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SET SURFACE APPROXIMATION CRITERIA

PSSAC


CALL SEQUENCE

CALL PSSAC(ACRI, LDR, DATREC)

INPUT PARAMETERS

INTEGER ACRI
Surface approximation criteria type
INTEGER LDR
Length of data record array
CHARACTER*80 DATREC (LDR)
Data record

PHIGS STATE

(PHOP,*,STOP,*)

EFFECT

A SET SURFACE APPROXIMATION CRITERIA element is inserted in the open structure after element pointer or replaces the element indicated by element pointer, depending on edit mode. Element pointer then points to the SET SURFACE APPROXIMATION CRITERIA element. The value specified by the parameter is associated with the element.

When an element of this type is interpreted, the current surface approximation criteria entry in the traversal state list is set to the values associated with the element. These values are used when displaying subsequent output primitives when the current surface approximation criteria ASF in the traversal state list is INDIVIDUAL.

Surface approximation criteria types are as follows:

PWDSA workstation dependent

PCBNSA constant parametric subdivision between knots

PCSWSA chordal size in WC

PCSNSA chordal size in NPC

PCSDSA chordal size in DC

PPDWSA planar deviation in WC

PPDNSA planar deviation in NPC

PPDDSA planar deviation in DC

PRWSA relative in WC

PRNSA relative in NPC

PRDSA relative in DC

When an element of this type is interpreted, if the specified approximation type is not available on a workstation, type PWDSA is used.

DATREC parameters to build SURFACE APPROXIMATION CRITERIA DATA

RECORD for ACRI =2(PCBNSA) :

The IA array contains :

- The actual data of u count

- The actual data of v count

The other arrays are empty.

IL = 2

IA(1) = u count

IA(2) = v count

RL = 0

RA = ()

SL = 0

LSTR = ()

STR = ()

DATREC parameters to build SURFACE APPROXIMATION CRITERIA DATA

RECORD for ACRI = 3(PCSWSA) or 4(PCSNSA) or 5(PCSDSA) :

The RA array contains :

- The actual data of u approximation value

- The actual data of v approximation value

The other arrays are empty.

IL = 0

IA = ()

RL = 2

RA(1) = u approximation value

RA(2) = v approximation value

SL = 0

LSTR = ()

STR =()

DATREC parameters to build SURFACE APPROXIMATION CRITERIA DATA

RECORD for ACRI =6(PPDWSA) or 7(PPDNSA) or 8(PPDDSA) or 9(PRWSA) or 10(PRNSA) or 11 (PRDSA) :

The RA array contains :

- The actual data of approximation value

The other arrays are empty.

IL = 0

IA = ()

RL = 1

RA(1) = approximation value

SL = 0

LSTR =()

STR = ()

EXTENSION TO THE PHIGS STANDARD

If GPHIGS is in NRS mode, the effect of this function is different from the effect described in the standard.

In NRS mode, (see OPEN PIPE), the element is not stored in a structure. It is sent to the workstation on which the pipe is opened.

ERRORS

5
Ignoring function, function requires state (PHOP,*, STOP,*)
138
Ignoring function, one or more of the fields in the specified data record is inconsistent with the specified type

SEE ALSO

non-uniform b-spline curve 3, non-uniform b-spline curve 3 with colour, open structure, open pipe (ext), inquire current element content, inquire current element type and size


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