PSCAC(3g) — Subroutines

Name

PSCAC − Indicates the minimum quality desired for the approximation of the curve’s geometry.

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

Old Syntax

DSCAC (APRXTP, LDR, DATREC)

Argument       Data Type      Access    Description
---------------------------------------------------------------------------
APRXTP         Integer        Read      Approximation type
LDR            Integer        Read      Length of the data record
DATREC(LDR)    Array of       Read      Data record
               character ∗80
---------------------------------------------------------------------------

New Syntax

PSCAC (ACRI, LDR, DATREC)

Argument       Data Type      Access    Description
---------------------------------------------------------------------------
ACRI           Integer        Read      Curve approximation criteria type
LDR            Integer        Read      Length of the data record
DATREC(LDR)    Array of       Read      Data record
               character ∗80
---------------------------------------------------------------------------

Constants

Defined Argument      Constant      Description
---------------------------------------------------------------------------
ACRI                  PWDCA         Workstation-dependent method
                      PCBKCA        Constant parametric subdivision
                                    between knots
                      PCSWCA        Metric, in world coordinates
                      PCSNCA        Metric, in normalized projection
                                    coordinates
                      PCSDCA        Metric, in device coordinates
                      PCDWCA        Chordal deviation, in world coordinates
                      PCDNCA        Chordal deviation, in normalized
                                    projection coordinates
                      PCDDCA        Chordal deviation, in device
                                    coordinates
                      PRWCA         Relative, in world coordinates
                      PRNCA         Relative, in normalized projection
                                    coordinates
                      PRDCA         Relative, in device coordinates
                      DCSDCA        Constant subdivision (non-PEX only)
                      DIDCA         Implementation-dependent method
                                    (PEX only)
---------------------------------------------------------------------------

Description

PSCAC indicates the minimum quality desired for the approximation of the curve’s geometry. Depending on the edit mode, this function either inserts the new structure element directly after the pointer or replaces the element indicated by the pointer. The pointer then points to the new set curve approximation criteria element.

During structure traversal, if the specified approximation type is undefined, Digital PHIGS uses type 1.

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

The new function syntax conforms to the ISO Fortran standard. Digital recommends that you code using the new function syntax.

Data Record Information

If ACRI is PWDCA, there is no data record.

If ACRI is PCBKCA or DCSDCA, the data record has the following format:

INTEGER IL    = 1    Number of integer values
INTEGER IA(1) =      Count
        RL    = 0
        RA    = ()
        SL    = 0
        LSTR = ()
        STR   = ()

If ACRI is PCSWCA, PCSNCA, PCSDCA, PCDWCA, PCDNCA, PCDDCA, PRWCA, PRNCA, or PRDCA, the data record has the following format:

        IL    = 0
        IA    = ()
        RL    = 1
INTEGER RA(1) =          Approximation value
        SL    = 0
        LSTR = ()
        STR   = 0

If ACRI is DIDCA, the data record has the following format:

        IL    = 0
        IA    = 0
        RL    = 1    Number of reals
        RA(1) =      Approximation value
        SL    = 0
        LSTR = ()
        STR   = ()

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