Name

PESC − Invokes the specified escape function. 

Operating States: PHOP, ∗, ∗, ∗
PHIGS standard function

Syntax

PESC (FCTID, LIDR, IDR, MLODR, LODR, ODR)

Argument     Data Type       Access    Description
---------------------------------------------------------------------------
FCTID        Integer         Read      Escape function identifier.
LIDR         Integer         Read      Dimension of input data record array.
IDR(LIDR)    Character ∗80   Read      Input data record.  Use PPREC to
                                       create the data record.
MLODR        Integer         Read      Maximum length of output data record.
LODR         Integer         Write     Number of array elements occupied
                                       in ODR.
ODR(MLODR)   Character ∗80   Write     Output data record.  Use PUREC to
                                       create an array of elements from the
                                       data record.
---------------------------------------------------------------------------

Description

PESC invokes the specified escape function.  The form of the escape data record is function-dependent. 

This function provides a method for individual Digital PHIGS implementations to access capabilities of a specific workstation that are not fully utilized by other functions. The form of the escape data record is function-dependent.  Each of the device specific chapters in the Device Specifics Reference Manual for DEC GKS and DEC PHIGS explains the requirements for the data records.  Note that a specific workstation type will support a subset of available escape functions.  Use the phigs_predef sample program to determine which escape functions your workstation supports. 

Escape Data Records

When you call the ESCAPE function, you may need to pass a data record.  See PPREC and Packing and Unpacking Data Records for information on packing data records. 

After performing a task, some escape functions pass information back to you through an output data record.  Use the PUREC function to access the information in the output data record. 

If you use an escape function and need to determine the size required by the entire output data record buffer, you can pass the value 0 to the output record buffer size (the MLODR argument).  When you pass the value 0 as this argument, ESCAPE does not perform the escape, but instead returns the size of the output data record to argument LODR.  In this manner, you can be sure that you declared an output data record buffer large enough to hold the entire data record. 

You must use the PHIGS$ binding entry point "phigs$escape" instead of the Fortran PESC function for the following escapes:

 --304   Inquire Window Identifiers
 --307   Inquire Pasteboard Identifier
 --308   Inquire Menu Bar Identifier
 --309   Inquire Shell Identifier
 --501   Set Background Pixmap
 --502   Inquire Double Buffer Pixmap
 --503   Inquire Background Pixmap
 --511   Set Plane Mask
 --512   Set Marker Pattern
 --513   Inquire Double Buffer Buffers
 --516   Inquire Closest Color

To use the PHIGS$ entry point for the escape function, you must include the file phigs_defs.f in your application and use %LOC to determine the address of the escape information.  See the phigs_defs.f file for the syntax of the phigs$escape function. 

See Also

PPREC
PUREC