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[ot-font] Accelerate cmap format4 get_glyph

This commit is contained in:
Behdad Esfahbod 2016-02-24 20:27:13 +09:00
parent e0f16a715b
commit 23335deaad
2 changed files with 77 additions and 48 deletions
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111
src/hb-ot-cmap-table.hh
View File

@ -69,61 +69,78 @@ struct CmapSubtableFormat0
struct CmapSubtableFormat4
{
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
struct accelerator_t
{
unsigned int segCount;
inline void init (const CmapSubtableFormat4 *subtable)
{
segCount = subtable->segCountX2 / 2;
endCount = subtable->values;
startCount = endCount + segCount + 1;
idDelta = startCount + segCount;
idRangeOffset = idDelta + segCount;
glyphIdArray = idRangeOffset + segCount;
glyphIdArrayLength = (subtable->length - 16 - 8 * segCount) / 2;
}
static inline bool get_glyph_func (const void *obj, hb_codepoint_t codepoint, hb_codepoint_t *glyph)
{
const accelerator_t *thiz = (const accelerator_t *) obj;
/* Custom two-array bsearch. */
int min = 0, max = (int) thiz->segCount - 1;
const USHORT *startCount = thiz->startCount;
const USHORT *endCount = thiz->endCount;
unsigned int i;
while (min <= max)
{
int mid = (min + max) / 2;
if (codepoint < startCount[mid])
max = mid - 1;
else if (codepoint > endCount[mid])
min = mid + 1;
else
{
i = mid;
goto found;
}
}
return false;
found:
hb_codepoint_t gid;
unsigned int rangeOffset = thiz->idRangeOffset[i];
if (rangeOffset == 0)
gid = codepoint + thiz->idDelta[i];
else
{
/* Somebody has been smoking... */
unsigned int index = rangeOffset / 2 + (codepoint - thiz->startCount[i]) + i - thiz->segCount;
if (unlikely (index >= thiz->glyphIdArrayLength))
return false;
gid = thiz->glyphIdArray[index];
if (unlikely (!gid))
return false;
gid += thiz->idDelta[i];
}
*glyph = gid & 0xFFFFu;
return true;
}
const USHORT *endCount;
const USHORT *startCount;
const USHORT *idDelta;
const USHORT *idRangeOffset;
const USHORT *glyphIdArray;
unsigned int segCount;
unsigned int glyphIdArrayLength;
};
segCount = this->segCountX2 / 2;
endCount = this->values;
startCount = endCount + segCount + 1;
idDelta = startCount + segCount;
idRangeOffset = idDelta + segCount;
glyphIdArray = idRangeOffset + segCount;
glyphIdArrayLength = (this->length - 16 - 8 * segCount) / 2;
/* Custom two-array bsearch. */
int min = 0, max = (int) segCount - 1;
unsigned int i;
while (min <= max)
{
int mid = (min + max) / 2;
if (codepoint < startCount[mid])
max = mid - 1;
else if (codepoint > endCount[mid])
min = mid + 1;
else
{
i = mid;
goto found;
}
}
return false;
found:
hb_codepoint_t gid;
unsigned int rangeOffset = idRangeOffset[i];
if (rangeOffset == 0)
gid = codepoint + idDelta[i];
else
{
/* Somebody has been smoking... */
unsigned int index = rangeOffset / 2 + (codepoint - startCount[i]) + i - segCount;
if (unlikely (index >= glyphIdArrayLength))
return false;
gid = glyphIdArray[index];
if (unlikely (!gid))
return false;
gid += idDelta[i];
}
*glyph = gid & 0xFFFFu;
return true;
inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
{
accelerator_t accel;
accel.init (this);
return accel.get_glyph_func (&accel, codepoint, glyph);
}
inline bool sanitize (hb_sanitize_context_t *c) const

14
src/hb-ot-font.cc
View File

@ -218,6 +218,7 @@ struct hb_ot_face_cmap_accelerator_t
{
hb_cmap_get_glyph_func_t get_glyph_func;
const void *get_glyph_data;
OT::CmapSubtableFormat4::accelerator_t format4_accel;
const OT::CmapSubtableFormat14 *uvs_table;
hb_blob_t *blob;
@ -255,8 +256,19 @@ struct hb_ot_face_cmap_accelerator_t
this->uvs_table = subtable_uvs;
this->get_glyph_func = get_glyph_from<OT::CmapSubtable>;
this->get_glyph_data = subtable;
switch (subtable->u.format) {
/* Accelerate format 4 and format 12. */
default: this->get_glyph_func = get_glyph_from<OT::CmapSubtable>; break;
case 12: this->get_glyph_func = get_glyph_from<OT::CmapSubtableFormat12>; break;
case 4:
{
this->format4_accel.init (&subtable->u.format4);
this->get_glyph_data = &this->format4_accel;
this->get_glyph_func = this->format4_accel.get_glyph_func;
}
break;
}
}
inline void fini (void)