766 lines
23 KiB
C++
766 lines
23 KiB
C++
/*
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* Copyright © 2011 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Google Author(s): Behdad Esfahbod
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*/
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#include "hb-ot-shape-complex-private.hh"
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/* buffer var allocations */
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#define indic_category() complex_var_persistent_u8_0() /* indic_category_t */
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#define indic_position() complex_var_persistent_u8_1() /* indic_matra_category_t */
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#define INDIC_TABLE_ELEMENT_TYPE uint8_t
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/* Cateories used in the OpenType spec:
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* https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
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*/
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/* Note: This enum is duplicated in the -machine.rl source file.
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* Not sure how to avoid duplication. */
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enum indic_category_t {
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OT_X = 0,
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OT_C,
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OT_Ra, /* Not explicitly listed in the OT spec, but used in the grammar. */
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OT_V,
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OT_N,
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OT_H,
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OT_ZWNJ,
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OT_ZWJ,
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OT_M,
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OT_SM,
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OT_VD,
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OT_A,
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OT_NBSP
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};
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/* Visual positions in a syllable from left to right. */
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enum indic_position_t {
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POS_PRE,
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POS_BASE,
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POS_ABOVE,
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POS_BELOW,
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POS_POST,
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};
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/* Categories used in IndicSyllabicCategory.txt from UCD */
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/* The assignments are guesswork */
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enum indic_syllabic_category_t {
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INDIC_SYLLABIC_CATEGORY_OTHER = OT_X,
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INDIC_SYLLABIC_CATEGORY_AVAGRAHA = OT_X,
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INDIC_SYLLABIC_CATEGORY_BINDU = OT_SM,
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INDIC_SYLLABIC_CATEGORY_CONSONANT = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER = OT_NBSP,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED = OT_C,
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INDIC_SYLLABIC_CATEGORY_CONSONANT_REPHA = OT_C,
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INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER = OT_X,
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INDIC_SYLLABIC_CATEGORY_NUKTA = OT_N,
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INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER = OT_X,
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INDIC_SYLLABIC_CATEGORY_TONE_LETTER = OT_X,
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INDIC_SYLLABIC_CATEGORY_TONE_MARK = OT_X,
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INDIC_SYLLABIC_CATEGORY_VIRAMA = OT_H,
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INDIC_SYLLABIC_CATEGORY_VISARGA = OT_SM,
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INDIC_SYLLABIC_CATEGORY_VOWEL = OT_V,
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INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT = OT_M,
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INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT = OT_V
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};
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/* Categories used in IndicSMatraCategory.txt from UCD */
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enum indic_matra_category_t {
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INDIC_MATRA_CATEGORY_NOT_APPLICABLE = POS_BASE,
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INDIC_MATRA_CATEGORY_LEFT = POS_PRE,
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INDIC_MATRA_CATEGORY_TOP = POS_ABOVE,
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INDIC_MATRA_CATEGORY_BOTTOM = POS_BELOW,
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INDIC_MATRA_CATEGORY_RIGHT = POS_POST,
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/* We don't really care much about these since we decompose them
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* in the generic pre-shaping layer. They will only be used if
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* the font does not cover the decomposition. In which case, we
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* define these as aliases to the place we want the split-matra
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* glyph to show up. Quite arbitrary. */
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INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM,
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INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT,
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INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM = INDIC_MATRA_CATEGORY_BOTTOM,
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INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT = INDIC_MATRA_CATEGORY_BOTTOM,
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INDIC_MATRA_CATEGORY_TOP_AND_LEFT = INDIC_MATRA_CATEGORY_LEFT,
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INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT = INDIC_MATRA_CATEGORY_LEFT,
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INDIC_MATRA_CATEGORY_TOP_AND_RIGHT = INDIC_MATRA_CATEGORY_RIGHT,
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INDIC_MATRA_CATEGORY_INVISIBLE = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
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INDIC_MATRA_CATEGORY_OVERSTRUCK = INDIC_MATRA_CATEGORY_NOT_APPLICABLE,
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INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT = INDIC_MATRA_CATEGORY_NOT_APPLICABLE
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};
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/* Note: We use ASSERT_STATIC_EXPR_ZERO() instead of ASSERT_STATIC_EXPR() and the comma operation
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* because gcc fails to optimize the latter and fills the table in at runtime. */
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#define INDIC_COMBINE_CATEGORIES(S,M) \
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(ASSERT_STATIC_EXPR_ZERO (M == INDIC_MATRA_CATEGORY_NOT_APPLICABLE || (S == INDIC_SYLLABIC_CATEGORY_VIRAMA || S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT)) + \
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ASSERT_STATIC_EXPR_ZERO (S < 16 && M < 16) + \
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((M << 4) | S))
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#include "hb-ot-shape-complex-indic-table.hh"
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/* XXX
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* This is a hack for now. We should:
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* 1. Move this data into the main Indic table,
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* and/or
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* 2. Probe font lookups to determine consonant positions.
