woff2 arbitrary flag tag writing

jbecke · Feb 18, 2018 · 325d9f2 · 325d9f2
1 parent 23078a5
commit 325d9f2
Show file tree

Hide file tree

Showing 5 changed files with 28 additions and 16 deletions.
diff --git a/src/main/java/org/mabb/fontverter/FontVerterUtils.java b/src/main/java/org/mabb/fontverter/FontVerterUtils.java
@@ -95,7 +95,7 @@ public static int readLowerBits(int inByte, int nBits) throws IOException {
         if (nBits > 8)
             throw new IOException("Number of bits exceeds 8");
 
-        return inByte & (0x1F);
+        return inByte & (0x3F);
     }
 
     public static byte[] toPrimative(Byte[] objArray) {

diff --git a/src/main/java/org/mabb/fontverter/woff/Woff2Font.java b/src/main/java/org/mabb/fontverter/woff/Woff2Font.java
@@ -37,11 +37,11 @@ public class Woff2Font extends WoffFont {
     private byte[] cachedCompressedBlock;
 
     public WoffTable createTable() {
-        return new Woff2Font.Woff2Table(new byte[0], arbitrary);
+        return new Woff2Font.Woff2Table(new byte[0], "arbitrary");
     }
 
     public void addFontTable(byte[] data, String tag, long checksum) {
-        WoffTable table = new Woff2Table(data, WoffConstants.TableFlagType.fromString(tag));
+        WoffTable table = new Woff2Table(data, tag);
         tables.add(table);
     }
 
@@ -103,11 +103,11 @@ public FontConverter createConverterForType(FontVerter.FontFormat fontFormat) th
 
     public static class Woff2Table extends WoffTable {
         private int transform = -1;
-        protected WoffConstants.TableFlagType flag;
+        protected String tag = "";
 
-        public Woff2Table(byte[] table, WoffConstants.TableFlagType flag) {
+        public Woff2Table(byte[] table, String tag) {
             super(table);
-            this.flag = flag;
+            this.tag = tag;
         }
 
         protected byte[] compress(byte[] bytes) throws IOException {
@@ -119,8 +119,15 @@ protected byte[] compress(byte[] bytes) throws IOException {
         public byte[] getDirectoryData() throws IOException {
             WoffOutputStream writer = new WoffOutputStream();
 
+            WoffConstants.TableFlagType flag = WoffConstants.TableFlagType.fromString(tag);
             writer.writeFlagByte(flag.getValue(), getTransform());
-            // todo tag here for arbitrary flag type
+
+            if (flag == arbitrary) {
+                // maybe should string pad < 4
+                assert tag.length() == 4;
+                writer.writeString(tag);
+            }
+
             writer.writeUIntBase128(tableData.length);
 
             if (isTableTransformed())
@@ -147,24 +154,24 @@ public int getTransform() {
         }
 
         private int initTransformValue() {
-            if (flag == glyf || flag == loca)
+            if (getFlag() == glyf || getFlag() == loca)
                 return 3;
             return 0;
         }
 
         boolean isTableTransformed() {
-            if (flag == WoffConstants.TableFlagType.glyf || flag == loca)
+            if (getFlag() == WoffConstants.TableFlagType.glyf || getFlag() == loca)
                 return transform != 3;
 
             return transform != 0;
         }
 
         public WoffConstants.TableFlagType getFlag() {
-            return flag;
+            return WoffConstants.TableFlagType.fromString(tag);
         }
 
         public String getTag() {
-            return flag.toString();
+            return getFlag().toString();
         }
     }
 }
diff --git a/src/main/java/org/mabb/fontverter/woff/Woff2Parser.java b/src/main/java/org/mabb/fontverter/woff/Woff2Parser.java
@@ -50,9 +50,10 @@ private void parseDirectoryEntry() throws IOException {
         int[] rawFlag = input.readSplitBits(2);
 
         table.setTransform(rawFlag[0]);
-        table.flag = TableFlagType.fromInt(rawFlag[1]);
+        TableFlagType flag = TableFlagType.fromInt(rawFlag[1]);
+        table.tag = flag.toString();
 
-        if (table.flag.getValue() == 63) {
+        if (flag.getValue() == 63) {
             String tagStr = new String(ByteBuffer.allocate(4).putInt(input.readInt()).array());
             log.error("!! arbitrary flag type not tested" + tagStr);
         }
@@ -66,7 +67,7 @@ private void parseDirectoryEntry() throws IOException {
             table.transformLength = table.originalLength;
 
         log.debug("Woff2 parse table dir read: {} {} o-len:" + table.originalLength + " t-len:" + table.transformLength,
-                table.flag, table.getTransform());
+                table.tag, table.getTransform());
 
         font.getTables().add(table);
     }

diff --git a/src/main/java/org/mabb/fontverter/woff/WoffConstants.java b/src/main/java/org/mabb/fontverter/woff/WoffConstants.java
@@ -53,7 +53,8 @@ public static TableFlagType fromInt(int i) {
                 if (typeOn.getValue() == i) {
                     return typeOn;
                 }
-            return null;
+
+            return arbitrary;
         }
 
         public static TableFlagType fromString(String str) {

diff --git a/src/test/java/org/mabb/fontverter/woff/TestOtfToWoffConverter.java b/src/test/java/org/mabb/fontverter/woff/TestOtfToWoffConverter.java
@@ -53,6 +53,9 @@ public void convertTtf_withUnsignedFlagByte() throws Exception {
         Woff2Font woffFont = (Woff2Font) FontVerter.convertFont(TEST_PATH + "comic.ttf", FontFormat.WOFF2);
         int otfLength = woffFont.getFonts().get(0).getData().length;
 
+        byte[] ttf = FontVerter.readFont(TEST_PATH + "comic.ttf").getData();
+        saveTempFile(ttf, "comic.ttf");
+
         byte[] fontData = woffFont.getData();
         saveTempFile(fontData, "comic.woff2");
 
@@ -98,7 +101,7 @@ public void convertCffToWoff2_thenAllOtfTableTypes_arePresentInWoff2Font() throw
         for (TableFlagType flagOn : flags) {
             boolean flagFound = false;
             for (WoffTable table : parsedFont.getTables()) {
-                if (flagOn == ((Woff2Font.Woff2Table)table).flag)
+                if (flagOn == ((Woff2Font.Woff2Table)table).getFlag())
                     flagFound = true;
             }