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

 Copyright (C) 2002-2006 Gilles Debunne (Gilles.Debunne@imag.fr)

This file is part of the QGLViewer library.
 Version 2.2.4-1, released on December 12, 2006.

 http://artis.imag.fr/Members/Gilles.Debunne/QGLViewer

 libQGLViewer 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.

 libQGLViewer 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 libQGLViewer; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

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

#include "3dsViewer.h"

#include <lib3ds/camera.h>
#include <lib3ds/mesh.h>
#include <lib3ds/material.h>
#include <lib3ds/matrix.h>
#include <lib3ds/vector.h>
#include <lib3ds/light.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include <qfiledialog.h>

using namespace std;
using namespace qglviewer;


void Viewer::keyPressEvent(QKeyEvent *e)
{
  switch (e->key())
    {
    case Qt::Key_L : loadFile(); break;
    default:         QGLViewer::keyPressEvent(e);
    }
}

QString Viewer::helpString() const
{
  QString text("<h2>3 d s V i e w e r</h2>");
  text += "This example uses the lib3ds library to load a 3ds object file.<br><br>";
  text += "Press <b>L</b>(oad) to open a 3ds file.<br><br>";
  text += "Note that certain 3ds files contain animated sequences that can ";
  text += "be played using the <b>Return</b> (animate) key.";
  return text;
}

void Viewer::loadFile()
{
#if QT_VERSION < 0x040000
  QString name = QFileDialog::getOpenFileName(".", "3DS files (*.3ds *.3DS);;All files (*)", this, "Choose", "Select a 3ds model");
#else
  QString name = QFileDialog::getOpenFileName(this, "Select a 3ds model", ".", "3DS files (*.3ds *.3DS);;All files (*)");
#endif

  // In case of Cancel
  if (name.isEmpty())
    return;

#if QT_VERSION < 0x040000
  file = lib3ds_file_load(name.latin1());
#else
  file = lib3ds_file_load(name.toLatin1().constData());
#endif
    if (!file)
    {
      qWarning("Error : Unable to open file ");
      exit(1);
    }

  if (file->cameras)
    camera_name = file->cameras->name;
  else
    camera_name = NULL;

  lib3ds_file_eval(file,0);

  initScene();

  float min[3], max[3];
  lib3ds_file_bounding_box(file, min, max);
  setSceneBoundingBox(Vec(min), Vec(max));
  
  if (!file->cameras)
    camera()->showEntireScene();
  else
    updateGL();
  stopAnimation();
}


void Viewer::init()
{
  glShadeModel(GL_SMOOTH);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glDisable(GL_LIGHT1);
  glDepthFunc(GL_LEQUAL);
  glEnable(GL_DEPTH_TEST);
  glDisable(GL_COLOR_MATERIAL);
  glEnable(GL_CULL_FACE);
  glCullFace(GL_BACK);

  setKeyDescription(Qt::Key_L, "Loads a new 3ds file");

  restoreStateFromFile();
  help();
  loadFile();
}


void Viewer::initScene()
{
  if (!file)
    return;

  // Lights
  GLfloat amb[] = {0.0, 0.0, 0.0, 1.0};
  GLfloat dif[] = {1.0, 1.0, 1.0, 1.0};
  GLfloat spe[] = {1.0, 1.0, 1.0, 1.0};
  GLfloat pos[] = {0.0, 0.0, 0.0, 1.0};
  int li=GL_LIGHT0;
  for (Lib3dsLight* l=file->lights; l; l=l->next)
    {
      glEnable(li);

      glLightfv(li, GL_AMBIENT,  amb);
      glLightfv(li, GL_DIFFUSE,  dif);
      glLightfv(li, GL_SPECULAR, spe);

      pos[0] = l->position[0];
      pos[1] = l->position[1];
      pos[2] = l->position[2];
      glLightfv(li, GL_POSITION, pos);

      if (!l->spot_light)
	  continue;

      pos[0] = l->spot[0] - l->position[0];
      pos[1] = l->spot[1] - l->position[1];
      pos[2] = l->spot[2] - l->position[2];
      glLightfv(li, GL_SPOT_DIRECTION, pos);
      ++li;
    }

  // Camera
  Lib3dsNode* c = lib3ds_file_node_by_name(file, camera_name, LIB3DS_CAMERA_NODE);
  Lib3dsNode* t = lib3ds_file_node_by_name(file, camera_name, LIB3DS_TARGET_NODE);
  if (!c || !t)
    return;

