ptri_strip3_data(3g) — Subroutines

Name

ptri_strip3_data − Specifies the 3D form of a triangle strip 3 with data primitive.

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

Syntax

void ptri_strip3_data (
Pint                     colr_type,   /∗ (I) Color type ∗/
const Pfacet_list       ∗facet_data, /∗ (I) List of facet data ∗/
const Pedge_flag_list   ∗edge_flags, /∗ (I) List of edge flags ∗/
const Pvertex3_list     ∗vertex_data /∗ (I) List of vertex data ∗/
)

Data Structures

typedef struct {
    Pint        num_facets;          /∗ number of facets ∗/
    Pint        num_data_per_facet; /∗ number of data values per facet ∗/
    Pcolrv_ptr facet_colrvs;        /∗ list of facet color values ∗/
    Pvec3      ∗facet_norms;         /∗ list of facet normals ∗/
    Pfloat     ∗facet_data;          /∗ list of facet data lists ∗/
} Pfacet_list;
    typedef union {
        Pint       ∗colr_ind;   /∗ pointer to color indices ∗/
        Pcolr_rep_ptr colr_reps;   /∗ pointer to color
                                       representations ∗/
    } Pcolrv_ptr;
        typedef union {
            Prgb        rgb;       /∗ red, green, and blue color
                                      specification ∗/
            Pcieluv     cieluv;    /∗ CIELUV color specification ∗/
            Phls        hls;       /∗ hue, lightness, and saturation color
                                      specification ∗/
            Phsv        hsv;       /∗ hue, saturation, and value color
                                      specification ∗/
            Pdata       unsupp;    /∗ color in an unsupported color
                                      model ∗/
            int         impl_dep; /∗ implementation-defined ∗/
        } Pcolr_rep;
            typedef struct {
                Pfloat   red;      /∗ red intensity   ∗/
                Pfloat   green;    /∗ green intensity ∗/
                Pfloat   blue;     /∗ blue intensity ∗/
            } Prgb;
            typedef struct {
                Pfloat   cieluv_x;      /∗ x coefficient ∗/
                Pfloat   cieluv_y;      /∗ y coefficient ∗/
                Pfloat   cieluv_y_lum; /∗ y luminance ∗/
            } Pcieluv;
            typedef struct {
                Pfloat   hue;        /∗ hue ∗/
                Pfloat   lightness; /∗ lightness ∗/
                Pfloat   satur;      /∗ saturation ∗/
            } Phls;
            typedef struct {
                Pfloat   hue;    /∗ hue ∗/
                Pfloat   satur; /∗ saturation ∗/
                Pfloat   value; /∗ value ∗/
            } Phsv;
            typedef struct {
                size_t   size;   /∗ size of data ∗/
                void    ∗data;   /∗ pointer to the data ∗/
            } Pdata;
    typedef struct {
        Pfloat    delta_x;    /∗ delta x value ∗/
        Pfloat    delta_y;    /∗ delta y value ∗/
        Pfloat    delta_z;    /∗ delta z value ∗/
    } Pvec3;
typedef struct {
    Pint             num_edges;    /∗ number of edges in the list ∗/
    Pedge_flag      ∗edge_flags;   /∗ list of edge flags ∗/
} Pedge_flag_list;
    typedef enum {
        PEDGE_OFF,   /∗ edges off ∗/
        PEDGE_ON     /∗ edges on ∗/
    } Pedge_flag;
typedef struct {
    Pint         num_vertices;         /∗ number of vertices ∗/
    Pint         num_data_per_vertex; /∗ number of data values per
                                          vertex ∗/
    Ppoint3     ∗vertex_points;        /∗ list of vertex points ∗/
    Pcolrv_ptr   vertex_colrvs;        /∗ list of vertex colors ∗/
    Pvec3       ∗vertex_norms;         /∗ list of vertex normals ∗/
    Pfloat      ∗vertex_data;          /∗ list of vertex data lists ∗/
} Pvertex3_list;
    typedef struct {
        Pfloat     x;    /∗ x coordinate ∗/
        Pfloat     y;    /∗ y coordinate ∗/
        Pfloat     z;    /∗ z coordinate ∗/
    } Ppoint3;

Constants

Defined Argument      Constant           Description
---------------------------------------------------------------------------
colr_type             PCOLR_INDIRECT     Indirect (indexed) color
                      PCOLR_RGB          Direct specification of red,
                                         green, and blue
                      PCOLR_CIELUV       Direct specification in the format
                                         of the Commission Internationale
                                         de l’Eclairage
                      PCOLR_HSV          Direct specification of hue,
                                         saturation, and value
                      PCOLR_HLS          Direct specification of hue,
                                         lightness, and saturation
---------------------------------------------------------------------------

Description

ptri_strip3_data specifies the three-dimensional form of the surface and the interior attributes of a triangle strip with data primitive. The triangle strip 3 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.

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 vertices <2,3,4>; ... ; the 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 3 with data element.

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

You can pass a null value for the facet_data or edge_flags arguments because that data is optional.

If you do not supply a value for facet_data or edge_flags, Digital PHIGS will not supply facet or edge flag data.