DIPD3(3g) — Subroutines

Name

DIPD3 − Specifies facet, edge, and vertex data and values.

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

Syntax

DIPD3 (SHPFLG, FCTFLG, VTXFLG, EDGFLG, CLRTYP, NFACET, FICOL, FCOL,
FNX, FNY, FNZ, NFA, EDGVIS, VPTR, NVTX, VXA, VYA, VZA, VICOL, VCOL, VNX, VNY,
VNZ)

Argument         Data Type      Access   Description
---------------------------------------------------------------------------
SHPFLG           Integer        Read     Shape of the facets
FCTFLG           Integer        Read     Data per facet flag
VTXFLG           Integer        Read     Data per vertex flag
EDFLAG           Integer        Read     Data per edge flag
CLRTYP           Integer        Read     Color type of facet and vertex
                                         color values
NFACET           Integer        Read     Number of facets
FICOL(NFACET)    Array of       Read     Indexed facet colors
                 integers
FCOL(∗)          Array of       Read     Direct facet colors (r,g,b,r,g,b)
                 reals
FNX(NFACET),     Array of                ReadFacet normals
FNY(NFACET),     reals
FNZ(NFACET)
NFA(NFACET)      Array of       Read     Array of end indexes for each facet
                 integers                (points into VPTR)
EDGVIS(∗)        Array of       Read     Array of edge visibility flags
                 integers
VPTR(∗)          Array of       Read     Array of vertex indexes
                 integers
NVTX             Integer        Read     Number of vertex data points
VXA(NVTX),       Array of       Read     Vertex list
VYA(NVTX),       reals
VZA(NVTX)
VICOL(NVTX)      Array of       Read     Indexed vertex colors
                 reals
VCOL(∗)          Array of       Read     Direct vertex colors (r,g,b,r,g,b)
                 reals
VNX(NVTX),       Array of       Read     Vertex normals
VNY(NVTX),       reals
VNZ(NVTX)
---------------------------------------------------------------------------

Constants

Defined Argument     Constant     Description
---------------------------------------------------------------------------
SHPFLG               DSHPCX       Some facets are self-intersecting.
                     DSHNON       Some facets are concave, but no facets are
                                  self-intersecting.
                     DSHCON       All facets are convex.
                     DSHUNK       Facet shape unknown.
FCTFLG               PFNO         No data per fill area.
                     PFC          Facet color per fill area.
                     PFN          Geometric normal per fill area.
                     PFCN         Facet color and geometric normal per
                                  fill area.
VTXFLG               PCD          No data per vertex.
                     PCDC         Color per vertex.
                     PCDN         Normal per vertex.
                     PCDCN        Color and normal per vertex.
EDGFLG               PENO         No data per edge.
                     PEVF         Edge visibility indicator per edge.
CLRTYP               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
---------------------------------------------------------------------------

Description

DSFSD3 specifies the following:

•Data per facet flag

•Data per edge flag

•Data per vertex flag

•Facet data

•Edge data

•Direct color model

•Vertex data

•Vertex indexes values

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 index polygons with data element.

The geometric description of this primitive consists of a list of vertices and a list of index lists. Each index list is a list of indexes into the vertex list, thereby implicitly defining a list of vertices (and optional per vertex data). Each such vertex list defines a facet of the index polygons, which is rendered as a single fill area set. However, the appearance of such a facet, which is self-intersecting, is indeterminate and device-dependent.

If the data per vertex flag specifies coordinates and colors, or coordinates, colors, and normals, then a list of colors (one for each vertex) must be specified.

If the data per vertex flag indicates that a color per vertex is specified, a direct color model value must also be specified for the output primitive.

During structure traversal, Digital PHIGS draws a number of facets. The facets can be noncoplanar. Digital PHIGS renders each facet as a fill area set with data. You specify the data for each vertex once only (in the vertex data list). You select the vertices that define the boundary of each facet in the vertex index list. Index 1 selects the first vertex in the list.

The facets do not necessarily form a closed surface. Even if a volume is implicitly specified, no additional effects are provided for rendering this type of primitive.

If Digital PHIGS is in immediate mode, it performs this function immediately, but the function does not create a structure element. If FCTFLG = PFNO or PFC, the function ignores the FNX, FNY, and FNZ arguments.

If FCTFLG = PFNO or PFN, the function ignores the FICOL and FCOL arguments.

If VTXFLG = PCD or PCDC, the function ignores the VNX, VNY, and VNZ arguments.

If VTXFLG = PCD or PCDN, the function ignores the VICOL and VCOL arguments.

If EDGFLG = PENO, the function ignores the EDGVIS argument.

Facet and vertex normals must be of unit length.

Museum

DIPD3(3g) — Subroutines

Name

Syntax

Constants

Description

See Also