Index: third_party/harfbuzz-ng/src/hb-ot-shape-complex-indic.cc |
diff --git a/third_party/harfbuzz-ng/src/hb-ot-shape-complex-indic.cc b/third_party/harfbuzz-ng/src/hb-ot-shape-complex-indic.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..9f50ef20fba45401c241a5b2f1f8282f158098fc |
--- /dev/null |
+++ b/third_party/harfbuzz-ng/src/hb-ot-shape-complex-indic.cc |
@@ -0,0 +1,765 @@ |
+/* |
+ * Copyright © 2011 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 |
+ */ |
+ |
+#include "hb-ot-shape-complex-private.hh" |
+ |
+ |
+ |
+/* buffer var allocations */ |
+#define indic_category() complex_var_persistent_u8_0() /* indic_category_t */ |
+#define indic_position() complex_var_persistent_u8_1() /* indic_matra_category_t */ |
+ |
+#define INDIC_TABLE_ELEMENT_TYPE uint8_t |
+ |
+/* Cateories used in the OpenType spec: |
+ * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx |
+ */ |
+/* 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, |
+ OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */ |
+ OT_V, |
+ OT_N, |
+ OT_H, |
+ OT_ZWNJ, |
+ OT_ZWJ, |
+ OT_M, |
+ OT_SM, |
+ OT_VD, |
+ OT_A, |
+ OT_NBSP |
+}; |
+ |
+/* Visual positions in a syllable from left to right. */ |
+enum indic_position_t { |
+ POS_PRE, |
+ POS_BASE, |
+ POS_ABOVE, |
+ POS_BELOW, |
+ POS_POST |
+}; |
+ |
+/* Categories used in IndicSyllabicCategory.txt from UCD */ |
+/* The assignments are guesswork */ |
+enum indic_syllabic_category_t { |
+ INDIC_SYLLABIC_CATEGORY_OTHER = OT_X, |
+ |
+ INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_X, |
+ INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA = OT_C, |
+ INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X, |
+ INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N, |
+ INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_X, |
+ INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X, |
+ INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_X, |
+ 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_BASE, |
+ |
+ INDIC_MATRA_CATEGORY_LEFT = POS_PRE, |
+ INDIC_MATRA_CATEGORY_TOP = POS_ABOVE, |
+ INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW, |
+ INDIC_MATRA_CATEGORY_RIGHT = POS_POST, |
+ |
+ /* We don't really care much about these since we decompose them |
+ * in the generic pre-shaping layer. They will only be used if |
+ * the font does not cover the decomposition. In which case, we |
+ * define these as aliases to the place we want the split-matra |
+ * glyph to show up. Quite arbitrary. */ |
+ INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM, |
+ INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT, |
+ INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM, |
+ INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM, |
+ INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_LEFT, |
+ INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT, |
+ INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT, |
+ |
+ INDIC_MATRA_CATEGORY_INVISIBLE = INDIC_MATRA_CATEGORY_NOT_APPLICABLE, |
+ INDIC_MATRA_CATEGORY_OVERSTRUCK = INDIC_MATRA_CATEGORY_NOT_APPLICABLE, |
+ INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = INDIC_MATRA_CATEGORY_NOT_APPLICABLE |
+}; |
+ |
+/* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation |
