From 057f8a8b3bc88d737ac4a6c38a9e94930063ecf9 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 13 Nov 2012 14:22:37 +0000
Subject: [PATCH] Added support for <image blending="ON" or blending="OFF"> to
 allow user definition of when to enable OpenGL blending for an image or not.

---
 include/osgPresentation/SlideShowConstructor | 12 +++++++++++-
 src/osgPlugins/p3d/ReaderWriterP3D.cpp       | 10 ++++++++++
 src/osgPresentation/SlideShowConstructor.cpp | 19 +++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/include/osgPresentation/SlideShowConstructor b/include/osgPresentation/SlideShowConstructor
index ed90f05ac..9a6808531 100644
--- a/include/osgPresentation/SlideShowConstructor
+++ b/include/osgPresentation/SlideShowConstructor
@@ -246,7 +246,8 @@ public:
             duration(-1.0),
             imageSequence(false),
             imageSequencePagingMode(osg::ImageSequence::PAGE_AND_DISCARD_USED_IMAGES),
-            imageSequenceInteractionMode(PLAY_AUTOMATICALLY_LIKE_MOVIE)
+            imageSequenceInteractionMode(PLAY_AUTOMATICALLY_LIKE_MOVIE),
+            blendingHint(USE_IMAGE_ALPHA)
         {}
 
         std::string                     options;
@@ -271,7 +272,16 @@ public:
             USE_MOUSE_Y_POSITION
         };
         ImageSequenceInteractionMode imageSequenceInteractionMode;
+
+        enum BlendingHint
+        {
+            USE_IMAGE_ALPHA,
+            OFF,
+            ON
+        };
         
+        BlendingHint blendingHint;
+
     };
 
     struct VolumeData
diff --git a/src/osgPlugins/p3d/ReaderWriterP3D.cpp b/src/osgPlugins/p3d/ReaderWriterP3D.cpp
index 9f0b7ecd6..287976686 100644
--- a/src/osgPlugins/p3d/ReaderWriterP3D.cpp
+++ b/src/osgPlugins/p3d/ReaderWriterP3D.cpp
@@ -935,6 +935,16 @@ bool ReaderWriterP3DXML::getProperties(osgDB::XmlNode*cur, osgPresentation::Slid
         OSG_NOTIFY(_notifyLevel)<<"read imageSequencePagingMode \""<<value.imageSequenceInteractionMode<<"\""<<std::endl;
     }
 
+    if (getProperty(cur, "blending", str))
+    {
+        propertiesRead = true;
+
+        if (str=="ON" || str=="On" || str=="on" || str=="enable" ) value.blendingHint = osgPresentation::SlideShowConstructor::ImageData::ON;
+        else if (str=="OFF" || str=="Off" || str=="off" || str=="disable" ) value.blendingHint = osgPresentation::SlideShowConstructor::ImageData::OFF;
+
+        OSG_NOTIFY(_notifyLevel)<<"read blendingHint \""<<value.blendingHint<<"\""<<std::endl;
+    }
+
     /*
     if (getProperty(cur, "texcoord_offset", value.texcoord_offset))
     {
diff --git a/src/osgPresentation/SlideShowConstructor.cpp b/src/osgPresentation/SlideShowConstructor.cpp
index efb874b43..e40150a27 100644
--- a/src/osgPresentation/SlideShowConstructor.cpp
+++ b/src/osgPresentation/SlideShowConstructor.cpp
@@ -1115,6 +1115,16 @@ void SlideShowConstructor::addImage(const std::string& filename, const PositionD
         isImageTranslucent = image->isImageTranslucent();
     }
 
+    if (imageData.blendingHint==ImageData::ON)
+    {
+        isImageTranslucent = true;
+    }
+    else if (imageData.blendingHint==ImageData::OFF)
+    {
+        isImageTranslucent = false;
+    }
+
+    
     float s = image->s();
     float t = image->t();
 
@@ -1274,6 +1284,15 @@ void SlideShowConstructor::addStereoImagePair(const std::string& filenameLeft, c
         isImageTranslucent = imageRight->isImageTranslucent();
     }
 
+    if (imageDataLeft.blendingHint==ImageData::ON || imageDataRight.blendingHint==ImageData::ON)
+    {
+        isImageTranslucent = true;
+    }
+    else if (imageDataLeft.blendingHint==ImageData::OFF || imageDataRight.blendingHint==ImageData::OFF)
+    {
+        isImageTranslucent = false;
+    }
+
 
     float s = imageLeft->s();
     float t = imageLeft->t();