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

#ifndef tools_sg_primitive_visitor
#define tools_sg_primitive_visitor

#include "../glprims"

#include "../vdata"

namespace tools {
namespace sg {

class primitive_visitor {
protected:
  virtual bool project(float& a_x,float& a_y,float& a_z,float& a_w) = 0;

  // xyzw
  virtual bool add_point(float,float,float,float) = 0;

  // xyzw & rgba
  virtual bool add_point(float,float,float,float,
                         float,float,float,float) = 0;

  // 2 xyzw
  virtual bool add_line(float,float,float,float,
                        float,float,float,float) = 0;

  // 2 (xyzw & rgba)
  virtual bool add_line(float,float,float,float, float,float,float,float,
                        float,float,float,float, float,float,float,float) = 0;


  // 3 xyzw
  virtual bool add_triangle(float,float,float,float,
                            float,float,float,float,
                            float,float,float,float) = 0;
  // 3 (xywz & rgba)
  virtual bool add_triangle(float,float,float,float, float,float,float,float,
                            float,float,float,float, float,float,float,float,
                            float,float,float,float, float,float,float,float) = 0;
public:
  primitive_visitor():m_mode(gl::points()){}
  virtual ~primitive_visitor(){}
public:
  primitive_visitor(const primitive_visitor&):m_mode(gl::points()){}
  primitive_visitor& operator=(const primitive_visitor&){return *this;}
public:
  void add_one_point(float a_x,float a_y,float a_z) {
    float w;
    project(a_x,a_y,a_z,w);
    add_point(a_x,a_y,a_z,w);    
  }

  bool add_triangle_fan(size_t a_floatn,const float* a_xyzs,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<3) return false;

    m_mode = gl::triangle_fan();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    const float* pos1 = a_xyzs+3*0;
    p1x = *(pos1+0);
    p1y = *(pos1+1);
    p1z = *(pos1+2);
    project(p1x,p1y,p1z,w1);
  
    const float* pos2 = a_xyzs+3*1;
    p2x = *(pos2+0);
    p2y = *(pos2+1);
    p2z = *(pos2+2);
    project(p2x,p2y,p2z,w2);
  
    for(size_t index=2;index<num;index++) {
      const float* pos = a_xyzs+3*index;
      p3x = *(pos+0);
      p3y = *(pos+1);
      p3z = *(pos+2);
      project(p3x,p3y,p3z,w3);

      if(!add_triangle(p1x,p1y,p1z,w1,
                       p2x,p2y,p2z,w2,
                       p3x,p3y,p3z,w3)) {
        if(a_stop) return false;
      }
  
      p2x = p3x;
      p2y = p3y;
      p2z = p3z;
      w2 = w3;
    }
    return true;
  }

  bool add_triangle_strip(size_t a_floatn,const float* a_xyzs,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<3) return false;

    m_mode = gl::triangle_strip();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    const float* pos1 = a_xyzs+3*0;
    p1x = *(pos1+0);
    p1y = *(pos1+1);
    p1z = *(pos1+2);
    project(p1x,p1y,p1z,w1);
  
    const float* pos2 = a_xyzs+3*1;
    p2x = *(pos2+0);
    p2y = *(pos2+1);
    p2z = *(pos2+2);
    project(p2x,p2y,p2z,w2);
  
    bool flip = false;
    for(size_t index=2;index<num;index++) {
      const float* pos = a_xyzs+3*index;
      p3x = *(pos+0);
      p3y = *(pos+1);
      p3z = *(pos+2);
      project(p3x,p3y,p3z,w3);

      if(flip){
        if(!add_triangle(p1x,p1y,p1z,w1,
                         p3x,p3y,p3z,w3,
                         p2x,p2y,p2z,w2)) {
          if(a_stop) return false;
        }
      } else {
        if(!add_triangle(p1x,p1y,p1z,w1,
                         p2x,p2y,p2z,w2,
                         p3x,p3y,p3z,w3)) {
          if(a_stop) return false;
        }
      }
  
      p1x = p2x;
      p1y = p2y;
      p1z = p2z;
      w1 = w2;

      p2x = p3x;
      p2y = p3y;
      p2z = p3z;
      w2 = w3;

      flip = flip?false:true;
    }
    return true;
  }

  bool add_triangles(size_t a_floatn,const float* a_xyzs,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<3) return false;

    m_mode = gl::triangles();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    for(size_t index=0;index<num;index+=3) {

      const float* pos = a_xyzs+3*index;

