#include "simpleViewer.h"
#include <math.h>

using namespace std;

// Draws a spiral
void Viewer::draw()
{
  const float nbSteps = 500.0;

  glBegin(GL_QUAD_STRIP);
  for (float i=0; i<nbSteps; ++i)
    {
      float ratio = i/nbSteps;
      float angle = 21.0*ratio;
      float c = cos(angle);
      float s = sin(angle);
      float r1 = 1.0 - 0.8*ratio;
      float r2 = 0.8 - 0.8*ratio;
      float alt = ratio - 0.5;
      const float nor = .5;
      const float up = sqrt(1.0-nor*nor);
      glColor3f(1.0-ratio, 0.2 , ratio);
      glNormal3f(nor*c, up, nor*s);
      glVertex3f(r1*c, alt, r1*s);
      glVertex3f(r2*c, alt+0.05, r2*s);
    }
  glEnd();
}

void Viewer::init()
{
  // Restore previous viewer state.
  restoreFromFile();

  help();
}

QString Viewer::helpString() const
{
  QString text("<h2>S i m p l e V i e w e r</h2>");
  text += "Use the mouse to move the camera around the object. ";
  text += "You can revolve around, zoom and translate with the three buttons. ";
  text += "Left and middle buttons pressed together rotate around the camera z axis<br><br>";
  text += "Pressing <b>Alt</b> and one of the function key (<b>F1</b>..<b>F12</b>) defines a camera keyFrame. ";
  text += "Simply press the function key again to restore it. Several keyFrames define a ";
  text += "camera path. Paths are saved when you quit the application.<br><br>";
  text += "Press <b>F</b> to display the frame rate, <b>A</b> for the world axis, ";
  text += "<b>Alt+Return</b> for full screen mode and <b>Control+S</b> to save a snapshot.<br><br>";
  text += "A double click aligns the closer axis with the camera (left, if close enough), fits ";
  text += "the zoom of the camera (middle) or re-center the scene (right).<br>";
  text += "A left double click while right button is pressed defines the <i>revolveAroundPoint</i>.";
  text += "With middle button pressed instead, it zooms on the pixel.<br><br>";
  text += "See also the <b>Shortcuts</b> and <b>Mouse</b> tabs and the documentation web pages.<br>";
  text += "Press <b>Escape</b> to exit the viewer.";
  return text;
}