[Complex Text Layouts] Add third-party TextServer dependencies (ICU, HarfBuzz, Graphite).

1 files changed, 436 insertions, 0 deletions

diff --git a/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh
new file mode 100644
index 0000000000..41bd8bd6cc
--- /dev/null
+++ b/thirdparty/harfbuzz/src/hb-ot-shape-complex-indic.hh
@@ -0,0 +1,436 @@
+/*
+ * Copyright © 2012  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_OT_SHAPE_COMPLEX_INDIC_HH
+#define HB_OT_SHAPE_COMPLEX_INDIC_HH
+
+#include "hb.hh"
+
+#include "hb-ot-shape-complex.hh"
+
+
+/* buffer var allocations */
+#define indic_category() complex_var_u8_0() /* indic_category_t */
+#define indic_position() complex_var_u8_1() /* indic_position_t */
+
+
+#define INDIC_TABLE_ELEMENT_TYPE uint16_t
+
+/* Cateories used in the OpenType spec:
+ * https://docs.microsoft.com/en-us/typography/script-development/devanagari
+ */
+/* Note: This enum is duplicated in the -machine.rl source file.
+ * Not sure how to avoid duplication. */
+enum indic_category_t {
+  OT_X = 0,
+  OT_C = 1,
+  OT_V = 2,
+  OT_N = 3,
+  OT_H = 4,
+  OT_ZWNJ = 5,
+  OT_ZWJ = 6,
+  OT_M = 7,
+  OT_SM = 8,
+  /* OT_VD = 9, UNUSED; we use OT_A instead. */
+  OT_A = 10,
+  OT_PLACEHOLDER = 11,
+  OT_DOTTEDCIRCLE = 12,
+  OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
+  OT_Coeng = 14, /* Khmer-style Virama. */
+  OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
+  OT_Ra = 16,
+  OT_CM = 17,  /* Consonant-Medial. */
+  OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
+  OT_CS = 19,
+
+  /* The following are used by Khmer & Myanmar shapers.  Defined
+   * here for them to share. */
+  OT_VAbv    = 26,
+  OT_VBlw    = 27,
+  OT_VPre    = 28,
+  OT_VPst    = 29,
+};
+
+#define MEDIAL_FLAGS (FLAG (OT_CM))
+
+/* Note:
+ *
+ * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
+ * cannot happen in a consonant syllable.  The plus side however is, we can call the
+ * consonant syllable logic from the vowel syllable function and get it all right! */
+#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
+#define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
+
+
+/* Visual positions in a syllable from left to right. */
+enum indic_position_t {
+  POS_START = 0,
+
+  POS_RA_TO_BECOME_REPH = 1,
+  POS_PRE_M = 2,
+  POS_PRE_C = 3,
+
+  POS_BASE_C = 4,
+  POS_AFTER_MAIN = 5,
+
+  POS_ABOVE_C = 6,
+
+  POS_BEFORE_SUB = 7,
+  POS_BELOW_C = 8,
+  POS_AFTER_SUB = 9,
+
+  POS_BEFORE_POST = 10,
+  POS_POST_C = 11,
+  POS_AFTER_POST = 12,
+
+  POS_FINAL_C = 13,
+  POS_SMVD = 14,
+
+  POS_END = 15
+};
+
+/* Categories used in IndicSyllabicCategory.txt from UCD. */
+enum indic_syllabic_category_t {
+  INDIC_SYLLABIC_CATEGORY_OTHER				= OT_X,
+
+  INDIC_SYLLABIC_CATEGORY_AVAGRAHA			= OT_Symbol,
+  INDIC_SYLLABIC_CATEGORY_BINDU				= OT_SM,
+  INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER		= OT_PLACEHOLDER, /* Don't care. */
+  INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK		= OT_A,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT			= OT_C,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD		= OT_C,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL		= OT_CM,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER		= OT_C,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER		= OT_M, /* U+17CD only. */
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL		= OT_CM,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER		= OT_PLACEHOLDER,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA	= OT_Repha,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED		= OT_X, /* Don't care. */
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED		= OT_CM,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA	= OT_CM,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER	= OT_CS,
