[subset] Do some refactoring in hb-subset-glyf.cc.
- Extract code out into helper methods in several places.
- Bundle loca address, size and is short into a struct.
diff --git a/src/hb-subset-glyf.cc b/src/hb-subset-glyf.cc
index e922285..7b4344b 100644
--- a/src/hb-subset-glyf.cc
+++ b/src/hb-subset-glyf.cc
@@ -29,32 +29,103 @@
#include "hb-set.h"
#include "hb-subset-glyf.hh"
+struct loca_data_t
+{
+ bool is_short;
+ void *data;
+ unsigned int size;
+
+ inline bool
+ _write_loca_entry (unsigned int id,
+ unsigned int offset)
+ {
+ unsigned int entry_size = is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32);
+ if ((id + 1) * entry_size <= size)
+ {
+ if (is_short) {
+ ((OT::HBUINT16*) data) [id].set (offset / 2);
+ } else {
+ ((OT::HBUINT32*) data) [id].set (offset);
+ }
+ return true;
+ }
+
+ // Offset was not written because the write is out of bounds.
+ DEBUG_MSG(SUBSET,
+ nullptr,
+ "WARNING: Attempted to write an out of bounds loca entry at index %d. Loca size is %d.",
+ id,
+ size);
+ return false;
+ }
+
+ inline bool
+ _add_empty_glyphs_to_loca (hb_codepoint_t from_gid,
+ hb_codepoint_t to_gid,
+ unsigned int offset)
+ {
+ bool success = true;
+ while (from_gid < to_gid)
+ {
+ success = success && _write_loca_entry (from_gid,
+ offset);
+ from_gid++;
+ }
+ return success;
+ }
+};
+
+/**
+ * If hints are being dropped find the range which in glyf at which
+ * the hinting instructions are located. Add them to the instruction_ranges
+ * vector.
+ */
+static bool
+_add_instructions_range (const OT::glyf::accelerator_t &glyf,
+ hb_codepoint_t glyph_id,
+ unsigned int glyph_start_offset,
+ unsigned int glyph_end_offset,
+ bool drop_hints,
+ hb_vector_t<unsigned int> *instruction_ranges /* OUT */)
+{
+ if (!instruction_ranges->resize (instruction_ranges->length + 2))
+ {
+ DEBUG_MSG(SUBSET, nullptr, "Failed to resize instruction_ranges.");
+ return false;
+ }
+ unsigned int *instruction_start = &(*instruction_ranges)[instruction_ranges->length - 2];
+ *instruction_start = 0;
+ unsigned int *instruction_end = &(*instruction_ranges)[instruction_ranges->length - 1];
+ *instruction_end = 0;
+
+ if (drop_hints)
+ {
+ if (unlikely (!glyf.get_instruction_offsets (glyph_start_offset, glyph_end_offset,
+ instruction_start, instruction_end)))
+ {
+ DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", glyph_id);
+ return false;
+ }
+ }
+
+ return true;
+}
+
static bool
_calculate_glyf_and_loca_prime_size (const OT::glyf::accelerator_t &glyf,
- hb_vector_t<hb_codepoint_t> &glyph_ids,
- const hb_map_t *glyph_map,
- hb_bool_t drop_hints,
- bool *use_short_loca /* OUT */,
- unsigned int *glyf_size /* OUT */,
- unsigned int *loca_size /* OUT */,
- hb_vector_t<unsigned int> *instruction_ranges /* OUT */)
+ const hb_subset_plan_t *plan,
+ loca_data_t *loca_data, /* OUT */
+ unsigned int *glyf_size /* OUT */,
+ hb_vector_t<unsigned int> *instruction_ranges /* OUT */)
{
unsigned int total = 0;
hb_codepoint_t max_new_gid = 0;
- for (unsigned int i = 0; i < glyph_ids.length; i++)
+ for (unsigned int i = 0; i < plan->glyphs.length; i++)
{
- hb_codepoint_t next_glyph = glyph_ids[i];
- hb_codepoint_t next_glyph_new_gid = glyph_map->get (next_glyph);
- max_new_gid = MAX (max_new_gid, next_glyph_new_gid);
- if (!instruction_ranges->resize (instruction_ranges->length + 2))
- {
- DEBUG_MSG(SUBSET, nullptr, "Failed to resize instruction_ranges.");
- return false;
- }
- unsigned int *instruction_start = &(*instruction_ranges)[instruction_ranges->length - 2];
- *instruction_start = 0;
- unsigned int *instruction_end = &(*instruction_ranges)[instruction_ranges->length - 1];
