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));
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;
92 else if (hex.size() == 6)
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;
102 printf("caught <%s>\n", s.c_str());
109 Color::rotate_uv(const Angle& theta)const
113 ret.set_hue(ret.get_hue()+theta);
117 a(angle::sin(theta).get()),
118 b(angle::cos(theta).get());
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());
130 Color::clamped_negative()const
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;
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;
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;
180 Color::clamped()const
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;
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;
205 typedef Color (*blendfunc)(Color &,Color &,float);
208 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
210 //c_dest'=c_src+(1.0-a_src)*c_dest
211 //a_dest'=a_src+(1.0-a_src)*a_dest
213 float a_src=src.get_a()*amount;
214 float a_dest=dest.get_a();
217 //if(fabsf(a_src)<COLOR_EPSILON) return dest;
219 // Scale the source and destination by their alpha values
223 dest=src + dest*(1.0f-a_src);
225 a_dest=a_src + a_dest*(1.0f-a_src);
228 if(fabsf(a_dest)>COLOR_EPSILON)
237 assert(dest.is_valid());
242 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
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'
247 // ie: if(amount==1.0)
248 //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
252 float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
255 if(fabsf(a_out)>COLOR_EPSILON)
256 // if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
258 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
264 assert(out.is_valid());
269 blendfunc_ONTO(Color &a,Color &b,float amount)
271 float alpha(b.get_a());
272 return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
276 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
278 a.set_a(a.get_a()*b.get_a());
279 return blendfunc_STRAIGHT(a,b,amount);
283 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
285 const float alpha(a.get_a()*amount);
287 if(b.get_r()<a.get_r()*alpha)
288 b.set_r(a.get_r()*alpha);
290 if(b.get_g()<a.get_g()*alpha)
291 b.set_g(a.get_g()*alpha);
293 if(b.get_b()<a.get_b()*alpha)
294 b.set_b(a.get_b()*alpha);
300 blendfunc_DARKEN(Color &a,Color &b,float amount)
302 const float alpha(a.get_a()*amount);
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);
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);
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);
318 blendfunc_ADD(Color &a,Color &b,float amount)
320 const float alpha(a.get_a()*amount);
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);
330 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
332 const float alpha(a.get_a()*amount);
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);
342 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
344 const float alpha(a.get_a()*amount);
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));
354 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
356 if(amount<0) a=~a, amount=-amount;
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());
366 blendfunc_DIVIDE(Color &a,Color &b,float amount)
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.
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());
383 blendfunc_COLOR(Color &a,Color &b,float amount)
386 temp.set_uv(a.get_u(),a.get_v());
387 return (temp-b)*amount*a.get_a()+b;
391 blendfunc_HUE(Color &a,Color &b,float amount)
394 temp.set_hue(a.get_hue());
395 return (temp-b)*amount*a.get_a()+b;
399 blendfunc_SATURATION(Color &a,Color &b,float amount)
402 temp.set_s(a.get_s());
403 return (temp-b)*amount*a.get_a()+b;
407 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
410 temp.set_y(a.get_y());
411 return (temp-b)*amount*a.get_a()+b;
415 blendfunc_BEHIND(Color &a,Color &b,float amount)
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);
423 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
425 if(a.get_a()<b.get_a()*amount)
426 return a.set_a(a.get_a()*amount);
431 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
433 if(a.get_a()*amount>b.get_a())
434 return a.set_a(a.get_a()*amount);
439 blendfunc_SCREEN(Color &a,Color &b,float amount)
441 if(amount<0) a=~a, amount=-amount;
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()));
447 return blendfunc_ONTO(a,b,amount);
451 blendfunc_OVERLAY(Color &a,Color &b,float amount)
453 if(amount<0) a=~a, amount=-amount;
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());
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()));
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());
471 return blendfunc_ONTO(ret,b,amount);
475 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
477 if(amount<0) a=~a, amount=-amount;
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));
486 return blendfunc_ONTO(a,b,amount);
490 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
494 //multiply the inverse alpha channel with the one below us
495 rm.set_a((1-a.get_a())*b.get_a());
497 return blendfunc_STRAIGHT(rm,b,amount);
502 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
505 if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
508 a=magenta().set_a(a.get_a());
510 a=black().set_a(a.get_a());
514 if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
517 b=magenta().set_a(b.get_a());
519 b=black().set_a(b.get_a());
525 if(!a.is_valid()&&b.is_valid())
528 if(a.is_valid()&&!b.is_valid())
531 if(!a.is_valid()||!b.is_valid())
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;
546 assert(type<BLEND_END);
548 const static blendfunc vtable[BLEND_END]=
560 blendfunc_SATURATION,
564 blendfunc_ALPHA_BRIGHTEN,
565 blendfunc_ALPHA_DARKEN,
567 blendfunc_HARD_LIGHT,
568 blendfunc_DIFFERENCE,
569 blendfunc_ALPHA_OVER,
571 blendfunc_STRAIGHT_ONTO,
574 return vtable[type](a,b,amount);