Re: [Plplot-devel] gd driver and dlopen() flags

[Maurice L. <mj...@ga...>]

Alan W. Irwin writes:
 > (2) Now that I have looked at the logic, I believe it needs changing some
 > more. I think Joao's system may be typical; a "parent" path to get to the
 > area where fonts occur with subdirectories/font files you would like to try.
 > The current logic (once some additional bogus logic is fixed) says if there
 > is a slash *anywhere* in the font file environment variable than treat it as
 > a complete path plus file name and ignore the font path altogether. Instead,
 > at least for the Unix side of things I would prefer to concatanate the font
 > path and font name string *always* except for the one narrow exception where
 > there is a *leading* slash on the font name.  This way you can comfortably
 > and flexibly deal with subdirectories in the font name, but if you really
 > want to specify absolute path+font file name, you are allowed to do so.

Agreed.  I vaguely noted that the current solution wasn't optimal, but like
you was trying to just get it working so I could play with it.  Having access
to an alternate font rendering engine is really nice, and is helping me debug
something I've been wanting to add for a long time -- storing strings as
strings in the metafile.  Then in principle you can do all kinds of cool
things with them in the renderer.

 > Note, I am right at the bleeding edge of my C skills here about dealing
 > with pointers for the
 > 
 > if (strchr(a,'/')!=NULL && *strchr(a,'/')==0)
 > 
 > statement so please correct that if wrong.  The point is that test should
 > succeed only if there is a leading "/" for the environment variable string,
 > a.  The only thing I have done to the DJGPP and MSDOS logic is replace the
 > FT->font_name[i] which has not been assigned a value, yet with the
 > environment variable string, a.

The second test won't ever succeed since the pointer value can't be zero.
But you could do pointer arithmetic:

if ( strchr(a,'/') && ( (strchr(a,'/') - a) == 0 ) )

(subtracting pointers is safe).  Also note it's good style (arguable but most
agree) to omit the test against NULL in the first expression.

But even simpler would be:

if (a[0] == '/')

:)

 > (3) What is the Unix standard for file name length when you are potentially
 > dealing with the complete path + file name?  I am uncomfortable with the
 > small (80-character) size of FT->font_name at the moment, and would like to
 > change it to something much larger and preferably the standard if somebody
 > could tell me what that is.

80 chars is way too short.  A limit like 1024 chars is much more appropriate.

-- 
Maurice LeBrun    mj...@ga...
Research Organization for Information Science and Technology of Japan (RIST)