//
//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
//   with this source distribution. 
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the GNU General Public License
//  as published by the Free Software Foundation; either version 2
//  of the License, or (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
///////////////////////////////////////////////////////////////////////////////

#include "Silhouette.h"
#include "SilhouetteGeomEngine.h"
#include "../geometry/GeomUtils.h"

using namespace std;

Vec3r SilhouetteGeomEngine::_Viewpoint = Vec3r(0,0,0);
real SilhouetteGeomEngine::_translation[3] = {0,0,0};
real SilhouetteGeomEngine::_modelViewMatrix[4][4] = {{1,0,0,0},
						     {0,1,0,0},
						     {0,0,1,0},
						     {0,0,0,1}};
real SilhouetteGeomEngine::_projectionMatrix[4][4] = {{1,0,0,0},
						     {0,1,0,0},
						     {0,0,1,0},
						     {0,0,0,1}};
real SilhouetteGeomEngine::_transform[4][4] = {{1,0,0,0},
					       {0,1,0,0},
					       {0,0,1,0},
					       {0,0,0,1}};
int SilhouetteGeomEngine::_viewport[4] = {1,1,1,1};              // the viewport
real SilhouetteGeomEngine::_Focal = 0.0;
  
real SilhouetteGeomEngine::_glProjectionMatrix[4][4] = {{1,0,0,0},
							{0,1,0,0},
							{0,0,1,0},
							{0,0,0,1}};
real SilhouetteGeomEngine::_glModelViewMatrix[4][4] = {{1,0,0,0},
						       {0,1,0,0},
						       {0,0,1,0},
						       {0,0,0,1}};
real SilhouetteGeomEngine::_znear = 0.0;
real SilhouetteGeomEngine::_zfar = 100.0;
bool SilhouetteGeomEngine::_isOrthographicProjection = false;  

SilhouetteGeomEngine * SilhouetteGeomEngine::_pInstance = 0;

void SilhouetteGeomEngine::setTransform(const real iModelViewMatrix[4][4], const real iProjectionMatrix[4][4], const int iViewport[4], real iFocal) 
{
  unsigned int i,j;
  _translation[0] = iModelViewMatrix[3][0];
  _translation[1] = iModelViewMatrix[3][1];
  _translation[2] = iModelViewMatrix[3][2];
  
  for(i=0; i<4; i++){
    for(j=0; j<4; j++)
    {
      _modelViewMatrix[i][j] = iModelViewMatrix[j][i];
      _glModelViewMatrix[i][j] = iModelViewMatrix[i][j];
    }
  }

  for(i=0; i<4; i++){
    for(j=0; j<4; j++)
    {
      _projectionMatrix[i][j] = iProjectionMatrix[j][i];
      _glProjectionMatrix[i][j] = iProjectionMatrix[i][j];
    }
  }
      
  for(i=0; i<4; i++){
    for(j=0; j<4; j++)
    {
      _transform[i][j] = 0;
      for(unsigned int k=0; k<4; k++)
        _transform[i][j] += _projectionMatrix[i][k] * _modelViewMatrix[k][j];
    }
  }
      
  for(i=0; i<4; i++){
    _viewport[i] = iViewport[i];
  }
  _Focal = iFocal;

	_isOrthographicProjection = (iProjectionMatrix[3][3] != 0.0);
}

void SilhouetteGeomEngine::setFrustum(real iZNear, real iZFar) 
{
  _znear = iZNear;
  _zfar = iZFar;
}

void SilhouetteGeomEngine::retrieveViewport(int viewport[4]){
  memcpy(viewport, _viewport, 4*sizeof(int));
}
//#define HUGE 1e9

void SilhouetteGeomEngine::ProjectSilhouette(vector<SVertex*>& ioVertices)
{
  Vec3r newPoint;
  //  real min=HUGE;
  //  real max=-HUGE;
  vector<SVertex*>::iterator sv, svend;
  
  for(sv=ioVertices.begin(), svend=ioVertices.end();
      sv!=svend;
      sv++)
    {
      GeomUtils::fromWorldToImage((*sv)->point3D(), newPoint, _modelViewMatrix, _projectionMatrix, _viewport);
      newPoint[2] = (-newPoint[2]-_znear)/(_zfar-_znear); // normalize Z between 0 and 1
      (*sv)->setPoint2D(newPoint);  
      //cerr << (*sv)->point2d().z() << "  ";
      //      real d=(*sv)->point2d()[2];
      //      if (d>max) max =d;
      //      if (d<min) min =d;
    }
      //  for(sv=ioVertices.begin(), svend=ioVertices.end();
      //      sv!=svend;
      //      sv++)
      //    {
      //      Vec3r P((*sv)->point2d());
      //      (*sv)->setPoint2D(Vec3r(P[0], P[1], 1.0-(P[2]-min)/(max-min)));
      //      //cerr<<(*sv)->point2d()[2]<<"  ";
      //    }
}

void SilhouetteGeomEngine::ProjectSilhouette(SVertex* ioVertex)
{
  Vec3r newPoint;
  //  real min=HUGE;
  //  real max=-HUGE;
  vector<SVertex*>::iterator sv, svend;
  GeomUtils::fromWorldToImage(ioVertex->point3D(), newPoint, _modelViewMatrix, _projectionMatrix, _viewport);
  newPoint[2] = (-newPoint[2]-_znear)/(_zfar-_znear); // normalize Z between 0 and 1
  ioVertex->setPoint2D(newPoint);  
}

real SilhouetteGeomEngine::ImageToWorldParameter(FEdge *fe, real t)
{
	if( _isOrthographicProjection )
		return t;

