1 /* === S Y N F I G ========================================================= */
8 ** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
9 ** Copyright (c) 2007 Chris Moore
11 ** This package is free software; you can redistribute it and/or
12 ** modify it under the terms of the GNU General Public License as
13 ** published by the Free Software Foundation; either version 2 of
14 ** the License, or (at your option) any later version.
16 ** This package is distributed in the hope that it will be useful,
17 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
18 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 ** General Public License for more details.
22 /* ========================================================================= */
24 /* === H E A D E R S ======================================================= */
42 using namespace synfig;
46 /* === M A C R O S ========================================================= */
48 #define COLOR_EPSILON (0.000001f)
50 /* === 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));
92 else if (hex.size() == 3)
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;
99 else if (hex.size() == 6)
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;
109 printf("caught <%s>\n", s.c_str());
115 Color::get_string(void)const
117 std::ostringstream o;
118 o << std::fixed << std::setprecision(3) << "#" << get_hex() << " : " << std::setw(6) << a_;
119 return String(o.str().c_str());
124 Color::rotate_uv(const Angle& theta)const
128 ret.set_hue(ret.get_hue()+theta);
132 a(angle::sin(theta).get()),
133 b(angle::cos(theta).get());
138 return set_uv(b*u-a*v,a*u+b*v);
139 //return YUV(get_y(),b*u-a*v,a*u+b*v,get_a());
145 Color::clamped_negative()const
174 if(ret.r_>1) ret.r_=1;
175 if(ret.g_>1) ret.g_=1;
176 if(ret.b_>1) ret.b_=1;
177 if(ret.a_>1) ret.a_=1;
179 if(isnan(ret.get_r())) ret.r_=0.5;
180 if(isnan(ret.get_g())) ret.g_=0.5;
181 if(isnan(ret.get_b())) ret.b_=0.5;
182 if(isnan(ret.get_a())) ret.a_=1;
185 if(ret.r_>1) { ret.g_/=ret.r_; ret.b_/=ret.r_; ret.r_=1; }
186 if(ret.g_>1) { ret.r_/=ret.g_; ret.b_/=ret.g_; ret.g_=1; }
187 if(ret.b_>1) { ret.g_/=ret.b_; ret.r_/=ret.b_; ret.b_=1; }
188 if(ret.a_>1) ret.a_=1;
195 Color::clamped()const
207 if(ret.r_>1) ret.r_=1;
208 if(ret.g_>1) ret.g_=1;
209 if(ret.b_>1) ret.b_=1;
210 if(ret.a_>1) ret.a_=1;
212 if(isnan(ret.get_r())) ret.r_=0.5;
213 if(isnan(ret.get_g())) ret.g_=0.5;
214 if(isnan(ret.get_b())) ret.b_=0.5;
215 if(isnan(ret.get_a())) ret.a_=1;
220 typedef Color (*blendfunc)(Color &,Color &,float);
223 blendfunc_COMPOSITE(Color &src,Color &dest,float amount)
225 //c_dest'=c_src+(1.0-a_src)*c_dest
226 //a_dest'=a_src+(1.0-a_src)*a_dest
228 float a_src=src.get_a()*amount;
229 float a_dest=dest.get_a();
232 //if(fabsf(a_src)<COLOR_EPSILON) return dest;
234 // Scale the source and destination by their alpha values
