From 6a4609c28f9a7646652d76884cffaaa2414f9782 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 27 Feb 2018 19:09:18 +0000
Subject: [PATCH] Fixed precision issue with filling in the last element of the
 TransferFunction1D's osg::Image.

---
 src/osg/TransferFunction.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/osg/TransferFunction.cpp b/src/osg/TransferFunction.cpp
index 4e5763e91..56c5a32d4 100644
--- a/src/osg/TransferFunction.cpp
+++ b/src/osg/TransferFunction.cpp
@@ -87,6 +87,10 @@ void TransferFunction1D::assignToImage(float lower_v, const osg::Vec4& lower_c,
     if (end_iPos < 0) return;
     if (end_iPos > endPos) end_iPos = endPos;
 
+    // clamp to ends to avoid any precision issues
+    if (lower_v == minimum) start_iPos = 0;
+    if (upper_v == maximum) end_iPos = endPos;
+
     //OSG_NOTICE<<"TransferFunction1D::assignToImage[lower_v="<<lower_v<<", lower_c="<<lower_c<<", upper_v="<<upper_v<<" upper_c="<<upper_c<<std::endl;
     //OSG_NOTICE<<"  lower_iPos="<<lower_iPos<<"  start_iPpos="<<start_iPos<<std::endl;
     //OSG_NOTICE<<"  upper_iPos="<<upper_iPos<<"  end_iPpos="<<end_iPos<<std::endl;