Merge pull request #339 from ironymark/master

Fix Type 2 CID Font Encoding

fonts.js

@@ -789,6 +789,8 @@ var Font = (function Font() {
     encoding: null,
 
     checkAndRepair: function font_checkAndRepair(name, font, properties) {
+      var kCmapGlyphOffset = 0xFF;
+
       function readTableEntry(file) {
         // tag
         var tag = file.getBytes(4);
@@ -1027,26 +1029,27 @@ var Font = (function Font() {
       if (properties.type == 'CIDFontType2') {
         // Type2 composite fonts map characters directly to glyphs so the cmap
         // table must be replaced.
+        // canvas fillText will reencode some characters even if the font has a
+        // glyph at that position - e.g. newline is converted to a space and U+00AD
+        // (soft hypen) is not drawn.
+        // So, offset all the glyphs by 0xFF to avoid these cases and use
+        // the encoding to map incoming characters to the new glyph positions
 
         var glyphs = [];
-        var charset = properties.charset;
-        if (!charset.length) {
-          // Type2 composite fonts map characters directly to glyphs so the cmap
-          for (var i = 1; i < numGlyphs; i++) {
-            glyphs.push({
-              unicode: i
-            });
-          }
-        } else {
-          for (var i = 1; i < charset.length; i++) {
-            var index = charset.indexOf(i);
-            if (index == -1)
-              break;
+        var encoding = properties.encoding;
 
-            glyphs.push({
-              unicode: index
-            });
+        for (var i = 1; i < numGlyphs; i++) {
+          glyphs.push({ unicode: i + kCmapGlyphOffset });
         }
+
+        if ('undefined' == typeof(encoding[0])) {
+          // the font is directly characters to glyphs with no encoding
+          // so create an identity encoding
+          for (i = 0; i < numGlyphs; i++)
+            encoding[i] = i + kCmapGlyphOffset;
+        } else {
+          for (var i in encoding)
+            encoding[i] = encoding[i] + kCmapGlyphOffset;
         }
 
         if (!cmap) {
@@ -1260,31 +1263,26 @@ var Font = (function Font() {
       if (!charsCache)
         charsCache = this.charsCache = Object.create(null);
 
-      if (this.compositeFont) {
-        // composite fonts have multi-byte strings convert the string from
-        // single-byte to multi-byte XXX assuming CIDFonts are two-byte - later
-        // need to extract the correct byte encoding according to the PDF spec
-        str = '';
-        var multiByteStr = '';
-        var length = chars.length;
-        for (var i = 0; i < length; i++) {
-          var byte1 = chars.charCodeAt(i++) & 0xFF;
-          var byte2;
-          if (i == length)
-            byte2 = 0;
-          else
-            byte2 = chars.charCodeAt(i) & 0xFF;
-          multiByteStr += String.fromCharCode((byte1 << 8) | byte2);
-        }
-        str = multiByteStr;
-      }
-      else {
       // translate the string using the font's encoding
       var encoding = this.encoding;
       if (!encoding)
         return chars;
-
       str = '';
+
+      if (this.compositeFont) {
+        // composite fonts have multi-byte strings convert the string from
+        // single-byte to multi-byte
+        // XXX assuming CIDFonts are two-byte - later need to extract the
+        // correct byte encoding according to the PDF spec
+        var length = chars.length - 1; // looping over two bytes at a time so
+                                       // loop should never end on the last byte
+        for (var i = 0; i < length; i++) {
+          var charcode = int16([chars.charCodeAt(i++), chars.charCodeAt(i)]);
+          var unicode = encoding[charcode];
+          str += String.fromCharCode(unicode);
+        }
+      }
+      else {
         for (var i = 0; i < chars.length; ++i) {
           var charcode = chars.charCodeAt(i);
           var unicode = encoding[charcode];

pdf.js

@@ -4028,14 +4028,15 @@ var PartialEvaluator = (function() {
         if (subType.name == 'CIDFontType2') {
           var cidToGidMap = descendant.get('CIDToGIDMap');
           if (cidToGidMap && IsRef(cidToGidMap)) {
-            // Extract the charset from the CIDToGIDMap
+            // Extract the encoding from the CIDToGIDMap
             var glyphsStream = xref.fetchIfRef(cidToGidMap);
             var glyphsData = glyphsStream.getBytes(0);
-            var i = 0;
             // Glyph ids are big-endian 2-byte values
+            encodingMap[0] = 0; //set this to 0 to verify the font has an encoding
             for (var j = 0; j < glyphsData.length; j++) {
               var glyphID = (glyphsData[j++] << 8) | glyphsData[j];
-              charset.push(glyphID);
+              if (glyphID != 0)
+                encodingMap[j>>1] = glyphID;
             }
           }
         }

test/test_manifest.json

@@ -64,6 +64,11 @@
        "rounds": 1,
        "type": "load"
     },
+    {  "id": "complexttffont-pdf",
+       "file": "pdfs/complex_ttf_font.pdf",
+       "rounds": 1,
+       "type": "load"
+    },
     {  "id": "i9-pdf",
        "file": "pdfs/i9.pdf",
        "link": true,