summaryrefslogtreecommitdiff
path: root/dviware/dvisvgm/src/ToUnicodeMap.cpp
diff options
context:
space:
mode:
authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /dviware/dvisvgm/src/ToUnicodeMap.cpp
Initial commit
Diffstat (limited to 'dviware/dvisvgm/src/ToUnicodeMap.cpp')
-rw-r--r--dviware/dvisvgm/src/ToUnicodeMap.cpp106
1 files changed, 106 insertions, 0 deletions
diff --git a/dviware/dvisvgm/src/ToUnicodeMap.cpp b/dviware/dvisvgm/src/ToUnicodeMap.cpp
new file mode 100644
index 0000000000..f002038aec
--- /dev/null
+++ b/dviware/dvisvgm/src/ToUnicodeMap.cpp
@@ -0,0 +1,106 @@
+/*************************************************************************
+** ToUnicodeMap.cpp **
+** **
+** This file is part of dvisvgm -- a fast DVI to SVG converter **
+** Copyright (C) 2005-2019 Martin Gieseking <martin.gieseking@uos.de> **
+** **
+** This program is free software; you can redistribute it and/or **
+** modify it under the terms of the GNU General Public License as **
+** published by the Free Software Foundation; either version 3 of **
+** the License, or (at your option) any later version. **
+** **
+** This program is distributed in the hope that it will be useful, but **
+** WITHOUT ANY WARRANTY; without even the implied warranty of **
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the **
+** GNU General Public License for more details. **
+** **
+** You should have received a copy of the GNU General Public License **
+** along with this program; if not, see <http://www.gnu.org/licenses/>. **
+*************************************************************************/
+
+#include <limits>
+#include "ToUnicodeMap.hpp"
+#include "Unicode.hpp"
+
+using namespace std;
+
+
+/** Adds valid but random mappings for all missing character indexes.
+ * If a font's cmap table doesn't provide Unicode mappings for some
+ * glyphs in the font, it's necessary to fill the gaps in order to
+ * handle all characters correctly. This functions assumes that the
+ * characters are numbered from 1 to maxIndex.
+ * @param[in] maxIndex largest character index to consider
+ * @return true on success */
+bool ToUnicodeMap::addMissingMappings (uint32_t maxIndex) {
+ bool success=true;
+ // collect Unicode points already in assigned
+ NumericRanges<uint32_t> codepoints;
+ for (size_t i=0; i < numRanges() && success; i++)
+ codepoints.addRange(rangeAt(i).minval(), rangeAt(i).maxval());
+ // fill unmapped ranges
+ if (empty()) // no Unicode mapping present at all?
+ success = fillRange(1, maxIndex, 1, codepoints, true);
+ else { // (partial) Unicode mapping present?
+ success = fillRange(1, rangeAt(0).min()-1, rangeAt(0).minval()-1, codepoints, false);
+ for (size_t i=0; i < numRanges()-1 && success; i++)
+ success = fillRange(rangeAt(i).max()+1, rangeAt(i+1).min()-1, rangeAt(i).maxval()+1, codepoints, true);
+ if (success)
+ success = fillRange(rangeAt(numRanges()-1).max()+1, maxIndex, rangeAt(numRanges()-1).maxval()+1, codepoints, true);
+ }
+ return success;
+}
+
+
+/** Checks if a given codepoint is valid and unused. Otherwise, try to find an alternative.
+ * @param[in,out] ucp codepoint to fix
+ * @param[in] used_codepoints codepoints already in use
+ * @param[in] ascending if true, increase ucp to look for valid/unused codepoints
+ * @return true on success */
+static bool fix_codepoint (uint32_t &ucp, const NumericRanges<uint32_t> &used_codepoints, bool ascending) {
+ uint32_t start = ucp;
+ while (!Unicode::isValidCodepoint(ucp) && used_codepoints.valueExists(ucp)) {
+ if (ascending)
+ ucp = (ucp == numeric_limits<uint32_t>::max()) ? 0 : ucp+1;
+ else
+ ucp = (ucp == 0) ? numeric_limits<uint32_t>::max() : ucp-1;
+ if (ucp == start) // no free Unicode point found
+ return false;
+ }
+ return true;
+}
+
+
+static bool is_less_or_equal (uint32_t a, uint32_t b) {return a <= b;}
+static bool is_greater_or_equal (uint32_t a, uint32_t b) {return a >= b;}
+
+
+/** Adds index to Unicode mappings for a given range of character indexes.
+ * @param[in] minIndex lower bound of range to fill
+ * @param[in] maxIndex upper bound of range to fill
+ * @param[in] ucp first Unicode point to add (if possible)
+ * @param[in,out] used_ucps Unicode points already in use
+ * @param[in] ascending if true, fill range from lower to upper bound
+ * @return true on success */
+bool ToUnicodeMap::fillRange (uint32_t minIndex, uint32_t maxIndex, uint32_t ucp, NumericRanges<uint32_t> &used_ucps, bool ascending) {
+ if (minIndex <= maxIndex) {
+ uint32_t first=minIndex, last=maxIndex;
+ int inc=1;
+ bool (*cmp)(uint32_t, uint32_t) = is_less_or_equal;
+ if (!ascending) {
+ swap(first, last);
+ inc = -1;
+ cmp = is_greater_or_equal;
+ }
+ for (uint32_t i=first; cmp(i, last); i += inc) {
+ if (!fix_codepoint(ucp, used_ucps, ascending))
+ return false;
+ else {
+ addRange(i, i, ucp);
+ used_ucps.addRange(ucp);
+ ucp += inc; // preferred Unicode point for the next character of the current range
+ }
+ }
+ }
+ return true;
+} \ No newline at end of file