rt::Sphere Struct Reference

A sphere is a concrete GraphicalObject that represents a sphere in 3D space. More...

#include <Sphere.h>

Inheritance diagram for rt::Sphere:

Public Member Functions
virtual	~Sphere ()
	Virtual destructor since object contains virtual methods.
	Sphere (Point3 xc, Real r, const Material &m)
	Creates a sphere of center xc and radius r.
Point3	localize (Real latitude, Real longitude) const
void	init (Viewer &)
void	draw (Viewer &viewer)
Vector3	getNormal (Point3 p)
Material	getMaterial (Point3 p)
Real	rayIntersection (const Ray &ray, Point3 &p)
Public Member Functions inherited from rt::GraphicalObject
	GraphicalObject ()
	Default constructor. Nothing to do.
virtual	~GraphicalObject ()
	Virtual destructor since object contains virtual methods.

Public Attributes
Point3	center
	The center of the sphere.
Real	radius
	The radius of the sphere.
Material	material
	The material (global to the sphere).

Static Public Attributes
static const int	NLAT = 16
	number of different latitudes for display
static const int	NLON = 24
	number of different longitudes for display

Detailed Description

A sphere is a concrete GraphicalObject that represents a sphere in 3D space.

Definition at line 15 of file Sphere.h.

Constructor & Destructor Documentation

~Sphere()

virtual rt::Sphere::~Sphere ( )

inlinevirtual

Virtual destructor since object contains virtual methods.

Definition at line 21 of file Sphere.h.

{}

Sphere()

rt::Sphere::Sphere ( Point3  xc, Real  r, const Material &  m  )

inline

Creates a sphere of center xc and radius r.

Definition at line 24 of file Sphere.h.

      : GraphicalObject(), center( xc ), radius( r ), material( m )
    {}

Member Function Documentation

draw()

void rt::Sphere::draw ( Viewer &  viewer )

virtual

This method is called by Scene::draw() at each frame to redisplay objects in the OpenGL window.

Implements rt::GraphicalObject.

Definition at line 8 of file Sphere.cpp.

{
  Material m = material;
  // Taking care of south pole
  glBegin( GL_TRIANGLE_FAN );
  glColor4fv( m.ambient );
  glMaterialfv(GL_FRONT, GL_DIFFUSE, m.diffuse);
  glMaterialfv(GL_FRONT, GL_SPECULAR, m.specular);
  glMaterialf(GL_FRONT, GL_SHININESS, m.shinyness );
  Point3 south_pole = localize( -90, 0 );
  glNormal3fv( getNormal( south_pole ) );
  glVertex3fv( south_pole );
  for ( int x = 0; x <= NLON; ++x )
    {
      Point3 p = localize( -90 + 180/NLAT, x * 360 / NLON );
      glNormal3fv( getNormal( p ) );
      glVertex3fv( p );
    }
  glEnd();
  // Taking care of in-between poles
  for ( int y = 1; y < NLAT - 1; ++y )
    {
      glBegin( GL_QUAD_STRIP);
      glColor4fv( m.ambient );
      glMaterialfv(GL_FRONT, GL_DIFFUSE, m.diffuse);
      glMaterialfv(GL_FRONT, GL_SPECULAR, m.specular);
      glMaterialf(GL_FRONT, GL_SHININESS, m.shinyness );
      for ( int x = 0; x <= NLON; ++x )
        {
          Point3 p = localize( -90 + y*180/NLAT,     x * 360 / NLON );
          Point3 q = localize( -90 + (y+1)*180/NLAT, x * 360 / NLON );
          glNormal3fv( getNormal( p ) );
          glVertex3fv( p );
          glNormal3fv( getNormal( q ) );
          glVertex3fv( q );
        }
      glEnd();
    }
  // Taking care of north pole
  glBegin( GL_TRIANGLE_FAN );
  glColor4fv( m.ambient );
  glMaterialfv(GL_FRONT, GL_DIFFUSE, m.diffuse);
  glMaterialfv(GL_FRONT, GL_SPECULAR, m.specular);
  glMaterialf(GL_FRONT, GL_SHININESS, m.shinyness );
  Point3 north_pole = localize( 90, 0 );
  glNormal3fv( getNormal( north_pole ) );
  glVertex3fv( north_pole );
  for ( int x = NLON; x >= 0; --x )
    {
      Point3 p = localize( -90 + (NLAT-1)*180/NLAT, x * 360 / NLON );
      glNormal3fv( getNormal( p ) );
      glVertex3fv( p );
    }
  glEnd();
}

getMaterial()

rt::Material rt::Sphere::getMaterial ( Point3  p )

virtual

Returns

the material associated to this part of the object

Implements rt::GraphicalObject.

Definition at line 86 of file Sphere.cpp.

{
  return material; // the material is constant along the sphere.
}

getNormal()

rt::Vector3 rt::Sphere::getNormal ( Point3  p )

virtual

Returns

the normal vector at point p on the sphere (p should be on or close to the sphere).

Implements rt::GraphicalObject.

Definition at line 77 of file Sphere.cpp.

{
  Vector3 u = p - center;
  Real   l2 = u.dot( u );
  if ( l2 != 0.0 ) u /= sqrt( l2 );
  return u;
}

init()

void rt::Sphere::init ( Viewer &  )

inlinevirtual

This method is called by Scene::init() at the beginning of the display in the OpenGL window. May be useful for some precomputations.

Implements rt::GraphicalObject.

Definition at line 38 of file Sphere.h.

{}

localize()

rt::Point3 rt::Sphere::localize	(	Real	latitude,
		Real	longitude
	)		const

Given latitude and longitude in degrees, returns the point on the sphere at these coordinates.

Definition at line 65 of file Sphere.cpp.

{
  static const Real conv_deg_rad = 2.0 * M_PI / 360.0;
  latitude  *= conv_deg_rad;
  longitude *= conv_deg_rad;
  return center 
    + radius * Point3( cos( longitude ) * cos( latitude ),
                       sin( longitude ) * cos( latitude ),
                       sin( latitude ) );
}

rayIntersection()

rt::Real rt::Sphere::rayIntersection ( const Ray &  ray, Point3 &  p  )

virtual

Parameters

[in]	ray	the incoming ray
[out]	returns	the point of intersection with the object (if any), or the closest point to it.

Returns

either a real < 0.0 if there is an intersection, or a kind of distance to the closest point of intersection.

Implements rt::GraphicalObject.

Definition at line 92 of file Sphere.cpp.

{
  // TO DO
  return 1.0f;
}

Member Data Documentation

center

Point3 rt::Sphere::center

The center of the sphere.

Definition at line 62 of file Sphere.h.

material

Material rt::Sphere::material

The material (global to the sphere).

Definition at line 66 of file Sphere.h.

NLAT

const int rt::Sphere::NLAT = 16

static

number of different latitudes for display

Definition at line 17 of file Sphere.h.

NLON

const int rt::Sphere::NLON = 24

static

number of different longitudes for display

Definition at line 18 of file Sphere.h.

radius

Real rt::Sphere::radius

The radius of the sphere.

Definition at line 64 of file Sphere.h.

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The documentation for this struct was generated from the following files:

• TP2/Sphere.h
• TP2/Sphere.cpp