// TnzTools includes

#include <tools assistant.h=""></tools>

#include <tools assistants="" guidelineline.h=""></tools>

#include <tools assistants="" guidelineellipse.h=""></tools>

// TnzCore includes

#include <tgl.h></tgl.h>

// std includes

#include <limits></limits>

//*****************************************************************************************

//    TAssistantEllipse implementation

//*****************************************************************************************

class TAssistantEllipse final : public TAssistant {

  Q_DECLARE_TR_FUNCTIONS(TAssistantEllipse)

public:

  const TStringId m_idRestricktA;

  const TStringId m_idRestricktB;

  const TStringId m_idRepeat;

  const TStringId m_idGrid;

  const TStringId m_idPerspective;

protected:

  TAssistantPoint &m_center;

  TAssistantPoint &m_a;

  TAssistantPoint &m_b;

  TAssistantPoint &m_grid0;

  TAssistantPoint &m_grid1;

public:

  TAssistantEllipse(TMetaObject &object):

    TAssistant(object),

    m_idRestricktA("restrictA"),

    m_idRestricktB("restrictB"),

    m_idRepeat("repeat"),

    m_idGrid("grid"),

    m_idPerspective("perspective"),

    m_center( addPoint("center", TAssistantPoint::CircleCross) ),

    m_a( addPoint("a", TAssistantPoint::CircleFill, TPointD(100.0, 0.0)) ),

    m_b( addPoint("b", TAssistantPoint::Circle,     TPointD(0.0,  50.0)) ),

    m_grid0( addPoint("grid0",  TAssistantPoint::CircleDoubleDots, TPointD(  0.0,-50.0)) ),

    m_grid1( addPoint("grid1",  TAssistantPoint::CircleDots,       TPointD( 25.0,-75.0)) )

  {

    addProperty( new TBoolProperty(m_idRestricktA.str(), getRestrictA()) );

    addProperty( new TBoolProperty(m_idRestricktB.str(), getRestrictB()) );

    addProperty( new TBoolProperty(m_idRepeat.str(), getRepeat()) );

    addProperty( new TBoolProperty(m_idGrid.str(), getGrid()) );

    addProperty( new TBoolProperty(m_idPerspective.str(), getPerspective()) );

  }

  static QString getLocalName()

    { return tr("Ellipse"); }

  void updateTranslation() const override {

    setTranslation(m_idRestricktA, tr("Restrict A"));

    setTranslation(m_idRestricktB, tr("Restrict B"));

    setTranslation(m_idRepeat, tr("Repeat"));

    setTranslation(m_idGrid, tr("Grid"));

    setTranslation(m_idPerspective, tr("Perspective"));

  }

  inline bool getRestrictA() const

    { return data()[m_idRestricktA].getBool(); }

  inline bool getRestrictB() const

    { return data()[m_idRestricktB].getBool(); }

  inline bool getRepeat() const

    { return data()[m_idRepeat].getBool(); }

  inline bool getGrid() const

    { return data()[m_idGrid].getBool(); }

  inline bool getPerspective() const

    { return data()[m_idPerspective].getBool(); }

  void onDataChanged(const TVariant &value) override {

    TAssistant::onDataChanged(value);

    m_grid0.visible = m_grid1.visible = getGrid();

  }

private:

  void fixBAndGgid1(const TPointD &previousCenter, const TPointD &previousA) {

    TPointD dx = previousA - previousCenter;

    double l = norm2(dx);

    if (l <= TConsts::epsilon*TConsts::epsilon) return;

    dx = dx*(1.0/sqrt(l));

    TPointD dy(-dx.y, dx.x);

    double r2 = dy*(m_b.position - m_center.position);

    TPointD g1 = m_grid1.position - m_grid0.position;

    g1 = TPointD(dx*g1, dy*g1);

    dx = m_a.position - m_center.position;

    l = norm2(dx);

    if (l <= TConsts::epsilon*TConsts::epsilon) return;

    dx = dx*(1.0/sqrt(l));

    dy = TPointD(-dx.y, dx.x);

    m_grid1.position = m_grid0.position + dx*g1.x + dy*g1.y;

    m_b.position = m_center.position + dy*r2;

  }

public:

  void onMovePoint(TAssistantPoint &point, const TPointD &position) override {

    TPointD previousCenter = m_center.position;

