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

#ifndef tools_sg_tex_quadrilateral
#define tools_sg_tex_quadrilateral

#include "node"
#include "mf"
#include "render_action"
#include "pick_action"
#include "bbox_action"
#include "event_action"
#include "render_manager"
#include "gstos"
#include "base_tex"

#include "../num2s"

namespace tools {
namespace sg {

class tex_quadrilateral : public node, public gstos, public base_tex {
  TOOLS_NODE_NO_CAST(tex_quadrilateral,tools::sg::tex_quadrilateral,node)
public:
  virtual void* cast(const std::string& a_class) const {
    {if(void* p = cmp_cast<tex_quadrilateral>(this,a_class)) return p;}
    {if(void* p = base_tex::cast(a_class)) return p;}
    return parent::cast(a_class);
  }
public:
  sf<bool> show_border;
  mf_vec<vec3f,float> corners;
public:
  virtual const desc_fields& node_desc_fields() const {
    TOOLS_FIELD_DESC_NODE_CLASS(tools::sg::tex_quadrilateral)
    static const desc_fields s_v(parent::node_desc_fields(),6, //WARNING : take care of count.
      TOOLS_ARG_FIELD_DESC(img),
      TOOLS_ARG_FIELD_DESC(back_color),
      TOOLS_ARG_FIELD_DESC(expand),
      TOOLS_ARG_FIELD_DESC(limit),
      TOOLS_ARG_FIELD_DESC(show_border),
      TOOLS_ARG_FIELD_DESC(corners)
    );
    return s_v;
  }
private:
  void add_fields(){
    add_field(&img);
    add_field(&back_color);
    add_field(&expand);
    add_field(&limit);
    add_field(&show_border);
    add_field(&corners);
  }
public:
  virtual void render(render_action& a_action) {
    //NOTE : we draw border (show_border is true) and background even if
    //       gen_texture() failed.

    if(touched()) {
      update_sg(a_action.out());
      reset_touched();
    }
    if(m_img.is_empty()) return;
    if(corners.size()!=4) return;

    unsigned int _id = get_tex_id(a_action.out(),a_action.render_manager(),m_img,nearest.value());

    const state& state = a_action.state();

    //image must be 2^n,2^m in size !
    // exa : 128x64

    f12 xyzs,nms;

    if(show_border.value()) {
      _front(xyzs,nms/*,0.01f*/); //have to revisit a_epsil.

      a_action.color4f(1,0,0,1);
      a_action.line_width(1);

      a_action.draw_vertex_array(gl::line_loop(),12,xyzs);

      //pushes back the filled polygons to avoid z-fighting with lines
      a_action.set_polygon_offset(true);

      a_action.color4f(state.m_color);
      a_action.line_width(state.m_line_width);
    }

    //draw a back face pointing toward negative z :
   {a_action.color4f(back_color.value());
    f18 tris,_nms;
    _tris(tris,_nms);
    a_action.draw_vertex_normal_array(gl::triangles(),18,tris,_nms);
    a_action.color4f(state.m_color);}

    if(_id) {
      _front(xyzs,nms);
      float tcs[8];
      set_tcs(tcs);
      a_action.draw_vertex_normal_array_texture(gl::triangle_fan(),12,xyzs,nms,_id,tcs);
    }
    a_action.set_polygon_offset(state.m_GL_POLYGON_OFFSET_FILL);
  }
  virtual void pick(pick_action& a_action) {
    if(touched()) {
      update_sg(a_action.out());
      reset_touched();
    }
    if(m_pick_bbox_check_image) {if(m_img.is_empty()) return;}
    if(corners.size()!=4) return;
    f12 xyzs,nms;
    _front(xyzs,nms);
    a_action.add__primitive(*this,gl::triangle_fan(),12,xyzs,true);
  }

