harfbuzz/src/hb-font.cc

964 lines
22 KiB
C++

/*
* Copyright © 2009 Red Hat, 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.
*
* Red Hat Author(s): Behdad Esfahbod
*/
#include "hb-private.hh"
#include "hb-ot-layout-private.hh"
#include "hb-font-private.hh"
#include "hb-blob.h"
#include "hb-open-file-private.hh"
#include "hb-ot-head-table.hh"
#include <string.h>
/*
* hb_font_funcs_t
*/
static hb_bool_t
hb_font_get_glyph_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t unicode,
hb_codepoint_t variation_selector,
hb_codepoint_t *glyph,
void *user_data HB_UNUSED)
{
if (font->parent)
return hb_font_get_glyph (font->parent, unicode, variation_selector, glyph);
*glyph = 0;
return FALSE;
}
static hb_position_t
hb_font_get_glyph_h_advance_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
void *user_data HB_UNUSED)
{
if (font->parent)
return font->parent_scale_x_distance (hb_font_get_glyph_h_advance (font->parent, glyph));
return font->x_scale;
}
static hb_position_t
hb_font_get_glyph_v_advance_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
void *user_data HB_UNUSED)
{
if (font->parent)
return font->parent_scale_y_distance (hb_font_get_glyph_v_advance (font->parent, glyph));
return font->y_scale;
}
static hb_bool_t
hb_font_get_glyph_h_origin_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
if (font->parent) {
hb_bool_t ret = hb_font_get_glyph_h_origin (font->parent,
glyph,
x, y);
if (ret)
font->parent_scale_position (x, y);
return ret;
}
*x = *y = 0;
return FALSE;
}
static hb_bool_t
hb_font_get_glyph_v_origin_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
if (font->parent) {
hb_bool_t ret = hb_font_get_glyph_v_origin (font->parent,
glyph,
x, y);
if (ret)
font->parent_scale_position (x, y);
return ret;
}
*x = *y = 0;
return FALSE;
}
static hb_position_t
hb_font_get_glyph_h_kerning_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t left_glyph,
hb_codepoint_t right_glyph,
void *user_data HB_UNUSED)
{
if (font->parent)
return font->parent_scale_x_distance (hb_font_get_glyph_h_kerning (font->parent, left_glyph, right_glyph));
return 0;
}
static hb_position_t
hb_font_get_glyph_v_kerning_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t top_glyph,
hb_codepoint_t bottom_glyph,
void *user_data HB_UNUSED)
{
if (font->parent)
return font->parent_scale_y_distance (hb_font_get_glyph_v_kerning (font->parent, top_glyph, bottom_glyph));
return 0;
}
static hb_bool_t
hb_font_get_glyph_extents_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
hb_glyph_extents_t *extents,
void *user_data HB_UNUSED)
{
if (font->parent) {
hb_bool_t ret = hb_font_get_glyph_extents (font->parent,
glyph,
extents);
if (ret) {
font->parent_scale_position (&extents->x_bearing, &extents->y_bearing);
font->parent_scale_distance (&extents->width, &extents->height);
}
return ret;
}
memset (extents, 0, sizeof (*extents));
return FALSE;
}
static hb_bool_t
hb_font_get_glyph_contour_point_nil (hb_font_t *font HB_UNUSED,
void *font_data HB_UNUSED,
hb_codepoint_t glyph,
unsigned int point_index,
hb_position_t *x,
hb_position_t *y,
void *user_data HB_UNUSED)
{
if (font->parent) {
hb_bool_t ret = hb_font_get_glyph_contour_point (font->parent,
glyph, point_index,
x, y);
if (ret)
font->parent_scale_position (x, y);
return ret;
}
*x = *y = 0;
return FALSE;
}
static hb_font_funcs_t _hb_font_funcs_nil = {
HB_OBJECT_HEADER_STATIC,
TRUE, /* immutable */
{
#define HB_FONT_FUNC_IMPLEMENT(name) hb_font_get_##name##_nil,
HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_FONT_FUNC_IMPLEMENT
}
};
hb_font_funcs_t *
