view.h

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* VCGLib                                                            o o     *
* Visual and Computer Graphics Library                            o     o   *
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* Copyright(C) 2004                                                \/)\/    *
* Visual Computing Lab                                            /\/|      *
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/****************************************************************************
  History

$Log: not supported by cvs2svn $
Revision 1.15  2007/01/18 01:24:32  cignoni
Added cast for mac compiling

Revision 1.14  2005/10/15 15:23:32  ponchio
Fixed viewport<->window coordinate change for the z. (z = 2*z -1 now)
Accordingly to gluUnproject documentation.

Revision 1.13  2005/02/11 11:53:18  tommyfranken
changed  pointf to point<t> in ViewLineFromWindow

Revision 1.12  2005/02/10 20:09:11  tarini
dispelled the mega-evil of GL_TRANSPOSE_*_MATRIX_ARB

Revision 1.11  2005/01/19 10:29:45  cignoni
Removed the inclusion of a glext.h

Revision 1.10  2005/01/18 16:47:42  ricciodimare
*** empty log message ***

Revision 1.9  2004/09/28 10:22:00  ponchio
Added #include <GL/gl.h>

Revision 1.8  2004/05/26 15:15:46  cignoni
Removed inclusion of gl extension stuff

Revision 1.7  2004/05/14 03:15:40  ponchio
Added ViewLineFromModel

Revision 1.6  2004/05/12 20:55:18  ponchio
*** empty log message ***

Revision 1.5  2004/05/07 12:46:08  cignoni
Restructured and adapted in a better way to opengl

Revision 1.4  2004/04/07 10:54:11  cignoni
Commented out unused parameter names and other minor warning related issues

Revision 1.3  2004/03/31 15:07:37  ponchio
CAMERA_H -> VCG_CAMERA_H

Revision 1.2  2004/03/25 14:55:25  ponchio
Adding copyright.


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

#ifndef __VCGLIB_WRAP_GUI_VIEW_H
#define __VCGLIB_WRAP_GUI_VIEW_H

/**********************
WARNING
Everything here assumes the opengl window coord system.
the 0,0 is bottom left
y is upward!
**********************/

#include <vcg/space/point3.h>
#include <vcg/space/plane3.h>
#include <vcg/space/line3.h>
#include <vcg/math/matrix44.h>
#include <wrap/gl/math.h>

#ifdef WIN32
#include <windows.h>
#endif

#if defined(__APPLE__)
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif

namespace vcg {
template <class T> class View {
public:
  View();
  void GetView();
  void SetView(const float *_proj, const float *_modelview, const int *_viewport);
  Point3<T> Project(const Point3<T> &p) const;
  Point3<T> UnProject(const Point3<T> &p) const;
  Point3<T> ViewPoint() const;

  Plane3<T> ViewPlaneFromModel(const Point3<T> &p);

  Line3<T> ViewLineFromModel(const Point3<T> &p);

  Line3<T> ViewLineFromWindow(const Point3<T> &p);

  Point3<T> NormDevCoordToWindowCoord(const Point3<T> &p) const;

  Point3<T> WindowCoordToNormDevCoord(const Point3<T> &p) const;

  Matrix44<T> proj;
  Matrix44<T> model;
  Matrix44<T> matrix;
  Matrix44<T> inverse;
  int viewport[4];
  bool isOrtho;
};

template <class T>   View<T>::View() {
  isOrtho=false;
}

template <class T> void View<T>::GetView() {
    glGetv(GL_PROJECTION_MATRIX,proj);
    glGetv(GL_MODELVIEW_MATRIX,model);
    glGetIntegerv(GL_VIEWPORT, (GLint*)viewport);

    if(proj[3][3]==0) isOrtho = false;
    else isOrtho = true;

    matrix = proj*model;
    inverse = vcg::Inverse(matrix);
}

template <class T> void View<T>::SetView(const float *_proj,
                                         const float *_modelview,
                                         const int *_viewport) {
  for(int i = 0; i < 4; i++) {
    for(int k =0; k < 4; k++) {
      proj[i][k] = _proj[4*i+k];
      model[i][k] = _modelview[4*i+k];
    }
    viewport[i] = _viewport[i];
  }
  matrix = proj*model;
  inverse = matrix;
  Invert(inverse);
}

template <class T> Point3<T> View<T>::ViewPoint() const {
  if(isOrtho) return vcg::Inverse(model)* Point3<T>(0, 0, 3);
  return vcg::Inverse(model)* Point3<T>(0, 0, 0);
}
// Note that p it is assumed to be in model coordinate.
template <class T> Plane3<T> View<T>::ViewPlaneFromModel(const Point3<T> &p)
{
  //compute normal, pointing away from view.
  Matrix44<T> imodel = vcg::Inverse(model);
  Point3<T> vp=ViewPoint();
  vcg::Point3f n = imodel * vcg::Point3<T>(0.0f, 0, -1.0f) - vp;

  Plane3<T> pl;
  pl.Init(p, n);
  return pl;
}

// Note that p it is assumed to be in model coordinate.
template <class T> Line3<T> View<T>::ViewLineFromModel(const Point3<T> &p)
{
  Line3<T> line;
  Point3<T> vp=ViewPoint();
  if(isOrtho){
    line.SetOrigin(p);
    line.SetDirection(- vp );
  }  else {
    line.SetOrigin(vp);
    line.SetDirection(p - vp);
  }
  return line;
}

// Note that p it is assumed to be in window coordinate.
template <class T> Line3<T> View<T>::ViewLineFromWindow(const Point3<T> &p)
{
  Line3<T> line;  // plane perpedicular to view direction and passing through manip center
  Point3<T> vp=ViewPoint();
  Point3<T> pp=UnProject(p);

  if(isOrtho){
    line.SetOrigin(pp);
    line.SetDirection(- vp );
  }  else {
    line.SetOrigin(vp);
    line.SetDirection(pp-vp);
  }
  return line;
}

template <class T> Point3<T> View<T>::Project(const Point3<T> &p) const {
  Point3<T> r;
  r = matrix * p;
  return NormDevCoordToWindowCoord(r);
 }

template <class T> Point3<T> View<T>::UnProject(const Point3<T> &p) const {
  Point3<T> s = WindowCoordToNormDevCoord(p);
  s =  inverse * s ;
  return s;
}

// Come spiegato nelle glspec
// dopo la perspective division le coordinate sono dette normalized device coords ( NDC ).
// Per passare alle window coords si deve fare la viewport transformation.
// Le coordinate di viewport stanno tra -1 e 1

template <class T> Point3<T> View<T>::NormDevCoordToWindowCoord(const Point3<T> &p) const {
  Point3<T> a;
  a[0] = (p[0]+1)*(viewport[2]/(T)2.0)+viewport[0];
    a[1] = (p[1]+1)*(viewport[3]/(T)2.0)+viewport[1];
  //a[1] = viewport[3] - a[1];
  a[2] = (p[2]+1)/2;
  return a;
}


template <class T> Point3<T> View<T>::WindowCoordToNormDevCoord(const Point3<T> &p) const {
  Point3<T> a;
  a[0] = (p[0]- viewport[0])/ (viewport[2]/(T)2.0) - 1;
    a[1] = (p[1]- viewport[1])/ (viewport[3]/(T)2.0) - 1;
  //a[1] = -a[1];
    a[2] = 2*p[2] - 1;
  return a;
}


}//namespace

#endif