+ * because gcc fails to optimize the latter and fills the table in at runtime. */ |
+#define INDIC_COMBINE_CATEGORIES(S,M) \ |
+ (ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)) + \ |
+ ASSERT_STATIC_EXPR_ZERO (S < 16 && M < 16) + \ |
+ ((M << 4) | S)) |
+ |
+#include "hb-ot-shape-complex-indic-table.hh" |
+ |
+/* XXX |
+ * This is a hack for now. We should: |
+ * 1. Move this data into the main Indic table, |
+ * and/or |
+ * 2. Probe font lookups to determine consonant positions. |
+ */ |
+static const struct consonant_position_t { |
+ hb_codepoint_t u; |
+ indic_position_t position; |
+} consonant_positions[] = { |
+ {0x0930, POS_BELOW}, |
+ {0x09AC, POS_BELOW}, |
+ {0x09AF, POS_POST}, |
+ {0x09B0, POS_BELOW}, |
+ {0x09F0, POS_BELOW}, |
+ {0x0A2F, POS_POST}, |
+ {0x0A30, POS_BELOW}, |
+ {0x0A35, POS_BELOW}, |
+ {0x0A39, POS_BELOW}, |
+ {0x0AB0, POS_BELOW}, |
+ {0x0B24, POS_BELOW}, |
+ {0x0B28, POS_BELOW}, |
+ {0x0B2C, POS_BELOW}, |
+ {0x0B2D, POS_BELOW}, |
+ {0x0B2E, POS_BELOW}, |
+ {0x0B2F, POS_POST}, |
+ {0x0B30, POS_BELOW}, |
+ {0x0B32, POS_BELOW}, |
+ {0x0B33, POS_BELOW}, |
+ {0x0B5F, POS_POST}, |
+ {0x0B71, POS_BELOW}, |
+ {0x0C15, POS_BELOW}, |
+ {0x0C16, POS_BELOW}, |
+ {0x0C17, POS_BELOW}, |
+ {0x0C18, POS_BELOW}, |
+ {0x0C19, POS_BELOW}, |
+ {0x0C1A, POS_BELOW}, |
+ {0x0C1B, POS_BELOW}, |
+ {0x0C1C, POS_BELOW}, |
+ {0x0C1D, POS_BELOW}, |
+ {0x0C1E, POS_BELOW}, |
+ {0x0C1F, POS_BELOW}, |
+ {0x0C20, POS_BELOW}, |
+ {0x0C21, POS_BELOW}, |
+ {0x0C22, POS_BELOW}, |
+ {0x0C23, POS_BELOW}, |
+ {0x0C24, POS_BELOW}, |
+ {0x0C25, POS_BELOW}, |
+ {0x0C26, POS_BELOW}, |
+ {0x0C27, POS_BELOW}, |
+ {0x0C28, POS_BELOW}, |
+ {0x0C2A, POS_BELOW}, |
+ {0x0C2B, POS_BELOW}, |
+ {0x0C2C, POS_BELOW}, |
+ {0x0C2D, POS_BELOW}, |
+ {0x0C2E, POS_BELOW}, |
+ {0x0C2F, POS_BELOW}, |
+ {0x0C30, POS_BELOW}, |
+ {0x0C32, POS_BELOW}, |
+ {0x0C33, POS_BELOW}, |
+ {0x0C35, POS_BELOW}, |
+ {0x0C36, POS_BELOW}, |
+ {0x0C37, POS_BELOW}, |
+ {0x0C38, POS_BELOW}, |
+ {0x0C39, POS_BELOW}, |
+ {0x0C95, POS_BELOW}, |
+ {0x0C96, POS_BELOW}, |
+ {0x0C97, POS_BELOW}, |
+ {0x0C98, POS_BELOW}, |
+ {0x0C99, POS_BELOW}, |
+ {0x0C9A, POS_BELOW}, |
+ {0x0C9B, POS_BELOW}, |
+ {0x0C9C, POS_BELOW}, |
+ {0x0C9D, POS_BELOW}, |
+ {0x0C9E, POS_BELOW}, |
+ {0x0C9F, POS_BELOW}, |
+ {0x0CA0, POS_BELOW}, |
+ {0x0CA1, POS_BELOW}, |
+ {0x0CA2, POS_BELOW}, |
+ {0x0CA3, POS_BELOW}, |
+ {0x0CA4, POS_BELOW}, |
+ {0x0CA5, POS_BELOW}, |
+ {0x0CA6, POS_BELOW}, |
+ {0x0CA7, POS_BELOW}, |
+ {0x0CA8, POS_BELOW}, |
+ {0x0CAA, POS_BELOW}, |
+ {0x0CAB, POS_BELOW}, |
+ {0x0CAC, POS_BELOW}, |
+ {0x0CAD, POS_BELOW}, |
+ {0x0CAE, POS_BELOW}, |
+ {0x0CAF, POS_BELOW}, |
+ {0x0CB0, POS_BELOW}, |
+ {0x0CB2, POS_BELOW}, |
+ {0x0CB3, POS_BELOW}, |
+ {0x0CB5, POS_BELOW}, |
+ {0x0CB6, POS_BELOW}, |
+ {0x0CB7, POS_BELOW}, |
+ {0x0CB8, POS_BELOW}, |
+ {0x0CB9, POS_BELOW}, |
+ {0x0CDE, POS_BELOW}, |
+ {0x0D2F, POS_POST}, |
+ {0x0D30, POS_POST}, |
+ {0x0D32, POS_BELOW}, |
+ {0x0D35, POS_POST}, |
+}; |
+ |
+/* XXX |
+ * This is a hack for now. We should move this data into the main Indic table. |
+ */ |
+static const hb_codepoint_t ra_chars[] = { |
+ 0x0930, /* Devanagari */ |
+ 0x09B0, /* Bengali */ |
+ 0x09F0, /* Bengali */ |
+//0x09F1, /* Bengali */ |
+//0x0A30, /* Gurmukhi */ |