      p1x = *pos;pos++;
      p1y = *pos;pos++;
      p1z = *pos;pos++;
      project(p1x,p1y,p1z,w1);
  
      p2x = *pos;pos++;
      p2y = *pos;pos++;
      p2z = *pos;pos++;
      project(p2x,p2y,p2z,w2);
  
      p3x = *pos;pos++;
      p3y = *pos;pos++;
      p3z = *pos;pos++;
      project(p3x,p3y,p3z,w3);

      if(!add_triangle(p1x,p1y,p1z,w1,
                       p2x,p2y,p2z,w2,
                       p3x,p3y,p3z,w3)) {
        if(a_stop) return false;
      }
    }
    return true;
  }

  bool add_triangles(size_t a_floatn,const float* a_xyzs,const float* a_rgbas,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<3) return false;

    m_mode = gl::triangles();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    float r1,g1,b1,a1;
    float r2,g2,b2,a2;
    float r3,g3,b3,a3;

    for(size_t index=0;index<num;index+=3) {

      const float* pos = a_xyzs+3*index;

      p1x = *pos;pos++;
      p1y = *pos;pos++;
      p1z = *pos;pos++;
      project(p1x,p1y,p1z,w1);
  
      p2x = *pos;pos++;
      p2y = *pos;pos++;
      p2z = *pos;pos++;
      project(p2x,p2y,p2z,w2);
  
      p3x = *pos;pos++;
      p3y = *pos;pos++;
      p3z = *pos;pos++;
      project(p3x,p3y,p3z,w3);

      const float* qos = a_rgbas+4*index;

      r1 = *qos;qos++;
      g1 = *qos;qos++;
      b1 = *qos;qos++;
      a1 = *qos;qos++;

      r2 = *qos;qos++;
      g2 = *qos;qos++;
      b2 = *qos;qos++;
      a2 = *qos;qos++;

      r3 = *qos;qos++;
      g3 = *qos;qos++;
      b3 = *qos;qos++;
      a3 = *qos;qos++;

      if(!add_triangle(p1x,p1y,p1z,w1,r1,g1,b1,a1,
                       p2x,p2y,p2z,w2,r2,g2,b2,a2,
                       p3x,p3y,p3z,w3,r3,g3,b3,a3)) {
        if(a_stop) return false;
      }
    }
    return true;
  }

  bool add_line_strip(size_t a_floatn,const float* a_xyzs,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_strip();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+3*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);
      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_line_strip(size_t a_floatn,const float* a_xyzs,const float* a_rgbas,bool a_stop = false){
    size_t num = a_floatn/3;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_strip();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float rb,gb,bb,ab,re,ge,be,ae;
    float* pos;
    float* qos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+3*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      qos = (float*)(a_rgbas+4*iseg);
      rb = *qos;qos++;
      gb = *qos;qos++;
      bb = *qos;qos++;
      ab = *qos;qos++;

      re = *qos;qos++;
      ge = *qos;qos++;
      be = *qos;qos++;
      ae = *qos;qos++;

      if(!add_line(xb,yb,zb,wb,rb,gb,bb,ab,
                   xe,ye,ze,we,re,ge,be,ae)) {
        if(a_stop) return false;
      }
    }
    return true;
  }

  bool add_line_loop(size_t a_floatn,const float* a_xyzs,bool a_stop = false) {
    size_t num = a_floatn/3;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_loop();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+3*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }

    //close the loop :
   {pos = (float*)(a_xyzs+3*(nseg-1)+3);
    xb = *pos;pos++;
    yb = *pos;pos++;
    zb = *pos;pos++;

    pos = (float*)(a_xyzs); //first point.
    xe = *pos;pos++;
    ye = *pos;pos++;
    ze = *pos;pos++;
    project(xb,yb,zb,wb);
    project(xe,ye,ze,we);

    if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)){if(a_stop) return false;}
    }

    return true;
  }
  
  bool add_line_loop(size_t a_floatn,const float* a_xyzs,const float* a_rgbas,bool a_stop = false) {
    size_t num = a_floatn/3;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_loop();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float rb,gb,bb,ab,re,ge,be,ae;
    float* pos;
    float* qos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+3*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      qos = (float*)(a_rgbas+4*iseg);
      rb = *qos;qos++;
      gb = *qos;qos++;
      bb = *qos;qos++;
      ab = *qos;qos++;

      re = *qos;qos++;
      ge = *qos;qos++;
      be = *qos;qos++;
      ae = *qos;qos++;

      if(!add_line(xb,yb,zb,wb,rb,gb,bb,ab,
                   xe,ye,ze,we,re,ge,be,ae)) {
        if(a_stop) return false;
      }
    }

