From 79f9cfae8072b88befba2cdc2fed43c21ff5d498 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 7 Feb 2018 18:28:17 +0000
Subject: [PATCH] From Ravi Mathur, "he freetype plugin currently forces the
 use of the first font within a truetype collection (.ttc index 0). I made a
 slight modification such that users can specify any font index via the
 userOptions input to osgText::readFontFile(). Specifically, the freetype
 plugin now accepts a new string option of the format "index=< unsigned int
 >". Example usage:

Code:
// Chooses the second font within the Menlo font collection
osg::ref_ptr<osgDB::Options> fontOptions = new osgDB::Options;
fontOptions->setObjectCacheHint(osgDB::Options::CACHE_OBJECTS);
fontOptions->setOptionString("index=1");
text->setFont(osgText::readFontFile("Menlo.ttc", fontOptions));

"
---
 .../freetype/ReaderWriterFreeType.cpp         | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/osgPlugins/freetype/ReaderWriterFreeType.cpp b/src/osgPlugins/freetype/ReaderWriterFreeType.cpp
index bdb8f7cf3..934b76ee6 100644
--- a/src/osgPlugins/freetype/ReaderWriterFreeType.cpp
+++ b/src/osgPlugins/freetype/ReaderWriterFreeType.cpp
@@ -11,7 +11,7 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
         ReaderWriterFreeType()
         {
             supportsExtension("ttf","true type font format");
-            supportsExtension("ttc","true type format");
+            supportsExtension("ttc","true type collection format");
             supportsExtension("pfb","type1 binary format");
             supportsExtension("pfa","type2 ascii format");
             supportsExtension("cid","Postscript CID-Fonts format");
@@ -23,6 +23,7 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
             supportsExtension("woff","web open font format");
 
             supportsOption("monochrome","Select monochrome font.");
+            supportsOption("index=<uint>", "Select index of font within ttc collection. Defaults to 0.");
         }
 
         virtual const char* className() const { return "FreeType Font Reader/Writer"; }
@@ -38,6 +39,20 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
             return flags;
         }
 
+        static unsigned int getIndex(const osgDB::ReaderWriter::Options* options)
+        {
+            if(!options) return 0;
+
+            std::string indexstr = options->getPluginStringData("index");
+            int index = std::atoi(indexstr.c_str());
+            if(index < 0)
+            {
+                OSG_WARN<< "Warning: invalid index string (" << indexstr << ") when loading freetype font. Attempting to use default index 0." << std::endl;
+                return 0;
+            }
+            else return (unsigned int)index;
+        }
+
         virtual ReadResult readObject(const std::string& file, const osgDB::ReaderWriter::Options* options) const
         {
             std::string ext = osgDB::getLowerCaseFileExtension(file);
@@ -53,7 +68,7 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
                 return ReadResult::ERROR_IN_READING_FILE;
             }
 
-            return freeTypeLibrary->getFont(fileName,0,getFlags(options));
+            return freeTypeLibrary->getFont(fileName, getIndex(options), getFlags(options));
         }
 
         virtual ReadResult readObject(std::istream& stream, const osgDB::ReaderWriter::Options* options) const
@@ -65,7 +80,7 @@ class ReaderWriterFreeType : public osgDB::ReaderWriter
                 return ReadResult::ERROR_IN_READING_FILE;
             }
 
-            return freeTypeLibrary->getFont(stream, 0, getFlags(options));
+            return freeTypeLibrary->getFont(stream, getIndex(options), getFlags(options));
         }
 };