+ 0x0AB0, /* Gujarati */ |
+ 0x0B30, /* Oriya */ |
+//0x0BB0, /* Tamil */ |
+//0x0C30, /* Telugu */ |
+ 0x0CB0, /* Kannada */ |
+//0x0D30, /* Malayalam */ |
+}; |
+ |
+static int |
+compare_codepoint (const void *pa, const void *pb) |
+{ |
+ hb_codepoint_t a = * (hb_codepoint_t *) pa; |
+ hb_codepoint_t b = * (hb_codepoint_t *) pb; |
+ |
+ return a < b ? -1 : a == b ? 0 : +1; |
+} |
+ |
+static indic_position_t |
+consonant_position (hb_codepoint_t u) |
+{ |
+ consonant_position_t *record; |
+ |
+ record = (consonant_position_t *) bsearch (&u, consonant_positions, |
+ ARRAY_LENGTH (consonant_positions), |
+ sizeof (consonant_positions[0]), |
+ compare_codepoint); |
+ |
+ return record ? record->position : POS_BASE; |
+} |
+ |
+static bool |
+is_ra (hb_codepoint_t u) |
+{ |
+ return !!bsearch (&u, ra_chars, |
+ ARRAY_LENGTH (ra_chars), |
+ sizeof (ra_chars[0]), |
+ compare_codepoint); |
+} |
+ |
+static bool |
+is_joiner (const hb_glyph_info_t &info) |
+{ |
+ return !!(FLAG (info.indic_category()) & (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))); |
+} |
+ |
+static bool |
+is_consonant (const hb_glyph_info_t &info) |
+{ |
+ return !!(FLAG (info.indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra))); |
+} |
+ |
+static const struct { |
+ hb_tag_t tag; |
+ hb_bool_t is_global; |
+} indic_basic_features[] = |
+{ |
+ {HB_TAG('n','u','k','t'), true}, |
+ {HB_TAG('a','k','h','n'), false}, |
+ {HB_TAG('r','p','h','f'), false}, |
+ {HB_TAG('r','k','r','f'), false}, |
+ {HB_TAG('p','r','e','f'), false}, |
+ {HB_TAG('b','l','w','f'), false}, |
+ {HB_TAG('h','a','l','f'), false}, |
+ {HB_TAG('v','a','t','u'), true}, |
+ {HB_TAG('p','s','t','f'), false}, |
+ {HB_TAG('c','j','c','t'), false}, |
+}; |
+ |
+/* Same order as the indic_basic_features array */ |
+enum { |
+ _NUKT, |
+ AKHN, |
+ RPHF, |
+ RKRF, |
+ PREF, |
+ BLWF, |
+ HALF, |
+ _VATU, |
+ PSTF, |
+ CJCT |
+}; |
+ |
+static const hb_tag_t indic_other_features[] = |
+{ |
+ HB_TAG('p','r','e','s'), |
+ HB_TAG('a','b','v','s'), |
+ HB_TAG('b','l','w','s'), |
+ HB_TAG('p','s','t','s'), |
+ HB_TAG('h','a','l','n'), |
+ |
+ HB_TAG('d','i','s','t'), |
+ HB_TAG('a','b','v','m'), |
+ HB_TAG('b','l','w','m'), |
+}; |
+ |
+ |
+static void |
+initial_reordering (const hb_ot_map_t *map, |
+ hb_face_t *face, |
+ hb_buffer_t *buffer, |
+ void *user_data HB_UNUSED); |
+static void |
+final_reordering (const hb_ot_map_t *map, |
+ hb_face_t *face, |
+ hb_buffer_t *buffer, |
+ void *user_data HB_UNUSED); |
+ |
+void |
+_hb_ot_shape_complex_collect_features_indic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props) |
+{ |
+ map->add_bool_feature (HB_TAG('l','o','c','l')); |
+ /* The Indic specs do not require ccmp, but we apply it here since if |
+ * there is a use of it, it's typically at the beginning. */ |
+ map->add_bool_feature (HB_TAG('c','c','m','p')); |
+ |
+ map->add_gsub_pause (initial_reordering, NULL); |
+ |
+ for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++) |
+ map->add_bool_feature (indic_basic_features[i].tag, indic_basic_features[i].is_global); |
+ |
+ map->add_gsub_pause (final_reordering, NULL); |
+ |
+ for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++) |
+ map->add_bool_feature (indic_other_features[i], true); |
+} |
+ |
