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[ot-font] Handle missing vertical metrics tables

This commit is contained in:
Behdad Esfahbod 2014-09-25 17:15:35 +03:00
parent be1cca2702
commit d7c160a153
1 changed files with 19 additions and 7 deletions
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26
src/hb-ot-font.cc
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@ -39,11 +39,15 @@ struct metrics_accel_t
{ {
unsigned int num_metrics; unsigned int num_metrics;
unsigned int num_advances; unsigned int num_advances;
unsigned int default_advance;
const OT::_mtx *table; const OT::_mtx *table;
hb_blob_t *blob; hb_blob_t *blob;
inline void init (hb_font_t *font, hb_tag_t _hea_tag, hb_tag_t _mtx_tag) inline void init (hb_font_t *font,
hb_tag_t _hea_tag, hb_tag_t _mtx_tag,
unsigned int default_advance)
{ {
this->default_advance = default_advance;
this->num_metrics = font->face->get_num_glyphs (); this->num_metrics = font->face->get_num_glyphs ();
hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (font->face->reference_table (_hea_tag)); hb_blob_t *_hea_blob = OT::Sanitizer<OT::_hea>::sanitize (font->face->reference_table (_hea_tag));
@ -55,6 +59,7 @@ struct metrics_accel_t
if (unlikely (!this->num_advances || if (unlikely (!this->num_advances ||
2 * (this->num_advances + this->num_metrics) < hb_blob_get_length (this->blob))) 2 * (this->num_advances + this->num_metrics) < hb_blob_get_length (this->blob)))
{ {
this->num_metrics = this->num_advances = 0;
hb_blob_destroy (this->blob); hb_blob_destroy (this->blob);
this->blob = hb_blob_get_empty (); this->blob = hb_blob_get_empty ();
} }
@ -69,7 +74,15 @@ struct metrics_accel_t
inline unsigned int get_advance (hb_codepoint_t glyph) const inline unsigned int get_advance (hb_codepoint_t glyph) const
{ {
if (unlikely (glyph >= this->num_metrics)) if (unlikely (glyph >= this->num_metrics))
return 0; {
/* If this->num_metrics is zero, it means we don't have the metrics table
* for this direction: return one EM. Otherwise, it means that the glyph
* index is out of bound: return zero. */
if (this->num_metrics)
return 0;
else
return this->default_advance;
}
if (glyph >= this->num_advances) if (glyph >= this->num_advances)
glyph = this->num_advances - 1; glyph = this->num_advances - 1;
@ -80,8 +93,6 @@ struct metrics_accel_t
struct hb_ot_font_t struct hb_ot_font_t
{ {
unsigned int num_glyphs;
metrics_accel_t h_metrics; metrics_accel_t h_metrics;
metrics_accel_t v_metrics; metrics_accel_t v_metrics;
@ -99,11 +110,11 @@ _hb_ot_font_create (hb_font_t *font)
if (unlikely (!ot_font)) if (unlikely (!ot_font))
return NULL; return NULL;
ot_font->num_glyphs = font->face->get_num_glyphs (); unsigned int upem = font->face->get_upem ();
ot_font->h_metrics.init (font, HB_OT_TAG_hhea, HB_OT_TAG_hmtx); ot_font->h_metrics.init (font, HB_OT_TAG_hhea, HB_OT_TAG_hmtx, upem>>1);
/* TODO Can we do this lazily? */ /* TODO Can we do this lazily? */
ot_font->v_metrics.init (font, HB_OT_TAG_vhea, HB_OT_TAG_vmtx); ot_font->v_metrics.init (font, HB_OT_TAG_vhea, HB_OT_TAG_vmtx, upem);
ot_font->cmap_blob = OT::Sanitizer<OT::cmap>::sanitize (font->face->reference_table (HB_OT_TAG_cmap)); 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); const OT::cmap *cmap = OT::Sanitizer<OT::cmap>::lock_instance (ot_font->cmap_blob);
@ -233,6 +244,7 @@ hb_ot_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,
hb_codepoint_t bottom_glyph HB_UNUSED, hb_codepoint_t bottom_glyph HB_UNUSED,
void *user_data HB_UNUSED) void *user_data HB_UNUSED)
{ {
/* OpenType doesn't have vertical-kerning other than GPOS. */
return 0; return 0;
} }