+  INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK		= OT_SM, /* https://github.com/harfbuzz/harfbuzz/issues/552 */
+  INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER		= OT_Coeng,
+  INDIC_SYLLABIC_CATEGORY_JOINER			= OT_ZWJ,
+  INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER		= OT_X,
+  INDIC_SYLLABIC_CATEGORY_NON_JOINER			= OT_ZWNJ,
+  INDIC_SYLLABIC_CATEGORY_NUKTA				= OT_N,
+  INDIC_SYLLABIC_CATEGORY_NUMBER			= OT_PLACEHOLDER,
+  INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER			= OT_PLACEHOLDER, /* Don't care. */
+  INDIC_SYLLABIC_CATEGORY_PURE_KILLER			= OT_M, /* Is like a vowel matra. */
+  INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER		= OT_RS,
+  INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER		= OT_SM,
+  INDIC_SYLLABIC_CATEGORY_TONE_LETTER			= OT_X,
+  INDIC_SYLLABIC_CATEGORY_TONE_MARK			= OT_N,
+  INDIC_SYLLABIC_CATEGORY_VIRAMA			= OT_H,
+  INDIC_SYLLABIC_CATEGORY_VISARGA			= OT_SM,
+  INDIC_SYLLABIC_CATEGORY_VOWEL				= OT_V,
+  INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT		= OT_M,
+  INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT		= OT_V
+};
+
+/* Categories used in IndicSMatraCategory.txt from UCD */
+enum indic_matra_category_t {
+  INDIC_MATRA_CATEGORY_NOT_APPLICABLE			= POS_END,
+
+  INDIC_MATRA_CATEGORY_LEFT				= POS_PRE_C,
+  INDIC_MATRA_CATEGORY_TOP				= POS_ABOVE_C,
+  INDIC_MATRA_CATEGORY_BOTTOM				= POS_BELOW_C,
+  INDIC_MATRA_CATEGORY_RIGHT				= POS_POST_C,
+
+  /* These should resolve to the position of the last part of the split sequence. */
+  INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
+  INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
+  INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM			= INDIC_MATRA_CATEGORY_BOTTOM,
+  INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_LEFT		= INDIC_MATRA_CATEGORY_BOTTOM,
+  INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
+  INDIC_MATRA_CATEGORY_TOP_AND_LEFT			= INDIC_MATRA_CATEGORY_TOP,
+  INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
+  INDIC_MATRA_CATEGORY_TOP_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
+
+  INDIC_MATRA_CATEGORY_OVERSTRUCK			= POS_AFTER_MAIN,
+  INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT		= POS_PRE_M
+};
+
+#define INDIC_COMBINE_CATEGORIES(S,M) \
+  ( \
+    ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
+    ( S | \
+     ( \
+      ( \
+       S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
+       S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
+       S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
+       S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
+       S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
+       S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
+       false \
+       ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
+      ) << 8 \
+     ) \
+    ) \
+   )
+
+HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
+hb_indic_get_categories (hb_codepoint_t u);
+
+
+static inline bool
+is_one_of (const hb_glyph_info_t &info, unsigned int flags)
+{
+  /* If it ligated, all bets are off. */
+  if (_hb_glyph_info_ligated (&info)) return false;
+  return !!(FLAG_UNSAFE (info.indic_category()) & flags);
+}
+
+static inline bool
+is_joiner (const hb_glyph_info_t &info)
+{
+  return is_one_of (info, JOINER_FLAGS);
+}
+
+static inline bool
+is_consonant (const hb_glyph_info_t &info)
+{
+  return is_one_of (info, CONSONANT_FLAGS);
+}
+
+static inline bool
+is_halant (const hb_glyph_info_t &info)
+{
+  return is_one_of (info, FLAG (OT_H));
+}
+
+#define IN_HALF_BLOCK(u, Base) (((u) & ~0x7Fu) == (Base))
+
+#define IS_DEVA(u) (IN_HALF_BLOCK (u, 0x0900u))
