Commit 0cd9648a authored by Tor Lillqvist's avatar Tor Lillqvist Committed by Tor Lillqvist

Provide script-specific short sample strings instead of "Aa" for fonts

2006-04-04  Tor Lillqvist  <tml@novell.com>

	* app/text/gimpfont.c (gimp_font_get_new_preview): Provide
	script-specific short sample strings instead of "Aa" for fonts
	that seem to be designed for some specific non-Latin
	script. Pending a complete redesign and reimplementation of
	font selection, this is at least an improvement, and a partial
	solution to #137624.
parent bde662b2
2006-04-04 Tor Lillqvist <tml@novell.com>
* app/text/gimpfont.c (gimp_font_get_new_preview): Provide
script-specific short sample strings instead of "Aa" for fonts
that seem to be designed for some specific non-Latin
script. Pending a complete redesign and reimplementation of font
selection, this is at least an improvement, and a partial solution
to #137624.
2006-04-04 Michael Natterer <mitch@gimp.org>
* app/plug-in/plug-in-params.c (plug_in_params_to_args): don't
......
......@@ -24,6 +24,9 @@
#include <glib-object.h>
#include <pango/pangoft2.h>
#define PANGO_ENABLE_ENGINE 1 /* Argh */
#include <pango/pango-ot.h>
#include <freetype/tttables.h>
#include "text-types.h"
......@@ -40,6 +43,7 @@
#define GIMP_FONT_POPUP_SIZE (PANGO_SCALE * 30)
#define DEBUGPRINT(x) /* g_print x */
enum
{
......@@ -236,6 +240,279 @@ gimp_font_get_new_preview (GimpViewable *viewable,
guchar *p;
guchar black = 0;
/* This is a table of scripts and corresponding short sample strings
* to be used instead of the Latin sample string Aa. The script
* codes are as in ISO15924 (see
* http://www.unicode.org/iso15924/iso15924-codes.html), but in
* lower case. The Unicode subrange bit numbers, as used in TrueType
* so-called OS/2 tables, are from
* http://www.microsoft.com/typography/otspec/os2.htm#ur .
*
* The table is mostly ordered by Unicode order. But as there are
* fonts that support several of these scripts, the ordering is
* be modified so that the script which such a font is more likely
* to be actually designed for comes first and matches.
*
* These sample strings are mostly just guesswork as for their
* usefulness. Usually they contain what I assume is the first
* letter in the corresponding alphabet, or two first letters if the
* first one happens to look too "trivial" to be recognizable by
* itself.
*
* This table is used to determine the primary script a font has
* been designed for.
*
* Very useful link: http://www.travelphrases.info/fonts.html
*/
static struct {
const gchar script[4];
int bit;
const gchar *sample;
} scripts[] = {
/* Han is first because fonts that support it presumably are primarily
* designed for it.
*/
{
"hani", /* Han Ideographic */
59,
"\346\260\270" /* U+6C38 "forever". Ed Trager says
* this is a "pan-stroke" often used
* in teaching Chinese calligraphy. It
* contains the eight basic Chinese
* stroke forms.
*/
},
{
"copt", /* Coptic */
7,
"\316\221\316\261" /* U+0410 GREEK CAPITAL LETTER ALPHA
U+0430 GREEK SMALL LETTER ALPHA
*/
},
{
"grek", /* Greek */
7,
"\316\221\316\261" /* U+0410 GREEK CAPITAL LETTER ALPHA
U+0430 GREEK SMALL LETTER ALPHA
*/
},
{
"cyrl", /* Cyrillic */
9,
"\320\220\325\260" /* U+0410 CYRILLIC CAPITAL LETTER A
U+0430 CYRILLIC SMALL LETTER A
*/
},
{
"armn", /* Armenian */
10,
"\324\261\325\241" /* U+0531 ARMENIAN CAPITAL LETTER AYB
U+0561 ARMENIAN SMALL LETTER AYB
*/
},
{
"hebr", /* Hebrew */
11,
"\327\220" /* U+05D0 HEBREW LETTER ALEF */
},
{
"arab", /* Arabic */
13,
"\330\247\330\250" /* U+0627 ARABIC LETTER ALEF
* U+0628 ARABIC LETTER BEH
*/
},
{
"syrc", /* Syriac */
71,
"\334\220\334\222" /* U+0710 SYRIAC LETTER ALAPH
* U+0712 SYRIAC LETTER BETH
*/
},
{
"thaa", /* Thaana */
72,
"\336\200\336\201" /* U+0780 THAANA LETTER HAA
* U+0781 THAANA LETTER SHAVIYANI
*/
},
/* Should really use some better sample strings for the complex
* scripts. Something that shows how well the font handles the
* complex processing for each script.
