harfbuzz/util/font-options.hh

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/*
* Copyright © 2011 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Google Author(s): Behdad Esfahbod
*/
#ifndef FONT_OPTIONS_HH
#define FONT_OPTIONS_HH
#include "face-options.hh"
#ifdef HAVE_FREETYPE
#include <hb-ft.h>
#endif
#include <hb-ot.h>
#define FONT_SIZE_UPEM 0x7FFFFFFF
#define FONT_SIZE_NONE 0
extern const unsigned DEFAULT_FONT_SIZE;
extern const unsigned SUBPIXEL_BITS;
struct font_options_t : face_options_t
{
~font_options_t ()
{
g_free (font_file);
free (variations);
g_free (font_funcs);
hb_font_destroy (font);
}
void add_options (option_parser_t *parser);
hb_font_t *get_font () const;
hb_variation_t *variations = nullptr;
unsigned int num_variations = 0;
int x_ppem = 0;
int y_ppem = 0;
double ptem = 0.;
unsigned int subpixel_bits = SUBPIXEL_BITS;
mutable double font_size_x = DEFAULT_FONT_SIZE;
mutable double font_size_y = DEFAULT_FONT_SIZE;
char *font_funcs = nullptr;
int ft_load_flags = 2;
private:
mutable hb_font_t *font = nullptr;
};
static struct supported_font_funcs_t {
char name[4];
void (*func) (hb_font_t *);
} supported_font_funcs[] =
{
#ifdef HAVE_FREETYPE
{"ft", hb_ft_font_set_funcs},
#endif
{"ot", hb_ot_font_set_funcs},
};
hb_font_t *
font_options_t::get_font () const
{
if (font)
return font;
auto *face = get_face ();
font = hb_font_create (face);
if (font_size_x == FONT_SIZE_UPEM)
font_size_x = hb_face_get_upem (face);
if (font_size_y == FONT_SIZE_UPEM)
font_size_y = hb_face_get_upem (face);
hb_font_set_ppem (font, x_ppem, y_ppem);
hb_font_set_ptem (font, ptem);
int scale_x = (int) scalbnf (font_size_x, subpixel_bits);
int scale_y = (int) scalbnf (font_size_y, subpixel_bits);
hb_font_set_scale (font, scale_x, scale_y);
hb_font_set_variations (font, variations, num_variations);
void (*set_font_funcs) (hb_font_t *) = nullptr;
if (!font_funcs)
{
set_font_funcs = supported_font_funcs[0].func;
}
else
{
for (unsigned int i = 0; i < ARRAY_LENGTH (supported_font_funcs); i++)
if (0 == g_ascii_strcasecmp (font_funcs, supported_font_funcs[i].name))
{
set_font_funcs = supported_font_funcs[i].func;
break;
}
if (!set_font_funcs)
{
GString *s = g_string_new (nullptr);
for (unsigned int i = 0; i < ARRAY_LENGTH (supported_font_funcs); i++)
{
if (i)
g_string_append_c (s, '/');
g_string_append (s, supported_font_funcs[i].name);
}
char *p = g_string_free (s, FALSE);
fail (false, "Unknown font function implementation `%s'; supported values are: %s; default is %s",
font_funcs,
p,
supported_font_funcs[0].name);
//free (p);
}
}
set_font_funcs (font);
#ifdef HAVE_FREETYPE
hb_ft_font_set_load_flags (font, ft_load_flags);
#endif
return font;
}
static gboolean
parse_variations (const char *name G_GNUC_UNUSED,
const char *arg,
gpointer data,
GError **error G_GNUC_UNUSED)
{
font_options_t *font_opts = (font_options_t *) data;
char *s = (char *) arg;
char *p;
font_opts->num_variations = 0;
g_free (font_opts->variations);
font_opts->variations = nullptr;
if (!*s)
return true;
/* count the variations first, so we can allocate memory */
p = s;
do {
font_opts->num_variations++;
p = strchr (p, ',');
if (p)
p++;
} while (p);
font_opts->variations = (hb_variation_t *) calloc (font_opts->num_variations, sizeof (*font_opts->variations));
if (!font_opts->variations)
return false;
/* now do the actual parsing */
p = s;
font_opts->num_variations = 0;
while (p && *p) {
char *end = strchr (p, ',');
if (hb_variation_from_string (p, end ? end - p : -1, &font_opts->variations[font_opts->num_variations]))
font_opts->num_variations++;
p = end ? end + 1 : nullptr;