+ |
+bool |
+_hb_ot_shape_complex_prefer_decomposed_indic (void) |
+{ |
+ /* We want split matras decomposed by the common shaping logic. */ |
+ return TRUE; |
+} |
+ |
+ |
+void |
+_hb_ot_shape_complex_setup_masks_indic (hb_ot_map_t *map, hb_buffer_t *buffer) |
+{ |
+ HB_BUFFER_ALLOCATE_VAR (buffer, indic_category); |
+ HB_BUFFER_ALLOCATE_VAR (buffer, indic_position); |
+ |
+ /* We cannot setup masks here. We save information about characters |
+ * and setup masks later on in a pause-callback. */ |
+ |
+ unsigned int count = buffer->len; |
+ for (unsigned int i = 0; i < count; i++) |
+ { |
+ unsigned int type = get_indic_categories (buffer->info[i].codepoint); |
+ |
+ buffer->info[i].indic_category() = type & 0x0F; |
+ buffer->info[i].indic_position() = type >> 4; |
+ |
+ if (buffer->info[i].indic_category() == OT_C) { |
+ buffer->info[i].indic_position() = consonant_position (buffer->info[i].codepoint); |
+ if (is_ra (buffer->info[i].codepoint)) |
+ buffer->info[i].indic_category() = OT_Ra; |
+ } else if (buffer->info[i].codepoint == 0x200C) |
+ buffer->info[i].indic_category() = OT_ZWNJ; |
+ else if (buffer->info[i].codepoint == 0x200D) |
+ buffer->info[i].indic_category() = OT_ZWJ; |
+ } |
+} |
+ |
+static int |
+compare_indic_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb) |
+{ |
+ int a = pa->indic_position(); |
+ int b = pb->indic_position(); |
+ |
+ return a < b ? -1 : a == b ? 0 : +1; |
+} |
+ |
+static void |
+found_consonant_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, |
+ unsigned int start, unsigned int end) |
+{ |
+ unsigned int i; |
+ hb_glyph_info_t *info = buffer->info; |
+ |
+ /* Comments from: |
+ * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */ |
+ |
+ /* 1. Find base consonant: |
+ * |
+ * The shaping engine finds the base consonant of the syllable, using the |
+ * following algorithm: starting from the end of the syllable, move backwards |
+ * until a consonant is found that does not have a below-base or post-base |
+ * form (post-base forms have to follow below-base forms), or that is not a |
+ * pre-base reordering Ra, or arrive at the first consonant. The consonant |
+ * stopped at will be the base. |
+ * |
+ * o If the syllable starts with Ra + Halant (in a script that has Reph) |
+ * and has more than one consonant, Ra is excluded from candidates for |
+ * base consonants. |
+ */ |
+ |
+ unsigned int base = end; |
+ |
+ /* -> starting from the end of the syllable, move backwards */ |
+ i = end; |
+ unsigned int limit = start; |
+ if (info[start].indic_category() == OT_Ra && start + 2 <= end) { |
+ limit += 2; |
+ base = start; |
+ }; |
+ do { |
+ i--; |
+ /* -> until a consonant is found */ |
+ if (is_consonant (info[i])) |
+ { |
+ /* -> that does not have a below-base or post-base form |
+ * (post-base forms have to follow below-base forms), */ |
+ if (info[i].indic_position() != POS_BELOW && |
+ info[i].indic_position() != POS_POST) |
+ { |
+ base = i; |
+ break; |
+ } |
+ |
+ /* -> or that is not a pre-base reordering Ra, |
+ * |
+ * TODO |
+ */ |
+ |
+ /* -> o If the syllable starts with Ra + Halant (in a script that has Reph) |
+ * and has more than one consonant, Ra is excluded from candidates for |
+ * base consonants. |
+ * |
+ * IMPLEMENTATION NOTES: |
