_a());
530 if(!a.is_valid()&&b.is_valid())
533 if(a.is_valid()&&!b.is_valid())
536 if(!a.is_valid()||!b.is_valid())
546 // No matter what blend method is being used,
547 // if the amount is equal to zero, then only B
548 // will shine through
549 if(fabsf(amount)<=COLOR_EPSILON)return b;
551 assert(type<BLEND_END);
553 const static blendfunc vtable[BLEND_END]=
565 blendfunc_SATURATION,
569 blendfunc_ALPHA_BRIGHTEN,
570 blendfunc_ALPHA_DARKEN,
572 blendfunc_HARD_LIGHT,
573 blendfunc_DIFFERENCE,
574 blendfunc_ALPHA_OVER,
576 blendfunc_STRAIGHT_ONTO,
579 return vtable[type](a,b,amount);