openvrml::frustum Class Reference

A view frustum. More...

#include <openvrml/frustum.h>

List of all members.


Public Member Functions

 frustum ()
 Construct a default frustum.
 frustum (float fovy, float aspect, double z_near, double z_far)
 Construct and initialize a frustum.

Public Attributes

float fovy
 Vertical field of view.
float fovx
 Horizontal field of view.
double z_near
 Distance to the near clipping plane.
double z_far
 Distance to the far clipping plane.
float left_plane [4]
 Left (looking down -z) side clip plane.
float right_plane [4]
 Right clipping plane.
float top_plane [4]
 Top clipping plane.
float bot_plane [4]
 Bottom clipping plane.

Private Member Functions

void update ()
 Update the plane equations.

Detailed Description

A view frustum.

A frustum is more or less a truncated pyramid. This class represents frustums with their wide end facing down the -z axis, and their (theoretical) tip at the origin. A frustum is a convenient representation of the volume of virtual space visible through the on-screen window when using a perspective projection.

See also:
openvrml::appearance_node::render_appearance

openvrml::child_node::render_child

openvrml::geometry_node::render_geometry

openvrml::viewer


Constructor & Destructor Documentation

openvrml::frustum::frustum (  ) 

Construct a default frustum.

fovy, fovx, near and far all get set to -1.

openvrml::frustum::frustum ( float  fovy,
float  aspect,
double  z_near,
double  z_far 
)

Construct and initialize a frustum.

The field of view should be less than 180 degrees. Extreme aspect ratios are unlikely to work well. The near and far plane distances are always positive (think distance, not position). anear must be less than afar. This is supposed to look like gluPerspective.

Parameters:
[in] fovy vertical field of view in degrees.
[in] aspect ratio of view width to height (not the ratio of the horizontal to vertial field-of-views).
[in] z_near distance to near clip plane.
[in] z_far distance to far clip plane.


Member Function Documentation

void openvrml::frustum::update (  )  [private]

Update the plane equations.

The plane equations are derived from the other members.


Member Data Documentation

Vertical field of view.

Horizontal field of view.

Distance to the near clipping plane.

Distance to the far clipping plane.

Left (looking down -z) side clip plane.

Format is (a,b,c,d) where (a,b,c) is the plane normal and d is the plane offset. For the momement the eyepoint is always the origin, so d is going to be 0.

Right clipping plane.

Top clipping plane.

Bottom clipping plane.