#include "tsegmentadjuster.h"

#include "tgl.h"

#include <qdebug></qdebug>

TSegmentAdjuster::TSegmentAdjuster() : m_traceEnabled(false) {}

void TSegmentAdjuster::compute(End &pa, End &pb) {

  m_a = m_c = pa;

  m_b = m_d = pb;

  m_links.clear();

  if (m_traceEnabled)

    m_links.push_back(std::make_pair(m_a.getPoint(), m_b.getPoint()));

  double u = m_a.m_w, v = m_b.m_w;

  // double ua=w0, va=w1;

  // TPointD c = (stroke0->getPoint(ua)+stroke1->getPoint(va))*0.5;

  int count = 0;

  for (;;) {

    if (++count > 1000) break;

    double du, dv;

    gradient(du, dv, u, v);

    double dd = sqrt(du * du + dv * dv);

    if (dd < 0.01) break;

    du *= 1.0 / dd;

    dv *= 1.0 / dd;

    double a_dsda = dsda(m_a.m_stroke, u, du);

    double b_dsda = dsda(m_b.m_stroke, v, dv);

    const double ds  = 0.5;

    const double eps = 0.0001;

    double a         = 0.01;

    double aa;

    if (a_dsda > eps && (aa = ds / a_dsda, aa < a)) a = aa;

    if (b_dsda > eps && (aa = ds / b_dsda, aa < a)) a = aa;

    u -= a * du;

    v -= a * dv;

    u = tcrop(u, m_a.m_wmin, m_a.m_wmax);

    v = tcrop(v, m_b.m_wmin, m_b.m_wmax);

    if (m_traceEnabled)

      m_links.push_back(

          std::make_pair(m_a.m_stroke->getPoint(u), m_b.m_stroke->getPoint(v)));

  }

  m_c.m_w = u;

  m_d.m_w = v;

  pa.m_w  = u;

  pb.m_w  = v;

}

void TSegmentAdjuster::draw() {

  for (int i = 0; i < (int)m_links.size(); i++) {

    glColor3d(0.9, 0.8, 0.7);

    tglDrawSegment(m_links[i].first, m_links[i].second);

  }

}