- *instruction_end = 0;
+ hb_codepoint_t next_glyph = plan->glyphs[i];
+ hb_codepoint_t new_gid_for_next_glyph;
+ if (plan->new_gid_for_old_gid (next_glyph, &new_gid_for_next_glyph))
+ max_new_gid = MAX (max_new_gid, new_gid_for_next_glyph);
unsigned int start_offset, end_offset;
if (unlikely (!(glyf.get_offsets (next_glyph, &start_offset, &end_offset) &&
@@ -63,63 +134,38 @@
DEBUG_MSG(SUBSET, nullptr, "Invalid gid %d", next_glyph);
continue;
}
- if (end_offset - start_offset < OT::glyf::GlyphHeader::static_size)
+
+ bool is_zero_length = end_offset - start_offset < OT::glyf::GlyphHeader::static_size;
+ if (!_add_instructions_range (glyf,
+ next_glyph,
+ start_offset,
+ end_offset,
+ plan->drop_hints && !is_zero_length,
+ instruction_ranges))
+ return false;
+
+ if (is_zero_length)
continue; /* 0-length glyph */
- if (drop_hints)
- {
- if (unlikely (!glyf.get_instruction_offsets (start_offset, end_offset,
- instruction_start, instruction_end)))
- {
- DEBUG_MSG(SUBSET, nullptr, "Unable to get instruction offsets for %d", next_glyph);
- return false;
- }
- }
-
- total += end_offset - start_offset - (*instruction_end - *instruction_start);
+ total += end_offset - start_offset
+ - ((*instruction_ranges)[instruction_ranges->length - 1]
+ - (*instruction_ranges)[instruction_ranges->length - 2]);
/* round2 so short loca will work */
total += total % 2;
}
*glyf_size = total;
- *use_short_loca = (total <= 131070);
- *loca_size = (max_new_gid + 2)
- * (*use_short_loca ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32));
+ loca_data->is_short = (total <= 131070);
+ loca_data->size = (max_new_gid + 2)
+ * (loca_data->is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32));
DEBUG_MSG(SUBSET, nullptr, "preparing to subset glyf: final size %d, loca size %d, using %s loca",
total,
- *loca_size,
- *use_short_loca ? "short" : "long");
+ loca_data->size,
+ loca_data->is_short ? "short" : "long");
return true;
}
-static bool
-_write_loca_entry (unsigned int id,
- unsigned int offset,
- bool is_short,
- void *loca_prime,
- unsigned int loca_size)
-{
- unsigned int entry_size = is_short ? sizeof (OT::HBUINT16) : sizeof (OT::HBUINT32);
- if ((id + 1) * entry_size <= loca_size)
- {
- if (is_short) {
- ((OT::HBUINT16*) loca_prime) [id].set (offset / 2);
- } else {
- ((OT::HBUINT32*) loca_prime) [id].set (offset);
- }
- return true;
- }
-
- // Offset was not written because the write is out of bounds.
- DEBUG_MSG(SUBSET,
- nullptr,
- "WARNING: Attempted to write an out of bounds loca entry at index %d. Loca size is %d.",
- id,
- loca_size);
- return false;
-}
-
static void
_update_components (const hb_subset_plan_t *plan,
char *glyph_start,
@@ -160,33 +206,28 @@
_write_glyf_and_loca_prime (const hb_subset_plan_t *plan,
const OT::glyf::accelerator_t &glyf,
const char *glyf_data,
- bool use_short_loca,
hb_vector_t<unsigned int> &instruction_ranges,
unsigned int glyf_prime_size,
char *glyf_prime_data /* OUT */,
- unsigned int loca_prime_size,
- char *loca_prime_data /* OUT */)
+ loca_data_t *loca_prime /* OUT */)
{
const hb_vector_t<hb_codepoint_t> &glyph_ids = plan->glyphs;
- const hb_map_t *glyph_map = plan->glyph_map;
char *glyf_prime_data_next = glyf_prime_data;
bool success = true;
- hb_codepoint_t gid = 0;
+ unsigned int current_gid = 0;
for (unsigned int i = 0; i < glyph_ids.length; i++)
{
- while (gid < glyph_map->get (glyph_ids[i]))
- {
- // If we are retaining existing gids then there will potentially be gaps
- // in the loca table between glyphs. Fill in this gap with glyphs that have
- // no outlines.
