Ok, now I found the way to set the path I need for fonts - before calling ps_findfont() make a call like this:
<?php ps_set_parameter($psdoc, 'SearchPath', $fonts_dir); ?>
It works for pslib 0.4.1 version. (Looks like it didn't work in some earlier versions.)
(PECL ps >= 1.1.0)
ps_findfont — Loads a font
Loads a font for later use. Before text is output with a loaded font it must be set with ps_setfont(). This function needs the adobe font metric file in order to calculate the space used up by the characters. A font which is loaded within a page will only be available on that page. Fonts which are to be used in the complete document have to be loaded before the first call of ps_begin_page(). Calling ps_findfont() between pages will make that font available for all following pages.
The name of the afm file must be fontname.afm. If the font shall be embedded the file fontname.pfb containing the font outline must be present as well.
Calling ps_findfont() before the first page requires to output the postscript header which includes the BoundingBox for the whole document. Usually the BoundingBox is set with the first call of ps_begin_page() which now comes after ps_findfont(). Consequently the BoundingBox has not been set and a warning will be issued when ps_findfont() is called. In order to prevent this situation, one should call ps_set_parameter() to set the BoundingBox before ps_findfont() is called.
Resource identifier of the postscript file as returned by ps_new().
The name of the font.
ps_findfont() will try to load the file passed in the parameter encoding. Encoding files are of the same syntax as those used by dvips(1). They contain a font encoding vector (which is currently not used but must be present) and a list of extra ligatures to extend the list of ligatures derived from the afm file.
encoding can be NULL or the empty string if the default encoding (TeXBase1) shall be used.
If the encoding is set to builtin then there will be no reencoding and the font specific encoding will be used. This is very useful with symbol fonts.
If set to a value >0 the font will be embedded into the document. This requires the font outline (.pfb file) to be present.
Returns the identifier of the font or zero in case of an error. The identifier is a positive number.
I've found out that pslib is searching for fonts in its data dir (/usr/share/pslib). There is no way to change the search path now.
I found out that you must copy the <fontname>.afm files next to your php because it's searched there in default.
I found that my Postscript files were taking an incredibly long time to generate and the file sizes were abnormally large. The problem was that, everytime I chose to set a font I would call ps_findfont() followed by ps_setfont().
It seems that every time ps_findfont() is called, the font gets embedded in the file. To prevent this, I keep an array of fonts I've already loaded, keyed by the font name. When I go to set the font, I first check this array to see if I've already loaded the font, and, if so, return the resource handle from that array. Otherwise, I call ps_findfont() and store the handle in the array.
Note that, if your call to ps_findfont() occurs while inside a page, the font will not be available on other pages. To get around this I just clear out the array at the end of each page.
My PS file went from 10 M to 75 K, and the time to create the file went from around 15 seconds to less than 1 second.