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

   Copyright (C) 2002-2008 Gilles Debunne. All rights reserved.

   This file is part of the QGLViewer library version 2.3.5.

   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 "box.h"
#include "cullingCamera.h"

using namespace std;
using namespace qglviewer;

// Static member initialization
Box* Box::Root;

void Box::draw() const
{
  glColor3f(0.3 * level, 0.2f, 1.0 - 0.3 * level);
  glLineWidth(level + 1);

  glBegin(GL_LINE_STRIP);
  glVertex3fv(Vec(p1.x, p1.y, p1.z));
  glVertex3fv(Vec(p1.x, p2.y, p1.z));
  glVertex3fv(Vec(p2.x, p2.y, p1.z));
  glVertex3fv(Vec(p2.x, p1.y, p1.z));
  glVertex3fv(Vec(p1.x, p1.y, p1.z));
  glVertex3fv(Vec(p1.x, p1.y, p2.z));
  glVertex3fv(Vec(p1.x, p2.y, p2.z));
  glVertex3fv(Vec(p2.x, p2.y, p2.z));
  glVertex3fv(Vec(p2.x, p1.y, p2.z));
  glVertex3fv(Vec(p1.x, p1.y, p2.z));
  glEnd();

  glBegin(GL_LINES);
  glVertex3fv(Vec(p1.x, p2.y, p1.z));
  glVertex3fv(Vec(p1.x, p2.y, p2.z));
  glVertex3fv(Vec(p2.x, p2.y, p1.z));
  glVertex3fv(Vec(p2.x, p2.y, p2.z));
  glVertex3fv(Vec(p2.x, p1.y, p1.z));
  glVertex3fv(Vec(p2.x, p1.y, p2.z));
  glEnd();
}

void Box::buildBoxHierarchy(int l)
{
  level = l;
  const Vec middle = (p1 + p2) / 2.0;
  for(unsigned int i = 0; i < 8; ++i) {
    // point in one of the 8 box corners
    const Vec point((i & 4) ? p1.x : p2.x, (i & 2) ? p1.y : p2.y, (i & 1) ? p1.z : p2.z);
    if(level > 0) {
      child[i] = new Box(point, middle);
      child[i]->buildBoxHierarchy(level - 1);
    } else
      child[i] = NULL;
  }
}

void Box::drawIfAllChildrenAreVisible(const CullingCamera* camera) const
{
  static bool* entirely = new bool;

  if(camera->aaBoxIsVisible(p1, p2, entirely)) {
    if(*entirely)
      draw();
    else if(child[0])
      for(int i = 0; i < 8; ++i)
        child[i]->drawIfAllChildrenAreVisible(camera);
    else
      draw();
  }
}
