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gimp/app/text/gimpfont.c

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/* GIMP - The GNU Image Manipulation Program
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* gimpfont.c
* Copyright (C) 2003 Michael Natterer <mitch@gimp.org>
* Sven Neumann <sven@gimp.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>
#include <pango/pangocairo.h>
#include <hb.h>
#include <hb-ot.h>
#include <hb-ft.h>
#define PANGO_ENABLE_ENGINE 1 /* Argh */
#include <pango/pango-ot.h>
#include <ft2build.h>
#include FT_TRUETYPE_TABLES_H
#include "text-types.h"
#include "core/gimptempbuf.h"
#include "gimpfont.h"
#include "gimp-intl.h"
/* This is a so-called pangram; it's supposed to
contain all characters found in the alphabet. */
#define GIMP_TEXT_PANGRAM N_("Pack my box with\nfive dozen liquor jugs.")
#define GIMP_FONT_POPUP_SIZE (PANGO_SCALE * 30)
#define DEBUGPRINT(x) /* g_print x */
enum
{
PROP_0,
PROP_PANGO_CONTEXT
};
struct _GimpFont
{
GimpViewable parent_instance;
PangoContext *pango_context;
PangoLayout *popup_layout;
gint popup_width;
gint popup_height;
};
struct _GimpFontClass
{
GimpViewableClass parent_class;
};
static void gimp_font_finalize (GObject *object);
static void gimp_font_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
static void gimp_font_get_preview_size (GimpViewable *viewable,
gint size,
gboolean popup,
gboolean dot_for_dot,
gint *width,
gint *height);
static gboolean gimp_font_get_popup_size (GimpViewable *viewable,
gint width,
gint height,
gboolean dot_for_dot,
gint *popup_width,
gint *popup_height);
static GimpTempBuf * gimp_font_get_new_preview (GimpViewable *viewable,
GimpContext *context,
gint width,
gint height);
static const gchar * gimp_font_get_sample_string (PangoContext *context,
PangoFontDescription *font_desc);
G_DEFINE_TYPE (GimpFont, gimp_font, GIMP_TYPE_VIEWABLE)
#define parent_class gimp_font_parent_class
static void
gimp_font_class_init (GimpFontClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GimpViewableClass *viewable_class = GIMP_VIEWABLE_CLASS (klass);
object_class->finalize = gimp_font_finalize;
object_class->set_property = gimp_font_set_property;
viewable_class->get_preview_size = gimp_font_get_preview_size;
viewable_class->get_popup_size = gimp_font_get_popup_size;
viewable_class->get_new_preview = gimp_font_get_new_preview;
viewable_class->default_icon_name = "gtk-select-font";
g_object_class_install_property (object_class, PROP_PANGO_CONTEXT,
g_param_spec_object ("pango-context",
NULL, NULL,
PANGO_TYPE_CONTEXT,
GIMP_PARAM_WRITABLE));
}
static void
gimp_font_init (GimpFont *font)
{
font->pango_context = NULL;
}
static void
gimp_font_finalize (GObject *object)
{
GimpFont *font = GIMP_FONT (object);
g_clear_object (&font->pango_context);
g_clear_object (&font->popup_layout);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gimp_font_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GimpFont *font = GIMP_FONT (object);
switch (property_id)
{
case PROP_PANGO_CONTEXT:
if (font->pango_context)
g_object_unref (font->pango_context);
font->pango_context = g_value_dup_object (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
gimp_font_get_preview_size (GimpViewable *viewable,
gint size,
gboolean popup,
gboolean dot_for_dot,
gint *width,
gint *height)
{
*width = size;
*height = size;
}
static gboolean
gimp_font_get_popup_size (GimpViewable *viewable,
gint width,
gint height,
gboolean dot_for_dot,
gint *popup_width,
gint *popup_height)
{
GimpFont *font = GIMP_FONT (viewable);
PangoFontDescription *font_desc;
PangoRectangle ink;
PangoRectangle logical;
const gchar *name;
if (! font->pango_context)
return FALSE;
name = gimp_object_get_name (font);
font_desc = pango_font_description_from_string (name);
g_return_val_if_fail (font_desc != NULL, FALSE);
pango_font_description_set_size (font_desc, GIMP_FONT_POPUP_SIZE);
if (font->popup_layout)
g_object_unref (font->popup_layout);
font->popup_layout = pango_layout_new (font->pango_context);
pango_layout_set_font_description (font->popup_layout, font_desc);
pango_font_description_free (font_desc);
pango_layout_set_text (font->popup_layout, gettext (GIMP_TEXT_PANGRAM), -1);
pango_layout_get_pixel_extents (font->popup_layout, &ink, &logical);
*popup_width = MAX (ink.width, logical.width) + 6;
*popup_height = MAX (ink.height, logical.height) + 6;
*popup_width = cairo_format_stride_for_width (CAIRO_FORMAT_A8, *popup_width);
font->popup_width = *popup_width;
font->popup_height = *popup_height;
return TRUE;
}
static GimpTempBuf *
gimp_font_get_new_preview (GimpViewable *viewable,
GimpContext *context,
gint width,
gint height)
{
GimpFont *font = GIMP_FONT (viewable);
PangoLayout *layout;
PangoRectangle ink;
PangoRectangle logical;
gint layout_width;
gint layout_height;
gint layout_x;
gint layout_y;