    //close the loop :
   {pos = (float*)(a_xyzs+3*nseg);
    xb = *pos;pos++;
    yb = *pos;pos++;
    zb = *pos;pos++;

    pos = (float*)(a_xyzs); //first point.
    xe = *pos;pos++;
    ye = *pos;pos++;
    ze = *pos;pos++;
    project(xb,yb,zb,wb);
    project(xe,ye,ze,we);

    qos = (float*)(a_rgbas+4*nseg);
    rb = *qos;qos++;
    gb = *qos;qos++;
    bb = *qos;qos++;
    ab = *qos;qos++;

    qos = (float*)(a_rgbas);
    re = *qos;qos++;
    ge = *qos;qos++;
    be = *qos;qos++;
    ae = *qos;qos++;

    if(!add_line(xb,yb,zb,wb,rb,gb,bb,ab,
                 xe,ye,ze,we,re,ge,be,ae)){if(a_stop) return false;}
    }

    return true;
  }
  
  bool add_lines(size_t a_floatn,const float* a_xyzs,const float* a_rgbas,bool a_stop = false) {
    //lines = segments.
    size_t num = a_floatn/3;

    size_t nseg = num/2;
    if(!nseg) return false;

    m_mode = gl::lines();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float rb,gb,bb,ab,re,ge,be,ae;
    float* pos;
    float* qos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+6*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      qos = (float*)(a_rgbas+8*iseg);
      rb = *qos;qos++;
      gb = *qos;qos++;
      bb = *qos;qos++;
      ab = *qos;qos++;

      re = *qos;qos++;
      ge = *qos;qos++;
      be = *qos;qos++;
      ae = *qos;qos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      if(!add_line(xb,yb,zb,wb,rb,gb,bb,ab, xe,ye,ze,we,re,ge,be,ae)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_lines(size_t a_floatn,const float* a_xyzs,bool a_stop = false) {
    //lines = segments.
    size_t num = a_floatn/3;

    size_t nseg = num/2;
    if(!nseg) return false;

    m_mode = gl::lines();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xyzs+6*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = *pos;pos++;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = *pos;pos++;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_points(size_t a_floatn,const float* a_xyzs,bool a_stop = false){
    size_t num = a_floatn/3;

    m_mode = gl::points();

    float x,y,z,w;
    float* pos;
    for(size_t ipt=0;ipt<num;ipt++) {
      pos = (float*)(a_xyzs+3*ipt);
      x = *pos;pos++;
      y = *pos;pos++;
      z = *pos;pos++;

      project(x,y,z,w);

      if(!add_point(x,y,z,w)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_points(size_t a_floatn,const float* a_xyzs,const float* a_rgbas,bool a_stop = false){
    size_t num = a_floatn/3;

    m_mode = gl::points();

    float x,y,z,w;
    float r,g,b,a;

    float* pos;
    float* qos;

    for(size_t ipt=0;ipt<num;ipt++) {
      pos = (float*)(a_xyzs+3*ipt);
      x = *pos;pos++;
      y = *pos;pos++;
      z = *pos;pos++;

      qos = (float*)(a_rgbas+4*ipt);
      r = *qos;qos++;
      g = *qos;qos++;
      b = *qos;qos++;
      a = *qos;qos++;

      project(x,y,z,w);

      if(!add_point(x,y,z,w,r,g,b,a)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_primitive(gl::mode_t a_mode,size_t a_floatn,const float* a_xyzs,bool a_stop = false) {

    if(a_mode==gl::points()) {
      return add_points(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::lines()) {
      return add_lines(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::line_loop()) {
      return add_line_loop(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::line_strip()) {
      return add_line_strip(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::triangles()) {
      return add_triangles(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::triangle_strip()) {
      return add_triangle_strip(a_floatn,a_xyzs,a_stop);

    } else if(a_mode==gl::triangle_fan()) {
      return add_triangle_fan(a_floatn,a_xyzs,a_stop);

    } else {
      return false;
    }
  }

  bool add_primitive(gl::mode_t a_mode,
                     size_t a_floatn,
                     const float* a_xyzs,
                     const float* a_rgbas,
                     bool a_stop = false){

    if(a_mode==gl::points()) {
      return add_points(a_floatn,a_xyzs,a_rgbas,a_stop);

