NAME

SET PARAMETRIC SURFACE CHARACTERISTICS − create a structure element to set the current parametric surface characteristics

SYNOPSIS

C Syntax

void
pset_para_surf_characs( psc_type, data )
Pintpsc_type;type
Ppara_surf_characs∗data; OUT data record

Required PHIGS Operating States

(PHOP, ∗, ∗, ∗)

DESCRIPTION

Purpose

SET PARAMETRIC SURFACE CHARACTERISTICS sets current parametric surface characteristics to be used when displaying subsequent parametric surface output primitives. 

C Input Parameters

psc_type
The parametric surface characteristic types.

1       PSC_NONENo Surface Characteristics Specified
2       PSC_WS_DEPWorkstation Dependent
3       PSC_ISOPARAMETRIC_CURVESIsoparametric Curves Specified
4       PSC_LEVEL_CURVES_MCLevel Curves Specified in Modelling Coordinates
5       PSC_LEVEL_CURVES_WCLevel Curves Specified in World Coordinates

C Output Parameters

dataThe surface characteristics data record.  A pointer to a structure Ppara_surf_characs.  Ppara_surf_characs is defined in phigs.h as follows:

typedef union {
struct {
Pintunused;
} psc_1;
struct {
Pintunused;
} psc_2;
struct {
Pcurve_placementplacement;
Pintu_count;
Pintv_count;
} psc_3;
struct {
Ppoint3origin;
Pvec3direction;
Pfloat_listparams;
} psc_4;
struct {
Ppoint3origin;
Pvec3direction;
Pfloat_listparams;
} psc_5;
} Ppara_surf_characs;

Pcurve_placement is defined in phigs.h as follows:

typedef enum {
PCP_UNIFORM,
PCP_NON_UNIFORM
} Pcurve_placement;

Execution

When the structure is traversed, SET PARAMETRIC SURFACE CHARACTERISTICS updates the current parametric surface characteristics entry in the traversal state list.  These values are used when displaying subsequent parametric surface output primitives.  When an element of this type is interpreted, if the specified parametric surface characteristic type is not available on a workstation, or the data record are invalid, type 1 is used and data record contents are workstation-dependent. 

ERRORS

005Ignoring function, function requires state (PHOP, ∗, STOP, ∗)

138Ignoring function, one or more of the fields in the specified data record is inconsistent with the specified type

SEE ALSO

NON-UNIFORM B-SPLINE SURFACE (3P+)

September 02, 1992