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

   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 "cameraViewer.h"

using namespace qglviewer;

CameraViewer::CameraViewer(Camera* camera)
  : c(camera){
};

void CameraViewer::draw()
{
  // Exactly the same draw than for 'Viewer'. The two viewers could also share a 'Scene' instance.
  const float nbSteps = 200.0;

  glBegin(GL_QUAD_STRIP);
  for(int i = 0; i < nbSteps; ++i) {
    const float ratio = i / nbSteps;
    const float angle = 21.0 * ratio;
    const float c = cos(angle);
    const float s = sin(angle);
    const float r1 = 1.0 - 0.8f * ratio;
    const float r2 = 0.8f - 0.8f * ratio;
    const float alt = ratio - 0.5f;
    const float nor = 0.5f;
    const float up = sqrt(1.0 - nor * nor);
    glColor3f(1.0 - ratio, 0.2f, ratio);
    glNormal3f(nor * c, up, nor * s);
    glVertex3f(r1 * c, alt, r1 * s);
    glVertex3f(r2 * c, alt + 0.05f, r2 * s);
  }
  glEnd();

  // Draws the other viewer's camera
  glDisable(GL_LIGHTING);
  glLineWidth(4.0);
  glColor4f(1.0, 1.0, 1.0, 0.5);
  c->draw();
  glEnable(GL_LIGHTING);
}

void CameraViewer::init()
{
  // Places the cameraViewer's camera far away in order to see the (other viewer) camera.
  if(!restoreStateFromFile()) {
    // Make near and far planes much further from scene in order not to clip c's display.
    camera()->setZClippingCoefficient(50.0);
    camera()->setViewDirection(qglviewer::Vec(0.0, -1.0, 0.0));
    showEntireScene();
  }

  // Enable semi-transparent culling planes
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
