fry@math.harvard.edu (David Fry) (03/01/91)
I'm trying to interface a THINK C library with a friend's THINK Pascal program. My C function is defined: pascal void MyFunc(Ptr aPtr, short aShort, unsigned char aByte); The problem is how to define it in Pascal and pass parameters to it so that aByte gets the proper values. I've tried a variety of things, and only PROCEDURE MyFunc(aPtr: Ptr; aShort: INTEGER; aByte: BOOLEAN); comes close. Defining aByte as a CHAR or Byte still uses 16-bits, so only the high byte is getting passed to the C routine. BOOLEAN uses 8-bits, but it is equivalent to a char, rather than an unsigned char, so the high bit is unusable. Should I define a type of PACKED ARRAY [1..1] of CHAR, or some such? Thanks for any help. David Fry fry@math.harvard.EDU Department of Mathematics fry@huma1.bitnet Harvard University ...!harvard!huma1!fry Cambridge, MA 02138
Lawson.English@p88.f15.n300.z1.fidonet.org (Lawson English) (03/03/91)
David Fry writes in a message to All
DF> pascal void MyFunc(Ptr aPtr, short aShort, unsigned char aByte);
DF> PROCEDURE MyFunc(aPtr: Ptr; aShort: INTEGER; aByte: BOOLEAN);
DF> Should I define a type of PACKED ARRAY [1..1] of CHAR, or some
DF> such?
As C has the more versatile way of defining parameters, why not redefine your
C function to interface properly with the Pascal, rather then try to force Pascal
to interface properly with the C? As you have the source to both, this shouldn't
be a problem. If it is, then you might define a glue routine in C that calls
your routine after making all necessary adjustments...
Lawson
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