[ot-font] Add metrics_accel_t

This commit is contained in:
Behdad Esfahbod 2014-09-25 16:53:24 +03:00
parent d41b809e9d
commit be1cca2702
3 changed files with 54 additions and 63 deletions

View File

@ -35,18 +35,55 @@
#include "hb-ot-hmtx-table.hh"
struct metrics_accel_t
{
unsigned int num_metrics;
unsigned int num_advances;
const OT::_mtx *table;
hb_blob_t *blob;
inline void init (hb_font_t *font, hb_tag_t _hea_tag, hb_tag_t _mtx_tag)
{
this->num_metrics = font->face->get_num_glyphs ();
hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (font->face->reference_table (_hea_tag));
const OT::_hea *_hea = OT::Sanitizer<OT::_hea>::lock_instance (_hea_blob);
this->num_advances = _hea->numberOfLongMetrics;
hb_blob_destroy (_hea_blob);
this->blob = OT::Sanitizer<OT::_mtx>::sanitize (font->face->reference_table (_mtx_tag));
if (unlikely (!this->num_advances ||
2 * (this->num_advances + this->num_metrics) < hb_blob_get_length (this->blob)))
{
hb_blob_destroy (this->blob);
this->blob = hb_blob_get_empty ();
}
this->table = OT::Sanitizer<OT::_mtx>::lock_instance (this->blob);
}
inline void fini (void)
{
hb_blob_destroy (this->blob);
}
inline unsigned int get_advance (hb_codepoint_t glyph) const
{
if (unlikely (glyph >= this->num_metrics))
return 0;
if (glyph >= this->num_advances)
glyph = this->num_advances - 1;
return this->table->longMetric[glyph].advance;
}
};
struct hb_ot_font_t
{
unsigned int num_glyphs;
unsigned int num_hmetrics;
const OT::hmtx *hmtx;
hb_blob_t *hmtx_blob;
unsigned int num_vmetrics;
const OT::vmtx *vmtx;
hb_blob_t *vmtx_blob;
metrics_accel_t h_metrics;
metrics_accel_t v_metrics;
const OT::CmapSubtable *cmap;
const OT::CmapSubtable *cmap_uvs;
@ -64,41 +101,9 @@ _hb_ot_font_create (hb_font_t *font)
ot_font->num_glyphs = font->face->get_num_glyphs ();
/* Setup horizontal metrics. */
{
hb_blob_t *hhea_blob = OT::Sanitizer<OT::hhea>::sanitize (font->face->reference_table (HB_OT_TAG_hhea));
const OT::hhea *hhea = OT::Sanitizer<OT::hhea>::lock_instance (hhea_blob);
ot_font->num_hmetrics = hhea->numberOfMetrics;
hb_blob_destroy (hhea_blob);
ot_font->hmtx_blob = OT::Sanitizer<OT::hmtx>::sanitize (font->face->reference_table (HB_OT_TAG_hmtx));
if (unlikely (!ot_font->num_hmetrics ||
2 * (ot_font->num_hmetrics + ot_font->num_glyphs) < hb_blob_get_length (ot_font->hmtx_blob)))
{
hb_blob_destroy (ot_font->hmtx_blob);
free (ot_font);
return NULL;
}
ot_font->hmtx = OT::Sanitizer<OT::hmtx>::lock_instance (ot_font->hmtx_blob);
}
/* Setup vertical metrics. */
{
hb_blob_t *vhea_blob = OT::Sanitizer<OT::vhea>::sanitize (font->face->reference_table (HB_OT_TAG_vhea));
const OT::vhea *vhea = OT::Sanitizer<OT::vhea>::lock_instance (vhea_blob);
ot_font->num_vmetrics = vhea->numberOfMetrics;
hb_blob_destroy (vhea_blob);
ot_font->vmtx_blob = OT::Sanitizer<OT::vmtx>::sanitize (font->face->reference_table (HB_TAG('v','m','t','x')));
if (unlikely (!ot_font->num_vmetrics ||
2 * (ot_font->num_vmetrics + ot_font->num_glyphs) < hb_blob_get_length (ot_font->vmtx_blob)))
{
hb_blob_destroy (ot_font->vmtx_blob);
free (ot_font);
return NULL;
}
ot_font->vmtx = OT::Sanitizer<OT::vmtx>::lock_instance (ot_font->vmtx_blob);
}
ot_font->h_metrics.init (font, HB_OT_TAG_hhea, HB_OT_TAG_hmtx);
/* TODO Can we do this lazily? */
ot_font->v_metrics.init (font, HB_OT_TAG_vhea, HB_OT_TAG_vmtx);
ot_font->cmap_blob = OT::Sanitizer<OT::cmap>::sanitize (font->face->reference_table (HB_OT_TAG_cmap));
const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (ot_font->cmap_blob);
@ -133,8 +138,8 @@ static void
_hb_ot_font_destroy (hb_ot_font_t *ot_font)
{
hb_blob_destroy (ot_font->cmap_blob);
hb_blob_destroy (ot_font->hmtx_blob);
hb_blob_destroy (ot_font->vmtx_blob);
ot_font->h_metrics.fini ();
ot_font->v_metrics.fini ();
free (ot_font);
}
@ -173,14 +178,7 @@ hb_ot_get_glyph_h_advance (hb_font_t *font HB_UNUSED,
void *user_data HB_UNUSED)
{
const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
if (unlikely (glyph >= ot_font->num_glyphs))
return 0;
if (glyph >= ot_font->num_hmetrics)
glyph = ot_font->num_hmetrics - 1;
return font->em_scale_x (ot_font->hmtx->longHorMetric[glyph].advance);
return font->em_scale_x (ot_font->h_metrics.get_advance (glyph));
}
static hb_position_t
@ -190,14 +188,7 @@ hb_ot_get_glyph_v_advance (hb_font_t *font HB_UNUSED,
void *user_data HB_UNUSED)
{
const hb_ot_font_t *ot_font = (const hb_ot_font_t *) font_data;
if (unlikely (glyph >= ot_font->num_glyphs))
return 0;
if (glyph >= ot_font->num_vmetrics)
glyph = ot_font->num_vmetrics - 1;
return font->em_scale_y (-ot_font->vmtx->longHorMetric[glyph].advance);
return font->em_scale_y (-ot_font->v_metrics.get_advance (glyph));
}
static hb_bool_t

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@ -80,7 +80,7 @@ struct _hea
SHORT reserved3; /* Set to 0. */
SHORT reserved4; /* Set to 0. */
SHORT metricDataFormat; /* 0 for current format. */
USHORT numberOfMetrics; /* Number of LongMetric entries in metric
USHORT numberOfLongMetrics; /* Number of LongMetric entries in metric
* table. */
public:
DEFINE_SIZE_STATIC (36);

View File

@ -63,7 +63,7 @@ struct _mtx
}
public:
LongMetric longHorMetric[VAR]; /* Paired advance width and leading
LongMetric longMetric[VAR]; /* Paired advance width and leading
* bearing values for each glyph. The
* value numOfHMetrics comes from
* the 'hhea' table. If the font is
@ -85,7 +85,7 @@ struct _mtx
* font to vary the side bearing
* values for each glyph. */
public:
DEFINE_SIZE_ARRAY2 (0, longHorMetric, leadingBearingX);
DEFINE_SIZE_ARRAY2 (0, longMetric, leadingBearingX);
};
struct hmtx : _mtx {