Stan Sieler wrote:
> Victor writes:
> > I need make a program in C/ix to read a dataset of a Turboimage...
> > My problem is with fields defined as I2 in Turboimage.

> Actually, an IMAGE I2, a C/iX "int", and a Pascal "integer" are all
> 32-bit signed integers.  (Assuming you didn't put "short" in front
> of the C/iX "int".)

I suspect the underlying problem is that if you define an image dataset
entry in the form of a C/iX struct, you get "strict alignment" on 32-bit
boundaries for an "int", whereas Image and most other languages use or
at least support 16-bit boundaries.  For example, if you have an Image
set with items:

    FOO1   I1,
    FOO2   I2, [...]

you occupy 48 bits of space - 16 for the I1 and 32 for the I2.  If you
try to define this in C/iX as a struct of (short foo1, int foo2), then
the C/iX compiler will add 16 bits after foo1 to pad the struct so that
foo2 is on a 32-bit boundary.

And no, unions don't work either (as far as I know); if you want to
deal with an 'int' in it's native form, you'll have to declare it as
a char[3] and memcpy() it to an int to deal with it (and don't forget
to copy it back before you update/put).

Jeff Kell <[log in to unmask]>