Resolves: fdo#33510 A way to query about likely font layout capabilities

1 files changed, 20 insertions, 2 deletions

diff --git a/vcl/source/fontsubset/gsub.cxx b/vcl/source/fontsubset/gsub.cxx
index 9fc03ca81185..e27b91d0e5a2 100644
--- a/vcl/source/fontsubset/gsub.cxx
+++ b/vcl/source/fontsubset/gsub.cxx
@@ -50,9 +50,9 @@ typedef sal_uInt8 FT_Byte;
 typedef std::map<USHORT,USHORT> GlyphSubstitution;
 
 
-inline long NEXT_Long( const unsigned char* &p )
+inline sal_uInt32 NEXT_Long( const unsigned char* &p )
 {
-    long nVal = (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
+    sal_uInt32 nVal = (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3];
     p += 4;
     return nVal;
 }
@@ -358,6 +358,24 @@ int HasVerticalGSUB( struct _TrueTypeFont* pTTFile )
     return pGlyphSubstitution ? +1 : 0;
 }
 
+void getTTFontLayoutCapabilities(FontLayoutCapabilities &rFontLayoutCapabilities, const unsigned char* pBase)
+{
+    // parse GSUB/GPOS header
+    const FT_Byte* pGsubHeader = pBase;
+    pGsubHeader+=4;
+    const USHORT nOfsScriptList = NEXT_UShort(pGsubHeader);
+
+    // parse Script Table
+    const FT_Byte* pScriptHeader = pBase + nOfsScriptList;
+    const USHORT nCntScript = NEXT_UShort(pScriptHeader);
+    for( USHORT nScriptIndex = 0; nScriptIndex < nCntScript; ++nScriptIndex )
+    {
+        sal_uInt32 nTag = NEXT_Long(pScriptHeader);
+        pScriptHeader += 2;
+        rFontLayoutCapabilities.push_back(nTag); // e.g. hani/arab/kana/hang
+    }
+}
+
 }
 
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