From 412717c151b9d080e94cde11a9b846acee5ed1b0 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Sat, 10 May 2008 17:25:42 +0000
Subject: [PATCH] From Paul Martz, "This change adds support for
 osg::Billboards to the OpenFlight exporter.

It might seem odd that the change actually removes the stub apply(Billboard&) method, but it turns out Billboards are easily supported in subordinate routines of the existing apply(Geode&) method with s dynamic_cast, so there's no need for a separate apply(Billboard&)."
---
 .../OpenFlight/FltExportVisitor.cpp           | 20 +++----------
 src/osgPlugins/OpenFlight/FltExportVisitor.h  |  1 -
 .../OpenFlight/expGeometryRecords.cpp         | 29 +++++++++++++++----
 3 files changed, 27 insertions(+), 23 deletions(-)

diff --git a/src/osgPlugins/OpenFlight/FltExportVisitor.cpp b/src/osgPlugins/OpenFlight/FltExportVisitor.cpp
index c449b468f..8ea917157 100644
--- a/src/osgPlugins/OpenFlight/FltExportVisitor.cpp
+++ b/src/osgPlugins/OpenFlight/FltExportVisitor.cpp
@@ -28,7 +28,6 @@
 
 #include <osgDB/FileUtils>
 #include <osgDB/WriteFile>
-#include <osg/Billboard>
 #include <osg/Geode>
 #include <osg/Geometry>
 #include <osg/LightSource>
@@ -336,6 +335,10 @@ FltExportVisitor::apply( osg::LightSource& node )
     writePushTraverseWritePop( node );
 }
 
+// Billboards also go through this code. The Geode is passed
+// to writeFace and writeMesh. If those methods successfully cast
+// the Geode to a Billboard, then they set the template mode
+// bit accordingly.
 void
 FltExportVisitor::apply( osg::Geode& node )
 {
@@ -436,21 +439,6 @@ FltExportVisitor::apply( osg::Geode& node )
     //   traverse( (osg::Node&)node );
 }
 
-void
-FltExportVisitor::apply( osg::Billboard& node )
-{
-    _firstNode = false;
-    ScopedStatePushPop guard( this, node.getStateSet() );
-
-    // TBD -- Not yet implemented, but HIGH priority.
-    //   Face record -- HIGH
-    //   Mesh record -- HIGH
-
-    writeMatrix( node.getUserData() );
-    writeComment( node );
-    writePushTraverseWritePop( node );
-}
-
 void
 FltExportVisitor::apply( osg::Node& node )
 {
diff --git a/src/osgPlugins/OpenFlight/FltExportVisitor.h b/src/osgPlugins/OpenFlight/FltExportVisitor.h
index 747429ba5..e41d6aac9 100644
--- a/src/osgPlugins/OpenFlight/FltExportVisitor.h
+++ b/src/osgPlugins/OpenFlight/FltExportVisitor.h
@@ -77,7 +77,6 @@ public:
     virtual void apply( osg::Transform& node );
     virtual void apply( osg::LightSource& node );
     virtual void apply( osg::Geode& node );
-    virtual void apply( osg::Billboard& node );
     virtual void apply( osg::Node& node );
     virtual void apply( osg::ProxyNode& node );
 
diff --git a/src/osgPlugins/OpenFlight/expGeometryRecords.cpp b/src/osgPlugins/OpenFlight/expGeometryRecords.cpp
index 58aed9e32..d54b3a63e 100644
--- a/src/osgPlugins/OpenFlight/expGeometryRecords.cpp
+++ b/src/osgPlugins/OpenFlight/expGeometryRecords.cpp
@@ -24,6 +24,7 @@
 #include <osg/BlendFunc>
 #include <osg/Geometry>
 #include <osg/Geode>
+#include <osg/Billboard>
 #include <osg/io_utils>
 #include <osg/Material>
 #include <osg/Texture2D>
@@ -249,10 +250,18 @@ FltExportVisitor::writeFace( const osg::Geode& geode, const osg::Geometry& geom,
         }
     }
 
-    // Check for blending. We're not a Billboard (TBD?)
-    //   so use either FIXED_NO_ALPHA_BLENDING or FIXED_ALPHA_BLENDING.
+    // Set the appropriate template mode based
+    // on blending or Billboarding.
     TemplateMode templateMode( FIXED_NO_ALPHA_BLENDING );
-    if ( ss->getMode( GL_BLEND ) & osg::StateAttribute::ON )
+    const osg::Billboard* bb = dynamic_cast< const osg::Billboard* >( &geode );
+    if (bb != NULL)
+    {
+        if( bb->getMode() == osg::Billboard::AXIAL_ROT )
+            templateMode = AXIAL_ROTATE_WITH_ALPHA_BLENDING;
+        else
+            templateMode = POINT_ROTATE_WITH_ALPHA_BLENDING;
+    }
+    else if ( ss->getMode( GL_BLEND ) & osg::StateAttribute::ON )
     {
         const osg::BlendFunc* bf = static_cast<const osg::BlendFunc*>(
             ss->getAttribute(osg::StateAttribute::BLENDFUNC) );
@@ -416,10 +425,18 @@ FltExportVisitor::writeMesh( const osg::Geode& geode, const osg::Geometry& geom
         }
     }
 
-    // Check for blending. We're not a Billboard (TBD?)
-    //   so use either FIXED_NO_ALPHA_BLENDING or FIXED_ALPHA_BLENDING.
+    // Set the appropriate template mode based
+    // on blending or Billboarding.
     TemplateMode templateMode( FIXED_NO_ALPHA_BLENDING );
-    if ( ss->getMode( GL_BLEND ) & osg::StateAttribute::ON )
+    const osg::Billboard* bb = dynamic_cast< const osg::Billboard* >( &geode );
+    if (bb != NULL)
+    {
+        if( bb->getMode() == osg::Billboard::AXIAL_ROT )
+            templateMode = AXIAL_ROTATE_WITH_ALPHA_BLENDING;
+        else
+            templateMode = POINT_ROTATE_WITH_ALPHA_BLENDING;
+    }
+    else if ( ss->getMode( GL_BLEND ) & osg::StateAttribute::ON )
     {
         const osg::BlendFunc* bf = static_cast<const osg::BlendFunc*>(
             ss->getAttribute(osg::StateAttribute::BLENDFUNC) );