[khmer] Remove indic_config->base_pos
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Behdad Esfahbod
parent
0c91638d48
commit
ffcd6c7efd
@ -273,11 +273,6 @@ set_khmer_properties (hb_glyph_info_t &info)
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* instead of adding a new flag in these structs.
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*/
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enum base_position_t {
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BASE_POS_FIRST,
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BASE_POS_LAST_SINHALA,
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BASE_POS_LAST
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};
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enum reph_position_t {
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REPH_POS_AFTER_MAIN = POS_AFTER_MAIN,
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REPH_POS_BEFORE_SUB = POS_BEFORE_SUB,
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@ -298,7 +293,6 @@ enum blwf_mode_t {
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};
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struct indic_config_t
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{
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base_position_t base_pos;
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reph_position_t reph_pos;
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reph_mode_t reph_mode;
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blwf_mode_t blwf_mode;
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@ -306,7 +300,7 @@ struct indic_config_t
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static const indic_config_t indic_configs[] =
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{
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{BASE_POS_FIRST,REPH_POS_DONT_CARE, REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST},
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{REPH_POS_DONT_CARE, REPH_MODE_VIS_REPHA,BLWF_MODE_PRE_AND_POST},
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};
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@ -504,8 +498,6 @@ struct khmer_shape_plan_t
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would_substitute_feature_t rphf;
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would_substitute_feature_t pref;
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would_substitute_feature_t blwf;
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would_substitute_feature_t pstf;
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hb_mask_t mask_array[INDIC_NUM_FEATURES];
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};
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@ -523,8 +515,6 @@ data_create_khmer (const hb_ot_shape_plan_t *plan)
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khmer_plan->rphf.init (&plan->map, HB_TAG('r','p','h','f'), true);
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khmer_plan->pref.init (&plan->map, HB_TAG('p','r','e','f'), true);
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khmer_plan->blwf.init (&plan->map, HB_TAG('b','l','w','f'), true);
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khmer_plan->pstf.init (&plan->map, HB_TAG('p','s','t','f'), true);
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for (unsigned int i = 0; i < ARRAY_LENGTH (khmer_plan->mask_array); i++)
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khmer_plan->mask_array[i] = (khmer_features[i].flags & F_GLOBAL) ?
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@ -539,35 +529,6 @@ data_destroy_khmer (void *data)
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free (data);
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}
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static khmer_position_t
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consonant_position_from_face (const khmer_shape_plan_t *khmer_plan,
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const hb_codepoint_t consonant,
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const hb_codepoint_t virama,
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hb_face_t *face)
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{
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/* For old-spec, the order of glyphs is Consonant,Virama,
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* whereas for new-spec, it's Virama,Consonant. However,
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* some broken fonts (like Free Sans) simply copied lookups
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* from old-spec to new-spec without modification.
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* And oddly enough, Uniscribe seems to respect those lookups.
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* Eg. in the sequence U+0924,U+094D,U+0930, Uniscribe finds
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* base at 0. The font however, only has lookups matching
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* 930,94D in 'blwf', not the expected 94D,930 (with new-spec
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* table). As such, we simply match both sequences. Seems
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* to work. */
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hb_codepoint_t glyphs[3] = {virama, consonant, virama};
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if (khmer_plan->blwf.would_substitute (glyphs , 2, face) ||
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khmer_plan->blwf.would_substitute (glyphs+1, 2, face))
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return POS_BELOW_C;
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if (khmer_plan->pstf.would_substitute (glyphs , 2, face) ||
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khmer_plan->pstf.would_substitute (glyphs+1, 2, face))
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return POS_POST_C;
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if (khmer_plan->pref.would_substitute (glyphs , 2, face) ||
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khmer_plan->pref.would_substitute (glyphs+1, 2, face))
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return POS_POST_C;
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return POS_BASE_C;
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}
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enum syllable_type_t {
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consonant_syllable,
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@ -617,33 +578,6 @@ compare_khmer_order (const hb_glyph_info_t *pa, const hb_glyph_info_t *pb)
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}
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static void
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update_consonant_positions (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) plan->data;
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if (khmer_plan->config->base_pos != BASE_POS_LAST)
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return;
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hb_codepoint_t virama;
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if (khmer_plan->get_virama_glyph (font, &virama))
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{
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hb_face_t *face = font->face;
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unsigned int count = buffer->len;
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hb_glyph_info_t *info = buffer->info;
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for (unsigned int i = 0; i < count; i++)
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if (info[i].khmer_position() == POS_BASE_C)
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{
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hb_codepoint_t consonant = info[i].codepoint;
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info[i].khmer_position() = consonant_position_from_face (khmer_plan, consonant, virama, face);
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}
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}
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}
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/* Rules from:
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* https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx */
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@ -710,101 +644,13 @@ initial_reordering_consonant_syllable (const hb_ot_shape_plan_t *plan,
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has_reph = true;
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}
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switch (khmer_plan->config->base_pos)
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{
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case BASE_POS_LAST:
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{
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/* -> starting from the end of the syllable, move backwards */
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unsigned int i = end;
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bool seen_below = false;
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do {
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i--;
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/* -> until a consonant is found */
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if (is_consonant (info[i]))
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{
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/* -> that does not have a below-base or post-base form
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* (post-base forms have to follow below-base forms), */
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if (info[i].khmer_position() != POS_BELOW_C &&
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(info[i].khmer_position() != POS_POST_C || seen_below))
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{
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base = i;
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break;
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}
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if (info[i].khmer_position() == POS_BELOW_C)
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seen_below = true;
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/* -> or that is not a pre-base-reordering Ra,
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*
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* IMPLEMENTATION NOTES:
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*
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* Our pre-base-reordering Ra's are marked POS_POST_C, so will be skipped
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* by the logic above already.
