geant4/source/externals/g4tools/include/tools/sg/ellipse

// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.

#ifndef tools_sg_ellipse
#define tools_sg_ellipse

// same logic as ROOT/TEllipse.

#include "node"
#include "sf"
#include "render_action"
#include "pick_action"
#include "bbox_action"

#include "../mathf"
#include "../curve"

namespace tools {
namespace sg {

class ellipse : public node,public curve {
  TOOLS_NODE_NO_CAST(ellipse,tools::sg::ellipse,node)
public:
  virtual void* cast(const std::string& a_class) const {
    if(void* p = cmp_cast<ellipse>(this,a_class)) return p;
    if(void* p = cmp_cast<curve>(this,a_class)) return p;
    return node::cast(a_class);
  }
public:
  sf<float> rx;
  sf<float> ry;
  sf<float> phi_min;  //radians
  sf<float> phi_max;  //radians
  sf<unsigned int> steps;
public:
  virtual const desc_fields& node_desc_fields() const {
    TOOLS_FIELD_DESC_NODE_CLASS(tools::sg::ellipse)
    static const desc_fields s_v(parent::node_desc_fields(),5, //WARNING : take care of count.
      TOOLS_ARG_FIELD_DESC(rx),
      TOOLS_ARG_FIELD_DESC(ry),
      TOOLS_ARG_FIELD_DESC(phi_min),
      TOOLS_ARG_FIELD_DESC(phi_max),
      TOOLS_ARG_FIELD_DESC(steps)
    );
    return s_v;
  }
private:
  void add_fields(){
    add_field(&rx);
    add_field(&ry);
    add_field(&phi_min);
    add_field(&phi_max);
    add_field(&steps);
  }
public: //curve
  virtual bool pos_tan_nor(float /*a_s*/,
                           vec3f& a_pos,
                           vec3f& a_tan,
                           vec3f& a_nor) const {

    float x,y,z;

   {//x = r*cs;y = r*sn;z = 0;
    x = 0;y = 0;z = 0;
    m_model.mul_3f(x,y,z);
    a_pos.set_value(x,y,z);}

   {//x = -sn;y = cs;z = 0;
    x = 0;y = 1;z = 0;
    m_model.mul_dir_3(x,y,z);
    a_tan.set_value(x,y,z);}

   {x = 0;y = 0;z = 1;
    m_model.mul_dir_3(x,y,z);
    a_nor.set_value(x,y,z);}

    return true;
  }
public:
  virtual void copy(curve*& a_new) const {a_new = new ellipse(*this);}
public:
  virtual void render(render_action& a_action) {
    if(touched()) {
      update_sg();
      reset_touched();
    }
    //Same logic as Inventor SoLightModel.model = BASE_COLOR.
    const state& state = a_action.state();
    a_action.set_lighting(false);
    a_action.add_line_strip(m_xyzs);
    a_action.set_lighting(state.m_GL_LIGHTING);
  }

  virtual void pick(pick_action& a_action) {
    if(touched()) {
      update_sg();
      reset_touched();
    }
    if(a_action.stop_at_first()){
      a_action.add_line_strip(m_xyzs);
      if(a_action.done()) a_action.set_node(this);
    } else {
      a_action.set_done(false);
      a_action.zs().clear();
      a_action.ws().clear();
      a_action.add_line_strip(m_xyzs);
      if(a_action.done()) {
        a_action.add_pick(*this,a_action.zs(),a_action.ws(),a_action.state());
        a_action.set_done(false);
      }
    }
  }
  virtual void bbox(bbox_action& a_action) {
    if(touched()) {
      update_sg();
      reset_touched();
    }
    a_action.add_line_strip(m_xyzs);
  }
public:
  ellipse()
  :parent()
  ,curve()
  ,rx(1)
  ,ry(1)
  ,phi_min(0)
  ,phi_max(tools::ftwo_pi())
  ,steps(40)
  {
    add_fields();
  }
  virtual ~ellipse(){}
public:
  ellipse(const ellipse& a_from)
  :parent(a_from)
  ,curve(a_from)
  ,rx(a_from.rx)
  ,ry(a_from.ry)
  ,phi_min(a_from.phi_min)
  ,phi_max(a_from.phi_max)
  ,steps(a_from.steps)
  {
    add_fields();
  }
  ellipse& operator=(const ellipse& a_from){
    parent::operator=(a_from);
    curve::operator=(a_from);
    rx = a_from.rx;
    ry = a_from.ry;
    phi_min = a_from.phi_min;
    phi_max = a_from.phi_max;
    steps = a_from.steps;
    return *this;
  }
protected:
  void update_sg() {
    m_xyzs.clear();
    if(!steps.value()) return;

    unsigned int num = steps.value();

   //set number of points approximatively proportional to the ellipse circumference
   //float circ = kPI*(r1+r2)*(phi2-phi1)/360;
   //Int_t n = (Int_t)(np*circ/((gPad->GetX2()-gPad->GetX1())+(gPad->GetY2()-gPad->GetY1())));
   //if (n < 8) n= 8;
   //if (n > np) n = np;

    m_xyzs.resize((num+1)*3);

    float phimin = phi_min.value();
    float phimax = phi_max.value();
    float r1 = rx.value();
    float r2 = ry.value();

    float phi1 = min_of<float>(phimin,phimax);
    float phi2 = max_of<float>(phimin,phimax);

    float angle,dx,dy;
    float dphi = (phi2-phi1)/float(num);
    size_t pos = 0;
    for(unsigned int i=0;i<=num;i++) {
      angle = phi1 + float(i)*dphi;
      dx    = r1*fcos(angle);
      dy    = r2*fsin(angle);
      m_xyzs[pos]  = dx;pos++;
      m_xyzs[pos]  = dy;pos++;
      m_xyzs[pos]  = 0;pos++;
    }
  }

protected:
  std::vector<float> m_xyzs;
};

}}

#endif