- success = success && _write_loca_entry (gid,
- glyf_prime_data_next - glyf_prime_data,
- use_short_loca,
- loca_prime_data,
- loca_prime_size);
- gid++;
- }
+ hb_codepoint_t next_gid = current_gid;
+ success = success && plan->new_gid_for_old_gid (glyph_ids[i], &next_gid);
+
+ // If we are retaining existing gids then there will potentially be gaps
+ // in the loca table between glyphs. Fill in this gap with glyphs that have
+ // no outlines.
+ success = success && loca_prime->_add_empty_glyphs_to_loca (current_gid,
+ next_gid,
+ glyf_prime_data_next - glyf_prime_data);
+ current_gid = next_gid;
unsigned int start_offset, end_offset;
if (unlikely (!(glyf.get_offsets (glyph_ids[i], &start_offset, &end_offset) &&
@@ -223,23 +264,19 @@
memset (glyf_prime_data_next + instruction_start - start_offset - 2, 0, 2);
}
- success = success && _write_loca_entry (gid,
- glyf_prime_data_next - glyf_prime_data,
- use_short_loca,
- loca_prime_data,
- loca_prime_size);
+ success = success && loca_prime->_write_loca_entry (current_gid,
+ glyf_prime_data_next - glyf_prime_data);
_update_components (plan, glyf_prime_data_next, length);
// TODO: don't align to two bytes if using long loca.
glyf_prime_data_next += length + (length % 2); // Align to 2 bytes for short loca.
- gid++;
+ current_gid++;
}
- success = success && _write_loca_entry (gid,
- glyf_prime_data_next - glyf_prime_data,
- use_short_loca,
- loca_prime_data,
- loca_prime_size);
+ // loca table has n+1 entries where the last entry signifies the end location of the last
+ // glyph.
+ success = success && loca_prime->_write_loca_entry (current_gid,
+ glyf_prime_data_next - glyf_prime_data);
return success;
}
@@ -248,53 +285,48 @@
const char *glyf_data,
hb_subset_plan_t *plan,
bool *use_short_loca,
- hb_blob_t **glyf_prime /* OUT */,
- hb_blob_t **loca_prime /* OUT */)
+ hb_blob_t **glyf_prime_blob /* OUT */,
+ hb_blob_t **loca_prime_blob /* OUT */)
{
// TODO(grieger): Sanity check allocation size for the new table.
- hb_vector_t<hb_codepoint_t> &glyphs_to_retain = plan->glyphs;
-
+ loca_data_t loca_prime;
unsigned int glyf_prime_size;
- unsigned int loca_prime_size;
hb_vector_t<unsigned int> instruction_ranges;
instruction_ranges.init ();
if (unlikely (!_calculate_glyf_and_loca_prime_size (glyf,
- glyphs_to_retain,
- plan->glyph_map,
- plan->drop_hints,
- use_short_loca,
+ plan,
+ &loca_prime,
&glyf_prime_size,
- &loca_prime_size,
&instruction_ranges))) {
instruction_ranges.fini ();
return false;
}
+ *use_short_loca = loca_prime.is_short;
char *glyf_prime_data = (char *) calloc (1, glyf_prime_size);
- char *loca_prime_data = (char *) calloc (1, loca_prime_size);
+ loca_prime.data = (void *) calloc (1, loca_prime.size);
if (unlikely (!_write_glyf_and_loca_prime (plan, glyf, glyf_data,
- *use_short_loca,
instruction_ranges,
glyf_prime_size, glyf_prime_data,
- loca_prime_size, loca_prime_data))) {
+ &loca_prime))) {
free (glyf_prime_data);
- free (loca_prime_data);
+ free (loca_prime.data);
instruction_ranges.fini ();
return false;
}
instruction_ranges.fini ();
- *glyf_prime = hb_blob_create (glyf_prime_data,
- glyf_prime_size,
- HB_MEMORY_MODE_READONLY,
- glyf_prime_data,
- free);
- *loca_prime = hb_blob_create (loca_prime_data,
- loca_prime_size,
- HB_MEMORY_MODE_READONLY,
- loca_prime_data,
- free);
+ *glyf_prime_blob = hb_blob_create (glyf_prime_data,
+ glyf_prime_size,
+ HB_MEMORY_MODE_READONLY,
+ glyf_prime_data,
+ free);
+ *loca_prime_blob = hb_blob_create ((char *) loca_prime.data,
+ loca_prime.size,
+ HB_MEMORY_MODE_READONLY,
+ loca_prime.data,
+ free);
return true;
}
