diff options
Diffstat (limited to 'thirdparty/harfbuzz/src/hb-ms-feature-ranges.cc')
| -rw-r--r-- | thirdparty/harfbuzz/src/hb-ms-feature-ranges.cc | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/thirdparty/harfbuzz/src/hb-ms-feature-ranges.cc b/thirdparty/harfbuzz/src/hb-ms-feature-ranges.cc new file mode 100644 index 0000000000..6d09b252d8 --- /dev/null +++ b/thirdparty/harfbuzz/src/hb-ms-feature-ranges.cc @@ -0,0 +1,177 @@ +/* + * Copyright © 2011,2012,2013 Google, Inc. + * Copyright © 2021 Khaled Hosny + * + * 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-ms-feature-ranges.hh" + +bool +hb_ms_setup_features (const hb_feature_t *features, + unsigned int num_features, + hb_vector_t<hb_ms_feature_t> &feature_records, /* OUT */ + hb_vector_t<hb_ms_range_record_t> &range_records /* OUT */) +{ + feature_records.shrink(0); + range_records.shrink(0); + + /* Sort features by start/end events. */ + hb_vector_t<hb_ms_feature_event_t> feature_events; + for (unsigned int i = 0; i < num_features; i++) + { + hb_ms_active_feature_t feature; + feature.fea.tag_le = hb_uint32_swap (features[i].tag); + feature.fea.value = features[i].value; + feature.order = i; + + hb_ms_feature_event_t *event; + + event = feature_events.push (); + event->index = features[i].start; + event->start = true; + event->feature = feature; + + event = feature_events.push (); + event->index = features[i].end; + event->start = false; + event->feature = feature; + } + feature_events.qsort (); + /* Add a strategic final event. */ + { + hb_ms_active_feature_t feature; + feature.fea.tag_le = 0; + feature.fea.value = 0; + feature.order = num_features + 1; + + auto *event = feature_events.push (); + event->index = 0; /* This value does magic. */ + event->start = false; + event->feature = feature; + } + + /* Scan events and save features for each range. */ + hb_vector_t<hb_ms_active_feature_t> active_features; + unsigned int last_index = 0; + for (unsigned int i = 0; i < feature_events.length; i++) + { + auto *event = &feature_events[i]; + + if (event->index != last_index) + { + /* Save a snapshot of active features and the range. */ + auto *range = range_records.push (); + auto offset = feature_records.length; + + active_features.qsort (); + for (unsigned int j = 0; j < active_features.length; j++) + { + if (!j || active_features[j].fea.tag_le != feature_records[feature_records.length - 1].tag_le) + { + feature_records.push (active_features[j].fea); + } + else + { + /* Overrides value for existing feature. */ + feature_records[feature_records.length - 1].value = active_features[j].fea.value; + } + } + + /* Will convert to pointer after all is ready, since feature_records.array + * may move as we grow it. */ + range->features.features = reinterpret_cast<hb_ms_feature_t *> (offset); + range->features.num_features = feature_records.length - offset; + range->index_first = last_index; + range->index_last = event->index - 1; + + last_index = event->index; + } + + if (event->start) + { + active_features.push (event->feature); + } + else + { + auto *feature = active_features.find (&event->feature); + if (feature) + active_features.remove (feature - active_features.arrayZ); + } + } + + if (!range_records.length) /* No active feature found. */ + num_features = 0; + + /* Fixup the pointers. */ + for (unsigned int i = 0; i < range_records.length; i++) + { + auto *range = &range_records[i]; + range->features.features = (hb_ms_feature_t *) feature_records + reinterpret_cast<uintptr_t> (range->features.features); + } + + return !!num_features; +} + +void +hb_ms_make_feature_ranges (hb_vector_t<hb_ms_feature_t> &feature_records, + hb_vector_t<hb_ms_range_record_t> &range_records, + unsigned int chars_offset, + unsigned int chars_len, + uint16_t *log_clusters, + hb_vector_t<hb_ms_features_t*> &range_features, /* OUT */ + hb_vector_t<uint32_t> &range_counts /* OUT */) +{ + range_features.shrink (0); + range_counts.shrink (0); + + auto *last_range = &range_records[0]; + for (unsigned int i = chars_offset; i < chars_len; i++) + { + auto *range = last_range; + while (log_clusters[i] < range->index_first) + range--; + while (log_clusters[i] > range->index_last) + range++; + if (!range_features.length || + &range->features != range_features[range_features.length - 1]) + { + auto **features = range_features.push (); + auto *c = range_counts.push (); + if (unlikely (!features || !c)) + { + range_features.shrink (0); + range_counts.shrink (0); + break; + } + *features = &range->features; + *c = 1; + } + else + { + range_counts[range_counts.length - 1]++; + } + + last_range = range; + } +} |