Revert of Updating OTS repo from https://github.com/khaledhosny/ots.git

third_party/ots/src/kern.cc

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "kern.h"
-
-// kern - Kerning
-// http://www.microsoft.com/typography/otspec/kern.htm
-
-#define TABLE_NAME "kern"
-
-#define DROP_THIS_TABLE(msg_) \
-  do { \
-    OTS_FAILURE_MSG(msg_ ", table discarded"); \
-    delete file->kern; \
-    file->kern = 0; \
-  } while (0)
-
-namespace ots {
-
-bool ots_kern_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
-  Buffer table(data, length);
-
-  OpenTypeKERN *kern = new OpenTypeKERN;
-  file->kern = kern;
-
-  uint16_t num_tables = 0;
-  if (!table.ReadU16(&kern->version) ||
-      !table.ReadU16(&num_tables)) {
-    return OTS_FAILURE_MSG("Failed to read kern header");
-  }
-
-  if (kern->version > 0) {
-    DROP_THIS_TABLE("bad table version");
-    return true;
-  }
-
-  if (num_tables == 0) {
-    DROP_THIS_TABLE("num_tables is zero");
-    return true;
-  }
-
-  kern->subtables.reserve(num_tables);
-  for (unsigned i = 0; i < num_tables; ++i) {
-    OpenTypeKERNFormat0 subtable;
-    uint16_t sub_length = 0;
-
-    if (!table.ReadU16(&subtable.version) ||
-        !table.ReadU16(&sub_length)) {
-      return OTS_FAILURE_MSG("Failed to read kern subtable %d header", i);
-    }
-
-    if (subtable.version > 0) {
-      OTS_WARNING("Bad subtable version: %d", subtable.version);
-      continue;
-    }
-
-    const size_t current_offset = table.offset();
-    if (current_offset - 4 + sub_length > length) {
-      return OTS_FAILURE_MSG("Bad kern subtable %d offset %ld", i, current_offset);
-    }
-
-    if (!table.ReadU16(&subtable.coverage)) {
-      return OTS_FAILURE_MSG("Cailed to read kern subtable %d coverage", i);
-    }
-
-    if (!(subtable.coverage & 0x1)) {
-      OTS_WARNING(
-          "We don't support vertical data as the renderer doesn't support it.");
-      continue;
-    }
-    if (subtable.coverage & 0xF0) {
-      DROP_THIS_TABLE("Reserved fields should zero-filled.");
-      return true;
-    }
-    const uint32_t format = (subtable.coverage & 0xFF00) >> 8;
-    if (format != 0) {
-      OTS_WARNING("Format %d is not supported.", format);
-      continue;
-    }
-
-    // Parse the format 0 field.
-    uint16_t num_pairs = 0;
-    if (!table.ReadU16(&num_pairs) ||
-        !table.ReadU16(&subtable.search_range) ||
-        !table.ReadU16(&subtable.entry_selector) ||
-        !table.ReadU16(&subtable.range_shift)) {
-      return OTS_FAILURE_MSG("Failed to read kern subtable %d format 0 fields", i);
-    }
-
-    if (!num_pairs) {
-      DROP_THIS_TABLE("Zero length subtable is found.");
-      return true;
-    }
-
-    // Sanity checks for search_range, entry_selector, and range_shift. See the
-    // comment in ots.cc for details.
-    const size_t kFormat0PairSize = 6;  // left, right, and value. 2 bytes each.
-    if (num_pairs > (65536 / kFormat0PairSize)) {
-      // Some fonts (e.g. calibri.ttf, pykes_peak_zero.ttf) have pairs >= 10923.