*/
{
"deva", /* Devanagari */
15,
"\340\244\205" /* U+0905 DEVANAGARI LETTER A*/
},
{
"beng", /* Bengali */
16,
"\340\246\205" /* U+0985 BENGALI LETTER A */
},
{
"guru", /* Gurmukhi */
17,
"\340\250\205" /* U+0A05 GURMUKHI LETTER A */
},
{
"gujr", /* Gujarati */
18,
"\340\252\205" /* U+0A85 GUJARATI LETTER A */
},
{
"orya", /* Oriya */
19,
"\340\254\205" /* U+0B05 ORIYA LETTER A */
},
{
"taml", /* Tamil */
20,
"\340\256\205" /* U+0B85 TAMIL LETTER A */
},
{
"telu", /* Telugu */
21,
"\340\260\205" /* U+0C05 TELUGU LETTER A */
},
{
"knda", /* Kannada */
22,
"\340\262\205" /* U+0C85 KANNADA LETTER A */
},
{
"mylm", /* Malayalam */
23,
"\340\264\205" /* U+0D05 MALAYALAM LETTER A */
},
{
"sinh", /* Sinhala */
73,
"\340\266\205" /* U+0D85 SINHALA LETTER AYANNA */
},
{
"thai", /* Thai */
24,
"\340\270\201\340\270\264"/* U+0E01 THAI CHARACTER KO KAI
* U+0E34 THAI CHARACTER SARA I
*/
},
{
"laoo", /* Lao */
25,
"\340\272\201\340\272\264"/* U+0E81 LAO LETTER KO
* U+0EB4 LAO VOWEL SIGN I
*/
},
{
"tibt", /* Tibetan */
70,
"\340\274\200" /* U+0F00 TIBETAN SYLLABLE OM */
},
{
"mymr", /* Myanmar */
74,
"\341\200\200" /* U+1000 MYANMAR LETTER KA */
},
{
"geor", /* Georgian */
26,
"\341\202\240\341\203\200" /* U+10A0 GEORGIAN CAPITAL LETTER AN
* U+10D0 GEORGIAN LETTER AN
*/
},
{
"hang", /* Hangul */
28,
"\341\204\200\341\204\201"/* U+1100 HANGUL CHOSEONG KIYEOK
* U+1101 HANGUL CHOSEONG SSANGKIYEOK
*/
},
{
"ethi", /* Ethiopic */
75,
"\341\210\200" /* U+1200 ETHIOPIC SYLLABLE HA */
},
{
"cher", /* Cherokee */
76,
"\341\216\243" /* U+13A3 CHEROKEE LETTER O */
},
{
"cans", /* Unified Canadian Aboriginal Syllabics */
77,
"\341\220\201" /* U+1401 CANADIAN SYLLABICS E */
},
{
"ogam", /* Ogham */
78,
"\341\232\201" /* U+1681 OGHAM LETTER BEITH */
},
{
"runr", /* Runic */
79,
"\341\232\240" /* U+16A0 RUNIC LETTER FEHU FEOH FE F */
},
{
"tglg", /* Tagalog */
84,
"\341\234\200" /* U+1700 TAGALOG LETTER A */
},
{
"hano", /* Hanunoo */
-1,
"\341\234\240" /* U+1720 HANUNOO LETTER A */
},
{
"buhd", /* Buhid */
-1,
"\341\235\200" /* U+1740 BUHID LETTER A */
},
{
"tagb", /* Tagbanwa */
-1,
"\341\235\240" /* U+1760 TAGBANWA LETTER A */
},
{
"khmr", /* Khmer */
80,
"\341\236\201\341\237\222\341\236\211\341\236\273\341\237\206"
/* U+1781 KHMER LETTER KHA
* U+17D2 KHMER LETTER SIGN COENG
* U+1789 KHMER LETTER NYO
* U+17BB KHMER VOWEL SIGN U
* U+17C6 KHMER SIGN NIKAHIT
* A common word meaning "I" that contains
* lots of complex processing.
*/
},
{
"mong", /* Mongolian */
81,
"\341\240\240" /* U+1820 MONGOLIAN LETTER A */
},
{
"limb", /* Limbu */
-1,
"\341\244\201" /* U+1901 LIMBU LETTER KA */
},
{
"tale", /* Tai Le */
-1,
"\341\245\220" /* U+1950 TAI LE LETTER KA */
},
{
"latn", /* Latin */
0,
"Aa"
}
};
int ot_alts[4];
int n_ot_alts = 0;
int sr_alts[20];
int n_sr_alts = 0;
if (! font->pango_context)
return NULL;
......@@ -243,11 +520,18 @@ gimp_font_get_new_preview (GimpViewable *viewable,
font->popup_width != width ||
font->popup_height != height)
{
PangoFont *pango_font;
PangoOTInfo *ot_info;
PangoFontDescription *font_desc;
const gchar *name;
PangoOTTableType tt;
const gchar *short_sample = NULL;
gint i;
name = gimp_object_get_name (GIMP_OBJECT (font));
DEBUGPRINT (("%s: ", name));
font_desc = pango_font_description_from_string (name);
g_return_val_if_fail (font_desc != NULL, NULL);
......@@ -256,9 +540,156 @@ gimp_font_get_new_preview (GimpViewable *viewable,
layout = pango_layout_new (font->pango_context);
pango_layout_set_font_description (layout, font_desc);
/* Guess a suitable short sample string for the font. */
pango_font = pango_context_load_font (font->pango_context,
font_desc);
ot_info = pango_ot_info_get (pango_ft2_font_get_face (pango_font));
/* First check what script(s), if any, the font has GSUB or GPOS
* OpenType layout tables for.