+ * |
+ * We do this by adjusting limit accordingly before entering the loop. |
+ */ |
+ |
+ /* -> or arrive at the first consonant. The consonant stopped at will |
+ * be the base. */ |
+ base = i; |
+ } |
+ else |
+ if (is_joiner (info[i])) |
+ break; |
+ } while (i > limit); |
+ if (base < start) |
+ base = start; /* Just in case... */ |
+ |
+ |
+ /* 2. Decompose and reorder Matras: |
+ * |
+ * Each matra and any syllable modifier sign in the cluster are moved to the |
+ * appropriate position relative to the consonant(s) in the cluster. The |
+ * shaping engine decomposes two- or three-part matras into their constituent |
+ * parts before any repositioning. Matra characters are classified by which |
+ * consonant in a conjunct they have affinity for and are reordered to the |
+ * following positions: |
+ * |
+ * o Before first half form in the syllable |
+ * o After subjoined consonants |
+ * o After post-form consonant |
+ * o After main consonant (for above marks) |
+ * |
+ * IMPLEMENTATION NOTES: |
+ * |
+ * The normalize() routine has already decomposed matras for us, so we don't |
+ * need to worry about that. |
+ */ |
+ |
+ |
+ /* 3. Reorder marks to canonical order: |
+ * |
+ * Adjacent nukta and halant or nukta and vedic sign are always repositioned |
+ * if necessary, so that the nukta is first. |
+ * |
+ * IMPLEMENTATION NOTES: |
+ * |
+ * We don't need to do this: the normalize() routine already did this for us. |
+ */ |
+ |
+ |
+ /* Reorder characters */ |
+ |
+ for (i = start; i < base; i++) |
+ info[i].indic_position() = POS_PRE; |
+ info[base].indic_position() = POS_BASE; |
+ |
+ |
+ /* Handle beginning Ra */ |
+ if (start + 3 <= end && |
+ info[start].indic_category() == OT_Ra && |
+ info[start + 1].indic_category() == OT_H && |
+ !is_joiner (info[start + 2])) |
+ { |
+ info[start].indic_position() = POS_POST; |
+ info[start].mask = mask_array[RPHF]; |
+ } |
+ |
+ /* For old-style Indic script tags, move the first post-base Halant after |
+ * last consonant. */ |
+ if ((map->get_chosen_script (0) & 0x000000FF) != '2') { |
+ /* We should only do this for Indic scripts which have a version two I guess. */ |
+ for (i = base + 1; i < end; i++) |
+ if (info[i].indic_category() == OT_H) { |
+ unsigned int j; |
+ for (j = end - 1; j > i; j--) |
+ if ((FLAG (info[j].indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra)))) |
+ break; |
+ if (j > i) { |
+ /* Move Halant to after last consonant. */ |
+ hb_glyph_info_t t = info[i]; |
+ memmove (&info[i], &info[i + 1], (j - i) * sizeof (info[0])); |
+ info[j] = t; |
+ } |
+ break; |
+ } |
+ } |
+ |
+ /* Attach ZWJ, ZWNJ, nukta, and halant to previous char to move with them. */ |
+ for (i = start + 1; i < end; i++) |
+ if ((FLAG (info[i].indic_category()) & |
+ (FLAG (OT_ZWNJ) | FLAG (OT_ZWJ) | FLAG (OT_N) | FLAG (OT_H)))) |
+ info[i].indic_position() = info[i - 1].indic_position(); |
+ |
+ /* We do bubble-sort, skip malicious clusters attempts */ |
+ if (end - start > 20) |
+ return; |
+ |
+ /* Sit tight, rock 'n roll! */ |
+ hb_bubble_sort (info + start, end - start, compare_indic_order); |
+ |
+ /* Setup masks now */ |
+ |
+ { |
+ hb_mask_t mask; |
+ |
+ /* Pre-base */ |
+ mask = mask_array[HALF] | mask_array[AKHN] | mask_array[CJCT]; |
