--- /dev/null
+/* === S Y N F I G ========================================================= */
+/*! \file gradient.cpp
+** \brief Color Gradient Class Member Definitions
+**
+** $Id: gradient.cpp,v 1.2 2005/01/21 19:29:10 darco Exp $
+**
+** \legal
+** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**
+** This package is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public License as
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** General Public License for more details.
+** \endlegal
+*/
+/* ========================================================================= */
+
+/* === H E A D E R S ======================================================= */
+
+#ifdef USING_PCH
+# include "pch.h"
+#else
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "gradient.h"
+#include "general.h"
+#include <stdexcept>
+#include "exception.h"
+
+#include <ETL/misc>
+#endif
+
+/* === U S I N G =========================================================== */
+
+using namespace std;
+using namespace etl;
+using namespace synfig;
+
+/* === M A C R O S ========================================================= */
+
+/* === G L O B A L S ======================================================= */
+
+/* === P R O C E D U R E S ================================================= */
+
+/* === M E T H O D S ======================================================= */
+
+synfig::Gradient::Gradient(const Color &c1, const Color &c2)
+{
+ push_back(CPoint(0.0,c1));
+ push_back(CPoint(1.0,c2));
+}
+
+synfig::Gradient::Gradient(const Color &c1, const Color &c2, const Color &c3)
+{
+ push_back(CPoint(0.0,c1));
+ push_back(CPoint(0.5,c2));
+ push_back(CPoint(1.0,c3));
+}
+
+// This sort algorithm MUST be stable
+// ie: it must not change the order of items with the same value.
+// I am using a bubble sort.
+// This algorithm will sort a nearly-sorted list at ~O(N), and
+// it will sort an inverse sorted list at ~O(N*N).
+void
+synfig::Gradient::sort()
+{
+ stable_sort(begin(),end());
+ /*
+ iterator iter;
+ iterator iter2,next;
+
+ for(iter=begin();iter!=end();iter++)
+ {
+ for(next=iter, iter2=next--;iter2!=begin();iter2=next--)
+ {
+ if(*iter<*next)
+ {
+ //insert(next,*iter);
+ //erase(iter);
+ iter_swap(next,iter);
+
+ continue;
+ }
+ else
+ break;
+ }
+ }
+ */
+}
+
+static synfig::ColorAccumulator
+supersample_helper(const synfig::Gradient::CPoint &color1, const synfig::Gradient::CPoint &color2, float begin, float end, float &weight)
+{
+ if(color1.pos==color2.pos || color1.pos>=end || color2.pos<=begin)
+ {
+ weight=0;
+ return Color::alpha();
+ }
+ if(color1.pos>=begin && color2.pos<end)
+ {
+ weight=color2.pos-color1.pos;
+ ColorAccumulator ret=Color::blend(color2.color,color1.color, 0.5, Color::BLEND_STRAIGHT);
+ ret.set_r(ret.get_r()*ret.get_a());
+ ret.set_g(ret.get_g()*ret.get_a());
+ ret.set_b(ret.get_b()*ret.get_a());
+ return ret*weight;
+ }
+ if(color1.pos>=begin && color2.pos>=end)
+ {
+ weight=end-color1.pos;
+ float pos((end+color1.pos)*0.5);
+ float amount((pos-color1.pos)/(color2.pos-color1.pos));
+ //if(abs(amount)>1)amount=(amount>0)?1:-1;
+ ColorAccumulator ret(Color::blend(color2.color,color1.color, amount, Color::BLEND_STRAIGHT));
+ ret.set_r(ret.get_r()*ret.get_a());
+ ret.set_g(ret.get_g()*ret.get_a());
+ ret.set_b(ret.get_b()*ret.get_a());
+ return ret*weight;
+ }
+ if(color1.pos<begin && color2.pos<end)
+ {
+ weight=color2.pos-begin;
+ float pos((begin+color2.pos)*0.5);
+ float amount((pos-color1.pos)/(color2.pos-color1.pos));
+ //if(abs(amount)>1)amount=(amount>0)?1:-1;
+ ColorAccumulator ret(Color::blend(color2.color,color1.color, amount, Color::BLEND_STRAIGHT));
+ ret.set_r(ret.get_r()*ret.get_a());
+ ret.set_g(ret.get_g()*ret.get_a());
+ ret.set_b(ret.get_b()*ret.get_a());
+ return ret*weight;
+ }
+ synfig::error("color1.pos=%f",color1.pos);
+ synfig::error("color2.pos=%f",color2.pos);
+ synfig::error("begin=%f",begin);
+ synfig::error("end=%f",end);
+
+ weight=0;
+ return Color::alpha();
+
+// assert(0);
+}
+
+Color
+synfig::Gradient::operator()(const Real &x,float supersample)const
+{
+ if(empty())
+ return Color(0,0,0,0);
+ if(supersample<0)
+ supersample=-supersample;
+ if(supersample>2.0)
+ supersample=2.0f;
+
+ float begin_sample(x-supersample*0.5);
+ float end_sample(x+supersample*0.5);
+
+ if(size()==1 || end_sample<=front().pos || isnan(x))
+ return front().color;
+
+ if(begin_sample>=back().pos)
+ return back().color;
+
+ /*
+ if(end_sample>=back().pos)
+ end_sample=back().pos;
+
+ if(begin_sample<=front().pos)
+ begin_sample=front().pos;
+ */
+
+ const_iterator iter,next;
+
+ /*
+ //optimizize...