    } else if(a_mode==gl::lines()) {
      return add_lines(a_floatn,a_xyzs,a_rgbas,a_stop);

    } else if(a_mode==gl::line_loop()) {
      return add_line_loop(a_floatn,a_xyzs,a_rgbas,a_stop);

    } else if(a_mode==gl::line_strip()) {
      return add_line_strip(a_floatn,a_xyzs,a_rgbas,a_stop);

    } else if(a_mode==gl::triangles()) {
      return add_triangles(a_floatn,a_xyzs,a_rgbas,a_stop);

    } else if(a_mode==gl::triangle_strip()) {
      return add_triangle_strip(a_floatn,a_xyzs,/*a_rgbas,*/a_stop);

    } else if(a_mode==gl::triangle_fan()) {
      return add_triangle_fan(a_floatn,a_xyzs,/*a_rgbas,*/a_stop);

    } else {
      return false;
    }
  }

  ////////////////////////////////////////////////////////
  /// points with x,y only ///////////////////////////////
  ////////////////////////////////////////////////////////

  bool add_points_xy(size_t a_floatn,const float* a_xys,bool a_stop = false) {
    size_t num = a_floatn/2;

    m_mode = gl::points();

    float x,y,z,w;
    float* pos;
    for(size_t ipt=0;ipt<num;ipt++) {
      pos = (float*)(a_xys+2*ipt);
      x = *pos;pos++;
      y = *pos;pos++;
      z = 0;

      project(x,y,z,w);

      if(!add_point(x,y,z,w)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_triangle_fan_xy(size_t a_floatn,const float* a_xys,
                           bool a_stop = false,
                           bool a_triangle_revert = false){
    size_t num = a_floatn/2;
    if(num<3) return false;

    m_mode = gl::triangle_fan();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    const float* pos1 = a_xys+2*0;
    p1x = *(pos1+0);
    p1y = *(pos1+1);
    p1z = 0;
    project(p1x,p1y,p1z,w1);
  
    const float* pos2 = a_xys+2*1;
    p2x = *(pos2+0);
    p2y = *(pos2+1);
    p2z = 0;
    project(p2x,p2y,p2z,w2);
  
    for(size_t index=2;index<num;index++) {
      const float* pos = a_xys+2*index;
      p3x = *(pos+0);
      p3y = *(pos+1);
      p3z = 0;
      project(p3x,p3y,p3z,w3);

      if(a_triangle_revert) {
        if(!add_triangle(p3x,p3y,p3z,w3,
                         p2x,p2y,p2z,w2,
                         p1x,p1y,p1z,w1)) {
          if(a_stop) return false;
        }
      } else {
        if(!add_triangle(p1x,p1y,p1z,w1,
                         p2x,p2y,p2z,w2,
                         p3x,p3y,p3z,w3)) {
          if(a_stop) return false;
        }
      }

  
      p2x = p3x;
      p2y = p3y;
      p2z = p3z;
      w2 = w3;
    }
    return true;
  }

  bool add_triangle_strip_xy(size_t a_floatn,const float* a_xys,
                             bool a_stop = false,
                             bool a_triangle_revert = false){
    size_t num = a_floatn/2;
    if(num<3) return false;

    m_mode = gl::triangle_strip();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    const float* pos1 = a_xys+2*0;
    p1x = *(pos1+0);
    p1y = *(pos1+1);
    p1z = 0;
    project(p1x,p1y,p1z,w1);
  
    const float* pos2 = a_xys+2*1;
    p2x = *(pos2+0);
    p2y = *(pos2+1);
    p2z = 0;
    project(p2x,p2y,p2z,w2);
  
    bool flip = false;
    for(size_t index=2;index<num;index++) {
      const float* pos = a_xys+2*index;
      p3x = *(pos+0);
      p3y = *(pos+1);
      p3z = 0;
      project(p3x,p3y,p3z,w3);

      if(a_triangle_revert) {

        if(flip){
          if(!add_triangle(p2x,p2y,p2z,w2,
                           p3x,p3y,p3z,w3,
                           p1x,p1y,p1z,w1)) {
            if(a_stop) return false;
          }
        } else {
          if(!add_triangle(p3x,p3y,p3z,w3,
                           p2x,p2y,p2z,w2,
                           p1x,p1y,p1z,w1)) {
            if(a_stop) return false;
          }
        }

