Re: Cannot get font metrics

[Behdad Esfahbod <behdad behdad org>]

Hi,

Things I can guess:

  - You have no fonts whatsoever on the machine?

  - You load pango using dlopen, then close it, then open again.

You may have more luck figuring out what's going on if you try it with pango 1.28.

behdad


On 05/12/2010 12:31 PM, Moore, Chad M wrote:
> Hi all,
>  
> I'm attempting to update OpenMotif to render text using Pango 1.14 and
> am having difficulties with font metrics.  I can successfully specify a
> font description via string, such as Sans 15, and render the text (looks
> awesome).  When I try to get the PangoFontMetrics (in order to get the
> average width, ascender, and descender) it appears to work on
> my one virtual machine but not on another, nor on a physical machine. 
> All three machines are RHEL 5.2.
>  
>  
> I'm only storing the PangoFontDescription * and try to use it later, as
> follows:
>  
> PangoFontMetrics * MY_GetFontMetrics( Display * display,
>                       PangoFontDescription * font )
>     PangoFontMetrics * metrics = 0;
>     PangoFontMap * fontmap =
> pango_cairo_font_map_get_default();                                      
>     if( fontmap )
>     {  
>         PangoContext * context
>             = pango_cairo_font_map_create_context( (PangoCairoFontMap
> *)fontmap );
>         if( context )
>         {  
>             pango_context_set_font_description( context, font );
>             PangoLanguage * lang = pango_language_from_string( "en_US"
> );  // also tried lang = NULL; same result
>             metrics = (PangoFontMetrics *)pango_context_get_metrics(
> context, font, lang );
>             g_object_unref( context );
>         }  
>     }  
>     return metrics;
> }
>  
>  
> Here's the error:
>  
> (process:6605): Pango-CRITICAL **: pango_font_map_load_fontset:
> assertion `fontmap != NULL' failed
>  
> (process:6605): Pango-CRITICAL **: pango_fontset_foreach: assertion
> `PANGO_IS_FONTSET (fontset)' failed
>  
> (process:6605): Pango-CRITICAL **: pango_font_map_load_fontset:
> assertion `fontmap != NULL' failed
>  
> (process:6605): GLib-GObject-CRITICAL **: g_object_get_qdata: assertion
> `G_IS_OBJECT (object)' failed
>  
> (process:6605): GLib-GObject-CRITICAL **: g_object_set_qdata_full:
> assertion `G_IS_OBJECT (object)' failed
>  
> (process:6605): Pango-CRITICAL **: pango_font_map_get_shape_engine_type:
> assertion `PANGO_IS_FONT_MAP (fontmap)' failed
>  
> (process:6605): GLib-CRITICAL **: g_quark_from_string: assertion `string
> != NULL' failed
> Segmentation fault (core dumped)
>  
> Here's the backtrace:
>  
> (gdb) where
> #0  0x001a6aca in strcmp () from /lib/libc.so.6
> #1  0x06277585 in pango_map_get_engine () from /usr/lib/libpango-1.0.so.0
> #2  0x0627775d in pango_find_map () from /usr/lib/libpango-1.0.so.0
> #3  0x0627a94a in pango_context_get_font_description () from
> /usr/lib/libpango-1.0.so.0
> #4  0x0627ab09 in pango_context_get_font_description () from
> /usr/lib/libpango-1.0.so.0
> #5  0x0627b688 in pango_context_get_metrics () from
> /usr/lib/libpango-1.0.so.0
> #6  0x00e6f979 in LoadFontMetrics (tf=0x9eac7f8) at TextF.c:6995
> #7  0x00e70500 in InitializeTextStruct (tf=0x9eac7f8) at TextF.c:7316
> #8  0x00e71540 in Initialize (request=0xbfcf8fb0, new_w=0x9eac7f8,
> args=0xbfcf9480, num_args=0xbfcf8f64)
>     at TextF.c:7837
> #9  0x06c23538 in XtCvtStringToCommandArgArray () from /usr/lib/libXt.so.6
> #10 0x06c23fa4 in _XtCreateHookObj () from /usr/lib/libXt.so.6
> #11 0x06c248bf in _XtCreateWidget () from /usr/lib/libXt.so.6
> #12 0x06c24c64 in XtCreateWidget () from /usr/lib/libXt.so.6
> #13 0x00e76a00 in XmCreateTextField (parent=0x9eb1650, name=0x9eb1650
> "0", arglist=0x9eb1650, argcount=166401616)
>     at TextF.c:10665
> #14 0x08048c4c in main (argc=1, argv=0xbfcf95a4) at XTest.C:97
> (gdb)
>  
> Hopefully, I just don't know what I'm doing and there's something I am
> overlooking.  Is there something else I need to retain in order to call
> these functions?  Any ideas?
>  
> Thanks!
>  
> Sincerely,
>  
>  
>  
> Chad Moore
> 
> 
> 
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