    TPointD previousA = m_a.position;

    point.position = position;

    if (&point == &m_center) {

      m_a.position += m_center.position - previousCenter;

      m_b.position += m_center.position - previousCenter;

    } else

    if (&point == &m_a || &point == &m_b)

      fixBAndGgid1(previousCenter, previousA);

  }

  TAffine calcEllipseMatrix() const {

    TPointD da = m_a.position - m_center.position;

    TPointD db = m_b.position - m_center.position;

    double r1 = norm(da);

    if (r1 <= TConsts::epsilon) return TAffine::zero();

    double r2 = fabs( (rotate90(da)*db)*(1.0/r1) );

    if (r2 <= TConsts::epsilon) return TAffine::zero();

    return TAffine::translation(m_center.position)

         * TAffine::rotation(atan(da))

         * TAffine::scale(r1, r2);

  }

  void getGuidelines(

    const TPointD &position,

    const TAffine &toTool,

    TGuidelineList &outGuidelines ) const override

  {

    bool restrictA = getRestrictA();

    bool restrictB = getRestrictB();

    bool repeat = getRepeat();

    TAffine matrix = calcEllipseMatrix();

    if (matrix.isZero()) return;

    if (!restrictA && restrictB) {

      std::swap(matrix.a11, matrix.a12);

      std::swap(matrix.a21, matrix.a22);

      std::swap(restrictA, restrictB);

    }

    matrix = toTool*matrix;

    TAffine matrixInv = matrix.inv();

    if (restrictA && restrictB) {

      // ellipse

      outGuidelines.push_back(TGuidelineP(

        new TGuidelineEllipse(

          getEnabled(),

          getMagnetism(),

          matrix,

          matrixInv )));

    } else

    if (!restrictA && !restrictB) {

      // scaled ellipse

      TPointD p = matrixInv*position;

      double l = norm(p);

      outGuidelines.push_back(TGuidelineP(

        new TGuidelineEllipse(

          getEnabled(),

          getMagnetism(),

          matrix * TAffine::scale(l) )));

    } else { // restrictA

      TPointD p = matrixInv*position;

      if (repeat) {

        double ox = round(0.5*p.x)*2.0;

        p.x -= ox;

        matrix *= TAffine::translation(ox, 0.0);

      }

      // scale by Y

      if (p.x <= TConsts::epsilon - 1.0) {

        // line x = -1

        outGuidelines.push_back(TGuidelineP(

          new TGuidelineInfiniteLine(

            getEnabled(),

            getMagnetism(),

            matrix*TPointD(-1.0, 0.0),

            matrix*TPointD(-1.0, 1.0) )));

      } else

      if (p.x >= 1.0 - TConsts::epsilon) {

        // line x = 1

        outGuidelines.push_back(TGuidelineP(

          new TGuidelineInfiniteLine(

            getEnabled(),

            getMagnetism(),

            matrix*TPointD(1.0, 0.0),

            matrix*TPointD(1.0, 1.0) )));

      } else {

        // ellipse scaled by Y

        double k = fabs(p.y/sqrt(1.0 - p.x*p.x));

        outGuidelines.push_back(TGuidelineP(

          new TGuidelineEllipse(

            getEnabled(),

            getMagnetism(),

            matrix * TAffine::scale(1.0, k) )));

      }

    }

  }

private:

  void drawEllipseRanges(

    const TAngleRangeSet &ranges,

    const TAffine &ellipseMatrix,

    const TAffine &screenMatrixInv,

    double pixelSize,

    double alpha ) const

  {

    assert(ranges.check());

    TAngleRangeSet actualRanges(ranges);

    const TRectD oneBox(-1.0, -1.0, 1.0, 1.0);

    if (!TGuidelineEllipse::truncateEllipse(actualRanges, ellipseMatrix.inv()*screenMatrixInv, oneBox))

      return;

    assert(actualRanges.check());

    int segments = TGuidelineEllipse::calcSegmentsCount(ellipseMatrix, pixelSize);

    double da = M_2PI/segments;

    double s = sin(da);

    double c = cos(da);

    for(TAngleRangeSet::Iterator i(actualRanges); i; ++i) {

      double a0 = i.d0();

      double a1 = i.d1greater();

      int cnt = (int)floor((a1 - a0)/da);