+ Real left = x-supersample/2, right = x+supersample/2;
+
+ if(left < front().pos) left = front().pos;
+ if(right > back().pos) right = back().pos;
+
+ //find using binary search...
+ const_iterator iterl,iterr;
+
+ //the binary search should give us the values BEFORE the point we're looking for...
+ iterl = binary_find(begin(),end(),left);
+ iterr = binary_find(iterl,end(),right);
+
+ //now integrate over the range of left to right...
+
+ if(iterl == iterr)
+ {
+ iterr++; //let's look at the next one shall we :)
+
+ //interpolate neighboring colors
+ const Real one = iterr->pos - iterl->pos;
+ const Real lambda = (x - iterl->pos)/one;
+
+ //(1-l)iterl + (l)iterr
+ return iterl->color.premult_alpha()*(1-lambda) + iterr->color.premult_alpha()*lambda;
+
+ //return Color::blend(iterr->color,iterl->color,lambda,Color::BLEND_STRAIGHT);
+ }else
+ {
+ //itegration madness
+ const_iterator i = iterl, ie = iterr+1;
+ Real wlast = left;
+
+ ColorAccumulator clast,cwork;
+ {
+ const Real lambda = (x - iterl->pos)/(iterr->pos - iterl->pos);
+
+ //premultiply because that's the form in which we can combine things...
+ clast = iterl->color.premult_alpha()*(1-lambda) + iterr->color.premult_alpha()*lambda;
+ //Color::blend((i+1)->color,i->color,(left - i->pos)/((i+1)->pos - i->pos),Color::BLEND_STRAIGHT);
+ }
+
+ ColorAccumulator accum = 0;
+
+ //loop through all the trapezoids and integrate them as we go...
+ // area of trap = (yi + yi1)*(xi1 - xi)
+ // yi = clast, xi = wlast, yi1 = i->color, xi1 = i->pos
+
+ for(;i<=iterr; wlast=i->pos,clast=i->color.premult_alpha(),++i)
+ {
+ const Real diff = i->pos - wlast;
+ if(diff > 0) //only accumulate if there will be area to add
+ {
+ cwork = i->color.premult_alpha();
+ accum += (cwork + clast)*diff;
+ }
+ }
+
+ {
+ const_iterator ibef = i-1;
+ const Real diff = right - ibef->pos;
+
+ if(diff > 0)
+ {
+ const Real lambda = diff/(i->pos - ibef->pos);
+ cwork = ibef->color.premult_alpha()*(1-lambda) + i->color.premult_alpha()*lambda;
+
+ accum += (cwork + clast)*diff; //can probably optimize this more... but it's not too bad
+ }
+ }
+
+ accum /= supersample; //should be the total area it was sampled over...
+ return accum.demult_alpha();
+ }*/
+
+ next=begin(),iter=next++;
+
+ //add for optimization
+ next = binary_find(begin(),end(),(Real)begin_sample);
+ iter = next++;
+
+ //! As a future optimization, this could be performed faster
+ //! using a binary search.
+ for(;iter<end();iter=next++)
+ {
+ if(next==end() || x>=iter->pos && x<next->pos && iter->pos!=next->pos)
+ {
+ // If the supersample region falls square in between
+ // two CPoints, then we don't have to do anything special.
+ if(next!=end() && (!supersample || (iter->pos<=begin_sample && next->pos>=end_sample)))
+ {
+ const Real dist(next->pos-iter->pos);
+ const Real pos(x-iter->pos);
+ const Real amount(pos/dist);
+ return Color::blend(next->color,iter->color, amount, Color::BLEND_STRAIGHT);
+ }
+ // In this case our supersample region extends over one or more
+ // CPoints. So, we need to calculate our coverage amount.