*/
for (tt = PANGO_OT_TABLE_GSUB;
n_ot_alts < G_N_ELEMENTS (ot_alts) && tt <= PANGO_OT_TABLE_GPOS;
tt++)
{
PangoOTTag *slist = pango_ot_info_list_scripts (ot_info, tt);
if (slist)
{
for (i = 0;
n_ot_alts < G_N_ELEMENTS (ot_alts) && i < G_N_ELEMENTS (scripts);
i++)
{
gint j, k;
for (k = 0; k < n_ot_alts; k++)
if (ot_alts[k] == i)
break;
if (k == n_ot_alts)
for (j = 0;
n_ot_alts < G_N_ELEMENTS (ot_alts) && slist[j];
j++)
{
#define TAG(s) FT_MAKE_TAG (s[0], s[1], s[2], s[3])
if (slist[j] == TAG (scripts[i].script))
{
ot_alts[n_ot_alts++] = i;
DEBUGPRINT (("%.4s ", scripts[i].script));
}
#undef TAG
}
}
g_free (slist);
}
}
DEBUGPRINT (("; OS/2: "));
/* Next check the OS/2 table for Unicode ranges the font claims
* to cover.
*/
if (PANGO_IS_FC_FONT (pango_font))
{
FT_Face face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font));
TT_OS2 *os2 = FT_Get_Sfnt_Table (face, ft_sfnt_os2);
gint i;
if (os2)
{
for (i = 0;
n_sr_alts < G_N_ELEMENTS (sr_alts) && i < G_N_ELEMENTS (scripts);
i++)
{
if (scripts[i].bit >= 0 &&
(&os2->ulUnicodeRange1)[scripts[i].bit/32] & (1 << (scripts[i].bit % 32)))
{
sr_alts[n_sr_alts++] = i;
DEBUGPRINT (("%.4s ", scripts[i].script));
}
}
}
pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
}
g_object_unref (pango_font);
if (n_ot_alts > 2)
{
/* The font has OpenType tables for several scripts. If it
* support Basic Latin as well, use Aa.
*/
gint i;
for (i = 0; i < n_sr_alts; i++)
if (scripts[sr_alts[i]].bit == 0)
{
DEBUGPRINT (("=> several OT, also latin, use Aa\n"));
short_sample = "Aa";
break;
}
}
if (! short_sample && n_ot_alts > 0 && n_sr_alts >= n_ot_alts + 3)
{
/* At least one script with an OpenType table, but many more
* subranges than such scripts. If it supports Basic Latin,
* use Aa, else the highest priority subrange.
*/
gint i;
for (i = 0; i < n_sr_alts; i++)
if (scripts[sr_alts[i]].bit == 0)
{
DEBUGPRINT (("=> several SR, also latin, use Aa\n"));
short_sample = "Aa";
break;
}
if (! short_sample)
{
DEBUGPRINT (("=> several SR, use %.4s\n", scripts[sr_alts[0]].script));
short_sample = scripts[sr_alts[0]].sample;
}
}
if (! short_sample && n_ot_alts > 0)
{
/* OpenType tables for at least one script, use the
* highest priority one
*/
DEBUGPRINT (("=> at least one OT, use %.4s\n", scripts[sr_alts[0]].script));
short_sample = scripts[ot_alts[0]].sample;
}
if (! short_sample && n_sr_alts > 0)
{
/* Use the highest priority subrange. This means that a
* font that supports Greek, Cyrillic and Latin (quite
* common), will get the Greek sample string. That is
* capital and lowercase alpha, which looks like capital A
* and lowercase alpha, so it's actually quite nice, and
* doesn't give a too strong impression that the font would
* be for Greek only.
*/
DEBUGPRINT (("=> at least one SR, use %.4s\n", scripts[sr_alts[0]].script));
short_sample = scripts[sr_alts[0]].sample;
}
/* Final fallback */
if (! short_sample)
{
DEBUGPRINT (("=> fallback, use Aa\n"));
short_sample = "Aa";
}
pango_font_description_free (font_desc);
pango_layout_set_text (layout, "Aa", -1);
pango_layout_set_text (layout, short_sample, -1);
}
else
{
......
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