1 files changed, 92 insertions, 0 deletions
diff --git a/pdf/pdf_unicode.c b/pdf/pdf_unicode.c
new file mode 100644
index 00000000..6c2d6372
--- /dev/null
+++ b/pdf/pdf_unicode.c
@@ -0,0 +1,92 @@
+#include "fitz.h"
+#include "mupdf.h"
+
+/* Load or synthesize ToUnicode map for fonts */
+
+fz_error
+pdf_loadtounicode(pdf_fontdesc *font, pdf_xref *xref,
+	char **strings, char *collection, fz_obj *cmapstm)
+{
+	fz_error error = fz_okay;
+	pdf_cmap *cmap;
+	int cid;
+	int ucsbuf[8];
+	int ucslen;
+	int i;
+
+	if (pdf_isstream(xref, fz_tonum(cmapstm), fz_togen(cmapstm)))
+	{
+		pdf_logfont("tounicode embedded cmap\n");
+
+		error = pdf_loadembeddedcmap(&cmap, xref, cmapstm);
+		if (error)
+			return fz_rethrow(error, "cannot load embedded cmap (%d %d R)", fz_tonum(cmapstm), fz_togen(cmapstm));
+
+		font->tounicode = pdf_newcmap();
+
+		for (i = 0; i < (strings ? 256 : 65536); i++)
+		{
+			cid = pdf_lookupcmap(font->encoding, i);
+			if (cid >= 0)
+			{
+				ucslen = pdf_lookupcmapfull(cmap, i, ucsbuf);
+				if (ucslen == 1)
+					pdf_maprangetorange(font->tounicode, cid, cid, ucsbuf[0]);
+				if (ucslen > 1)
+					pdf_maponetomany(font->tounicode, cid, ucsbuf, ucslen);
+			}
+		}
+
+		pdf_sortcmap(font->tounicode);
+
+		pdf_dropcmap(cmap);
+	}
+
+	else if (collection)
+	{
+		pdf_logfont("tounicode cid collection (%s)\n", collection);
+
+		error = fz_okay;
+
+		if (!strcmp(collection, "Adobe-CNS1"))
+			error = pdf_loadsystemcmap(&font->tounicode, "Adobe-CNS1-UCS2");
+		else if (!strcmp(collection, "Adobe-GB1"))
+			error = pdf_loadsystemcmap(&font->tounicode, "Adobe-GB1-UCS2");
+		else if (!strcmp(collection, "Adobe-Japan1"))
+			error = pdf_loadsystemcmap(&font->tounicode, "Adobe-Japan1-UCS2");
+		else if (!strcmp(collection, "Adobe-Japan2"))
+			error = pdf_loadsystemcmap(&font->tounicode, "Adobe-Japan2-UCS2"); /* where's this? */
+		else if (!strcmp(collection, "Adobe-Korea1"))
+			error = pdf_loadsystemcmap(&font->tounicode, "Adobe-Korea1-UCS2");
+
+		if (error)
+			return fz_rethrow(error, "cannot load tounicode system cmap %s-UCS2", collection);
+	}
+
+	if (strings)
+	{
+		pdf_logfont("tounicode strings\n");
+
+		/* TODO one-to-many mappings */
+
+		font->ncidtoucs = 256;
+		font->cidtoucs = fz_calloc(256, sizeof(unsigned short));
+
+		for (i = 0; i < 256; i++)
+		{
+			if (strings[i])
+				font->cidtoucs[i] = pdf_lookupagl(strings[i]);
+			else
+				font->cidtoucs[i] = '?';
+		}
+	}
+
+	if (!font->tounicode && !font->cidtoucs)
+	{
+		pdf_logfont("tounicode could not be loaded\n");
+		/* TODO: synthesize a ToUnicode if it's a freetype font with
+		* cmap and/or post tables or if it has glyph names. */
+	}
+
+	return fz_okay;
+}