VertexArray.h

// Gmsh - Copyright (C) 1997-2009 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file for license information. Please report all
// bugs and problems to <gmsh@geuz.org>.

#ifndef _VERTEX_ARRAY_H_
#define _VERTEX_ARRAY_H_

#include <vector>
#include <set>
#include "SVector3.h"
#include "SBoundingBox3d.h"

class MElement;

template<int N>
class ElementData {
 private:
  float _x[N], _y[N], _z[N], _nx[N], _ny[N], _nz[N];
  unsigned char _r[N], _g[N], _b[N], _a[N];
  MElement *_ele;
 public:
  ElementData(double *x, double *y, double *z, SVector3 *n, unsigned char *r,
              unsigned char *g, unsigned char *b, unsigned char *a, MElement *ele)
  {
    for(int i = 0; i < N; i++){
      _x[i] = (float)x[i];
      _y[i] = (float)y[i];
      _z[i] = (float)z[i];
      if(n){
        _nx[i] = (float)n[i].x();
        _ny[i] = (float)n[i].y();
        _nz[i] = (float)n[i].z();
      }
      else
        _nx[i] = _ny[i] = _nz[i] = 0.;
      if(r && g && b && a){
        _r[i] = r[i];
        _g[i] = g[i];
        _b[i] = b[i];
        _a[i] = a[i];
      }
      else
        _r[i] = _g[i] = _b[i] = _a[i] = 0;
    }
    _ele = ele;
  }
  inline float x(int i) const { return _x[i]; }
  inline float y(int i) const { return _y[i]; }
  inline float z(int i) const { return _z[i]; }
  inline float nx(int i) const { return _nx[i]; }
  inline float ny(int i) const { return _ny[i]; }
  inline float nz(int i) const { return _nz[i]; }
  inline unsigned char r(int i) const { return _r[i]; }
  inline unsigned char g(int i) const { return _g[i]; }
  inline unsigned char b(int i) const { return _b[i]; }
  inline unsigned char a(int i) const { return _a[i]; }
  inline MElement *ele() const { return _ele; }
  SPoint3 barycenter() const
  {
    SPoint3 p(0., 0., 0.);
    for(int i = 0; i < N; i++){
      p[0] += _x[i];
      p[1] += _y[i];
      p[2] += _z[i];
    }
    p[0] /= (double)N;
    p[1] /= (double)N;
    p[2] /= (double)N;
    return p;
  }
};

template<int N>
class ElementDataLessThan{
 public:
  static float tolerance;
  bool operator()(const ElementData<N> &e1, const ElementData<N> &e2) const
  {
    SPoint3 p1 = e1.barycenter();
    SPoint3 p2 = e2.barycenter();
    if(p1.x() - p2.x() >  tolerance) return true;
    if(p1.x() - p2.x() < -tolerance) return false;
    if(p1.y() - p2.y() >  tolerance) return true;
    if(p1.y() - p2.y() < -tolerance) return false;
    if(p1.z() - p2.z() >  tolerance) return true;
    return false;
  }
};

class Barycenter {
 private:
  float _x, _y, _z;
 public:
  Barycenter(double x, double y, double z) 
    : _x((float)x), _y((float)y), _z((float)z){}
  inline float x() const { return _x; }
  inline float y() const { return _y; }
  inline float z() const { return _z; }
  void operator+=(const Barycenter &p){ _x += p.x(); _y += p.y(); _z += p.z(); }
};

class BarycenterLessThan{
 public:
  static float tolerance;
  bool operator()(const Barycenter &p1, const Barycenter &p2) const
  {
    if(p1.x() - p2.x() >  tolerance) return true;
    if(p1.x() - p2.x() < -tolerance) return false;
    if(p1.y() - p2.y() >  tolerance) return true;
    if(p1.y() - p2.y() < -tolerance) return false;
    if(p1.z() - p2.z() >  tolerance) return true;
    return false;
  }
};

class VertexArray{
 private:
  int _numVerticesPerElement;
  std::vector<float> _vertices;
  std::vector<char> _normals;
  std::vector<unsigned char> _colors;
  std::vector<MElement*> _elements;
  std::set<ElementData<3>, ElementDataLessThan<3> > _data3;
  std::set<Barycenter, BarycenterLessThan> _barycenters;
  // add stuff in the arrays
  void _addVertex(float x, float y, float z);
  void _addNormal(float nx, float ny, float nz);
  void _addColor(unsigned char r, unsigned char g, unsigned char b, 
                 unsigned char a);
  void _addElement(MElement *ele);
 public:
  VertexArray(int numVerticesPerElement, int numElements);
  ~VertexArray(){}
  // return the number of vertices in the array
  int getNumVertices() { return _vertices.size() / 3; }
  // return the number of vertices per element
  int getNumVerticesPerElement() { return _numVerticesPerElement; }
  // return the number of element pointers
  int getNumElementPointers() { return _elements.size(); }
  // return a pointer to the raw vertex array (warning: 1) we don't 
  // range check 2) calling this if _vertices.size() == 0 will cause
  // some compilers to throw an exception)
  float *getVertexArray(int i=0){ return &_vertices[i]; }
  // return a pointer to the raw normal array
  char *getNormalArray(int i=0){ return &_normals[i]; }
  // return a pointer to the raw color array
  unsigned char *getColorArray(int i=0){ return &_colors[i]; }
  // return a pointer to the raw element array
  MElement **getElementPointerArray(int i=0){ return &_elements[i]; }
  // add element data in the arrays (if unique is set, only add the
  // element if another one with the same barycenter is not already
  // present)
  void add(double *x, double *y, double *z, SVector3 *n, unsigned int *col, 
           MElement *ele=0, bool unique=true, bool boundary=false);
  void add(double *x, double *y, double *z, SVector3 *n, unsigned char *r=0, 
           unsigned char *g=0, unsigned char *b=0, unsigned char *a=0,
           MElement *ele=0, bool unique=true, bool boundary=false);
  // finalize the arrays
  void finalize();
  // sort the arrays with elements back to front wrt the eye position
  void sort(double x, double y, double z);
  // estimate the size of the vertex array in megabytes
  int getMemoryUsage();
  // serialize the vertex array into a string (for sending over the
  // network)
  char *toChar(int num, int type, double min, double max, double time,
               SBoundingBox3d bbox, int &len);
  void fromChar(const char *bytes);
};

#endif