harfbuzz-ng roll

third_party/harfbuzz-ng/src/hb-ot-layout-private.hh

Index: third_party/harfbuzz-ng/src/hb-ot-layout-private.hh
diff --git a/third_party/harfbuzz-ng/src/hb-ot-layout-private.hh b/third_party/harfbuzz-ng/src/hb-ot-layout-private.hh
index f860e7bd1dec93a6df8971bbb75ad0f31a43bf5e..70fda8ead8e4c82c75788238ee1cc1bbdcc9b763 100644
--- a/third_party/harfbuzz-ng/src/hb-ot-layout-private.hh
+++ b/third_party/harfbuzz-ng/src/hb-ot-layout-private.hh
@@ -1,5 +1,6 @@
 /*
  * Copyright © 2007,2008,2009  Red Hat, Inc.
+ * Copyright © 2012  Google, Inc.
  *
  *  This is part of HarfBuzz, a text shaping library.
  *
@@ -22,6 +23,7 @@
  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
  */
 
 #ifndef HB_OT_LAYOUT_PRIVATE_HH
@@ -33,15 +35,20 @@
 
 #include "hb-font-private.hh"
 #include "hb-buffer-private.hh"
-#include "hb-ot-shape-complex-private.hh"
+#include "hb-set-private.hh"
 
 
+/* buffer var allocations, used during the GSUB/GPOS processing */
+#define glyph_props()		var1.u16[0] /* GDEF glyph properties */
+#define syllable()		var1.u8[2] /* GSUB/GPOS shaping boundaries */
+#define lig_props()		var1.u8[3] /* GSUB/GPOS ligature tracking */
+
+#define hb_ot_layout_from_face(face) ((hb_ot_layout_t *) face->shaper_data.ot)
 
 /*
  * GDEF
  */
 
-/* XXX cleanup */
 typedef enum {
   HB_OT_LAYOUT_GLYPH_CLASS_UNCLASSIFIED	= 0x0001,
   HB_OT_LAYOUT_GLYPH_CLASS_BASE_GLYPH	= 0x0002,
@@ -51,21 +58,126 @@ typedef enum {
 } hb_ot_layout_glyph_class_t;
 
 
-HB_INTERNAL unsigned int
-_hb_ot_layout_get_glyph_property (hb_face_t       *face,
-				  hb_glyph_info_t *info);
+
+/*
+ * GSUB/GPOS
+ */
+
+/* lig_id / lig_comp
+ *
+ * When a ligature is formed:
+ *
+ *   - The ligature glyph and any marks in between all the same newly allocated
+ *     lig_id,
+ *   - The ligature glyph will get lig_num_comps set to the number of components
+ *   - The marks get lig_comp > 0, reflecting which component of the ligature
+ *     they were applied to.
+ *   - This is used in GPOS to attach marks to the right component of a ligature
+ *     in MarkLigPos.
+ *
+ * When a multiple-substitution is done:
+ *
+ *   - All resulting glyphs will have lig_id = 0,
+ *   - The resulting glyphs will have lig_comp = 0, 1, 2, ... respectively.
+ *   - This is used in GPOS to attach marks to the first component of a
+ *     multiple substitution in MarkBasePos.
+ *
+ * The numbers are also used in GPOS to do mark-to-mark positioning only
+ * to marks that belong to the same component of a ligature in MarkMarPos.
+ */
+#define IS_LIG_BASE 0x10
+static inline void
+set_lig_props_for_ligature (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_num_comps)
+{
+  info.lig_props() = (lig_id << 5) | IS_LIG_BASE | (lig_num_comps & 0x0F);
+}
+static inline void
+set_lig_props_for_mark (hb_glyph_info_t &info, unsigned int lig_id, unsigned int lig_comp)
+{
+  info.lig_props() = (lig_id << 5) | (lig_comp & 0x0F);
+}
+static inline void
+set_lig_props_for_component (hb_glyph_info_t &info, unsigned int comp)
+{
+  set_lig_props_for_mark (info, 0, comp);
+}
+
+static inline unsigned int
+get_lig_id (const hb_glyph_info_t &info)
+{
+  return info.lig_props() >> 5;
+}
+static inline bool
+is_a_ligature (const hb_glyph_info_t &info)
+{
+  return !!(info.lig_props() & IS_LIG_BASE);
+}
+static inline unsigned int
+get_lig_comp (const hb_glyph_info_t &info)
+{
+  if (is_a_ligature (info))
+    return 0;
+  else
+    return info.lig_props() & 0x0F;
+}
+static inline unsigned int
+get_lig_num_comps (const hb_glyph_info_t &info)
+{
+  if ((info.glyph_props() & HB_OT_LAYOUT_GLYPH_CLASS_LIGATURE) && is_a_ligature (info))
+    return info.lig_props() & 0x0F;
+  else
+    return 1;
+}
+
+static inline uint8_t allocate_lig_id (hb_buffer_t *buffer) {
+  uint8_t lig_id = buffer->next_serial () & 0x07;
+  if (unlikely (!lig_id))
+    lig_id = allocate_lig_id (buffer); /* in case of overflow */
+  return lig_id;
+}
+
 
