/* * Copyright © 2011,2012 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 */ #include "hb-ot-shape-fallback-private.hh" static void zero_mark_advances (hb_buffer_t *buffer, unsigned int start, unsigned int end) { for (unsigned int i = start; i < end; i++) if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) { buffer->pos[i].x_advance = 0; buffer->pos[i].y_advance = 0; } } static unsigned int recategorize_combining_class (unsigned int modified_combining_class) { if (modified_combining_class >= 200) return modified_combining_class; /* This should be kept in sync with modified combining class mapping * from hb-unicode.cc. */ switch (modified_combining_class) { /* Hebrew */ case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */ case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */ case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */ case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */ case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */ case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */ case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */ case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */ case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */ case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */ case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */ return HB_UNICODE_COMBINING_CLASS_BELOW; case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */ return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE; case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */ return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT; case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */ case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */ return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT; case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */ return HB_UNICODE_COMBINING_CLASS_ABOVE; case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */ break; /* Arabic and Syriac */ case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */ case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */ case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */ case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */ case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */ case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */ case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */ case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */ return HB_UNICODE_COMBINING_CLASS_ABOVE; case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */ case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */ return HB_UNICODE_COMBINING_CLASS_BELOW; /* Thai */ /* Note: to be useful we also need to position U+0E3A that has ccc=9 (virama). * But viramas can be both above and below based on the codepoint / script. */ case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */ return HB_UNICODE_COMBINING_CLASS_BELOW; case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */ return HB_UNICODE_COMBINING_CLASS_ABOVE; /* Lao */ case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */ return HB_UNICODE_COMBINING_CLASS_BELOW; case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */ return HB_UNICODE_COMBINING_CLASS_ABOVE; /* Tibetan */ case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */ return HB_UNICODE_COMBINING_CLASS_BELOW; case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/ return HB_UNICODE_COMBINING_CLASS_ABOVE; case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */ return HB_UNICODE_COMBINING_CLASS_BELOW; } return modified_combining_class; } static inline void position_mark (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer, hb_glyph_extents_t &base_extents, unsigned int i, unsigned int combining_class) { hb_glyph_extents_t mark_extents; if (!font->get_glyph_extents (buffer->info[i].codepoint, &mark_extents)) return; hb_position_t y_gap = font->y_scale / 16; hb_glyph_position_t &pos = buffer->pos[i]; pos.x_offset = pos.y_offset = 0; /* We dont position LEFT and RIGHT marks. */ /* X positioning */ switch (combining_class) { case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW: case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE: if (buffer->props.direction == HB_DIRECTION_LTR) { pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing; break; } else if (buffer->props.direction == HB_DIRECTION_RTL) { pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing; break; } /* Fall through */ case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW: case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE: case HB_UNICODE_COMBINING_CLASS_BELOW: case HB_UNICODE_COMBINING_CLASS_ABOVE: /* Center align. */ pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing; break; case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT: case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT: case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT: /* Left align. */ pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing; break; case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT: case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT: case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT: /* Right align. */ pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing; break; } /* Y positioning */ switch (combining_class) { case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW: case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT: case HB_UNICODE_COMBINING_CLASS_BELOW: case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT: /* Add gap, fall-through. */ base_extents.height -= y_gap; case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT: case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW: pos.y_offset += base_extents.y_bearing + base_extents.height - mark_extents.y_bearing; base_extents.height += mark_extents.height; break; case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE: case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT: case HB_UNICODE_COMBINING_CLASS_ABOVE: case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT: /* Add gap, fall-through. */ base_extents.y_bearing += y_gap; base_extents.height -= y_gap; case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE: case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT: pos.y_offset += base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height); base_extents.y_bearing -= mark_extents.height; base_extents.height += mark_extents.height; break; } } static inline void position_around_base (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer, unsigned int base, unsigned int end) { hb_glyph_extents_t base_extents; if (!font->get_glyph_extents (buffer->info[base].codepoint, &base_extents)) { /* If extents don't work, zero marks and go home. */ zero_mark_advances (buffer, base + 1, end); return; } base_extents.x_bearing += buffer->pos[base].x_offset; base_extents.y_bearing += buffer->pos[base].y_offset; /* XXX Handle ligature component positioning... */ HB_UNUSED bool is_ligature = is_a_ligature (buffer->info[base]); hb_position_t x_offset = 0, y_offset = 0; if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) { x_offset -= buffer->pos[base].x_advance; y_offset -= buffer->pos[base].y_advance; } unsigned int last_combining_class = 255; hb_glyph_extents_t cluster_extents; for (unsigned int i = base + 1; i < end; i++) if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) { unsigned int this_combining_class = recategorize_combining_class (_hb_glyph_info_get_modified_combining_class (&buffer->info[i])); if (this_combining_class != last_combining_class) cluster_extents = base_extents; position_mark (plan, font, buffer, base_extents, i, this_combining_class); buffer->pos[i].x_advance = 0; buffer->pos[i].y_advance = 0; buffer->pos[i].x_offset += x_offset; buffer->pos[i].y_offset += y_offset; /* combine cluster extents. */ last_combining_class = this_combining_class; } else { if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) { x_offset -= buffer->pos[i].x_advance; y_offset -= buffer->pos[i].y_advance; } else { x_offset += buffer->pos[i].x_advance; y_offset += buffer->pos[i].y_advance; } } } static inline void position_cluster (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer, unsigned int start, unsigned int end) { if (end - start < 2) return; /* Find the base glyph */ for (unsigned int i = start; i < end; i++) if (is_a_ligature (buffer->info[i]) || !(FLAG (_hb_glyph_info_get_general_category (&buffer->info[i])) & (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) | FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) | FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))) { position_around_base (plan, font, buffer, i, end); break; } } void _hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) { unsigned int start = 0; unsigned int last_cluster = buffer->info[0].cluster; unsigned int count = buffer->len; for (unsigned int i = 1; i < count; i++) if (buffer->info[i].cluster != last_cluster) { position_cluster (plan, font, buffer, start, i); start = i; last_cluster = buffer->info[i].cluster; } position_cluster (plan, font, buffer, start, count); }