-      DROP_THIS_TABLE("Too large subtable.");
-      return true;
-    }
-    unsigned max_pow2 = 0;
-    while (1u << (max_pow2 + 1) <= num_pairs) {
-      ++max_pow2;
-    }
-    const uint16_t expected_search_range = (1u << max_pow2) * kFormat0PairSize;
-    if (subtable.search_range != expected_search_range) {
-      OTS_WARNING("bad search range");
-      subtable.search_range = expected_search_range;
-    }
-    if (subtable.entry_selector != max_pow2) {
-      return OTS_FAILURE_MSG("Bad subtable %d entry selector %d", i, subtable.entry_selector);
-    }
-    const uint16_t expected_range_shift =
-        kFormat0PairSize * num_pairs - subtable.search_range;
-    if (subtable.range_shift != expected_range_shift) {
-      OTS_WARNING("bad range shift");
-      subtable.range_shift = expected_range_shift;
-    }
-
-    // Read kerning pairs.
-    subtable.pairs.reserve(num_pairs);
-    uint32_t last_pair = 0;
-    for (unsigned j = 0; j < num_pairs; ++j) {
-      OpenTypeKERNFormat0Pair kerning_pair;
-      if (!table.ReadU16(&kerning_pair.left) ||
-          !table.ReadU16(&kerning_pair.right) ||
-          !table.ReadS16(&kerning_pair.value)) {
-        return OTS_FAILURE_MSG("Failed to read subtable %d kerning pair %d", i, j);
-      }
-      const uint32_t current_pair
-          = (kerning_pair.left << 16) + kerning_pair.right;
-      if (j != 0 && current_pair <= last_pair) {
-        // Many free fonts don't follow this rule, so we don't call OTS_FAILURE
-        // in order to support these fonts.
-        DROP_THIS_TABLE("Kerning pairs are not sorted.");
-        return true;
-      }
-      last_pair = current_pair;
-      subtable.pairs.push_back(kerning_pair);
-    }
-
-    kern->subtables.push_back(subtable);
-  }
-
-  if (!kern->subtables.size()) {
-    DROP_THIS_TABLE("All subtables are removed.");
-    return true;
-  }
-
-  return true;
-}
-
-bool ots_kern_should_serialise(OpenTypeFile *file) {
-  if (!file->glyf) return false;  // this table is not for CFF fonts.
-  return file->kern != NULL;
-}
-
-bool ots_kern_serialise(OTSStream *out, OpenTypeFile *file) {
-  const OpenTypeKERN *kern = file->kern;
-
-  const uint16_t num_subtables = static_cast<uint16_t>(kern->subtables.size());
-  if (num_subtables != kern->subtables.size() ||
-      !out->WriteU16(kern->version) ||
-      !out->WriteU16(num_subtables)) {
-    return OTS_FAILURE_MSG("Can't write kern table header");
-  }
-
-  for (uint16_t i = 0; i < num_subtables; ++i) {
-    const size_t length = 14 + (6 * kern->subtables[i].pairs.size());
-    if (length > std::numeric_limits<uint16_t>::max() ||
-        !out->WriteU16(kern->subtables[i].version) ||
-        !out->WriteU16(static_cast<uint16_t>(length)) ||
-        !out->WriteU16(kern->subtables[i].coverage) ||
-        !out->WriteU16(
-            static_cast<uint16_t>(kern->subtables[i].pairs.size())) ||
-        !out->WriteU16(kern->subtables[i].search_range) ||
-        !out->WriteU16(kern->subtables[i].entry_selector) ||
-        !out->WriteU16(kern->subtables[i].range_shift)) {
-      return OTS_FAILURE_MSG("Failed to write kern subtable %d", i);
-    }
-    for (unsigned j = 0; j < kern->subtables[i].pairs.size(); ++j) {
-      if (!out->WriteU16(kern->subtables[i].pairs[j].left) ||
-          !out->WriteU16(kern->subtables[i].pairs[j].right) ||
-          !out->WriteS16(kern->subtables[i].pairs[j].value)) {
-        return OTS_FAILURE_MSG("Failed to write kern pair %d for subtable %d", j, i);
-      }
-    }
-  }
-
-  return true;
-}
-
-void ots_kern_free(OpenTypeFile *file) {
-  delete file->kern;
-}
-
-}  // namespace ots
-
-#undef TABLE_NAME
-#undef DROP_THIS_TABLE