      } else {

        if(flip){
          if(!add_triangle(p1x,p1y,p1z,w1,
                           p3x,p3y,p3z,w3,
                           p2x,p2y,p2z,w2)) {
            if(a_stop) return false;
          }
        } else {
          if(!add_triangle(p1x,p1y,p1z,w1,
                           p2x,p2y,p2z,w2,
                           p3x,p3y,p3z,w3)) {
            if(a_stop) return false;
          }
        }

      }
  
      p1x = p2x;
      p1y = p2y;
      p1z = p2z;
      w1 = w2;

      p2x = p3x;
      p2y = p3y;
      p2z = p3z;
      w2 = w3;

      flip = flip?false:true;
    }
    return true;
  }

  bool add_triangles_xy(size_t a_floatn,const float* a_xys,bool a_stop = false,bool a_triangle_revert = false){
    size_t num = a_floatn/2;
    if(num<3) return false;

    m_mode = gl::triangles();

    float p1x,p1y,p1z,w1=1;
    float p2x,p2y,p2z,w2=1;
    float p3x,p3y,p3z,w3=1;

    for(size_t index=0;index<num;index+=3) {

      const float* pos1 = a_xys+2*index;
      p1x = *(pos1+0);
      p1y = *(pos1+1);
      p1z = 0;
      project(p1x,p1y,p1z,w1);
  
      const float* pos2 = a_xys+2*(index+1);
      p2x = *(pos2+0);
      p2y = *(pos2+1);
      p2z = 0;
      project(p2x,p2y,p2z,w2);
  
      const float* pos3 = a_xys+2*(index+2);
      p3x = *(pos3+0);
      p3y = *(pos3+1);
      p3z = 0;
      project(p3x,p3y,p3z,w3);

      if(a_triangle_revert) {
        if(!add_triangle(p3x,p3y,p3z,w3,
                         p2x,p2y,p2z,w2,
                         p1x,p1y,p1z,w1)) {
          if(a_stop) return false;
        }
      } else {
        if(!add_triangle(p1x,p1y,p1z,w1,
                         p2x,p2y,p2z,w2,
                         p3x,p3y,p3z,w3)) {
          if(a_stop) return false;
        }
      }
    }
    return true;
  }

  bool add_line_loop_xy(size_t a_floatn,const float* a_xys,bool a_stop = false){
    size_t num = a_floatn/2;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_loop();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xys+2*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = 0;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = 0;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }

    //close the loop :
   {pos = (float*)(a_xys+2*(nseg-1)+2);
    xb = *pos;pos++;
    yb = *pos;pos++;
    zb = 0;

    pos = (float*)(a_xys); //first point.
    xe = *pos;pos++;
    ye = *pos;pos++;
    ze = 0;
    project(xb,yb,zb,wb);
    project(xe,ye,ze,we);

    if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)){if(a_stop) return false;}
    }

    return true;
  }
  
  bool add_line_strip_xy(size_t a_floatn,const float* a_xys,bool a_stop = false){
    size_t num = a_floatn/2;
    if(num<=1) return false;
    size_t nseg = num-1;

    m_mode = gl::line_strip();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xys+2*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = 0;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = 0;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);
      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_lines_xy(size_t a_floatn,const float* a_xys,bool a_stop = false){
    //lines = segments.  Each point having only (x,y) (no z).
    //used in exlib::sg::[text_freetype, text_hershey].

    size_t num = a_floatn/2;

    size_t nseg = num/2;
    if(!nseg) return false;

    m_mode = gl::lines();

    float xb,yb,zb,wb,xe,ye,ze,we;
    float* pos;
    for(size_t iseg = 0;iseg<nseg;iseg++) {
      pos = (float*)(a_xys+4*iseg);
      xb = *pos;pos++;
      yb = *pos;pos++;
      zb = 0;

      xe = *pos;pos++;
      ye = *pos;pos++;
      ze = 0;

      project(xb,yb,zb,wb);
      project(xe,ye,ze,we);

      if(!add_line(xb,yb,zb,wb, xe,ye,ze,we)) {if(a_stop) return false;}
    }
    return true;
  }

  bool add_primitive_xy(gl::mode_t a_mode,
                        size_t a_floatn,const float* a_xys,
                        bool a_stop = false,
                        bool a_triangle_revert = false){

    if(a_mode==gl::points()) {
      return add_points_xy(a_floatn,a_xys,a_stop);

    } else if(a_mode==gl::lines()) {
      return add_lines_xy(a_floatn,a_xys,a_stop);

    } else if(a_mode==gl::line_loop()) {
      return add_line_loop_xy(a_floatn,a_xys,a_stop);