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*/
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static const struct consonant_position_t {
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hb_codepoint_t u;
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indic_position_t position;
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} consonant_positions[] = {
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{0x0930, POS_BELOW},
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{0x09AC, POS_BELOW},
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{0x09AF, POS_POST},
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{0x09B0, POS_BELOW},
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{0x09F0, POS_BELOW},
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{0x0A2F, POS_POST},
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{0x0A30, POS_BELOW},
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{0x0A35, POS_BELOW},
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{0x0A39, POS_BELOW},
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{0x0AB0, POS_BELOW},
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{0x0B24, POS_BELOW},
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{0x0B28, POS_BELOW},
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{0x0B2C, POS_BELOW},
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{0x0B2D, POS_BELOW},
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{0x0B2E, POS_BELOW},
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{0x0B2F, POS_POST},
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{0x0B30, POS_BELOW},
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{0x0B32, POS_BELOW},
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{0x0B33, POS_BELOW},
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{0x0B5F, POS_POST},
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{0x0B71, POS_BELOW},
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{0x0C15, POS_BELOW},
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{0x0C16, POS_BELOW},
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{0x0C17, POS_BELOW},
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{0x0C18, POS_BELOW},
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{0x0C19, POS_BELOW},
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{0x0C1A, POS_BELOW},
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{0x0C1B, POS_BELOW},
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{0x0C1C, POS_BELOW},
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{0x0C1D, POS_BELOW},
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{0x0C1E, POS_BELOW},
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{0x0C1F, POS_BELOW},
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{0x0C20, POS_BELOW},
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{0x0C21, POS_BELOW},
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{0x0C22, POS_BELOW},
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{0x0C23, POS_BELOW},
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{0x0C24, POS_BELOW},
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{0x0C25, POS_BELOW},
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{0x0C26, POS_BELOW},
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{0x0C27, POS_BELOW},
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{0x0C28, POS_BELOW},
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{0x0C2A, POS_BELOW},
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{0x0C2B, POS_BELOW},
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{0x0C2C, POS_BELOW},
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{0x0C2D, POS_BELOW},
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{0x0C2E, POS_BELOW},
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{0x0C2F, POS_BELOW},
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{0x0C30, POS_BELOW},
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{0x0C32, POS_BELOW},
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{0x0C33, POS_BELOW},
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{0x0C35, POS_BELOW},
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{0x0C36, POS_BELOW},
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{0x0C37, POS_BELOW},
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{0x0C38, POS_BELOW},
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{0x0C39, POS_BELOW},
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{0x0C95, POS_BELOW},
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{0x0C96, POS_BELOW},
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{0x0C97, POS_BELOW},
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{0x0C98, POS_BELOW},
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{0x0C99, POS_BELOW},
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{0x0C9A, POS_BELOW},
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{0x0C9B, POS_BELOW},
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{0x0C9C, POS_BELOW},
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{0x0C9D, POS_BELOW},
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{0x0C9E, POS_BELOW},
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{0x0C9F, POS_BELOW},
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{0x0CA0, POS_BELOW},
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{0x0CA1, POS_BELOW},
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{0x0CA2, POS_BELOW},
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{0x0CA3, POS_BELOW},
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{0x0CA4, POS_BELOW},
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{0x0CA5, POS_BELOW},
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{0x0CA6, POS_BELOW},
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{0x0CA7, POS_BELOW},
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{0x0CA8, POS_BELOW},
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{0x0CAA, POS_BELOW},
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{0x0CAB, POS_BELOW},
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{0x0CAC, POS_BELOW},
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{0x0CAD, POS_BELOW},
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{0x0CAE, POS_BELOW},
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{0x0CAF, POS_BELOW},
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{0x0CB0, POS_BELOW},
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{0x0CB2, POS_BELOW},
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{0x0CB3, POS_BELOW},
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{0x0CB5, POS_BELOW},
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{0x0CB6, POS_BELOW},
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{0x0CB7, POS_BELOW},
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{0x0CB8, POS_BELOW},
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{0x0CB9, POS_BELOW},
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{0x0CDE, POS_BELOW},
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{0x0D2F, POS_POST},
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{0x0D30, POS_POST},
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{0x0D32, POS_BELOW},
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{0x0D35, POS_POST},
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};
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/* XXX
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* This is a hack for now. We should move this data into the main Indic table.
