1 files changed, 90 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/OT/glyf/glyf-helpers.hh b/gfx/harfbuzz/src/OT/glyf/glyf-helpers.hh
new file mode 100644
index 0000000000..181c33d06d
--- /dev/null
+++ b/gfx/harfbuzz/src/OT/glyf/glyf-helpers.hh
@@ -0,0 +1,90 @@
+#ifndef OT_GLYF_GLYF_HELPERS_HH
+#define OT_GLYF_GLYF_HELPERS_HH
+
+
+#include "../../hb-open-type.hh"
+#include "../../hb-subset-plan.hh"
+
+#include "loca.hh"
+
+
+namespace OT {
+namespace glyf_impl {
+
+
+template<typename IteratorIn, typename IteratorOut,
+	 hb_requires (hb_is_source_of (IteratorIn, unsigned int)),
+	 hb_requires (hb_is_sink_of (IteratorOut, unsigned))>
+static void
+_write_loca (IteratorIn&& it, bool short_offsets, IteratorOut&& dest)
+{
+  unsigned right_shift = short_offsets ? 1 : 0;
+  unsigned int offset = 0;
+  dest << 0;
+  + it
+  | hb_map ([=, &offset] (unsigned int padded_size)
+	    {
+	      offset += padded_size;
+	      DEBUG_MSG (SUBSET, nullptr, "loca entry offset %d", offset);
+	      return offset >> right_shift;
+	    })
+  | hb_sink (dest)
+  ;
+}
+
+static bool
+_add_head_and_set_loca_version (hb_subset_plan_t *plan, bool use_short_loca)
+{
+  hb_blob_t *head_blob = hb_sanitize_context_t ().reference_table<head> (plan->source);
+  hb_blob_t *head_prime_blob = hb_blob_copy_writable_or_fail (head_blob);
+  hb_blob_destroy (head_blob);
+
+  if (unlikely (!head_prime_blob))
+    return false;
+
+  head *head_prime = (head *) hb_blob_get_data_writable (head_prime_blob, nullptr);
+  head_prime->indexToLocFormat = use_short_loca ? 0 : 1;
+  bool success = plan->add_table (HB_OT_TAG_head, head_prime_blob);
+
+  hb_blob_destroy (head_prime_blob);
+  return success;
+}
+
+template<typename Iterator,
+	 hb_requires (hb_is_source_of (Iterator, unsigned int))>
+static bool
+_add_loca_and_head (hb_subset_plan_t * plan, Iterator padded_offsets, bool use_short_loca)
+{
+  unsigned num_offsets = padded_offsets.len () + 1;
+  unsigned entry_size = use_short_loca ? 2 : 4;
+  char *loca_prime_data = (char *) hb_calloc (entry_size, num_offsets);
+
+  if (unlikely (!loca_prime_data)) return false;
+
+  DEBUG_MSG (SUBSET, nullptr, "loca entry_size %d num_offsets %d size %d",
+	     entry_size, num_offsets, entry_size * num_offsets);
+
+  if (use_short_loca)
+    _write_loca (padded_offsets, true, hb_array ((HBUINT16 *) loca_prime_data, num_offsets));
+  else
+    _write_loca (padded_offsets, false, hb_array ((HBUINT32 *) loca_prime_data, num_offsets));
+
+  hb_blob_t *loca_blob = hb_blob_create (loca_prime_data,
+					 entry_size * num_offsets,
+					 HB_MEMORY_MODE_WRITABLE,
+					 loca_prime_data,
+					 hb_free);
+
+  bool result = plan->add_table (HB_OT_TAG_loca, loca_blob)
+	     && _add_head_and_set_loca_version (plan, use_short_loca);
+
+  hb_blob_destroy (loca_blob);
+  return result;
+}
+
+
+} /* namespace glyf_impl */
+} /* namespace OT */
+
+
+#endif /* OT_GLYF_GLYF_HELPERS_HH */