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openvrml::frustum Class Reference

List of all members.

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:
node::render

viewer


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.

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

openvrml::frustum::fovy
 

Vertical field of view.

openvrml::frustum::fovx
 

Horizontal field of view.

openvrml::frustum::z_near
 

Distance to the near clipping plane.

openvrml::frustum::z_far
 

Distance to the far clipping plane.

openvrml::frustum::left_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.

openvrml::frustum::right_plane
 

Right clipping plane.

openvrml::frustum::top_plane
 

Top clipping plane.

openvrml::frustum::bot_plane
 

Bottom clipping plane.