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*/
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static const hb_codepoint_t ra_chars[] = {
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0x0930, /* Devanagari */
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0x09B0, /* Bengali */
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0x09F0, /* Bengali */
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//0x09F1, /* Bengali */
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//0x0A30, /* Gurmukhi */
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0x0AB0, /* Gujarati */
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0x0B30, /* Oriya */
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//0x0BB0, /* Tamil */
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//0x0C30, /* Telugu */
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0x0CB0, /* Kannada */
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//0x0D30, /* Malayalam */
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};
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static int
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compare_codepoint (const void *pa, const void *pb)
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{
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hb_codepoint_t a = * (hb_codepoint_t *) pa;
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hb_codepoint_t b = * (hb_codepoint_t *) pb;
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return a < b ? -1 : a == b ? 0 : +1;
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}
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static indic_position_t
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consonant_position (hb_codepoint_t u)
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{
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consonant_position_t *record;
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record = (consonant_position_t *) bsearch (&u, consonant_positions,
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ARRAY_LENGTH (consonant_positions),
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sizeof (consonant_positions[0]),
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compare_codepoint);
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return record ? record->position : POS_BASE;
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}
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static bool
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is_ra (hb_codepoint_t u)
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{
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return !!bsearch (&u, ra_chars,
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ARRAY_LENGTH (ra_chars),
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sizeof (ra_chars[0]),
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compare_codepoint);
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}
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static bool
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is_joiner (const hb_glyph_info_t &info)
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{
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return !!(FLAG (info.indic_category()) & (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ)));
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}
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static bool
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is_consonant (const hb_glyph_info_t &info)
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{
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return !!(FLAG (info.indic_category()) & (FLAG (OT_C) | FLAG (OT_Ra)));
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}
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static const struct {
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hb_tag_t tag;
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hb_bool_t is_global;
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} indic_basic_features[] =
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{
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{HB_TAG('n','u','k','t'), true},
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{HB_TAG('a','k','h','n'), false},
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{HB_TAG('r','p','h','f'), false},
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{HB_TAG('r','k','r','f'), false},
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{HB_TAG('p','r','e','f'), false},
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{HB_TAG('b','l','w','f'), false},
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{HB_TAG('h','a','l','f'), false},
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{HB_TAG('v','a','t','u'), true},
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{HB_TAG('p','s','t','f'), false},
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{HB_TAG('c','j','c','t'), false},
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};
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/* Same order as the indic_basic_features array */
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enum {
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_NUKT,
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AKHN,
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RPHF,
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RKRF,
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PREF,
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BLWF,
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HALF,
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_VATU,
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PSTF,
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CJCT,
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};
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static const hb_tag_t indic_other_features[] =
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{
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HB_TAG('p','r','e','s'),
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HB_TAG('a','b','v','s'),
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HB_TAG('b','l','w','s'),
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HB_TAG('p','s','t','s'),
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HB_TAG('h','a','l','n'),
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HB_TAG('d','i','s','t'),
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HB_TAG('a','b','v','m'),
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HB_TAG('b','l','w','m'),
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};
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static void
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initial_reordering (const hb_ot_map_t *map,
|
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hb_face_t *face,
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hb_buffer_t *buffer,
|
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void *user_data HB_UNUSED);
|
||
static void
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final_reordering (const hb_ot_map_t *map,
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hb_face_t *face,
|
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hb_buffer_t *buffer,
|
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void *user_data HB_UNUSED);
|
||
|
||
void
|
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_hb_ot_shape_complex_collect_features_indic (hb_ot_map_builder_t *map, const hb_segment_properties_t *props)
|
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{
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map->add_bool_feature (HB_TAG('l','o','c','l'));
|
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/* The Indic specs do not require ccmp, but we apply it here since if
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* there is a use of it, it's typically at the beginning. */
|
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map->add_bool_feature (HB_TAG('c','c','m','p'));
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|
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map->add_gsub_pause (initial_reordering, NULL);
|
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|
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for (unsigned int i = 0; i < ARRAY_LENGTH (indic_basic_features); i++)
|
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map->add_bool_feature (indic_basic_features[i].tag, indic_basic_features[i].is_global);
|
||
|
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map->add_gsub_pause (final_reordering, NULL);
|
||
|
||
for (unsigned int i = 0; i < ARRAY_LENGTH (indic_other_features); i++)
|
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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);
|
||
}
|
||
|
||
|
||
|