🚀 go-pugleaf

In article <1991Jun3.151557.10753@forwiss.uni-passau.de> fraus@forwiss.uni-passau.de (Uli Fraus) writes:
> So maybe the variable inch (from file defs.h) is initialized by defining 
> a World variable.

Precisely.

> Is this a bug or a feature???

It's a bug or a feature, depending on how you look at it.  :-)

The global variable "inch" is set by the InterViews library to be the
number of *pixels* per inch in a *particular* World, i.e. X display.  Since
display resolutions differ widely, this variable can't be set until a World
has been created (establishing a connection to an X server, which can
provide appropriate information about resolution).

> How is it possible to have (global) constants based on 'inch'?

It isn't, but is that what you really want?  If you use a hard constant,
your software will only work at one resolution.  If you use inch instead
(or something based on inch), things should scale nicely.

In my Reconfig functions, I frequently begin with a statement like:

    const Coord spacer = round(inch/4);

I then use spacer to express the Shape's of other components.  This works
fine because Reconfig can't (well... never should) be called before a World
has been created.

Why is this a bug and not just a feature?  It is possible to have two
Worlds with different resolutions.  I've never had to worry about this,
myself.

--
Glenn P. Parker       glenn@bitstream.com       Bitstream, Inc.
                      uunet!huxley!glenn        215 First Street
                      BIX: parker               Cambridge, MA 02142-1270