  virtual void bbox(bbox_action& a_action) {
    if(touched()) {
      update_sg(a_action.out());
      reset_touched();
    }
    if(m_pick_bbox_check_image) if(m_img.is_empty()) return;
    if(corners.size()!=4) return;
    f12 xyzs,nms;
    _front(xyzs,nms);
    a_action.add_points(12,xyzs);
  }
public:
  virtual bool intersect_value(std::ostream&,intersect_type,const line<vec3f>& a_line,std::string& a_s) const {
    // a_line is in local world coordinate.
    float x,y;
    if(!line_2_img_ndc(a_line,x,y)) {a_s.clear();return false;}
    return img_ndc_value(x,y,a_s);
  }
public:
  tex_quadrilateral()
  :parent()
  ,base_tex()
  ,show_border(false)
  ,corners()
  ,m_pick_bbox_check_image(true)
  {
    add_fields();
    corners.add(vec3f(-1,-1,0));
    corners.add(vec3f( 1,-1,0));
    corners.add(vec3f( 1, 1,0));
    corners.add(vec3f(-1, 1,0));
  }
  virtual ~tex_quadrilateral(){}
public:
  tex_quadrilateral(const tex_quadrilateral& a_from)
  :parent(a_from)
  ,gstos(a_from)
  ,base_tex(a_from)
  ,show_border(a_from.show_border)
  ,corners(a_from.corners)
  ,m_pick_bbox_check_image(a_from.m_pick_bbox_check_image)
  {
    add_fields();
  }
  tex_quadrilateral& operator=(const tex_quadrilateral& a_from){
    parent::operator=(a_from);
    gstos::operator=(a_from);
    base_tex::operator=(a_from);
    if(&a_from==this) return *this;
    show_border = a_from.show_border;
    corners = a_from.corners;
    m_pick_bbox_check_image = a_from.m_pick_bbox_check_image;
    return *this;
  }
protected:
  void update_sg(std::ostream& a_out) {
    plane<vec3f> plane(corners[0],corners[1],corners[3]);
    m_normal = plane.normal();
    clean_gstos(); //must reset for all render_manager.
    base_tex::_update_sg_(a_out);
  }
protected:
  bool img_ndc_value(float a_x,float a_y,std::string& a_s) const {
    const img_byte& _img = img.value();
    if(_img.is_empty()) {a_s.clear();return false;}

    int ix = int(float(_img.width())*a_x);
    int iy = int(float(_img.height())*a_y);

    //rgb of pixel :
    std::vector<unsigned char> pixel;
    if((ix<0)||(iy<0)||!_img.pixel(ix,iy,pixel)) {a_s.clear();return false;}

    a_s.clear();
    for(unsigned int ipix=0;ipix<pixel.size();ipix++) {
      if(ipix) a_s += " ";
      if(!numas<float>(float(pixel[ipix])/255.0f,a_s)){}
    }

    return true;
  }

  bool point_2_img_ndc(const vec3f& a_point,float& a_x,float& a_y) const {
    // a_point is assumed to be in the corners[0,1,3] plane.

    if(corners.size()!=4) {a_x = 0;a_y = 0;return false;}
    // In fact, in the below corners[2] is not used.

    // we assume that :
    //  corners[0] is the bottom-left of image
    //  corners[1] is the bottom-right of image
    //  corners[2] is the top-right of image
    //  corners[3] is the top-left of image
    vec3f x_axis = corners[1]-corners[0];
    float l_01 = x_axis.normalize();
    if(l_01==0.0f) {a_x = 0;a_y = 0;return false;}
    vec3f y_axis = corners[3]-corners[0];
    float l_03 = y_axis.normalize();
    if(l_03==0.0f) {a_x = 0;a_y = 0;return false;}

    float alpha = x_axis.dot(y_axis);
    float alpha_sq = alpha*alpha;
    if(alpha_sq==1.0f) {a_x = 0;a_y = 0;return false;}

    vec3f Op = a_point-corners[0];

    float px = Op.dot(x_axis);
    float py = Op.dot(y_axis);

    float lambda = (px-alpha*py)/(1.0f-alpha_sq);
    float mu = (py-alpha*px)/(1-alpha_sq);

    // We must have : Op = lambda*x_axis+mu*y_axis;

    a_x = lambda/l_01;
    a_y = mu/l_03;

    return true;
  }

  bool line_2_img_ndc(const line<vec3f>& a_line,float& a_x,float& a_y) const {
    // a_line is in local world coordinate.
    if(corners.size()!=4) {a_x = 0;a_y = 0;return false;}
    // In fact corners[2] is not used, only [0,1,3].
    plane<vec3f> plane(corners[0],corners[1],corners[3]);
    vec3f p;
    if(!plane.intersect(a_line,p)) {a_x = 0;a_y = 0;return false;}
    return point_2_img_ndc(p,a_x,a_y);
  }

  bool img_ndc_2_point(float a_x,float a_y,vec3f& a_point) const {
    if(corners.size()!=4) {a_point.set_value(0,0,0);return false;}
    // In fact, in the below corners[2] is not used.

