Process HTML text for directionality.

After we parse html text from an ebook run it through the
unicode bidirectional algorithm to determine the directionality
of each fragment. This may require splitting of fragments.

Currently we don't do anything with this information.

1 files changed, 55 insertions, 0 deletions

diff --git a/include/mupdf/fitz/bidi.h b/include/mupdf/fitz/bidi.h
index 0b5b9553..978696ef 100644
--- a/include/mupdf/fitz/bidi.h
+++ b/include/mupdf/fitz/bidi.h
@@ -199,6 +199,61 @@ Bidi_Direction Bidi_processLine(fz_context *ctx,
                                 int                        *more);
 
 
+int Bidi_isEuropeanNumber(const uint16_t *str, unsigned int len);
+
+/**
+ * returns a character's mirrored equivalent
+ *
+ * @param     u     Unicode character to process
+ */
+uint16_t Bidi_mirrorChar(const uint16_t u);
+
+
+
+/**
+ * Prototype for callback function supplied to Bidi_fragmentText.
+ *
+ * @param     fragment      first character in fragment
+ * @param     fragmentLen   number of characters in fragment
+ * @param     rightToLeft   true if fragment is right-to-left
+ * @param     mirror        The mirror code of the fragment if it exists
+ * @param     arg           data from caller of Bidi_fragmentText
+ */
+typedef void (Bidi_Fragment_Callback)(const uint16_t *fragment,
+					size_t fragmentLen,
+					int rightToLeft,
+					uint16_t mirror,
+					void *arg);
+
+
+
+/**
+ * Partitions the given Unicode sequence into one or more unidirectional
+ * fragments and invokes the given callback function for each fragment.
+ *
+ * For example, if directionality of text is:
+ *               0123456789
+ *               rrlllrrrrr,
+ * we'll invoke callback with:
+ *               &text[0], length == 2, rightToLeft ==  true
+ *               &text[2], length == 3, rightToLeft == false
+ *               &text[5], length == 5, rightToLeft ==  true.
+ *
+ * @param[in] text      start of Unicode sequence
+ * @param[in] textlen   number of Unicodes to analyse
+ * @param[in] baseDir   direction of paragraph (specify Bidi_Neutral
+ *                      to force auto-detection)
+ * @param[in] callback  function to be called for each fragment
+ * @param[in] arg       data to be passed to the callback function
+ * @param[in] bidiFlag  flag to be passed to the callback function
+ */
+void Bidi_fragmentText(fz_context *ctx,
+			const uint16_t *text,
+			size_t textlen,
+			Bidi_Direction *baseDir,
+			Bidi_Fragment_Callback callback,
+			void *arg,
+			int bidiFlag);
 
 #endif /* BIDI_BIDI_H */