pset_back_refl_props(3g) — Subroutines

Name

pset_back_refl_props − Specifies the surface properties of the back-facing portions of area primitives.

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

Syntax

void pset_back_refl_props (
const Prefl_prop ∗refl_data /∗ (I) Back reflectance property data ∗/
)

Data Structures

typedef struct {
    Pint              type;    /∗ reflectance property type ∗/
    union Prefl_prop_data {
        struct Prefl_prop_simple_refl {
            Pfloat   amb_coeff;    /∗ ambient reflection coefficient ∗/
            Pfloat   diff_coeff;   /∗ diffuse reflection coefficient ∗/
            Pfloat   spec_coeff;   /∗ specular reflection coefficient ∗/
            Pgcolr   spec_colr;    /∗ specular color ∗/
            Pfloat   spec_exp;     /∗ specular exponent ∗/
        } simple_refl;
        Pdata     unsupp;    /∗ unsupported reflectance property data ∗/
    } data;
} Prefl_prop;

        typedef struct {
            Pint     colr_type;   /∗ color type ∗/
            Pcolrv   colr_value; /∗ color value ∗/
        } Pgcolr;
            typedef union {
                Pint         colr_ind;    /∗ color index ∗/
                Pcolr_rep    colr_rep;    /∗ color representation ∗/
            } Pcolrv;
                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;

Constants

Data Structure Constants     Constant         Description
---------------------------------------------------------------------------
Reflectance property         PREFL_PROPS_     Simple reflectance
type                         SIMPLE_REFL
Color types                  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

pset_back_refl_props specifies the surface properties of the back-facing portions of area primitives. The argument values of this function help to define the lighting calculation conceptually applied at one or more points on the back-facing areas of the primitive Digital PHIGS illuminates and shades. The aspects defined by the pset_back_int_colr function also affect the back-facing areas. These aspects, in conjunction with the face processing mode, determine the appearance of the back-facing area.

Depending on the current edit mode, the 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 set back reflectance properties element.

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