hb_font_funcs_create (void)
{
hb_font_funcs_t *ffuncs;
if (!(ffuncs = hb_object_create<hb_font_funcs_t> ()))
return &_hb_font_funcs_nil;
ffuncs->get = _hb_font_funcs_nil.get;
return ffuncs;
}
hb_font_funcs_t *
hb_font_funcs_get_empty (void)
{
return &_hb_font_funcs_nil;
}
hb_font_funcs_t *
hb_font_funcs_reference (hb_font_funcs_t *ffuncs)
{
return hb_object_reference (ffuncs);
}
void
hb_font_funcs_destroy (hb_font_funcs_t *ffuncs)
{
if (!hb_object_destroy (ffuncs)) return;
#define HB_FONT_FUNC_IMPLEMENT(name) if (ffuncs->destroy.name) \
ffuncs->destroy.name (ffuncs->user_data.name);
HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_FONT_FUNC_IMPLEMENT
free (ffuncs);
}
hb_bool_t
hb_font_funcs_set_user_data (hb_font_funcs_t *ffuncs,
hb_user_data_key_t *key,
void * data,
hb_destroy_func_t destroy,
hb_bool_t replace)
{
return hb_object_set_user_data (ffuncs, key, data, destroy, replace);
}
void *
hb_font_funcs_get_user_data (hb_font_funcs_t *ffuncs,
hb_user_data_key_t *key)
{
return hb_object_get_user_data (ffuncs, key);
}
void
hb_font_funcs_make_immutable (hb_font_funcs_t *ffuncs)
{
if (hb_object_is_inert (ffuncs))
return;
ffuncs->immutable = TRUE;
}
hb_bool_t
hb_font_funcs_is_immutable (hb_font_funcs_t *ffuncs)
{
return ffuncs->immutable;
}
#define HB_FONT_FUNC_IMPLEMENT(name) \
\
void \
hb_font_funcs_set_##name##_func (hb_font_funcs_t *ffuncs, \
hb_font_get_##name##_func_t func, \
void *user_data, \
hb_destroy_func_t destroy) \
{ \
if (ffuncs->immutable) \
return; \
\
if (ffuncs->destroy.name) \
ffuncs->destroy.name (ffuncs->user_data.name); \
\
if (func) { \
ffuncs->get.name = func; \
ffuncs->user_data.name = user_data; \
ffuncs->destroy.name = destroy; \
} else { \
ffuncs->get.name = hb_font_get_##name##_nil; \
ffuncs->user_data.name = NULL; \
ffuncs->destroy.name = NULL; \
} \
}
HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
#undef HB_FONT_FUNC_IMPLEMENT
hb_bool_t
hb_font_get_glyph (hb_font_t *font,
hb_codepoint_t unicode, hb_codepoint_t variation_selector,
hb_codepoint_t *glyph)
{
*glyph = 0;
return font->klass->get.glyph (font, font->user_data,
unicode, variation_selector, glyph,
font->klass->user_data.glyph);
}
hb_position_t
hb_font_get_glyph_h_advance (hb_font_t *font,
hb_codepoint_t glyph)
{
return font->klass->get.glyph_h_advance (font, font->user_data,
glyph,
font->klass->user_data.glyph_h_advance);
}
hb_position_t
hb_font_get_glyph_v_advance (hb_font_t *font,
hb_codepoint_t glyph)
{
return font->klass->get.glyph_v_advance (font, font->user_data,
glyph,
font->klass->user_data.glyph_v_advance);
}
hb_bool_t
hb_font_get_glyph_h_origin (hb_font_t *font,
hb_codepoint_t glyph,
hb_position_t *x, hb_position_t *y)
{
*x = *y = 0;
return font->klass->get.glyph_h_origin (font, font->user_data,
glyph, x, y,
font->klass->user_data.glyph_h_origin);
}
hb_bool_t
hb_font_get_glyph_v_origin (hb_font_t *font,
hb_codepoint_t glyph,
hb_position_t *x, hb_position_t *y)
{
*x = *y = 0;
return font->klass->get.glyph_v_origin (font, font->user_data,
glyph, x, y,
font->klass->user_data.glyph_v_origin);
}
hb_position_t
hb_font_get_glyph_h_kerning (hb_font_t *font,
hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
{
return font->klass->get.glyph_h_kerning (font, font->user_data,
left_glyph, right_glyph,
font->klass->user_data.glyph_h_kerning);
}
hb_position_t
hb_font_get_glyph_v_kerning (hb_font_t *font,
hb_codepoint_t left_glyph, hb_codepoint_t right_glyph)
{
return font->klass->get.glyph_v_kerning (font, font->user_data,
left_glyph, right_glyph,
font->klass->user_data.glyph_v_kerning);
}
hb_bool_t