	// we need to compute for each parameter t the corresponding 
	// parameter T which gives the intersection in 3D.
	real T;

	// suffix w for world, c for camera, r for retina, i for image
	Vec3r Aw = (fe)->vertexA()->point3D();
	Vec3r Bw = (fe)->vertexB()->point3D();
	Vec3r Ac, Bc;
	GeomUtils::fromWorldToCamera(Aw, Ac, _modelViewMatrix);
	GeomUtils::fromWorldToCamera(Bw, Bc, _modelViewMatrix);
	Vec3r ABc = Bc - Ac;
#if 0
	cout << "Ac " << Ac << endl;
	cout << "Bc " << Bc << endl;
	cout << "ABc " << ABc << endl;
#endif
	Vec3r Ai = (fe)->vertexA()->point2D();
	Vec3r Bi = (fe)->vertexB()->point2D();
	Vec3r Ii = Ai + t * (Bi - Ai); // the intersection point in the 2D image space
	Vec3r Ir, Ic;
	GeomUtils::fromImageToRetina(Ii, Ir, _viewport);

	real alpha, beta, denom;
	real m11 = _projectionMatrix[0][0];
	real m13 = _projectionMatrix[0][2];
	real m22 = _projectionMatrix[1][1];
	real m23 = _projectionMatrix[1][2];

	if (fabs(ABc[0]) > 1e-6) {

		alpha = ABc[2] / ABc[0];
		beta = Ac[2] - alpha * Ac[0];
		denom = alpha * (Ir[0] + m13) + m11;
		if (fabs(denom) < 1e-6)
			goto iter;
		Ic[0] = -beta * (Ir[0] + m13) / denom;
//		Ic[1] = -(Ir[1] + m23) * (alpha * Ic[0] + beta) / m22;
//		Ic[2] = alpha * (Ic[0] - Ac[0]) + Ac[2];
		T = (Ic[0] - Ac[0]) / ABc[0];

	} else if (fabs(ABc[1]) > 1e-6) {

		alpha = ABc[2] / ABc[1];
		beta = Ac[2] - alpha * Ac[1];
		denom = alpha * (Ir[1] + m23) + m22;
		if (fabs(denom) < 1e-6)
			goto iter;
		Ic[1] = -beta * (Ir[1] + m23) / denom;
//		Ic[0] = -(Ir[0] + m13) * (alpha * Ic[1] + beta) / m11;
//		Ic[2] = alpha * (Ic[1] - Ac[1]) + Ac[2];
		T = (Ic[1] - Ac[1]) / ABc[1];

	} else {

iter:	bool x_coords, less_than;
		if (fabs(Bi[0] - Ai[0]) > 1e-6) {
			x_coords = true;
			less_than = Ai[0] < Bi[0];
		} else {
			x_coords = false;
			less_than = Ai[1] < Bi[1];
		}
		Vec3r Pc, Pr, Pi;
		real T_sta = 0.0;
		real T_end = 1.0;
		real delta_x, delta_y, dist, dist_threshold = 1e-6;
		int i, max_iters = 100;
		for (i = 0; i < max_iters; i++) {
			T = T_sta + 0.5 * (T_end - T_sta);
			Pc = Ac + T * ABc;
			GeomUtils::fromCameraToRetina(Pc, Pr, _projectionMatrix);
			GeomUtils::fromRetinaToImage(Pr, Pi, _viewport);
			delta_x = Ii[0] - Pi[0];
			delta_y = Ii[1] - Pi[1];
			dist = sqrt(delta_x * delta_x + delta_y * delta_y);
			if (dist < dist_threshold)
				break;
			if (x_coords) {
				if (less_than) {
					if (Pi[0] < Ii[0]) { T_sta = T; } else { T_end = T; }
				} else {
					if (Pi[0] > Ii[0]) { T_sta = T; } else { T_end = T; }
				}
			} else {
				if (less_than) {
					if (Pi[1] < Ii[1]) { T_sta = T; } else { T_end = T; }
				} else {
					if (Pi[1] > Ii[1]) { T_sta = T; } else { T_end = T; }
				}
			}
		}
#if 0
		printf("SilhouetteGeomEngine::ImageToWorldParameter(): #iters = %d, dist = %e\n", i, dist);
#endif
		if (i == max_iters)
			printf("SilhouetteGeomEngine::ImageToWorldParameter(): reached to max_iters (dist = %e)\n", dist);
	}

	return T;
}

Vec3r SilhouetteGeomEngine::WorldToImage(const Vec3r& M)

{

  Vec3r newPoint;
  GeomUtils::fromWorldToImage(M, newPoint, _transform, _viewport);
  newPoint[2] = (-newPoint[2]-_znear)/(_zfar-_znear); // normalize Z between 0 and 1
  return newPoint;

}