+ for (i = start; i < base; i++) |
+ info[i].mask |= mask; |
+ /* Base */ |
+ mask = mask_array[AKHN] | mask_array[CJCT]; |
+ info[base].mask |= mask; |
+ /* Post-base */ |
+ mask = mask_array[BLWF] | mask_array[PSTF] | mask_array[CJCT]; |
+ for (i = base + 1; i < end; i++) |
+ info[i].mask |= mask; |
+ } |
+ |
+ /* Apply ZWJ/ZWNJ effects */ |
+ for (i = start + 1; i < end; i++) |
+ if (is_joiner (info[i])) { |
+ bool non_joiner = info[i].indic_category() == OT_ZWNJ; |
+ unsigned int j = i; |
+ |
+ do { |
+ j--; |
+ |
+ /* Reading the Unicode and OpenType specs, I think the following line |
+ * is correct, but this is not what the test suite expects currently. |
+ * The test suite has been drinking, not me... But disable while |
+ * investigating. |
+ */ |
+ //info[j].mask &= !mask_array[CJCT]; |
+ if (non_joiner) |
+ info[j].mask &= !mask_array[HALF]; |
+ |
+ } while (j > start && !is_consonant (info[j])); |
+ } |
+} |
+ |
+ |
+static void |
+found_vowel_syllable (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, |
+ unsigned int start, unsigned int end) |
+{ |
+ /* TODO |
+ * Not clear to me how this should work. Do the matras move to before the |
+ * independent vowel? No idea. |
+ */ |
+} |
+ |
+static void |
+found_standalone_cluster (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, |
+ unsigned int start, unsigned int end) |
+{ |
+ /* TODO |
+ * Easiest thing to do here is to convert the NBSP to consonant and |
+ * call found_consonant_syllable. |
+ */ |
+} |
+ |
+static void |
+found_non_indic (const hb_ot_map_t *map, hb_buffer_t *buffer, hb_mask_t *mask_array, |
+ unsigned int start, unsigned int end) |
+{ |
+ /* Nothing to do right now. If we ever switch to using the output |
+ * buffer in the reordering process, we'd need to next_glyph() here. */ |
+} |
+ |
+#include "hb-ot-shape-complex-indic-machine.hh" |
+ |
+static void |
+remove_joiners (hb_buffer_t *buffer) |
+{ |
+ /* For now we remove joiners. However, Uniscbire seems to keep them |
+ * and output a zero-width space glyph for them. It is not clear to |
+ * me how that is supposed to interact with GSUB. */ |
+ |
+ buffer->clear_output (); |
+ unsigned int count = buffer->len; |
+ for (buffer->idx = 0; buffer->idx < count;) |
+ if (unlikely (is_joiner (buffer->info[buffer->idx]))) |
+ buffer->skip_glyph (); |
+ else |
+ buffer->next_glyph (); |
+ |
+ buffer->swap_buffers (); |
+} |
+ |
+static void |
+initial_reordering (const hb_ot_map_t *map, |
+ hb_face_t *face, |
+ hb_buffer_t *buffer, |
+ void *user_data HB_UNUSED) |
+{ |
+ hb_mask_t mask_array[ARRAY_LENGTH (indic_basic_features)] = {0}; |
+ unsigned int num_masks = ARRAY_LENGTH (indic_basic_features); |
+ for (unsigned int i = 0; i < num_masks; i++) |
+ mask_array[i] = map->get_1_mask (indic_basic_features[i].tag); |
+ |
+ find_syllables (map, buffer, mask_array); |
+ |
+ remove_joiners (buffer); |
+} |
+ |
+static void |
+final_reordering (const hb_ot_map_t *map, |
+ hb_face_t *face, |
+ hb_buffer_t *buffer, |
+ void *user_data HB_UNUSED) |
+{ |
+ /* 4. Final reordering: |
+ * |
+ * After the localized forms and basic shaping forms GSUB features have been |
+ * applied (see below), the shaping engine performs some final glyph |
+ * reordering before applying all the remaining font features to the entire |