      TPointD r(cos(a0), sin(a0));

      TPointD p0 = ellipseMatrix*r;

      for(int j = 0; j < cnt; ++j) {

        r = TPointD(r.x*c - r.y*s, r.y*c + r.x*s);

        TPointD p1 = ellipseMatrix*r;

        drawSegment(p0, p1, pixelSize, alpha);

        p0 = p1;

      }

      drawSegment(p0, ellipseMatrix*TPointD(cos(a1), sin(a1)), pixelSize, alpha);

    }

  }

  void drawEllipse(

    const TAffine &ellipseMatrix,

    const TAffine &screenMatrixInv,

    double pixelSize,

    double alpha ) const

      { drawEllipseRanges(TAngleRangeSet(true), ellipseMatrix, screenMatrixInv, pixelSize, alpha); }

  void drawRuler(const TAffine &ellipseMatrix, double pixelSize) const {

    double minStep = 10.0*pixelSize;

    double alpha = getDrawingGridAlpha();

    const TAffine &em = ellipseMatrix;

    double r = sqrt(0.5*(norm2(TPointD(em.a11, em.a21)) + norm2(TPointD(em.a12, em.a22))));

    double actualMinStep = minStep/r;

    TAffine ellipseMatrixInv = ellipseMatrix.inv();

    TPointD g0 = ellipseMatrixInv*m_grid0.position;

    TPointD g1 = ellipseMatrixInv*m_grid1.position;

    if (norm2(g0) <= TConsts::epsilon*TConsts::epsilon) return;

    if (norm2(g1) <= TConsts::epsilon*TConsts::epsilon) return;

    double ga0 = atan(g0);

    double ga1 = atan(g1);

    if (getPerspective()) {

      // draw perspective

      if (ga0 < 0.0) { if (ga1 > 0.0) ga1 -= M_2PI; }

                else { if (ga1 < 0.0) ga1 += M_2PI; }

      double k = 0.0, begin = 0.0, end = 0.0;

      if (!calcPerspectiveStep(actualMinStep, 0.0, M_2PI, 0.0, fabs(ga0), ga1, k, begin, end)) return;

      for(double x = begin; fabs(x) < fabs(end); x *= k)

        drawDot(ellipseMatrix * TPointD(cos(x), (ga0 < 0.0 ? -1.0 : 1.0)*sin(x)));

    } else {

      // draw linear

      double da = ga1 - ga0;

      if (da < 0.0)         { da = -da;        std::swap(ga0, ga1); }

      if (ga1 - ga0 > M_PI) { da = M_2PI - da; std::swap(ga0, ga1); }

      if (da < actualMinStep) return;

      for(double a = ga0 - floor(M_PI/da)*da; a < ga0 + M_PI; a += da)

        drawDot(ellipseMatrix * TPointD(cos(a), sin(a)));

    }

  }

  void drawConcentricGrid(

    const TAffine &ellipseMatrix,

    const TAffine &screenMatrixInv,

    double pixelSize ) const

  {

    double minStep = 20.0*pixelSize;

    double alpha = getDrawingGridAlpha();

    TAffine ellipseMatrixInv = ellipseMatrix.inv();

    // calculate bounds

    TAffine matrixInv = ellipseMatrixInv * screenMatrixInv;

    TPointD o  = matrixInv * TPointD(-1.0, -1.0);

    TPointD dx = matrixInv.transformDirection( TPointD(2.0, 0.0) );

    TPointD dy = matrixInv.transformDirection( TPointD(0.0, 2.0) );

    double max = 0.0;

    double min = std::numeric_limits<double>::infinity();</double>

    // distance to points

    TPointD corners[] = { o, o+dx, o+dx+dy, o+dy };

    for(int i = 0; i < 4; ++i) {

      double k = norm(corners[i]);

      if (k < min) min = k;

      if (k > max) max = k;

    }

    // distance to sides

    TPointD lines[] = { dx, dy, -1.0*dx, -1.0*dy };

    int positive = 0, negative = 0;

    for(int i = 0; i < 4; ++i) {

      double len2 = norm2(lines[i]);

      if (len2 <= TConsts::epsilon*TConsts::epsilon) continue;

      double k = (corners[i]*rotate90(lines[i]))/sqrt(len2);

      if (k > TConsts::epsilon) ++positive;

      if (k < TConsts::epsilon) ++negative;

      double l = -(corners[i]*lines[i]);

      if (l <= TConsts::epsilon || l >= len2 - TConsts::epsilon) continue;

      k = fabs(k);

      if (k < min) min = k;

      if (k > max) max = k;