}
return true;
}
static gboolean
parse_font_size (const char *name G_GNUC_UNUSED,
const char *arg,
gpointer data,
GError **error G_GNUC_UNUSED)
{
font_options_t *font_opts = (font_options_t *) data;
if (0 == strcmp (arg, "upem"))
{
font_opts->font_size_y = font_opts->font_size_x = FONT_SIZE_UPEM;
return true;
}
switch (sscanf (arg, "%lf%*[ ,]%lf", &font_opts->font_size_x, &font_opts->font_size_y)) {
case 1: font_opts->font_size_y = font_opts->font_size_x; HB_FALLTHROUGH;
case 2: return true;
default:
g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
"%s argument should be one or two space-separated numbers",
name);
return false;
}
}
static gboolean
parse_font_ppem (const char *name G_GNUC_UNUSED,
const char *arg,
gpointer data,
GError **error G_GNUC_UNUSED)
{
font_options_t *font_opts = (font_options_t *) data;
switch (sscanf (arg, "%d%*[ ,]%d", &font_opts->x_ppem, &font_opts->y_ppem)) {
case 1: font_opts->y_ppem = font_opts->x_ppem; HB_FALLTHROUGH;
case 2: return true;
default:
g_set_error (error, G_OPTION_ERROR, G_OPTION_ERROR_BAD_VALUE,
"%s argument should be one or two space-separated numbers",
name);
return false;
}
}
void
font_options_t::add_options (option_parser_t *parser)
{
face_options_t::add_options (parser);
char *text = nullptr;
{
static_assert ((ARRAY_LENGTH_CONST (supported_font_funcs) > 0),
"No supported font-funcs found.");
GString *s = g_string_new (nullptr);
g_string_printf (s, "Set font functions implementation to use (default: %s)\n\n Supported font function implementations are: %s",
supported_font_funcs[0].name,
supported_font_funcs[0].name);
for (unsigned int i = 1; i < ARRAY_LENGTH (supported_font_funcs); i++)
{
g_string_append_c (s, '/');
g_string_append (s, supported_font_funcs[i].name);
}
text = g_string_free (s, FALSE);
parser->free_later (text);
}
char *font_size_text;
if (DEFAULT_FONT_SIZE == FONT_SIZE_UPEM)
font_size_text = (char *) "Font size (default: upem)";
else
{
font_size_text = g_strdup_printf ("Font size (default: %d)", DEFAULT_FONT_SIZE);
parser->free_later (font_size_text);
}
int font_size_flags = DEFAULT_FONT_SIZE == FONT_SIZE_NONE ? G_OPTION_FLAG_HIDDEN : 0;
GOptionEntry entries[] =
{
{"font-size", 0, font_size_flags,
G_OPTION_ARG_CALLBACK, (gpointer) &parse_font_size, font_size_text, "1/2 integers or 'upem'"},
{"font-ppem", 0, font_size_flags,
G_OPTION_ARG_CALLBACK, (gpointer) &parse_font_ppem, "Set x,y pixels per EM (default: 0; disabled)", "1/2 integers"},
{"font-ptem", 0, 0,
G_OPTION_ARG_DOUBLE, &this->ptem, "Set font point-size (default: 0; disabled)", "point-size"},
{"font-funcs", 0, 0, G_OPTION_ARG_STRING, &this->font_funcs, text, "impl"},
{"ft-load-flags", 0, 0, G_OPTION_ARG_INT, &this->ft_load_flags, "Set FreeType load-flags (default: 2)", "integer"},
{nullptr}
};
parser->add_group (entries,
"font",
"Font-instance options:",
"Options for the font instance",
this);
const gchar *variations_help = "Comma-separated list of font variations\n"
"\n"
" Variations are set globally. The format for specifying variation settings\n"
" follows. All valid CSS font-variation-settings values other than 'normal'\n"
" and 'inherited' are also accepted, though, not documented below.\n"
"\n"
" The format is a tag, optionally followed by an equals sign, followed by a\n"
" number. For example:\n"
"\n"
" \"wght=500\"\n"
" \"slnt=-7.5\"\n";
GOptionEntry entries2[] =
{
{"variations", 0, 0, G_OPTION_ARG_CALLBACK, (gpointer) &parse_variations, variations_help, "list"},
{nullptr}
};
parser->add_group (entries2,
"variations",
"Variations options:",
"Options for font variations used",
this);
}
#endif