-/* === 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");
-}