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

 Copyright (C) 2002-2014 Gilles Debunne. All rights reserved.

 This file is part of the QGLViewer library version 2.6.1.

 http://www.libqglviewer.com - contact@libqglviewer.com

 This file may be used under the terms of the GNU General Public License 
 versions 2.0 or 3.0 as published by the Free Software Foundation and
 appearing in the LICENSE file included in the packaging of this file.
 In addition, as a special exception, Gilles Debunne gives you certain 
 additional rights, described in the file GPL_EXCEPTION in this package.

 libQGLViewer uses dual licensing. Commercial/proprietary software must
 purchase a libQGLViewer Commercial License.

 This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

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

#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>
#include <QKeyEvent>

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_of_objects(file, true, true, true, min, max);
  //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();
}