  // Lib3dsMatrix M;
  // lib3ds_matrix_camera(M, c->data.camera.pos, t->data.target.pos, c->data.camera.roll);

  // cout << "Pos = " << Vec(c->data.camera.pos) << endl;
  // cout << "Tar = " << Vec(t->data.target.pos) << endl;
  // cout << "Rol = " << c->data.camera.roll << endl;

  camera()->setPosition(Vec(c->data.camera.pos));
  camera()->lookAt(Vec(t->data.target.pos));
  Vec up=camera()->frame()->transformOf(Vec(0.0, 0.0, 1.0));
  float angle=atan2(up.x, up.y);
  Quaternion q(Vec(0.0, 0.0, 1.0), c->data.camera.roll-angle);
  camera()->frame()->rotate(q);
  camera()->setFieldOfView(M_PI/180.0*c->data.camera.fov);
}


void Viewer::renderNode(Lib3dsNode *node)
{
  for (Lib3dsNode* p=node->childs; p!=0; p=p->next)
    renderNode(p);

  if (node->type == LIB3DS_OBJECT_NODE)
    {
      if (strcmp(node->name,"$$$DUMMY")==0)
	return;

      if (!node->user.d)
	{
	  Lib3dsMesh *mesh=lib3ds_file_mesh_by_name(file, node->name);
	  if (!mesh)
	    return;

	  node->user.d = glGenLists(1);
	  glNewList(node->user.d, GL_COMPILE);

	  Lib3dsVector *normalL = new Lib3dsVector[3*mesh->faces];

	  Lib3dsMatrix M;
	  lib3ds_matrix_copy(M, mesh->matrix);
	  lib3ds_matrix_inv(M);
	  glMultMatrixf(&M[0][0]);

	  lib3ds_mesh_calculate_normals(mesh, normalL);

	  for (unsigned int p=0; p<mesh->faces; ++p)
	    {
	      Lib3dsFace *f=&mesh->faceL[p];
	      Lib3dsMaterial *mat=0;
	      if (f->material[0])
		mat=lib3ds_file_material_by_name(file, f->material);

	      if (mat)
		{
		  static GLfloat a[4]={0,0,0,1};
		  float s;
		  glMaterialfv(GL_FRONT, GL_AMBIENT, a);
		  glMaterialfv(GL_FRONT, GL_DIFFUSE, mat->diffuse);
		  glMaterialfv(GL_FRONT, GL_SPECULAR, mat->specular);
		  s = pow(2, 10.0*mat->shininess);
		  if (s>128.0)
		    s=128.0;
		  glMaterialf(GL_FRONT, GL_SHININESS, s);
		}
	      else
		{
		  Lib3dsRgba a={0.2, 0.2, 0.2, 1.0};
		  Lib3dsRgba d={0.8, 0.8, 0.8, 1.0};
		  Lib3dsRgba s={0.0, 0.0, 0.0, 1.0};
		  glMaterialfv(GL_FRONT, GL_AMBIENT, a);
		  glMaterialfv(GL_FRONT, GL_DIFFUSE, d);
		  glMaterialfv(GL_FRONT, GL_SPECULAR, s);
		}

	      glBegin(GL_TRIANGLES);
	      glNormal3fv(f->normal);
	      for (int i=0; i<3; ++i)
		{
		  glNormal3fv(normalL[3*p+i]);
		  glVertex3fv(mesh->pointL[f->points[i]].pos);
		}
	      glEnd();
	    }

	  delete[] normalL;

	  glEndList();
	}

      if (node->user.d)
	{
	  glPushMatrix();
	  Lib3dsObjectData* d = &node->data.object;
	  glMultMatrixf(&node->matrix[0][0]);
	  glTranslatef(-d->pivot[0], -d->pivot[1], -d->pivot[2]);
	  glCallList(node->user.d);
	  glPopMatrix();
	}
    }
}


void Viewer::draw()
{
  if (!file)
    return;

  for (Lib3dsNode* p=file->nodes; p!=0; p=p->next)
    renderNode(p);
}


void Viewer::animate()
{
  current_frame++;
  if (current_frame > file->frames)
    current_frame=0;
  lib3ds_file_eval(file, current_frame);
  initScene();
}