+ ColorAccumulator pool(Color::alpha());
+ float divisor(0.0),weight(0);
+
+ const_iterator iter2,next2;
+ iter2=iter;
+ if(iter==begin() && iter->pos>x)
+ {
+ weight=x-iter->pos;
+ //weight*=iter->color.get_a();
+ pool+=ColorAccumulator(iter->color)*(float)iter->color.get_a()*weight;
+ divisor+=weight;
+ }
+ else
+ {
+ while(iter2->pos>=begin_sample)
+ {
+ if(iter2==begin())
+ {
+ weight=iter2->pos-(begin_sample);
+ //weight*=iter2->color.get_a();
+ pool+=ColorAccumulator(iter2->color)*(float)iter2->color.get_a()*weight;
+ divisor+=weight;
+ break;
+ }
+ next2=iter2--;
+ pool+=supersample_helper(*iter2, *next2, begin_sample, end_sample, weight);
+ divisor+=weight;
+ }
+ }
+
+ next2=iter;
+ iter2=next2++;
+ while(iter2->pos<=end_sample)
+ {
+ if(next2==end())
+ {
+ weight=(end_sample)-iter2->pos;
+ pool+=ColorAccumulator(iter2->color)*(float)iter2->color.get_a()*weight;
+ divisor+=weight;
+ break;
+ }
+ pool+=supersample_helper(*iter2, *next2, begin_sample, end_sample, weight);
+ divisor+=weight;
+ iter2=next2++;
+ }
+
+ if(divisor && pool.get_a() && pool.is_valid())
+ {
+/*
+ pool.set_r(pool.get_r()/pool.get_a());
+ pool.set_g(pool.get_g()/pool.get_a());
+ pool.set_b(pool.get_b()/pool.get_a());
+ pool.set_a(pool.get_a()/divisor);
+*/
+ pool/=divisor;
+ pool.set_r(pool.get_r()/pool.get_a());
+ pool.set_g(pool.get_g()/pool.get_a());
+ pool.set_b(pool.get_b()/pool.get_a());
+ if(pool.is_valid())
+ return pool;
+ else
+ return Color::alpha();
+ }
+ else
+ return Color::alpha();
+ }
+ }
+
+ // We should never get to this point.
+
+ synfig::error("synfig::Gradient::operator()(): Logic Error (x=%f)",x);
+ assert(0);
+ throw std::logic_error(strprintf("synfig::Gradient::operator()(): Logic Error (x=%f)",x));
+}
+
+synfig::Gradient::iterator
+synfig::Gradient::proximity(const Real &x)
+{
+ iterator iter;
+ float dist(100000000);
+ float prev_pos(-0230);
+ // This algorithm requires a sorted list.
+ for(iter=begin();iter<end();iter++)
+ {
+ float new_dist;
+
+ if(prev_pos==iter->pos)
+ new_dist=(abs(x-iter->pos-0.00001));
+ else
+ new_dist=(abs(x-iter->pos));
+
+ if(new_dist>dist)
+ {
+ iter--;
+ return iter;
+ }
+ dist=new_dist;
+ prev_pos=iter->pos;
+ }
+ iter--;
+ return iter;
+}
+
+synfig::Gradient::const_iterator
+synfig::Gradient::proximity(const Real &x)const
+{
+ return const_cast<Gradient*>(this)->proximity(x);
+ /*
+ const_iterator iter;
+ float dist(100000000);
+
+ // This algorithm requires a sorted list.
+ for(iter=begin();iter<end();iter++)
+ {
+ const float new_dist(abs(x-iter->pos));
+ if(new_dist>dist)
+ {
+ iter--;
+ return iter;
+ }
+ dist=new_dist;
+ }
+ iter--;
+ return iter;
+ */
+}
+
+synfig::Gradient::iterator
+synfig::Gradient::find(const UniqueID &id)
+{
+ iterator iter;
+
+ for(iter=begin();iter<end();iter++)
+ {
+ if(id==*iter)
+ return iter;
+ }
+
+ throw Exception::NotFound("synfig::Gradient::find(): Unable to find UniqueID in gradient");
+}
+
+synfig::Gradient::const_iterator
+synfig::Gradient::find(const UniqueID &id)const
+{
+ const_iterator iter;
+
+ for(iter=begin();iter<end();iter++)
+ {
+ if(id==*iter)
+ return iter;
+ }
+
+ throw Exception::NotFound("synfig::Gradient::find()const: Unable to find UniqueID in gradient");
+}
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