+#define IS_BENG(u) (IN_HALF_BLOCK (u, 0x0980u))
+#define IS_GURU(u) (IN_HALF_BLOCK (u, 0x0A00u))
+#define IS_GUJR(u) (IN_HALF_BLOCK (u, 0x0A80u))
+#define IS_ORYA(u) (IN_HALF_BLOCK (u, 0x0B00u))
+#define IS_TAML(u) (IN_HALF_BLOCK (u, 0x0B80u))
+#define IS_TELU(u) (IN_HALF_BLOCK (u, 0x0C00u))
+#define IS_KNDA(u) (IN_HALF_BLOCK (u, 0x0C80u))
+#define IS_MLYM(u) (IN_HALF_BLOCK (u, 0x0D00u))
+#define IS_SINH(u) (IN_HALF_BLOCK (u, 0x0D80u))
+
+
+#define MATRA_POS_LEFT(u)	POS_PRE_M
+#define MATRA_POS_RIGHT(u)	( \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_BENG(u) ? POS_AFTER_POST : \
+				  IS_GURU(u) ? POS_AFTER_POST : \
+				  IS_GUJR(u) ? POS_AFTER_POST : \
+				  IS_ORYA(u) ? POS_AFTER_POST : \
+				  IS_TAML(u) ? POS_AFTER_POST : \
+				  IS_TELU(u) ? (u <= 0x0C42u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
+				  IS_KNDA(u) ? (u < 0x0CC3u || u > 0xCD6u ? POS_BEFORE_SUB : POS_AFTER_SUB) : \
+				  IS_MLYM(u) ? POS_AFTER_POST : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+#define MATRA_POS_TOP(u)	( /* BENG and MLYM don't have top matras. */ \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_GURU(u) ? POS_AFTER_POST : /* Deviate from spec */ \
+				  IS_GUJR(u) ? POS_AFTER_SUB  : \
+				  IS_ORYA(u) ? POS_AFTER_MAIN : \
+				  IS_TAML(u) ? POS_AFTER_SUB  : \
+				  IS_TELU(u) ? POS_BEFORE_SUB : \
+				  IS_KNDA(u) ? POS_BEFORE_SUB : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+#define MATRA_POS_BOTTOM(u)	( \
+				  IS_DEVA(u) ? POS_AFTER_SUB  : \
+				  IS_BENG(u) ? POS_AFTER_SUB  : \
+				  IS_GURU(u) ? POS_AFTER_POST : \
+				  IS_GUJR(u) ? POS_AFTER_POST : \
+				  IS_ORYA(u) ? POS_AFTER_SUB  : \
+				  IS_TAML(u) ? POS_AFTER_POST : \
+				  IS_TELU(u) ? POS_BEFORE_SUB : \
+				  IS_KNDA(u) ? POS_BEFORE_SUB : \
+				  IS_MLYM(u) ? POS_AFTER_POST : \
+				  IS_SINH(u) ? POS_AFTER_SUB  : \
+				  /*default*/  POS_AFTER_SUB    \
+				)
+
+static inline indic_position_t
+matra_position_indic (hb_codepoint_t u, indic_position_t side)
+{
+  switch ((int) side)
+  {
+    case POS_PRE_C:	return MATRA_POS_LEFT (u);
+    case POS_POST_C:	return MATRA_POS_RIGHT (u);
+    case POS_ABOVE_C:	return MATRA_POS_TOP (u);
+    case POS_BELOW_C:	return MATRA_POS_BOTTOM (u);
+  }
+  return side;
+}
+
+/* XXX
+ * This is a hack for now.  We should move this data into the main Indic table.
+ * Or completely remove it and just check in the tables.
+ */
+static const hb_codepoint_t ra_chars[] = {
+  0x0930u, /* Devanagari */
+  0x09B0u, /* Bengali */
+  0x09F0u, /* Bengali */
+  0x0A30u, /* Gurmukhi */	/* No Reph */
+  0x0AB0u, /* Gujarati */
+  0x0B30u, /* Oriya */
+  0x0BB0u, /* Tamil */		/* No Reph */
+  0x0C30u, /* Telugu */		/* Reph formed only with ZWJ */
+  0x0CB0u, /* Kannada */
+  0x0D30u, /* Malayalam */	/* No Reph, Logical Repha */
+
+  0x0DBBu, /* Sinhala */	/* Reph formed only with ZWJ */
+
+  0x179Au, /* Khmer */
+};
+
+static inline bool
+is_ra (hb_codepoint_t u)
+{
+  for (unsigned int i = 0; i < ARRAY_LENGTH (ra_chars); i++)
+    if (u == ra_chars[i])
+      return true;
+  return false;
+}
+
+static inline void
+set_indic_properties (hb_glyph_info_t &info)
+{
+  hb_codepoint_t u = info.codepoint;
+  unsigned int type = hb_indic_get_categories (u);
+  indic_category_t cat = (indic_category_t) (type & 0x7Fu);
+  indic_position_t pos = (indic_position_t) (type >> 8);
+
+
+  /*
+   * Re-assign category
+   */
+
+  /* The following act more like the Bindus. */
+  if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x0953u, 0x0954u)))
+    cat = OT_SM;
+  /* The following act like consonants. */
+  else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0x0A72u, 0x0A73u,
+				      0x1CF5u, 0x1CF6u)))
+    cat = OT_C;
+  /* TODO: The following should only be allowed after a Visarga.