    }

    // if center is inside bounds

    if (min < 0.0 || positive == 0 || negative == 0) min = 0.0;

    if (max <= min) return;

    // draw

    const TAffine &em = ellipseMatrix;

    double r = sqrt(0.5*(norm2(TPointD(em.a11, em.a21)) + norm2(TPointD(em.a12, em.a22))));

    double actualMinStep = minStep/r;

    double gs0 = norm(ellipseMatrixInv*m_grid0.position);

    double gs1 = norm(ellipseMatrixInv*m_grid1.position);

    if (gs0 <= TConsts::epsilon*TConsts::epsilon) return;

    if (gs1 <= TConsts::epsilon*TConsts::epsilon) return;

    if (getPerspective()) {

      // draw perspective

      double k = 0.0, begin = 0.0, end = 0.0;

      if (!calcPerspectiveStep(actualMinStep, min, max, 0.0, gs0, gs1, k, begin, end)) return;

      for(double x = begin; fabs(x) < fabs(end); x *= k)

        drawEllipse(ellipseMatrix * TAffine::scale(x), screenMatrixInv, pixelSize, alpha);

    } else {

      // draw linear

      double dx = fabs(gs1 - gs0);

      if (dx*r < minStep) return;

      for(double x = gs0 + ceil((min - gs0)/dx)*dx; x < max; x += dx)

        drawEllipse(ellipseMatrix * TAffine::scale(x), screenMatrixInv, pixelSize, alpha);

    }

  }

  void drawParallelGrid(

    const TAffine &ellipseMatrix,

    const TAffine &screenMatrixInv,

    double pixelSize ) const

  {

    double minStep = 10.0*pixelSize;

    double alpha = getDrawingGridAlpha();

    TAffine ellipseMatrixInv = ellipseMatrix.inv();

    const TAffine &em = ellipseMatrix;

    double r = sqrt(0.5*(norm2(TPointD(em.a11, em.a21)) + norm2(TPointD(em.a12, em.a22))));

    double actualMinStep = minStep/r;

    TPointD g0 = ellipseMatrixInv*m_grid0.position;

    TPointD g1 = ellipseMatrixInv*m_grid1.position;

    if (getRepeat())

      { g0.x -= round(0.5*g0.x)*2.0; g1.x -= round(0.5*g1.x)*2.0; }

    if (fabs(g0.x) >= 1.0 - TConsts::epsilon) return;

    if (fabs(g1.x) >= 1.0 - TConsts::epsilon) return;

    double gs0 = g0.y/sqrt(1.0 - g0.x*g0.x);

    double gs1 = g1.y/sqrt(1.0 - g1.x*g1.x);

    if (fabs(gs0) >= 1.0 - TConsts::epsilon) return;

    if (fabs(gs1) >= 1.0 - TConsts::epsilon) return;

    TAngleRangeSet ranges;

    ranges.add( TAngleRangeSet::fromDouble(0.0), TAngleRangeSet::fromDouble(M_PI) );

    if (getPerspective()) {

      // draw perspective (actually angular)

      double k = 0.0, begin = 0.0, end = 0.0;

      double a0 = asin(gs0);

      double a1 = asin(gs1);

      double da = fabs(a1 - a0);

      if (fabs(sin(da)) < 2.0*actualMinStep) return;

      for(double a = a0 + ceil((-M_PI_2 - a0)/da)*da; a < M_PI_2; a += da)

        drawEllipseRanges(

          ranges,

          ellipseMatrix*TAffine::scale(a < 0.0 ? -1.0 : 1.0, sin(a)),

          screenMatrixInv,

          pixelSize,

          alpha );

    } else {

      // draw linear

      double dx = fabs(gs1 - gs0);

      if (dx < actualMinStep) return;

      for(double x = gs0 + ceil((-1.0 - gs0)/dx)*dx; x < 1.0; x += dx)

        drawEllipseRanges(

          ranges,

          ellipseMatrix*TAffine::scale(x < 0.0 ? -1.0 : 1.0, x),

          screenMatrixInv,

          pixelSize,

          alpha );