    // we assume that :
    //  corners[0] is the bottom-left of image
    //  corners[1] is the bottom-right of image
    //  corners[2] is the top-right of image
    //  corners[3] is the top-left of image
    vec3f x_axis = corners[1]-corners[0];
    float l_01 = x_axis.normalize();
    if(l_01==0.0f) {a_point.set_value(0,0,0);return false;}
    vec3f y_axis = corners[3]-corners[0];
    float l_03 = y_axis.normalize();
    if(l_03==0.0f) {a_point.set_value(0,0,0);return false;}

    float alpha = x_axis.dot(y_axis);

    float lambda = a_x*l_01;
    float mu = a_y*l_03;

    float px = lambda+mu*alpha;
    float py = lambda*alpha+mu;

    vec3f Op = px*x_axis+py*y_axis;

    a_point = Op+corners[0];

    return true;
  }

  typedef float f12[12];
  void _front(f12& a_front,f12& a_nms,float a_epsil = 0.0f) {
    const std::vector<vec3f>& cs = corners.values();

    a_front[0] =  cs[0].x()-a_epsil;
    a_front[1] =  cs[0].y()-a_epsil;
    a_front[2] =  cs[0].z();

    a_front[3] =  cs[1].x()+a_epsil;
    a_front[4] =  cs[1].y()-a_epsil;
    a_front[5] =  cs[1].z();

    a_front[6] =  cs[2].x()+a_epsil;
    a_front[7] =  cs[2].y()+a_epsil;
    a_front[8] =  cs[2].z();

    a_front[ 9] = cs[3].x()-a_epsil;
    a_front[10] = cs[3].y()+a_epsil;
    a_front[11] = cs[3].z();

    a_nms[0] = m_normal.x();
    a_nms[1] = m_normal.y();
    a_nms[2] = m_normal.z();

    a_nms[3] = m_normal.x();
    a_nms[4] = m_normal.y();
    a_nms[5] = m_normal.z();

    a_nms[6] = m_normal.x();
    a_nms[7] = m_normal.y();
    a_nms[8] = m_normal.z();

    a_nms[9]  = m_normal.x();
    a_nms[10] = m_normal.y();
    a_nms[11] = m_normal.z();
  }

  void _back(f12& a_back) {
    const std::vector<vec3f>& cs = corners.values();

    a_back[0] =  cs[1].x();
    a_back[1] =  cs[1].y();
    a_back[2] =  cs[1].z();

    a_back[3] =  cs[0].x();
    a_back[4] =  cs[0].y();
    a_back[5] =  cs[0].z();

    a_back[6] =  cs[3].x();
    a_back[7] =  cs[3].y();
    a_back[8] =  cs[3].z();

    a_back[ 9] = cs[2].x();
    a_back[10] = cs[2].y();
    a_back[11] = cs[2].z();
  }

  typedef float f18[18];
  void _tris(f18& a_tris,f18& a_nms){
    f12 back;
    _back(back);

    a_tris[0] = back[0];
    a_tris[1] = back[1];
    a_tris[2] = back[2];

    a_tris[3] = back[3];
    a_tris[4] = back[4];
    a_tris[5] = back[5];

    a_tris[6] = back[6];
    a_tris[7] = back[7];
    a_tris[8] = back[8];
    //
    a_tris[9]  = back[6];
    a_tris[10] = back[7];
    a_tris[11] = back[8];

    a_tris[12] = back[9];
    a_tris[13] = back[10];
    a_tris[14] = back[11];

    a_tris[15] = back[0];
    a_tris[16] = back[1];
    a_tris[17] = back[2];

    ///////////////////// back
    a_nms[0] = -m_normal.x();
    a_nms[1] = -m_normal.y();
    a_nms[2] = -m_normal.z();

    a_nms[3] = -m_normal.x();
    a_nms[4] = -m_normal.y();
    a_nms[5] = -m_normal.z();

    a_nms[6] = -m_normal.x();
    a_nms[7] = -m_normal.y();
    a_nms[8] = -m_normal.z();
    //
    a_nms[9]  = -m_normal.x();
    a_nms[10] = -m_normal.y();
    a_nms[11] = -m_normal.z();

    a_nms[12] = -m_normal.x();
    a_nms[13] = -m_normal.y();
    a_nms[14] = -m_normal.z();

    a_nms[15] = -m_normal.x();
    a_nms[16] = -m_normal.y();
    a_nms[17] = -m_normal.z();
  }
protected:
  vec3f m_normal;
  bool m_pick_bbox_check_image; //for SDSS_image.
};

}}

#endif