+   * For now, just treat them like regular tone marks. */
+  else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x1CE2u, 0x1CE8u)))
+    cat = OT_A;
+  /* TODO: The following should only be allowed after some of
+   * the nasalization marks, maybe only for U+1CE9..U+1CF1.
+   * For now, just treat them like tone marks. */
+  else if (unlikely (u == 0x1CEDu))
+    cat = OT_A;
+  /* The following take marks in standalone clusters, similar to Avagraha. */
+  else if (unlikely (hb_in_ranges<hb_codepoint_t> (u, 0xA8F2u, 0xA8F7u,
+				      0x1CE9u, 0x1CECu,
+				      0x1CEEu, 0x1CF1u)))
+  {
+    cat = OT_Symbol;
+    static_assert (((int) INDIC_SYLLABIC_CATEGORY_AVAGRAHA == OT_Symbol), "");
+  }
+  else if (unlikely (u == 0x0A51u))
+  {
+    /* https://github.com/harfbuzz/harfbuzz/issues/524 */
+    cat = OT_M;
+    pos = POS_BELOW_C;
+  }
+
+  /* According to ScriptExtensions.txt, these Grantha marks may also be used in Tamil,
+   * so the Indic shaper needs to know their categories. */
+  else if (unlikely (u == 0x11301u || u == 0x11303u)) cat = OT_SM;
+  else if (unlikely (u == 0x1133Bu || u == 0x1133Cu)) cat = OT_N;
+
+  else if (unlikely (u == 0x0AFBu)) cat = OT_N; /* https://github.com/harfbuzz/harfbuzz/issues/552 */
+
+  else if (unlikely (u == 0x0980u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/issues/538 */
+  else if (unlikely (u == 0x09FCu)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/1613 */
+  else if (unlikely (u == 0x0C80u)) cat = OT_PLACEHOLDER; /* https://github.com/harfbuzz/harfbuzz/pull/623 */
+  else if (unlikely (hb_in_range<hb_codepoint_t> (u, 0x2010u, 0x2011u)))
+				    cat = OT_PLACEHOLDER;
+  else if (unlikely (u == 0x25CCu)) cat = OT_DOTTEDCIRCLE;
+
+
+  /*
+   * Re-assign position.
+   */
+
+  if ((FLAG_UNSAFE (cat) & CONSONANT_FLAGS))
+  {
+    pos = POS_BASE_C;
+    if (is_ra (u))
+      cat = OT_Ra;
+  }
+  else if (cat == OT_M)
+  {
+    pos = matra_position_indic (u, pos);
+  }
+  else if ((FLAG_UNSAFE (cat) & (FLAG (OT_SM) /* | FLAG (OT_VD) */ | FLAG (OT_A) | FLAG (OT_Symbol))))
+  {
+    pos = POS_SMVD;
+  }
+
+  if (unlikely (u == 0x0B01u)) pos = POS_BEFORE_SUB; /* Oriya Bindu is BeforeSub in the spec. */
+
+
+
+  info.indic_category() = cat;
+  info.indic_position() = pos;
+}
+
+struct hb_indic_would_substitute_feature_t
+{
+  void init (const hb_ot_map_t *map, hb_tag_t feature_tag, bool zero_context_)
+  {
+    zero_context = zero_context_;
+    map->get_stage_lookups (0/*GSUB*/,
+			    map->get_feature_stage (0/*GSUB*/, feature_tag),
+			    &lookups, &count);
+  }
+
+  bool would_substitute (const hb_codepoint_t *glyphs,
+			 unsigned int          glyphs_count,
+			 hb_face_t            *face) const
+  {
+    for (unsigned int i = 0; i < count; i++)
+      if (hb_ot_layout_lookup_would_substitute (face, lookups[i].index, glyphs, glyphs_count, zero_context))
+	return true;
+    return false;
+  }
+
+  private:
+  const hb_ot_map_t::lookup_map_t *lookups;
+  unsigned int count;
+  bool zero_context;
+};
+
+
+#endif /* HB_OT_SHAPE_COMPLEX_INDIC_HH */