hb_font_get_glyph_extents (hb_font_t *font,
hb_codepoint_t glyph,
hb_glyph_extents_t *extents)
{
memset (extents, 0, sizeof (*extents));
return font->klass->get.glyph_extents (font, font->user_data,
glyph,
extents,
font->klass->user_data.glyph_extents);
}
hb_bool_t
hb_font_get_glyph_contour_point (hb_font_t *font,
hb_codepoint_t glyph, unsigned int point_index,
hb_position_t *x, hb_position_t *y)
{
*x = *y = 0;
return font->klass->get.glyph_contour_point (font, font->user_data,
glyph, point_index,
x, y,
font->klass->user_data.glyph_contour_point);
}
/* A bit higher-level, and with fallback */
void
hb_font_get_glyph_advance_for_direction (hb_font_t *font,
hb_codepoint_t glyph,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
*x = hb_font_get_glyph_h_advance (font, glyph);
*y = 0;
} else {
*x = 0;
*y = hb_font_get_glyph_v_advance (font, glyph);
}
}
static void
guess_v_origin_minus_h_origin (hb_font_t *font,
hb_codepoint_t glyph,
hb_position_t *x, hb_position_t *y)
{
*x = hb_font_get_glyph_h_advance (font, glyph) / 2;
/* TODO use font_metics.ascent */
*y = font->y_scale;
}
void
hb_font_get_glyph_origin_for_direction (hb_font_t *font,
hb_codepoint_t glyph,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
hb_bool_t ret = hb_font_get_glyph_h_origin (font, glyph, x, y);
if (!ret && (ret = hb_font_get_glyph_v_origin (font, glyph, x, y))) {
hb_position_t dx, dy;
guess_v_origin_minus_h_origin (font, glyph, &dx, &dy);
*x -= dx; *y -= dy;
}
} else {
hb_bool_t ret = hb_font_get_glyph_v_origin (font, glyph, x, y);
if (!ret && (ret = hb_font_get_glyph_h_origin (font, glyph, x, y))) {
hb_position_t dx, dy;
guess_v_origin_minus_h_origin (font, glyph, &dx, &dy);
*x += dx; *y += dy;
}
}
}
void
hb_font_add_glyph_origin_for_direction (hb_font_t *font,
hb_codepoint_t glyph,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
hb_position_t origin_x, origin_y;
hb_font_get_glyph_origin_for_direction (font, glyph, direction, &origin_x, &origin_y);
*x += origin_x;
*y += origin_y;
}
void
hb_font_subtract_glyph_origin_for_direction (hb_font_t *font,
hb_codepoint_t glyph,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
hb_position_t origin_x, origin_y;
hb_font_get_glyph_origin_for_direction (font, glyph, direction, &origin_x, &origin_y);
*x -= origin_x;
*y -= origin_y;
}
void
hb_font_get_glyph_kerning_for_direction (hb_font_t *font,
hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
*x = hb_font_get_glyph_h_kerning (font, first_glyph, second_glyph);
*y = 0;
} else {
*x = 0;
*y = hb_font_get_glyph_v_kerning (font, first_glyph, second_glyph);
}
}
hb_bool_t
hb_font_get_glyph_extents_for_origin (hb_font_t *font,
hb_codepoint_t glyph,
hb_direction_t direction,
hb_glyph_extents_t *extents)
{
hb_bool_t ret = hb_font_get_glyph_extents (font, glyph, extents);
if (ret)
hb_font_subtract_glyph_origin_for_direction (font, glyph, direction, &extents->x_bearing, &extents->y_bearing);
return ret;
}
hb_bool_t
hb_font_get_glyph_contour_point_for_origin (hb_font_t *font,
hb_codepoint_t glyph, unsigned int point_index,
hb_direction_t direction,
hb_position_t *x, hb_position_t *y)
{
hb_bool_t ret = hb_font_get_glyph_contour_point (font, glyph, point_index, x, y);
if (ret)
hb_font_subtract_glyph_origin_for_direction (font, glyph, direction, x, y);
return ret;
}
/*
* hb_face_t
*/
static hb_face_t _hb_face_nil = {
HB_OBJECT_HEADER_STATIC,
TRUE, /* immutable */
NULL, /* reference_table */
NULL, /* user_data */
NULL, /* destroy */
NULL, /* ot_layout */
0, /* index */
1000 /* upem */
};
hb_face_t *
hb_face_create_for_tables (hb_reference_table_func_t reference_table,
