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authorBruno de Oliveira Abinader <bruno@mapbox.com>2016-12-12 12:46:24 +0200
committerBruno de Oliveira Abinader <bruno@mapbox.com>2016-12-12 22:34:52 +0200
commitce5ed9e6498a832f070400fb281e46cd04e39ea1 (patch)
tree68b51821738b03558da85d981903b4febb3e39af /platform/default/bidi.cpp
parenteff986bfc42c450ebca075a9a2b59940d5cd8e33 (diff)
downloadqtlocation-mapboxgl-ce5ed9e6498a832f070400fb281e46cd04e39ea1.tar.gz
[build] ICU is now configured per platform
Diffstat (limited to 'platform/default/bidi.cpp')
-rw-r--r--platform/default/bidi.cpp125
1 files changed, 125 insertions, 0 deletions
diff --git a/platform/default/bidi.cpp b/platform/default/bidi.cpp
new file mode 100644
index 0000000000..7d5f6313bc
--- /dev/null
+++ b/platform/default/bidi.cpp
@@ -0,0 +1,125 @@
+#include <memory>
+
+#include <mbgl/text/bidi.hpp>
+#include <unicode/ubidi.h>
+#include <unicode/ushape.h>
+
+namespace mbgl {
+
+// Takes UTF16 input in logical order and applies Arabic shaping to the input while maintaining
+// logical order
+// Output won't be intelligible until the bidirectional algorithm is applied
+std::u16string applyArabicShaping(const std::u16string& input) {
+ UErrorCode errorCode = U_ZERO_ERROR;
+
+ int32_t outputLength =
+ u_shapeArabic(input.c_str(), static_cast<int32_t>(input.size()), NULL, 0,
+ (U_SHAPE_LETTERS_SHAPE & U_SHAPE_LETTERS_MASK) |
+ (U_SHAPE_TEXT_DIRECTION_LOGICAL & U_SHAPE_TEXT_DIRECTION_MASK),
+ &errorCode);
+
+ // Pre-flighting will always set U_BUFFER_OVERFLOW_ERROR
+ errorCode = U_ZERO_ERROR;
+
+ std::unique_ptr<UChar[]> outputText = std::make_unique<UChar[]>(outputLength);
+ u_shapeArabic(input.c_str(), static_cast<int32_t>(input.size()), outputText.get(), outputLength,
+ (U_SHAPE_LETTERS_SHAPE & U_SHAPE_LETTERS_MASK) |
+ (U_SHAPE_TEXT_DIRECTION_LOGICAL & U_SHAPE_TEXT_DIRECTION_MASK),
+ &errorCode);
+
+ // If the algorithm fails for any reason, fall back to non-transformed text
+ if (U_FAILURE(errorCode))
+ return input;
+
+ return std::u16string(outputText.get(), outputLength);
+}
+
+ProcessedBiDiText::ProcessedBiDiText(BiDi& p_bidi) : bidi(p_bidi) {
+}
+
+void ProcessedBiDiText::mergeParagraphLineBreaks(std::set<int32_t>& lineBreakPoints) {
+ int32_t paragraphCount = ubidi_countParagraphs(bidi.bidiText);
+ for (int32_t i = 0; i < paragraphCount; i++) {
+ UErrorCode errorCode = U_ZERO_ERROR;
+ int32_t paragraphEndIndex;
+ ubidi_getParagraphByIndex(bidi.bidiText, i, NULL, &paragraphEndIndex, NULL, &errorCode);
+
+ if (U_FAILURE(errorCode))
+ throw std::runtime_error(std::string("ProcessedBiDiText::mergeParagraphLineBreaks: ") +
+ u_errorName(errorCode));
+
+ lineBreakPoints.insert(paragraphEndIndex);
+ }
+}
+
+std::vector<std::u16string>
+ProcessedBiDiText::applyLineBreaking(std::set<int32_t> lineBreakPoints) {
+ // BiDi::getLine will error if called across a paragraph boundary, so we need to ensure that all
+ // paragraph
+ // boundaries are included in the set of line break points. The calling code might not include
+ // the line break because it
+ // didn't need to wrap at that point, or because the text was separated with a more exotic code
+ // point such as (U+001C)
+ mergeParagraphLineBreaks(lineBreakPoints);
+
+ std::vector<std::u16string> transformedLines;
+ int32_t start = 0;
+ for (int32_t lineBreakPoint : lineBreakPoints) {
+ transformedLines.push_back(bidi.getLine(start, lineBreakPoint));
+ start = lineBreakPoint;
+ }
+
+ return transformedLines;
+}
+
+BiDi::BiDi() {
+ bidiText = ubidi_open();
+ bidiLine = ubidi_open();
+}
+
+BiDi::~BiDi() {
+ if (bidiText)
+ ubidi_close(bidiText);
+
+ if (bidiLine)
+ ubidi_close(bidiLine);
+}
+
+ProcessedBiDiText BiDi::processText(const std::u16string& input) {
+ UErrorCode errorCode = U_ZERO_ERROR;
+
+ ubidi_setPara(bidiText, input.c_str(), static_cast<int32_t>(input.size()), UBIDI_DEFAULT_LTR,
+ NULL, &errorCode);
+
+ if (U_FAILURE(errorCode))
+ throw std::runtime_error(std::string("BiDi::processText: ") + u_errorName(errorCode));
+
+ return ProcessedBiDiText(*this);
+}
+
+std::u16string BiDi::getLine(int32_t start, int32_t end) {
+ UErrorCode errorCode = U_ZERO_ERROR;
+ ubidi_setLine(bidiText, start, end, bidiLine, &errorCode);
+
+ if (U_FAILURE(errorCode))
+ throw std::runtime_error(std::string("BiDi::getLine (setLine): ") + u_errorName(errorCode));
+
+ // Because we set UBIDI_REMOVE_BIDI_CONTROLS, the output may be smaller than what we reserve
+ // Setting UBIDI_INSERT_LRM_FOR_NUMERIC would require
+ // ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi)
+ int32_t outputLength = ubidi_getProcessedLength(bidiLine);
+ std::unique_ptr<UChar[]> outputText = std::make_unique<UChar[]>(outputLength);
+
+ // UBIDI_DO_MIRRORING: Apply unicode mirroring of characters like parentheses
+ // UBIDI_REMOVE_BIDI_CONTROLS: Now that all the lines are set, remove control characters so that
+ // they don't show up on screen (some fonts have glyphs representing them)
+ ubidi_writeReordered(bidiLine, outputText.get(), outputLength,
+ UBIDI_DO_MIRRORING | UBIDI_REMOVE_BIDI_CONTROLS, &errorCode);
+
+ if (U_FAILURE(errorCode))
+ throw std::runtime_error(std::string("BiDi::getLine (writeReordered): ") + u_errorName(errorCode));
+
+ return std::u16string(outputText.get(), outputLength);
+}
+
+} // end namespace mbgl