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 ======================================================= */
52 /* === P R O C E D U R E S ================================================= */
54 /* === M E T H O D S ======================================================= */
59 Color::hex2real(String s)
61 std::istringstream i(s);
65 throw String("bad conversion from hex string \"") + s + String("\"");
70 Color::real2hex(ColorReal c)
77 o << hex << int(c*255.0f);
82 Color::set_hex(String& hex)
89 r = hex2real(hex.substr(0,1)+hex.substr(0,1));
90 g = hex2real(hex.substr(1,1)+hex.substr(1,1));
91 b = hex2real(hex.substr(2,1)+hex.substr(2,1));
92 r_ = r; g_ = g; b_ = b;
94 else if (hex.size() == 6)
96 r = hex2real(hex.substr(0,2));
97 g = hex2real(hex.substr(2,2));
98 b = hex2real(hex.substr(4,2));
99 r_ = r; g_ = g; b_ = b;
104 printf("caught <%s>\n", s.c_str());
111 Color::rotate_uv(const Angle& theta)const
115 ret.set_hue(ret.get_hue()+theta);
119 a(angle::sin(theta).get()),
120 b(angle::cos(theta).get());
125 return set_uv(b*u-a*v,a*u+b*v);
126 //return YUV(get_y(),b*u-a*v,a*u+b*v,get_a());
132 Color::clamped_negative()const
161 if(ret.r_>1) ret.r_=1;
162 if(ret.g_>1) ret.g_=1;
163 if(ret.b_>1) ret.b_=1;
164 if(ret.a_>1) ret.a_=1;
166 if(isnan(ret.get_r())) ret.r_=0.5;
167 if(isnan(ret.get_g())) ret.g_=0.5;
168 if(isnan(ret.get_b())) ret.b_=0.5;
169 if(isnan(ret.get_a())) ret.a_=1;
172 if(ret.r_>1) { ret.g_/=ret.r_; ret.b_/=ret.r_; ret.r_=1; }
173 if(ret.g_>1) { ret.r_/=ret.g_; ret.b_/=ret.g_; ret.g_=1; }
174 if(ret.b_>1) { ret.g_/=ret.b_; ret.r_/=ret.b_; ret.b_=1; }
175 if(ret.a_>1) ret.a_=1;
182 Color::clamped()const
194 if(ret.r_>1) ret.r_=1;
195 if(ret.g_>1) ret.g_=1;
196 if(ret.b_>1) ret.b_=1;
197 if(ret.a_>1) ret.a_=1;
199 if(isnan(ret.get_r())) ret.r_=0.5;
200 if(isnan(ret.get_g())) ret.g_=0.5;
201 if(isnan(ret.get_b())) ret.b_=0.5;
202 if(isnan(ret.get_a())) ret.a_=1;
207 typedef Color (*blendfunc)(Color &,Color &,float);
210 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
212 //c_dest'=c_src+(1.0-a_src)*c_dest
213 //a_dest'=a_src+(1.0-a_src)*a_dest
215 float a_src=src.get_a()*amount;
216 float a_dest=dest.get_a();
219 //if(fabsf(a_src)<COLOR_EPSILON) return dest;
221 // Scale the source and destination by their alpha values
225 dest=src + dest*(1.0f-a_src);
227 a_dest=a_src + a_dest*(1.0f-a_src);
230 if(fabsf(a_dest)>COLOR_EPSILON)
239 assert(dest.is_valid());
244 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
246 //a_out'=(a_src-a_bg)*amount+a_bg
247 //c_out'=(((c_src*a_src)-(c_bg*a_bg))*amount+(c_bg*a_bg))/a_out'
249 // ie: if(amount==1.0)
250 //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
254 float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
257 if(fabsf(a_out)>COLOR_EPSILON)
258 // if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
260 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
266 assert(out.is_valid());
271 blendfunc_ONTO(Color &a,Color &b,float amount)
273 float alpha(b.get_a());
274 return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
278 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
280 a.set_a(a.get_a()*b.get_a());
281 return blendfunc_STRAIGHT(a,b,amount);
285 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
287 const float alpha(a.get_a()*amount);
289 if(b.get_r()<a.get_r()*alpha)
290 b.set_r(a.get_r()*alpha);
292 if(b.get_g()<a.get_g()*alpha)
293 b.set_g(a.get_g()*alpha);
295 if(b.get_b()<a.get_b()*alpha)
296 b.set_b(a.get_b()*alpha);
302 blendfunc_DARKEN(Color &a,Color &b,float amount)
304 const float alpha(a.get_a()*amount);
306 if(b.get_r()>(a.get_r()-1.0f)*alpha+1.0f)
307 b.set_r((a.get_r()-1.0f)*alpha+1.0f);
309 if(b.get_g()>(a.get_g()-1.0f)*alpha+1.0f)
310 b.set_g((a.get_g()-1.0f)*alpha+1.0f);
312 if(b.get_b()>(a.get_b()-1.0f)*alpha+1.0f)
313 b.set_b((a.get_b()-1.0f)*alpha+1.0f);
320 blendfunc_ADD(Color &a,Color &b,float amount)
322 const float alpha(a.get_a()*amount);
324 b.set_r(b.get_r()+a.get_r()*alpha);
325 b.set_g(b.get_g()+a.get_g()*alpha);
326 b.set_b(b.get_b()+a.get_b()*alpha);
332 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
334 const float alpha(a.get_a()*amount);
336 b.set_r(b.get_r()-a.get_r()*alpha);
337 b.set_g(b.get_g()-a.get_g()*alpha);
338 b.set_b(b.get_b()-a.get_b()*alpha);
344 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
346 const float alpha(a.get_a()*amount);
348 b.set_r(abs(b.get_r()-a.get_r()*alpha));
349 b.set_g(abs(b.get_g()-a.get_g()*alpha));
350 b.set_b(abs(b.get_b()-a.get_b()*alpha));
356 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
358 if(amount<0) a=~a, amount=-amount;
361 b.set_r(((b.get_r()*a.get_r())-b.get_r())*(amount)+b.get_r());
362 b.set_g(((b.get_g()*a.get_g())-b.get_g())*(amount)+b.get_g());
363 b.set_b(((b.get_b()*a.get_b())-b.get_b())*(amount)+b.get_b());
368 blendfunc_DIVIDE(Color &a,Color &b,float amount)
372 // We add COLOR_EPSILON in order to avoid a divide-by-zero condition.
