PTSTD(3g) — Subroutines

Name

PTSTD − Specifies the 2D, shorthand form of a triangle strip with data primitive.

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

Syntax

PTSTD (FFLAG, EFLAG, VFLAG, CTYPE, NCC, NP, FCOLI, FCOLR,
FNXA, FNYA, FNZA, FDLEN, FDATA, EDATA, PXA, PYA, VCOLI, VCOLR,
VNXA, VNYA, VNZA, VDLEN, VDATA)

Argument        Data Type      Access   Description
---------------------------------------------------------------------------
FFLAG           Integer        Read     Data per facet flag
EFLAG           Integer        Read     Data per edge flag
VFLAG           Integer        Read     Data per vertex flag
CTYPE           Integer        Read     Color type
NCC             Integer        Read     Number of color value components
NP              Integer        Read     Number of points
FCOLI(NP-2)     Integer        Read     Facet color indexes
FCOLR(NCC∗      Real           Read     Facet color values
(NP-2))
FNXA(NP-2),     Real           Read     Facet normal data, in modeling
FNYA(NP-2),                             coordinates
FNZA(NP-2)
FDLEN           Integer        Read     Length of the data list per facet
FDATA(FDLEN∗    Real           Read     Facet data
(NP-2))
EDATA(2∗NP-3)   Integer        Read     Edge data
PXA(NP),        Real           Read     Coordinates of the points, in
PYA(NP)                                 modeling coordinates
VCOLI(NP)       Integer        Read     Vertex color indexes
VCOLR(NCC∗NP)   Real           Read     Vertex color values
VNXA(NP),       Real           Read     Vertex normal data, in modeling
VNYA(NP),                               coordinates
VNZA(NP)
VDLEN           Integer        Read     Length of the data list per vertex
VDATA(VDLEN     Real           Read     Vertex data
∗NP)
---------------------------------------------------------------------------

Constants

Defined Argument     Constant     Description
---------------------------------------------------------------------------
FFLAG                PFNO         No facet data
                     PFC          Color per facet
                     PFN          Geometric normal per facet
                     PFD          Data per facet
                     PFCN         Color and geometric normal per facet
                     PFCD         Color and data per facet
                     PFND         Geometric normal and data per facet
                     PFCND        Color, geometric normal, and data per
                                  facet
EFLAG                PENO         No edge data
                     PEVF         Edge visibility flag
VFLAG                PCD          Coordinate only
                     PCDC         Color per vertex
                     PCDN         Normal per vertex
                     PCDD         Data per vertex
                     PCDCN        Color and geometric normal per vertex
                     PCDCD        Color and data per vertex
                     PCDND        Geometric normal and data per vertex
                     PCDCND       Color, geometric normal, and data per
                                  vertex
CTYPE                PINDIR       Indirect (indexed) color
                     PRGB         Direct specification of red, green, and
                                  blue
                     PCIE         Direct specification in the format of the
                                  Commission Internationale de l’Eclairage
                     PHSV         Direct specification of hue, saturation,
                                  and value
                     PHLS         Direct specification of hue, lightness,
                                  and saturation
EDATA                POFF         Edges off
                     PON          Edges on
---------------------------------------------------------------------------

Description

PTSTD specifies the two-dimensional shorthand form of the surface and the interior attributes of a triangle strip with data primitive. The triangle strip is a sequence of triangles, the edges of which are line segments forming the boundaries of all triangles in the strip. It generates a sequence of n triangles from n + 2 vertices. Digital PHIGS assumes the z-coordinate value for each vertex is 0.

If the data per facet flag indicates that you have specified a facet color, or if the data per vertex flag indicates that you have specified vertex colors, you must also have specified a color type.

The vertex data is a two-dimensional array (of mxn) where the data in each set of four neighboring array elements defines a triangle strip, which need not be planar. Digital PHIGS uses a workstation-dependent method to render, decompose, or both, the triangle strip. Digital PHIGS considers a triangle strip with n < 2 or m < 2 degenerate, and treats it in an implementation-dependent manner.

During structure traversal, Digital PHIGS draws a triangle strip using the same attribute set as that used by the fill area set with data primitive.

The strip is composed of n--2 triangles, where n is the number of vertices. The first triangle is formed from vertices <1,2,3>; the second triangle from n--2 triangle from vertices <n--2, n--1, n>. A strip with fewer than three vertices is considered degenerate and is treated in an implementation-dependent manner. If information per facet is present, there will be n--2 pieces of information.

Depending on the 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 triangle strip with data element.

If Digital PHIGS is in immediate mode, it performs this function immediately, but the function does not create a structure element. Facet and vertex normals must be of unit length.

Digital PHIGS Version 3.1 does not support this function.

Museum

PTSTD(3g) — Subroutines

Name

Syntax

Constants

Description

See Also