From 22cf4c18c338f2ae6bbaae31f1e699f6413cde6c Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 23 Jan 2015 13:50:12 +0000
Subject: [PATCH] Added MultiTextureControl event handling of shift 012 i.e.
 ')', '!', '"' and 'A' to toggle full on for each of the respective or all
 texture units.

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14674 16af8721-9629-0410-8352-f15c8da7e697
---
 examples/osgterrain/CMakeLists.txt |  2 +-
 examples/osgterrain/osgterrain.cpp | 53 +++++++++++++++++++++++++++---
 2 files changed, 49 insertions(+), 6 deletions(-)

diff --git a/examples/osgterrain/CMakeLists.txt b/examples/osgterrain/CMakeLists.txt
index a942afd07..89b723654 100644
--- a/examples/osgterrain/CMakeLists.txt
+++ b/examples/osgterrain/CMakeLists.txt
@@ -2,7 +2,7 @@ SET(TARGET_SRC
     osgterrain.cpp
 )
 
-SET(TARGET_ADDED_LIBRARIES osgTerrain )
+SET(TARGET_ADDED_LIBRARIES osgTerrain osgFX)
 
 #### end var setup  ###
 SETUP_EXAMPLE(osgterrain)
diff --git a/examples/osgterrain/osgterrain.cpp b/examples/osgterrain/osgterrain.cpp
index 625bc269e..bc160fba2 100644
--- a/examples/osgterrain/osgterrain.cpp
+++ b/examples/osgterrain/osgterrain.cpp
@@ -36,6 +36,8 @@
 #include <osgTerrain/DisplacementMappingTechnique>
 #include <osgTerrain/Layer>
 
+#include <osgFX/MultiTextureControl>
+
 
 #include <iostream>
 
@@ -79,8 +81,9 @@ T* findTopMostNodeOfType(osg::Node* node)
 class TerrainHandler : public osgGA::GUIEventHandler {
 public:
 
-    TerrainHandler(osgTerrain::Terrain* terrain):
-        _terrain(terrain) {}
+    TerrainHandler(osgTerrain::Terrain* terrain, osgFX::MultiTextureControl* mtc):
+        _terrain(terrain),
+        _mtc(mtc) {}
 
     bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa)
     {
@@ -112,6 +115,26 @@ public:
                     osg::notify(osg::NOTICE)<<"Vertical scale "<<_terrain->getVerticalScale()<<std::endl;
                     return true;
                 }
+                else if (ea.getKey()=='!') // shift 1
+                {
+                    assignTextureWeightToSingleTextureUnit(1);
+                    return true;
+                }
+                else if (ea.getKey()=='"') // shift 1
+                {
+                    assignTextureWeightToSingleTextureUnit(2);
+                    return true;
+                }
+                else if (ea.getKey()==')') // shift 1
+                {
+                    assignTextureWeightToSingleTextureUnit(0);
+                    return true;
+                }
+                else if (ea.getKey()=='A')
+                {
+                    assignedToAll();
+                    return true;
+                }
 
                 return false;
             }
@@ -124,9 +147,28 @@ protected:
 
     ~TerrainHandler() {}
 
-    osg::ref_ptr<osgTerrain::Terrain>  _terrain;
-};
+    void assignTextureWeightToSingleTextureUnit(unsigned int unit)
+    {
+        if (!_mtc) return;
+        for(unsigned int i=0; i<_mtc->getNumTextureWeights(); ++i)
+        {
+            _mtc->setTextureWeight(i, (i==unit) ? 1.0f : 0.0f);
+        }
+    }
 
+    void assignedToAll()
+    {
+        if (!_mtc && _mtc->getNumTextureWeights()>0) return;
+        float div = 1.0f/static_cast<float>(_mtc->getNumTextureWeights());
+        for(unsigned int i=0; i<_mtc->getNumTextureWeights(); ++i)
+        {
+            _mtc->setTextureWeight(i, div);
+        }
+    }
+
+    osg::ref_ptr<osgTerrain::Terrain>           _terrain;
+    osg::ref_ptr<osgFX::MultiTextureControl>    _mtc;
+};
 
 class CleanTechniqueReadFileCallback : public osgDB::ReadFileCallback
 {
@@ -285,6 +327,7 @@ int main(int argc, char** argv)
     terrain->setVerticalScale(verticalScale);
     terrain->setBlendingPolicy(blendingPolicy);
 
+
     if (useDisplacementMappingTechnique)
     {
         terrain->setTerrainTechniquePrototype(new osgTerrain::DisplacementMappingTechnique());
@@ -292,7 +335,7 @@ int main(int argc, char** argv)
 
 
     // register our custom handler for adjust Terrain settings
-    viewer.addEventHandler(new TerrainHandler(terrain.get()));
+    viewer.addEventHandler(new TerrainHandler(terrain.get(), findTopMostNodeOfType<osgFX::MultiTextureControl>(rootnode.get())));
 
     // add a viewport to the viewer and attach the scene graph.
     viewer.setSceneData( rootnode.get() );