void *user_data,
hb_destroy_func_t destroy)
{
hb_face_t *face;
if (!reference_table || !(face = hb_object_create<hb_face_t> ())) {
if (destroy)
destroy (user_data);
return &_hb_face_nil;
}
face->reference_table = reference_table;
face->user_data = user_data;
face->destroy = destroy;
face->ot_layout = _hb_ot_layout_create (face);
face->upem = 0;
return face;
}
typedef struct _hb_face_for_data_closure_t {
hb_blob_t *blob;
unsigned int index;
} hb_face_for_data_closure_t;
static hb_face_for_data_closure_t *
_hb_face_for_data_closure_create (hb_blob_t *blob, unsigned int index)
{
hb_face_for_data_closure_t *closure;
closure = (hb_face_for_data_closure_t *) malloc (sizeof (hb_face_for_data_closure_t));
if (unlikely (!closure))
return NULL;
closure->blob = blob;
closure->index = index;
return closure;
}
static void
_hb_face_for_data_closure_destroy (hb_face_for_data_closure_t *closure)
{
hb_blob_destroy (closure->blob);
free (closure);
}
static hb_blob_t *
_hb_face_for_data_reference_table (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)
{
hb_face_for_data_closure_t *data = (hb_face_for_data_closure_t *) user_data;
if (tag == HB_TAG_NONE)
return hb_blob_reference (data->blob);
const OpenTypeFontFile &ot_file = *Sanitizer<OpenTypeFontFile>::lock_instance (data->blob);
const OpenTypeFontFace &ot_face = ot_file.get_face (data->index);
const OpenTypeTable &table = ot_face.get_table_by_tag (tag);
hb_blob_t *blob = hb_blob_create_sub_blob (data->blob, table.offset, table.length);
return blob;
}
hb_face_t *
hb_face_create (hb_blob_t *blob,
unsigned int index)
{
hb_face_t *face;
if (unlikely (!blob || !hb_blob_get_length (blob)))
return &_hb_face_nil;
hb_face_for_data_closure_t *closure = _hb_face_for_data_closure_create (Sanitizer<OpenTypeFontFile>::sanitize (hb_blob_reference (blob)), index);
if (unlikely (!closure))
return &_hb_face_nil;
face = hb_face_create_for_tables (_hb_face_for_data_reference_table,
closure,
(hb_destroy_func_t) _hb_face_for_data_closure_destroy);
hb_face_set_index (face, index);
return face;
}
hb_face_t *
hb_face_get_empty (void)
{
return &_hb_face_nil;
}
hb_face_t *
hb_face_reference (hb_face_t *face)
{
return hb_object_reference (face);
}
void
hb_face_destroy (hb_face_t *face)
{
if (!hb_object_destroy (face)) return;
_hb_ot_layout_destroy (face->ot_layout);
if (face->destroy)
face->destroy (face->user_data);
free (face);
}
hb_bool_t
hb_face_set_user_data (hb_face_t *face,
hb_user_data_key_t *key,
void * data,
hb_destroy_func_t destroy,
hb_bool_t replace)
{
return hb_object_set_user_data (face, key, data, destroy, replace);
}
void *
hb_face_get_user_data (hb_face_t *face,
hb_user_data_key_t *key)
{
return hb_object_get_user_data (face, key);
}
void
hb_face_make_immutable (hb_face_t *face)
{
if (hb_object_is_inert (face))
return;
face->immutable = true;
}
hb_bool_t
hb_face_is_immutable (hb_face_t *face)
{
return face->immutable;
}
hb_blob_t *
hb_face_reference_table (hb_face_t *face,
hb_tag_t tag)
{
hb_blob_t *blob;
if (unlikely (!face || !face->reference_table))
return hb_blob_get_empty ();
blob = face->reference_table (face, tag, face->user_data);
if (unlikely (!blob))
return hb_blob_get_empty ();
return blob;
}
hb_blob_t *
hb_face_reference_blob (hb_face_t *face)
{
return hb_face_reference_table (face, HB_TAG_NONE);
}
void
hb_face_set_index (hb_face_t *face,
unsigned int index)
{
if (hb_object_is_inert (face))
return;
face->index = 0;
}
unsigned int
hb_face_get_index (hb_face_t *face)
{
return face->index;
}
void
hb_face_set_upem (hb_face_t *face,
unsigned int upem)
