From 995ead176a9b8b2c6f0097b77a325e7c9d612b2f Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Sat, 13 Sep 2008 09:09:51 +0000
Subject: [PATCH] Introduced TransferFunction1D::assign(ValueMap&).

---
 include/osg/TransferFunction             | 21 +++++++
 src/osg/TransferFunction.cpp             | 78 ++++++++++++++++++++++++
 src/osgWrappers/osg/TransferFunction.cpp | 14 +++++
 3 files changed, 113 insertions(+)

diff --git a/include/osg/TransferFunction b/include/osg/TransferFunction
index 09ec18594..9d76c46f6 100644
--- a/include/osg/TransferFunction
+++ b/include/osg/TransferFunction
@@ -17,6 +17,8 @@
 #include <osg/Texture>
 #include <osg/Shader>
 
+#include <map>
+
 namespace osg {
 
 
@@ -77,6 +79,25 @@ class OSG_EXPORT TransferFunction1D : public osg::TransferFunction
         void setValue(unsigned int i, const osg::Vec4& color) { _colors[i] = color; if (_image.valid()) _image->dirty(); }
         const osg::Vec4& getValue(unsigned int i) const { return _colors[i]; }
 
+        osg::Vec4 getInterpolatedValue(float v) const
+        {
+            float iPos = (v-_minimum)*float(_colors.size()-1)/(_maximum-_minimum);
+            if (iPos<0.0) return _colors[0];
+            if (iPos>float(_colors.size()-1)) return _colors[_colors.size()-1];
+            
+            unsigned int iLower = (unsigned int)(iPos);
+            unsigned int iUpper = iLower+1;
+            if (iUpper>=_colors.size()) return _colors[iLower];
+            
+            float r = iPos-floorf(iLower);
+            const osg::Vec4& cLower = _colors[iLower];
+            const osg::Vec4& cUpper = _colors[iUpper];
+            return cLower + (cUpper-cLower)*r;
+        }
+        
+        typedef std::map<float, osg::Vec4> ValueMap;
+        void assign(const ValueMap& vcm, bool updateMinMaxRange);
+
     protected:
     
         float _minimum;
diff --git a/src/osg/TransferFunction.cpp b/src/osg/TransferFunction.cpp
index a68655f80..9d71b883c 100644
--- a/src/osg/TransferFunction.cpp
+++ b/src/osg/TransferFunction.cpp
@@ -13,6 +13,10 @@
 
 #include <osg/TransferFunction>
 
+#include <osg/Notify>
+#include <osg/io_utils>
+
+
 using namespace osg;
 
 ///////////////////////////////////////////////////////////////////////
@@ -59,3 +63,77 @@ void TransferFunction1D::clear(const osg::Vec4& color)
         *itr = color;
     }
 }
+
+
+void TransferFunction1D::assign(const ValueMap& vcm, bool updateMinMaxRange)
+{
+    if (vcm.empty()) return;
+    
+    if (updateMinMaxRange)
+    {
+        _minimum = vcm.begin()->first;
+        _maximum = vcm.rbegin()->first;
+    }
+    
+    if (_colors.empty()) allocate(1024);
+    
+    
+    float multiplier = float(_colors.size()-1)/(_maximum - _minimum);
+    
+    if (vcm.size()==1)
+    {
+        osg::Vec4 color = vcm.begin()->second;
+        if (_minimum == _maximum)
+        {
+            clear(color);
+        }
+        else
+        {
+            float iPos = (vcm.begin()->first - _minimum)*multiplier;
+            if (iPos>=0.0f || iPos<float(_colors.size()))
+            {
+                float iFloor = floorf(iPos);
+                unsigned int i = (unsigned int)(iFloor);
+                _colors[i] = color;
+            }
+        }
+        return;
+    }
+    
+    ValueMap::const_iterator lower_itr = vcm.begin();
+    ValueMap::const_iterator upper_itr = lower_itr;
+    ++upper_itr;
+    
+    for(;
+        upper_itr != vcm.end();
+        ++upper_itr)
+    {
+        float lower_v = lower_itr->first;
+        const osg::Vec4& lower_c = lower_itr->second;
+        float upper_v = upper_itr->first;
+        const osg::Vec4& upper_c = upper_itr->second;
+        
+        float lower_iPos = (lower_v - _minimum)*multiplier; 
+        float upper_iPos = (upper_v - _minimum)*multiplier;
+
+        float start_iPos = ceilf(lower_iPos);
+        if (start_iPos<0.0f) start_iPos=0.0f;
+        if (start_iPos>float(_colors.size()-1)) break;
+        
+        float end_iPos = floorf(upper_iPos);
+        if (end_iPos<0.0f) continue;
+        if (end_iPos>float(_colors.size()-1)) end_iPos=_colors.size()-1;
+
+        Vec4 delta_c = (upper_c-lower_c)/(upper_iPos-lower_iPos);
+        unsigned int i=static_cast<unsigned int>(start_iPos);
+        for(float iPos=start_iPos;
+            iPos<=end_iPos; 
+            ++iPos, ++i)
+        {
+            _colors[i] = lower_c + delta_c*(iPos-lower_v);
+        }
+        
+        lower_itr = upper_itr;      
+    }
+}
+
diff --git a/src/osgWrappers/osg/TransferFunction.cpp b/src/osgWrappers/osg/TransferFunction.cpp
index c5a7a30e2..9c1736f97 100644
--- a/src/osgWrappers/osg/TransferFunction.cpp
+++ b/src/osgWrappers/osg/TransferFunction.cpp
@@ -71,6 +71,8 @@ BEGIN_OBJECT_REFLECTOR(osg::TransferFunction)
 	                 0);
 END_REFLECTOR
 
+TYPE_NAME_ALIAS(std::map< float COMMA  osg::Vec4 >, osg::TransferFunction1D::ValueMap)
+
 BEGIN_OBJECT_REFLECTOR(osg::TransferFunction1D)
 	I_DeclaringFile("osg/TransferFunction");
 	I_BaseType(osg::TransferFunction);
@@ -127,6 +129,16 @@ BEGIN_OBJECT_REFLECTOR(osg::TransferFunction1D)
 	          __C5_osg_Vec4_R1__getValue__unsigned_int,
 	          "",
 	          "");
+	I_Method1(osg::Vec4, getInterpolatedValue, IN, float, v,
+	          Properties::NON_VIRTUAL,
+	          __osg_Vec4__getInterpolatedValue__float,
+	          "",
+	          "");
+	I_Method2(void, assign, IN, const osg::TransferFunction1D::ValueMap &, vcm, IN, bool, updateMinMaxRange,
+	          Properties::NON_VIRTUAL,
+	          __void__assign__C5_ValueMap_R1__bool,
+	          "",
+	          "");
 	I_SimpleProperty(float, Maximum, 
 	                 __float__getMaximum, 
 	                 __void__setMaximum__float);
@@ -142,3 +154,5 @@ BEGIN_OBJECT_REFLECTOR(osg::TransferFunction1D)
 	                  0);
 END_REFLECTOR
 
+STD_MAP_REFLECTOR(std::map< float COMMA  osg::Vec4 >)
+