Name

PEXViewOrientationMatrix2D

Synopsis

int PEXViewOrientationMatrix2D(PEXCoord2D ∗vrp, PEXVector2D ∗vup, PEXMatrix3x3 matrix_return)

Arguments

vrpview reference point

vupview up vector

matrix_return
matrix in which result is stored

Returns

Zero if successful; otherwise, one of the following:

PEXBadVector - vup is zero length.

Description

This function creates a view orientation matrix that transforms world coordinates (WC) to view reference coordinates (VRC).  This matrix is used in conjunction with a view mapping matrix as the viewing matrices for a designated view. 

The view reference point (VRP) defines the point in world coordinate space that is to be used as the origin of the view reference coordinate system.  The point is in the WC z=0 plane. 

The view plane normal (VPN) is in the direction of the positive Z axis of WC. 

The view up vector (VUP) is a 2D vector in the WC z=0 plane.  It determines the positive Y axis of VRC.  It’s defined in world coordinates relative to the view reference point. 

The X axis of VRC is defined such that the VRC system forms a right-handed coordinate system. 

Errors

None

See Also

PEXViewOrientationMatrix, PEXViewMappingMatrix, PEXViewMappingMatrix2D