+ * cluster. |
+ * |
+ * o Reorder matras: |
+ * |
+ * If a pre-base matra character had been reordered before applying basic |
+ * features, the glyph can be moved closer to the main consonant based on |
+ * whether half-forms had been formed. Actual position for the matra is |
+ * defined as “after last standalone halant glyph, after initial matra |
+ * position and before the main consonant”. If ZWJ or ZWNJ follow this |
+ * halant, position is moved after it. |
+ * |
+ * o Reorder reph: |
+ * |
+ * Reph’s original position is always at the beginning of the syllable, |
+ * (i.e. it is not reordered at the character reordering stage). However, |
+ * it will be reordered according to the basic-forms shaping results. |
+ * Possible positions for reph, depending on the script, are; after main, |
+ * before post-base consonant forms, and after post-base consonant forms. |
+ * |
+ * 1. If reph should be positioned after post-base consonant forms, |
+ * proceed to step 5. |
+ * |
+ * 2. If the reph repositioning class is not after post-base: target |
+ * position is after the first explicit halant glyph between the |
+ * first post-reph consonant and last main consonant. If ZWJ or ZWNJ |
+ * are following this halant, position is moved after it. If such |
+ * position is found, this is the target position. Otherwise, |
+ * proceed to the next step. |
+ * |
+ * Note: in old-implementation fonts, where classifications were |
+ * fixed in shaping engine, there was no case where reph position |
+ * will be found on this step. |
+ * |
+ * 3. If reph should be repositioned after the main consonant: from the |
+ * first consonant not ligated with main, or find the first |
+ * consonant that is not a potential pre-base reordering Ra. |
+ * |
+ * |
+ * 4. If reph should be positioned before post-base consonant, find |
+ * first post-base classified consonant not ligated with main. If no |
+ * consonant is found, the target position should be before the |
+ * first matra, syllable modifier sign or vedic sign. |
+ * |
+ * 5. If no consonant is found in steps 3 or 4, move reph to a position |
+ * immediately before the first post-base matra, syllable modifier |
+ * sign or vedic sign that has a reordering class after the intended |
+ * reph position. For example, if the reordering position for reph |
+ * is post-main, it will skip above-base matras that also have a |
+ * post-main position. |
+ * |
+ * 6. Otherwise, reorder reph to the end of the syllable. |
+ * |
+ * o Reorder pre-base reordering consonants: |
+ * |
+ * If a pre-base reordering consonant is found, reorder it according to |
+ * the following rules: |
+ * |
+ * 1. Only reorder a glyph produced by substitution during application |
+ * of the feature. (Note that a font may shape a Ra consonant with |
+ * the feature generally but block it in certain contexts.) |
+ * |
+ * 2. Try to find a target position the same way as for pre-base matra. |
+ * If it is found, reorder pre-base consonant glyph. |
+ * |
+ * 3. If position is not found, reorder immediately before main |
+ * consonant. |
+ */ |
+ |
+ /* TODO */ |
+ |
+ |
+ |
+ HB_BUFFER_DEALLOCATE_VAR (buffer, indic_category); |
+ HB_BUFFER_DEALLOCATE_VAR (buffer, indic_position); |
+} |
+ |
+ |
+ |