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*/
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/* -> or arrive at the first consonant. The consonant stopped at will
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* be the base. */
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base = i;
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}
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else
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{
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/* A ZWJ after a Halant stops the base search, and requests an explicit
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* half form.
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* A ZWJ before a Halant, requests a subjoined form instead, and hence
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* search continues. This is particularly important for Bengali
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* sequence Ra,H,Ya that should form Ya-Phalaa by subjoining Ya. */
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if (start < i &&
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info[i].khmer_category() == OT_ZWJ &&
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info[i - 1].khmer_category() == OT_H)
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break;
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}
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} while (i > limit);
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}
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break;
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case BASE_POS_LAST_SINHALA:
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{
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/* Sinhala base positioning is slightly different from main Indic, in that:
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* 1. Its ZWJ behavior is different,
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* 2. We don't need to look into the font for consonant positions.
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*/
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if (!has_reph)
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base = limit;
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/* Find the last base consonant that is not blocked by ZWJ. If there is
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* a ZWJ right before a base consonant, that would request a subjoined form. */
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for (unsigned int i = limit; i < end; i++)
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if (is_consonant (info[i]))
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{
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if (limit < i && info[i - 1].khmer_category() == OT_ZWJ)
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break;
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else
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base = i;
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}
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/* Mark all subsequent consonants as below. */
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for (unsigned int i = base + 1; i < end; i++)
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if (is_consonant (info[i]))
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info[i].khmer_position() = POS_BELOW_C;
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}
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break;
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case BASE_POS_FIRST:
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{
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/* The first consonant is always the base. */
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assert (khmer_plan->config->reph_mode == REPH_MODE_VIS_REPHA);
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assert (!has_reph);
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base = start;
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/* Mark all subsequent consonants as below. */
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for (unsigned int i = base + 1; i < end; i++)
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if (is_consonant (info[i]))
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info[i].khmer_position() = POS_BELOW_C;
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}
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break;
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}
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/* -> If the syllable starts with Ra + Halant (in a script that has Reph)
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* and has more than one consonant, Ra is excluded from candidates for
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@ -1146,7 +992,6 @@ initial_reordering (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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update_consonant_positions (plan, font, buffer);
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insert_dotted_circles (plan, font, buffer);
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foreach_syllable (buffer, start, end)
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@ -1579,11 +1424,6 @@ decompose_khmer (const hb_ot_shape_normalize_context_t *c,
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{
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switch (ab)
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{
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/* Don't decompose these. */
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case 0x0931u : return false; /* DEVANAGARI LETTER RRA */
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case 0x0B94u : return false; /* TAMIL LETTER AU */
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/*
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* Decompose split matras that don't have Unicode decompositions.
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*/
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@ -1594,58 +1434,6 @@ decompose_khmer (const hb_ot_shape_normalize_context_t *c,
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case 0x17C0u : *a = 0x17C1u; *b= 0x17C0u; return true;
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case 0x17C4u : *a = 0x17C1u; *b= 0x17C4u; return true;
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case 0x17C5u : *a = 0x17C1u; *b= 0x17C5u; return true;
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#if 0
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/* Gujarati */
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/* This one has no decomposition in Unicode, but needs no decomposition either. */
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/* case 0x0AC9u : return false; */
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/* Oriya */
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case 0x0B57u : *a = no decomp, -> RIGHT; return true;
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#endif
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}
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if ((ab == 0x0DDAu || hb_in_range<hb_codepoint_t> (ab, 0x0DDCu, 0x0DDEu)))
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{
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/*
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* Sinhala split matras... Let the fun begin.
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*
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* These four characters have Unicode decompositions. However, Uniscribe
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* decomposes them "Khmer-style", that is, it uses the character itself to
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* get the second half. The first half of all four decompositions is always
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* U+0DD9.
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*
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* Now, there are buggy fonts, namely, the widely used lklug.ttf, that are
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* broken with Uniscribe. But we need to support them. As such, we only
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* do the Uniscribe-style decomposition if the character is transformed into
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* its "sec.half" form by the 'pstf' feature. Otherwise, we fall back to
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* Unicode decomposition.
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*
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* Note that we can't unconditionally use Unicode decomposition. That would
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* break some other fonts, that are designed to work with Uniscribe, and
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* don't have positioning features for the Unicode-style decomposition.
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*
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* Argh...
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*
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* The Uniscribe behavior is now documented in the newly published Sinhala
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* spec in 2012:
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*
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* http://www.microsoft.com/typography/OpenTypeDev/sinhala/intro.htm#shaping
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*/
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const khmer_shape_plan_t *khmer_plan = (const khmer_shape_plan_t *) c->plan->data;
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hb_codepoint_t glyph;
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if (hb_options ().uniscribe_bug_compatible ||
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(c->font->get_nominal_glyph (ab, &glyph) &&
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khmer_plan->pstf.would_substitute (&glyph, 1, c->font->face)))
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{
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/* Ok, safe to use Uniscribe-style decomposition. */
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*a = 0x0DD9u;
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*b = ab;
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return true;
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}
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}
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return (bool) c->unicode->decompose (ab, a, b);
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@ -1661,9 +1449,6 @@ compose_khmer (const hb_ot_shape_normalize_context_t *c,
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if (HB_UNICODE_GENERAL_CATEGORY_IS_MARK (c->unicode->general_category (a)))
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return false;
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/* Composition-exclusion exceptions that we want to recompose. */
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if (a == 0x09AFu && b == 0x09BCu) { *ab = 0x09DFu; return true; }
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return (bool) c->unicode->compose (a, b, ab);
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}
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