238 dest=src + dest*(1.0f-a_src);
240 a_dest=a_src + a_dest*(1.0f-a_src);
243 if(fabsf(a_dest)>COLOR_EPSILON)
252 assert(dest.is_valid());
257 blendfunc_STRAIGHT(Color &src,Color &bg,float amount)
259 //a_out'=(a_src-a_bg)*amount+a_bg
260 //c_out'=(((c_src*a_src)-(c_bg*a_bg))*amount+(c_bg*a_bg))/a_out'
262 // ie: if(amount==1.0)
263 //if(fabsf(amount-1.0f)<COLOR_EPSILON)return src;
267 float a_out((src.get_a()-bg.get_a())*amount+bg.get_a());
270 if(fabsf(a_out)>COLOR_EPSILON)
271 // if(a_out>COLOR_EPSILON || a_out<-COLOR_EPSILON)
273 out=((src*src.get_a()-bg*bg.get_a())*amount+bg*bg.get_a())/a_out;
279 assert(out.is_valid());
284 blendfunc_ONTO(Color &a,Color &b,float amount)
286 float alpha(b.get_a());
287 return blendfunc_COMPOSITE(a,b.set_a(1.0f),amount).set_a(alpha);
291 blendfunc_STRAIGHT_ONTO(Color &a,Color &b,float amount)
293 a.set_a(a.get_a()*b.get_a());
294 return blendfunc_STRAIGHT(a,b,amount);
298 blendfunc_BRIGHTEN(Color &a,Color &b,float amount)
300 const float alpha(a.get_a()*amount);
302 if(b.get_r()<a.get_r()*alpha)
303 b.set_r(a.get_r()*alpha);
305 if(b.get_g()<a.get_g()*alpha)
306 b.set_g(a.get_g()*alpha);
308 if(b.get_b()<a.get_b()*alpha)
309 b.set_b(a.get_b()*alpha);
315 blendfunc_DARKEN(Color &a,Color &b,float amount)
317 const float alpha(a.get_a()*amount);
319 if(b.get_r()>(a.get_r()-1.0f)*alpha+1.0f)
320 b.set_r((a.get_r()-1.0f)*alpha+1.0f);
322 if(b.get_g()>(a.get_g()-1.0f)*alpha+1.0f)
323 b.set_g((a.get_g()-1.0f)*alpha+1.0f);
325 if(b.get_b()>(a.get_b()-1.0f)*alpha+1.0f)
326 b.set_b((a.get_b()-1.0f)*alpha+1.0f);
333 blendfunc_ADD(Color &a,Color &b,float amount)
335 const float alpha(a.get_a()*amount);
337 b.set_r(b.get_r()+a.get_r()*alpha);
338 b.set_g(b.get_g()+a.get_g()*alpha);
339 b.set_b(b.get_b()+a.get_b()*alpha);
345 blendfunc_SUBTRACT(Color &a,Color &b,float amount)
347 const float alpha(a.get_a()*amount);
349 b.set_r(b.get_r()-a.get_r()*alpha);
350 b.set_g(b.get_g()-a.get_g()*alpha);
351 b.set_b(b.get_b()-a.get_b()*alpha);
357 blendfunc_DIFFERENCE(Color &a,Color &b,float amount)
359 const float alpha(a.get_a()*amount);
361 b.set_r(abs(b.get_r()-a.get_r()*alpha));
362 b.set_g(abs(b.get_g()-a.get_g()*alpha));
363 b.set_b(abs(b.get_b()-a.get_b()*alpha));
369 blendfunc_MULTIPLY(Color &a,Color &b,float amount)
371 if(amount<0) a=~a, amount=-amount;
374 b.set_r(((b.get_r()*a.get_r())-b.get_r())*(amount)+b.get_r());
375 b.set_g(((b.get_g()*a.get_g())-b.get_g())*(amount)+b.get_g());
376 b.set_b(((b.get_b()*a.get_b())-b.get_b())*(amount)+b.get_b());
381 blendfunc_DIVIDE(Color &a,Color &b,float amount)
385 // We add COLOR_EPSILON in order to avoid a divide-by-zero condition.
386 // This causes DIVIDE to bias toward positive values, but the effect is
387 // really negligible. There is a reason why we use COLOR_EPSILON--we
388 // want the change to be imperceptable.