    } else if(a_mode==gl::line_strip()) {
      return add_line_strip_xy(a_floatn,a_xys,a_stop);

    } else if(a_mode==gl::triangles()) {
      return add_triangles_xy(a_floatn,a_xys,a_stop,a_triangle_revert);

    } else if(a_mode==gl::triangle_strip()) {
      return add_triangle_strip_xy(a_floatn,a_xys,a_stop,a_triangle_revert);

    } else if(a_mode==gl::triangle_fan()) {
      return add_triangle_fan_xy(a_floatn,a_xys,a_stop,a_triangle_revert);

    } else {
      return false;
    }
  }

public:
  bool add_primitive(gl::mode_t a_mode,const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_primitive(a_mode,a_xyzs.size(),_xyzs,a_stop);
  }
  bool add_primitive_xy(gl::mode_t a_mode,const std::vector<float>& a_xys,bool a_stop = false,bool a_triangle_revert = false){
    const float* _xys = tools::vec_data<float>(a_xys);
    return add_primitive_xy(a_mode,a_xys.size(),_xys,a_stop,a_triangle_revert);
  }
  bool add_line_strip(const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_line_strip(a_xyzs.size(),_xyzs,a_stop);
  }
  bool add_line_loop(const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_line_loop(a_xyzs.size(),_xyzs,a_stop);
  }
  bool add_lines(const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_lines(a_xyzs.size(),_xyzs,a_stop);
  }
  bool add_points(const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_points(a_xyzs.size(),_xyzs,a_stop);
  }

  bool add_triangle_strip(const std::vector<float>& a_xyzs,bool a_stop = false){
    const float* _xyzs = tools::vec_data<float>(a_xyzs);
    return add_triangle_strip(a_xyzs.size(),_xyzs,a_stop);
  }

  bool add_points_xy(const std::vector<float>& a_xys,bool a_stop = false){
    const float* _xys = tools::vec_data<float>(a_xys);
    return add_points_xy(a_xys.size(),_xys,a_stop);
  }
  bool add_lines_xy(const std::vector<float>& a_xys,bool a_stop = false){
    const float* _xys = tools::vec_data<float>(a_xys);
    return add_lines_xy(a_xys.size(),_xys,a_stop);
  }
  bool add_triangle_strip_xy(const std::vector<float>& a_xys,bool a_stop = false){
    const float* _xys = tools::vec_data<float>(a_xys);
    return add_triangle_strip_xy(a_xys.size(),_xys,a_stop);
  }


public:
  //for sg::[tex_]sphere::visit() template :
  bool add_triangle_fan(size_t a_floatn,const float* a_xyzs,const float* /*a_nms*/) {
    return add_triangle_fan(a_floatn,a_xyzs);
  }
  bool add_triangle_fan(size_t a_floatn,const float* a_xyzs,const float* /*a_rgbas*/,const float* /*a_nms*/) {
    return add_triangle_fan(a_floatn,a_xyzs);
  }
/*
  bool add_triangles_texture(size_t a_floatn,const float* a_xyzs,unsigned int,const float*){
    return add_triangles(a_floatn,a_xyzs);
  }
  bool add_triangle_fan_texture(size_t a_floatn,const float* a_xyzs,unsigned int,const float*){
    return add_triangle_fan(a_floatn,a_xyzs);
  }
  bool add_triangle_strip_texture(size_t a_floatn,const float* a_xyzs,unsigned int,const float*){
    return add_triangle_strip(a_floatn,a_xyzs,false);
  }
*/
  bool add_triangle_fan_texture(size_t a_floatn,const float* a_xyzs,const float* /*a_nms*/,unsigned int,const float*){
    return add_triangle_fan(a_floatn,a_xyzs);
  }
  bool add_triangle_strip_texture(size_t a_floatn,const float* a_xyzs,const float* /*a_nms*/,unsigned int,const float*){
    return add_triangle_strip(a_floatn,a_xyzs,false);
  }

  bool add_triangle_strip(size_t a_floatn,const float* a_xyzs,const float* /*a_nms*/) {
    return add_triangle_strip(a_floatn,a_xyzs,false);
  }
  bool add_triangle_strip(size_t a_floatn,const float* a_xyzs,const float* /*a_rgbas*/,const float* /*a_nms*/) {
    return add_triangle_strip(a_floatn,a_xyzs,false);
  }

protected:
  gl::mode_t m_mode;
};

}}

#endif