{
if (hb_object_is_inert (face))
return;
face->upem = upem;
}
unsigned int
hb_face_get_upem (hb_face_t *face)
{
if (unlikely (!face->upem)) {
hb_blob_t *head_blob = Sanitizer<head>::sanitize (hb_face_reference_table (face, HB_OT_TAG_head));
const head *head_table = Sanitizer<head>::lock_instance (head_blob);
face->upem = head_table->get_upem ();
hb_blob_destroy (head_blob);
}
return face->upem;
}
/*
* hb_font_t
*/
static hb_font_t _hb_font_nil = {
HB_OBJECT_HEADER_STATIC,
TRUE, /* immutable */
NULL, /* parent */
&_hb_face_nil,
0, /* x_scale */
0, /* y_scale */
0, /* x_ppem */
0, /* y_ppem */
&_hb_font_funcs_nil, /* klass */
NULL, /* user_data */
NULL /* destroy */
};
hb_font_t *
hb_font_create (hb_face_t *face)
{
hb_font_t *font;
if (unlikely (!face))
face = &_hb_face_nil;
if (unlikely (hb_object_is_inert (face)))
return &_hb_font_nil;
if (!(font = hb_object_create<hb_font_t> ()))
return &_hb_font_nil;
hb_face_make_immutable (face);
font->face = hb_face_reference (face);
font->klass = &_hb_font_funcs_nil;
return font;
}
hb_font_t *
hb_font_create_sub_font (hb_font_t *parent)
{
if (unlikely (!parent))
return &_hb_font_nil;
hb_font_t *font = hb_font_create (parent->face);
if (unlikely (hb_object_is_inert (font)))
return font;
hb_font_make_immutable (parent);
font->parent = hb_font_reference (parent);
font->x_scale = parent->x_scale;
font->y_scale = parent->y_scale;
font->x_ppem = parent->x_ppem;
font->y_ppem = parent->y_ppem;
font->klass = &_hb_font_funcs_nil;
return font;
}
hb_font_t *
hb_font_get_empty (void)
{
return &_hb_font_nil;
}
hb_font_t *
hb_font_reference (hb_font_t *font)
{
return hb_object_reference (font);
}
void
hb_font_destroy (hb_font_t *font)
{
if (!hb_object_destroy (font)) return;
hb_font_destroy (font->parent);
hb_face_destroy (font->face);
hb_font_funcs_destroy (font->klass);
if (font->destroy)
font->destroy (font->user_data);
free (font);
}
hb_bool_t
hb_font_set_user_data (hb_font_t *font,
hb_user_data_key_t *key,
void * data,
hb_destroy_func_t destroy,
hb_bool_t replace)
{
return hb_object_set_user_data (font, key, data, destroy, replace);
}
void *
hb_font_get_user_data (hb_font_t *font,
hb_user_data_key_t *key)
{
return hb_object_get_user_data (font, key);
}
void
hb_font_make_immutable (hb_font_t *font)
{
if (hb_object_is_inert (font))
return;
font->immutable = true;
}
hb_bool_t
hb_font_is_immutable (hb_font_t *font)
{
return font->immutable;
}
hb_font_t *
hb_font_get_parent (hb_font_t *font)
{
return font->parent;
}
hb_face_t *
hb_font_get_face (hb_font_t *font)
{
return font->face;
}
void
hb_font_set_funcs (hb_font_t *font,
hb_font_funcs_t *klass,
void *user_data,
hb_destroy_func_t destroy)
{
if (font->immutable)
return;
if (font->destroy)
font->destroy (font->user_data);
if (!klass)
klass = &_hb_font_funcs_nil;
hb_font_funcs_reference (klass);
hb_font_funcs_destroy (font->klass);
font->klass = klass;
font->user_data = user_data;
font->destroy = destroy;
}
void
hb_font_set_scale (hb_font_t *font,
int x_scale,
int y_scale)
{
if (font->immutable)
return;
font->x_scale = x_scale;
font->y_scale = y_scale;
}
void
hb_font_get_scale (hb_font_t *font,
int *x_scale,
int *y_scale)
{
if (x_scale) *x_scale = font->x_scale;
if (y_scale) *y_scale = font->y_scale;
}
void
hb_font_set_ppem (hb_font_t *font,
unsigned int x_ppem,
unsigned int y_ppem)
{
if (font->immutable)
return;
font->x_ppem = x_ppem;
font->y_ppem = y_ppem;
}
void
hb_font_get_ppem (hb_font_t *font,
unsigned int *x_ppem,
unsigned int *y_ppem)
{
if (x_ppem) *x_ppem = font->x_ppem;
if (y_ppem) *y_ppem = font->y_ppem;
}