PTX3S(3g) — Subroutines

Name

PTX3S − Writes and positions a character string (3D form).

Operating States: PHOP, ∗, STOP, ∗
PHIGS standard function
Creates a structure element

Syntax

PTX3S (PX, PY, PZ, TDX, TDY, TDZ, LSTR, CHARS)

Argument        Data Type       Access     Description
---------------------------------------------------------------------------
PX, PY, PZ      Real            Read       Text position, in modeling
                                           coordinates
TDX(2),         Array of        Read       Text direction vectors, in
TDY(2),         reals                      modeling coordinates
TDZ(2)
LSTR            Integer         Read       Length of the text string, in
                                           characters
CHARS           Character ∗80   Read       Text string
---------------------------------------------------------------------------

Description

PTX3S writes a character string and positions it for display according to the text point specified in modeling coordinate units. Associated text attributes, normalization transformation, and the capabilities of the workstation also affect the appearance of the string.

Depending on the current edit mode, this function either inserts the new structure element directly after the element indicated by the pointer or replaces the element indicated by the pointer. The pointer then points to the new text 3 element.

The PTX3S function specifies the three-dimensional (x, y, and z) form of the text primitive. A call to this function has the following effects during structure traversal:

•Digital PHIGS generates a character string in the text position on a text plane.

The text plane and the local coordinate system, in which all geometric text attributes are measured on that plane, are defined by a point and two vectors contained in the definition of the primitive. This point is the text position. The two vectors are the first direction vector and the second direction vector. To illustrate the use of the local coordinate system, assume the following:

•P is the text position.

•U and V are the first and second text direction vectors.

•T is a vector perpendicular to U and in the text plane.

The text plane is the plane that contains P and is perpendicular to UxV. The origin of the local coordinate system is at the point P. The positive x-axis of the local coordinate system is parallel to U. If the dot product of TxV is positive,
the positive y-axis is parallel to T. Otherwise, the positive y-axis is opposite T.

•Digital PHIGS binds the current values of the text 3 attributes, as defined in the PHIGS traversal state list, to the text 3 primitive.

The text precision attribute affects text clipping.

If Digital PHIGS is in immediate mode, it performs this function immediately, but the function does not create a structure element.

Museum

PTX3S(3g) — Subroutines

Name

Syntax

Description

See Also