GimpTempBuf *temp_buf;
cairo_t *cr;
cairo_surface_t *surface;
if (! font->pango_context)
return NULL;
if (! font->popup_layout ||
font->popup_width != width || font->popup_height != height)
{
PangoFontDescription *font_desc;
const gchar *name;
name = gimp_object_get_name (font);
DEBUGPRINT (("%s: ", name));
font_desc = pango_font_description_from_string (name);
g_return_val_if_fail (font_desc != NULL, NULL);
pango_font_description_set_size (font_desc,
PANGO_SCALE * height * 2.0 / 3.0);
layout = pango_layout_new (font->pango_context);
pango_layout_set_font_description (layout, font_desc);
pango_layout_set_text (layout,
gimp_font_get_sample_string (font->pango_context,
font_desc),
-1);
pango_font_description_free (font_desc);
}
else
{
layout = g_object_ref (font->popup_layout);
}
width = cairo_format_stride_for_width (CAIRO_FORMAT_A8, width);
temp_buf = gimp_temp_buf_new (width, height, babl_format ("Y' u8"));
memset (gimp_temp_buf_get_data (temp_buf), 255, width * height);
surface = cairo_image_surface_create_for_data (gimp_temp_buf_get_data (temp_buf),
CAIRO_FORMAT_A8,
width, height, width);
pango_layout_get_pixel_extents (layout, &ink, &logical);
layout_width = MAX (ink.width, logical.width);
layout_height = MAX (ink.height, logical.height);
layout_x = (width - layout_width) / 2;
layout_y = (height - layout_height) / 2;
if (ink.x < logical.x)
layout_x += logical.x - ink.x;
if (ink.y < logical.y)
layout_y += logical.y - ink.y;
cr = cairo_create (surface);
cairo_translate (cr, layout_x, layout_y);
cairo_set_operator (cr, CAIRO_OPERATOR_CLEAR);
pango_cairo_show_layout (cr, layout);
cairo_destroy (cr);
cairo_surface_destroy (surface);
g_object_unref (layout);
return temp_buf;
}
GimpFont *
gimp_font_get_standard (void)
{
static GimpFont *standard_font = NULL;
if (! standard_font)
standard_font = g_object_new (GIMP_TYPE_FONT,
"name", "Sans-serif",
NULL);
return standard_font;
}
static inline gboolean
gimp_font_covers_string (PangoFcFont *font,
const gchar *sample)
{
const gchar *p;
for (p = sample; *p; p = g_utf8_next_char (p))
{
if (! pango_fc_font_has_char (font, g_utf8_get_char (p)))
return FALSE;
}
return TRUE;
}
/* This function was picked up from Pango's pango-ot-info.c. Until there
* is a better way to get the tag, we use this.
*/
static hb_tag_t
get_hb_table_type (PangoOTTableType table_type)
{
switch (table_type)
{
case PANGO_OT_TABLE_GSUB:
return HB_OT_TAG_GSUB;
case PANGO_OT_TABLE_GPOS:
return HB_OT_TAG_GPOS;
default:
return HB_TAG_NONE;
}
}
/* Guess a suitable short sample string for the font. */
static const gchar *
gimp_font_get_sample_string (PangoContext *context,
PangoFontDescription *font_desc)
{
PangoFont *font;
hb_face_t *hb_face;
FT_Face face;
TT_OS2 *os2;
PangoOTTableType tt;
gint i;
/* 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 const struct
{
const gchar script[4];
gint 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"
}
};
gint ot_alts[4];
gint n_ot_alts = 0;
gint sr_alts[20];
gint n_sr_alts = 0;
font = pango_context_load_font (context, font_desc);
g_return_val_if_fail (PANGO_IS_FC_FONT (font), "Aa");
face = pango_fc_font_lock_face (PANGO_FC_FONT (font));
g_return_val_if_fail (face != NULL, "Aa");
hb_face = hb_ft_face_create (face, NULL);
/* 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++)
{
hb_tag_t tag;
unsigned int count;
PangoOTTag *slist;
tag = get_hb_table_type (tt);
count = hb_ot_layout_table_get_script_tags (hb_face, tag, 0, NULL, NULL);
slist = g_new (PangoOTTag, count + 1);
hb_ot_layout_table_get_script_tags (hb_face, tag, 0, &count, slist);
slist[count] = 0;
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) &&
gimp_font_covers_string (PANGO_FC_FONT (font),
scripts[i].sample))
{
ot_alts[n_ot_alts++] = i;
DEBUGPRINT (("%.4s ", scripts[i].script));
}
#undef TAG
}
}
}
g_free (slist);
}
hb_face_destroy (hb_face);
DEBUGPRINT (("; OS/2: "));
/* Next check the OS/2 table for Unicode ranges the font claims
* to cover.
*/
os2 = FT_Get_Sfnt_Table (face, ft_sfnt_os2);
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)) &&
gimp_font_covers_string (PANGO_FC_FONT (font),
scripts[i].sample))
{
sr_alts[n_sr_alts++] = i;
DEBUGPRINT (("%.4s ", scripts[i].script));
}
}
}
pango_fc_font_unlock_face (PANGO_FC_FONT (font));
g_object_unref (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"));
return "Aa";
}
}
if (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"));
return "Aa";
}
DEBUGPRINT (("=> several SR, use %.4s\n", scripts[sr_alts[0]].script));
return scripts[sr_alts[0]].sample;
}
if (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));
return scripts[ot_alts[0]].sample;
}
if (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));
return scripts[sr_alts[0]].sample;
}
/* Final fallback */
DEBUGPRINT (("=> fallback, use Aa\n"));
return "Aa";
}
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