From f3ba656303b43c855fb52a5ee4338dfbe243560f Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 16 Sep 2014 11:00:01 +0000
Subject: [PATCH] Added write support

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14449 16af8721-9629-0410-8352-f15c8da7e697
---
 src/osgPlugins/tf/ReaderWriterTF.cpp | 47 ++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/src/osgPlugins/tf/ReaderWriterTF.cpp b/src/osgPlugins/tf/ReaderWriterTF.cpp
index 46d53c62c..17df7cfea 100644
--- a/src/osgPlugins/tf/ReaderWriterTF.cpp
+++ b/src/osgPlugins/tf/ReaderWriterTF.cpp
@@ -130,6 +130,53 @@ class ReaderWriterTF : public osgDB::ReaderWriter
             else return ReadResult::ERROR_IN_READING_FILE;
         }
 
+        virtual WriteResult writeTransferFunction(const osg::TransferFunction1D* tf, std::ostream& fout, float colorScale) const
+        {
+            if (colorScale == 0.0) colorScale = 1.0f;
+
+            const osg::TransferFunction1D::ColorMap& cm = tf->getColorMap();
+            for(osg::TransferFunction1D::ColorMap::const_iterator itr = cm.begin();
+                itr != cm.end();
+                ++itr)
+            {
+                const osg::Vec4& c = itr->second;
+                fout << itr->first <<" "<< c.r()*colorScale <<" "<< c.g()*colorScale << " "<< c.b()*colorScale<<" "<<c.a()*colorScale<<std::endl;
+            }
+
+            return WriteResult::FILE_SAVED;
+        }
+
+
+        virtual WriteResult writeObject(const osg::Object& object, std::ostream& fout, const osgDB::ReaderWriter::Options* options) const
+        {
+            const osg::TransferFunction1D* tf = dynamic_cast<const osg::TransferFunction1D*>(&object);
+            if (!tf) return WriteResult::FILE_NOT_HANDLED;
+
+            float colorScale = 0.0f; // default auto-detect scale
+            readColorScale(options, colorScale);
+
+            return writeTransferFunction(tf, fout, colorScale);
+        }
+
+        virtual WriteResult writeObject(const osg::Object& object, const std::string& fileName, const osgDB::ReaderWriter::Options* options) const
+        {
+            OSG_NOTICE<<"ReaderWriterTF::writeObject"<<fileName<<std::endl;
+
+            const osg::TransferFunction1D* tf = dynamic_cast<const osg::TransferFunction1D*>(&object);
+            if (!tf) return WriteResult::FILE_NOT_HANDLED;
+
+            std::string ext = osgDB::getFileExtension(fileName);
+            if (!acceptsExtension(ext)) return WriteResult::FILE_NOT_HANDLED;
+
+            float colorScale = 0.0f; // default auto-detect scale
+            if (ext=="tf-255") colorScale = 1.0f/255.0f;
+            readColorScale(options, colorScale);
+
+            osgDB::ofstream fout(fileName.c_str(), std::ios::out | std::ios::binary);
+            if(!fout) return WriteResult::ERROR_IN_WRITING_FILE;
+
+            return writeTransferFunction(tf, fout, colorScale);
+        }
 };
 
 // now register with Registry to instantiate the above