 HB_INTERNAL hb_bool_t
-_hb_ot_layout_check_glyph_property (hb_face_t    *face,
-				    hb_glyph_info_t *ginfo,
-				    unsigned int  lookup_props,
-				    unsigned int *property_out);
+hb_ot_layout_would_substitute_lookup_fast (hb_face_t            *face,
+					   unsigned int          lookup_index,
+					   const hb_codepoint_t *glyphs,
+					   unsigned int          glyphs_length,
+					   hb_bool_t             zero_context);
+
+
+/* Should be called before all the substitute_lookup's are done. */
+HB_INTERNAL void
+hb_ot_layout_substitute_start (hb_font_t    *font,
+			       hb_buffer_t  *buffer);
+
+HB_INTERNAL hb_bool_t
+hb_ot_layout_substitute_lookup (hb_font_t    *font,
+				hb_buffer_t  *buffer,
+				unsigned int  lookup_index,
+				hb_mask_t     mask);
+
+/* Should be called after all the substitute_lookup's are done */
+HB_INTERNAL void
+hb_ot_layout_substitute_finish (hb_font_t    *font,
+				hb_buffer_t  *buffer);
+
+
+/* Should be called before all the position_lookup's are done.  Resets positions to zero. */
+HB_INTERNAL void
+hb_ot_layout_position_start (hb_font_t    *font,
+			     hb_buffer_t  *buffer);
 
 HB_INTERNAL hb_bool_t
-_hb_ot_layout_skip_mark (hb_face_t    *face,
-			 hb_glyph_info_t *ginfo,
-			 unsigned int  lookup_props,
-			 unsigned int *property_out);
+hb_ot_layout_position_lookup (hb_font_t    *font,
+			      hb_buffer_t  *buffer,
+			      unsigned int  lookup_index,
+			      hb_mask_t     mask);
+
+/* Should be called after all the position_lookup's are done */
+HB_INTERNAL void
+hb_ot_layout_position_finish (hb_font_t    *font,
+			      hb_buffer_t  *buffer,
+			      hb_bool_t     zero_width_attached_marks);
 
 
 
@@ -73,15 +185,27 @@ _hb_ot_layout_skip_mark (hb_face_t    *face,
  * hb_ot_layout_t
  */
 
+namespace OT {
+  struct GDEF;
+  struct GSUB;
+  struct GPOS;
+}
+
 struct hb_ot_layout_t
 {
   hb_blob_t *gdef_blob;
   hb_blob_t *gsub_blob;
   hb_blob_t *gpos_blob;
 
-  const struct GDEF *gdef;
-  const struct GSUB *gsub;
-  const struct GPOS *gpos;
+  const struct OT::GDEF *gdef;
+  const struct OT::GSUB *gsub;
+  const struct OT::GPOS *gpos;
+
+  unsigned int gsub_lookup_count;
+  unsigned int gpos_lookup_count;
+
+  hb_set_digest_t *gsub_digests;
+  hb_set_digest_t *gpos_digests;
 };