    }

  }

  void draw(

    const TAffine &ellipseMatrix,

    const TAffine &screenMatrixInv,

    double ox,

    double pixelSize,

    bool enabled ) const

  {

    const double crossSize = 0.1;

    double alpha = getDrawingAlpha(enabled);

    bool grid = getGrid();

    bool ruler = getRestrictA() && getRestrictB();

    bool concentric = !getRestrictA() && !getRestrictB();

    bool perspective = getPerspective();

    drawSegment( ellipseMatrix*TPointD(-crossSize, 0.0),

                 ellipseMatrix*TPointD( crossSize, 0.0), pixelSize, alpha);

    drawSegment( ellipseMatrix*TPointD(0.0, -crossSize),

                 ellipseMatrix*TPointD(0.0,  crossSize), pixelSize, alpha);

    drawEllipse(ellipseMatrix, screenMatrixInv, pixelSize, alpha);

    if (ox > 1.0)

      drawSegment( ellipseMatrix*TPointD(-1.0, -1.0),

                   ellipseMatrix*TPointD(-1.0,  1.0), pixelSize, alpha);

    else if (ox < -1.0)

      drawSegment( ellipseMatrix*TPointD( 1.0, -1.0),

                   ellipseMatrix*TPointD( 1.0,  1.0), pixelSize, alpha);

    if (!grid) return;

    if (ruler) {

      drawRuler(ellipseMatrix, pixelSize);

    } else

    if (concentric) {

      drawConcentricGrid(ellipseMatrix, screenMatrixInv, pixelSize);

    } else {

      drawParallelGrid(ellipseMatrix, screenMatrixInv, pixelSize);

    }

  }

public:

  void draw(TToolViewer *viewer, bool enabled) const override {

    bool restrictA = getRestrictA();

    bool restrictB = getRestrictB();

    bool repeat = getRepeat();

    double minStep = 30.0;

    TAffine ellipseMatrix = calcEllipseMatrix();

    if (ellipseMatrix.isZero()) return;

    if (!restrictA && restrictB) {

      std::swap(ellipseMatrix.a11, ellipseMatrix.a12);

      std::swap(ellipseMatrix.a21, ellipseMatrix.a22);

    }

    // common data about viewport

    const TRectD oneBox(-1.0, -1.0, 1.0, 1.0);

    TAffine4 modelview, projection;

    glGetDoublev(GL_MODELVIEW_MATRIX, modelview.a);

    glGetDoublev(GL_PROJECTION_MATRIX, projection.a);

    TAffine matrix = (projection*modelview).get2d();

    TAffine matrixInv = matrix.inv();

    double pixelSize = sqrt(tglGetPixelSize2());

    if (!repeat || restrictA == restrictB || norm(TPointD(ellipseMatrix.a11, ellipseMatrix.a21)) < minStep*pixelSize) {

      draw(ellipseMatrix, matrixInv, 0.0, pixelSize, enabled);

    } else {

      // calculate bounds

      TPointD o(ellipseMatrix.a13, ellipseMatrix.a23);

      TPointD proj(ellipseMatrix.a11, ellipseMatrix.a21);

      proj = proj * (1.0/norm2(proj));

      TPointD corners[4] = {

        TPointD(oneBox.x0, oneBox.y0),

        TPointD(oneBox.x0, oneBox.y1),

        TPointD(oneBox.x1, oneBox.y0),

        TPointD(oneBox.x1, oneBox.y1) };

      double minX = 0.0, maxX = 0.0;

      for(int i = 0; i < 4; ++i) {

        double x = proj * (matrixInv*corners[i] - o);

        if (i == 0 || x < minX) minX = x;

        if (i == 0 || x > maxX) maxX = x;

      }

      if (maxX <= minX) return;

      // draw

      for(double ox = round(0.5*minX)*2.0; ox - 1.0 < maxX; ox += 2.0)

        draw(ellipseMatrix*TAffine::translation(ox, 0.0), matrixInv, ox, pixelSize, enabled);

    }

  }

};

//*****************************************************************************************

//    Registration

//*****************************************************************************************

static TAssistantTypeT<tassistantellipse> assistantEllipse("assistantEllipse");</tassistantellipse>