390 b.set_r(((b.get_r()/(a.get_r()+COLOR_EPSILON))-b.get_r())*(amount)+b.get_r());
391 b.set_g(((b.get_g()/(a.get_g()+COLOR_EPSILON))-b.get_g())*(amount)+b.get_g());
392 b.set_b(((b.get_b()/(a.get_b()+COLOR_EPSILON))-b.get_b())*(amount)+b.get_b());
398 blendfunc_COLOR(Color &a,Color &b,float amount)
401 temp.set_uv(a.get_u(),a.get_v());
402 return (temp-b)*amount*a.get_a()+b;
406 blendfunc_HUE(Color &a,Color &b,float amount)
409 temp.set_hue(a.get_hue());
410 return (temp-b)*amount*a.get_a()+b;
414 blendfunc_SATURATION(Color &a,Color &b,float amount)
417 temp.set_s(a.get_s());
418 return (temp-b)*amount*a.get_a()+b;
422 blendfunc_LUMINANCE(Color &a,Color &b,float amount)
425 temp.set_y(a.get_y());
426 return (temp-b)*amount*a.get_a()+b;
430 blendfunc_BEHIND(Color &a,Color &b,float amount)
432 if(a.get_a()==0)a.set_a(COLOR_EPSILON); //!< \hack
433 a.set_a(a.get_a()*amount);
434 return blendfunc_COMPOSITE(b,a,1.0);
438 blendfunc_ALPHA_BRIGHTEN(Color &a,Color &b,float amount)
440 if(a.get_a()<b.get_a()*amount)
441 return a.set_a(a.get_a()*amount);
446 blendfunc_ALPHA_DARKEN(Color &a,Color &b,float amount)
448 if(a.get_a()*amount>b.get_a())
449 return a.set_a(a.get_a()*amount);
454 blendfunc_SCREEN(Color &a,Color &b,float amount)
456 if(amount<0) a=~a, amount=-amount;
458 a.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
459 a.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
460 a.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
462 return blendfunc_ONTO(a,b,amount);
466 blendfunc_OVERLAY(Color &a,Color &b,float amount)
468 if(amount<0) a=~a, amount=-amount;
471 rm.set_r(b.get_r()*a.get_r());
472 rm.set_g(b.get_g()*a.get_g());
473 rm.set_b(b.get_b()*a.get_b());
476 rs.set_r(1.0-(1.0f-a.get_r())*(1.0f-b.get_r()));
477 rs.set_g(1.0-(1.0f-a.get_g())*(1.0f-b.get_g()));
478 rs.set_b(1.0-(1.0f-a.get_b())*(1.0f-b.get_b()));
482 ret.set_r(a.get_r()*rs.get_r() + (1.0-a.get_r())*rm.get_r());
483 ret.set_g(a.get_g()*rs.get_g() + (1.0-a.get_g())*rm.get_g());
484 ret.set_b(a.get_b()*rs.get_b() + (1.0-a.get_b())*rm.get_b());
486 return blendfunc_ONTO(ret,b,amount);
490 blendfunc_HARD_LIGHT(Color &a,Color &b,float amount)
492 if(amount<0) a=~a, amount=-amount;
494 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()));
495 else a.set_r(b.get_r()*(a.get_r()*2.0f));
496 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()));
497 else a.set_g(b.get_g()*(a.get_g()*2.0f));
498 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()));
499 else a.set_b(b.get_b()*(a.get_b()*2.0f));
501 return blendfunc_ONTO(a,b,amount);
505 blendfunc_ALPHA_OVER(Color &a,Color &b,float amount)
509 //multiply the inverse alpha channel with the one below us
510 rm.set_a((1-a.get_a())*b.get_a());
512 return blendfunc_STRAIGHT(rm,b,amount);
517 Color::blend(Color a, Color b,float amount, Color::BlendMethod type)
520 if(isnan(a.get_r()) || isnan(a.get_g()) || isnan(a.get_b()))
523 a=magenta().set_a(a.get_a());
525 a=black().set_a(a.get_a());
529 if(isnan(b.get_r()) || isnan(b.get_g()) || isnan(b.get_b()))
532 b=magenta().set_a(b.get_a());
534 b=black().set_a(b.get_a());
540 if(!a.is_valid()&&b.is_valid())
543 if(a.is_valid()&&!b.is_valid())
546 if(!a.is_valid()||!b.is_valid())
556 // No matter what blend method is being used,
557 // if the amount is equal to zero, then only B
558 // will shine through
559 if(fabsf(amount)<=COLOR_EPSILON)return b;
561 assert(type<BLEND_END);
563 const static blendfunc vtable[BLEND_END]=
575 blendfunc_SATURATION,
579 blendfunc_ALPHA_BRIGHTEN,
580 blendfunc_ALPHA_DARKEN,
582 blendfunc_HARD_LIGHT,
583 blendfunc_DIFFERENCE,
584 blendfunc_ALPHA_OVER,
586 blendfunc_STRAIGHT_ONTO,
589 return vtable[type](a,b,amount);