373 // This causes DIVIDE to bias toward positive values, but the effect is
374 // really neglegable. There is a reason why we use COLOR_EPSILON--we
375 // want the change to be imperceptable.
377 b.set_r(((b.get_r()/(a.get_r()+COLOR_EPSILON))-b.get_r())*(amount)+b.get_r());
378 b.set_g(((b.get_g()/(a.get_g()+COLOR_EPSILON))-b.get_g())*(amount)+b.get_g());
379 b.set_b(((b.get_b()/(a.get_b()+COLOR_EPSILON))-b.get_b())*(amount)+b.get_b());
385 blendfunc_COLOR(Color &a,Color &b,float amount)
388 temp.set_uv(a.get_u(),a.get_v());
389 return (temp-b)*amount*a.get_a()+b;
393 blendfunc_HUE(Color &a,Color &b,float amount)
396 temp.set_hue(a.get_hue());
397 return (temp-b)*amount*a.get_a()+b;
401 blendfunc_SATURATION(Color &a,Color &b,float amount)
404 temp.set_s(a.get_s());
405 return (temp-b)*amount*a.get_a()+b;
409 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
412 temp.set_y(a.get_y());
413 return (temp-b)*amount*a.get_a()+b;
417 blendfunc_BEHIND(Color &a,Color &b,float amount)
419 if(a.get_a()==0)a.set_a(COLOR_EPSILON); //!< \hack
420 a.set_a(a.get_a()*amount);
421 return blendfunc_COMPOSITE(b,a,1.0);
425 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
427 if(a.get_a()<b.get_a()*amount)
428 return a.set_a(a.get_a()*amount);
433 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
435 if(a.get_a()*amount>b.get_a())
436 return a.set_a(a.get_a()*amount);
441 blendfunc_SCREEN(Color &a,Color &b,float amount)
443 if(amount<0) a=~a, amount=-amount;
445 a.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
446 a.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
447 a.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
449 return blendfunc_ONTO(a,b,amount);
453 blendfunc_OVERLAY(Color &a,Color &b,float amount)
455 if(amount<0) a=~a, amount=-amount;
458 rm.set_r(b.get_r()*a.get_r());
459 rm.set_g(b.get_g()*a.get_g());
460 rm.set_b(b.get_b()*a.get_b());
463 rs.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
464 rs.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
465 rs.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
469 ret.set_r(a.get_r()*rs.get_r() + (1.0-a.get_r())*rm.get_r());
470 ret.set_g(a.get_g()*rs.get_g() + (1.0-a.get_g())*rm.get_g());
471 ret.set_b(a.get_b()*rs.get_b() + (1.0-a.get_b())*rm.get_b());
473 return blendfunc_ONTO(ret,b,amount);
477 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
479 if(amount<0) a=~a, amount=-amount;
481 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()));
482 else a.set_r(b.get_r()*(a.get_r()*2.0f));
483 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()));
484 else a.set_g(b.get_g()*(a.get_g()*2.0f));
485 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()));
486 else a.set_b(b.get_b()*(a.get_b()*2.0f));
488 return blendfunc_ONTO(a,b,amount);
492 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
496 //multiply the inverse alpha channel with the one below us
497 rm.set_a((1-a.get_a())*b.get_a());
499 return blendfunc_STRAIGHT(rm,b,amount);
504 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
507 if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
510 a=magenta().set_a(a.get_a());
512 a=black().set_a(a.get_a());
516 if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
519 b=magenta().set_a(b.get_a());
521 b=black().set_a(b.get_a());
527 if(!a.is_valid()&&b.is_valid())
530 if(a.is_valid()&&!b.is_valid())
533 if(!a.is_valid()||!b.is_valid())
543 // No matter what blend method is being used,
544 // if the amount is equal to zero, then only B
545 // will shine through
546 if(fabsf(amount)<=COLOR_EPSILON)return b;
548 assert(type<BLEND_END);
550 const static blendfunc vtable[BLEND_END]=
562 blendfunc_SATURATION,
566 blendfunc_ALPHA_BRIGHTEN,
567 blendfunc_ALPHA_DARKEN,
569 blendfunc_HARD_LIGHT,
570 blendfunc_DIFFERENCE,
571 blendfunc_ALPHA_OVER,
573 blendfunc_STRAIGHT_ONTO,
576 return vtable[type](a,b,amount);