From 350756e7381868abac8505143916477ab0e36c80 Mon Sep 17 00:00:00 2001
From: Julien Valentin <pascal@pcpascal.WORKGROUP>
Date: Mon, 28 Aug 2017 18:42:22 +0200
Subject: [PATCH] add 2 method to VertexInfluenceMap: normalize and
 cullInfluenceCountPerVertex

---
 include/osgAnimation/VertexInfluence |  6 ++
 src/osgAnimation/VertexInfluence.cpp | 82 ++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/include/osgAnimation/VertexInfluence b/include/osgAnimation/VertexInfluence
index 9c9e38738..ff0403134 100644
--- a/include/osgAnimation/VertexInfluence
+++ b/include/osgAnimation/VertexInfluence
@@ -65,6 +65,12 @@ namespace osgAnimation
             std::map<std::string, BoneInfluenceList>(org),
             osg::Object(org, copyop)
         {}
+        ///normalize per vertex weights given numvert of the attached mesh
+        void normalize(unsigned int numvert);
+
+        ///remove weakest influences in order to fit targetted numbonepervertex
+        void cullInfluenceCountPerVertex(unsigned int maxnumbonepervertex, float minweight=0, bool renormalize=true);
+
     };
 
 }
diff --git a/src/osgAnimation/VertexInfluence.cpp b/src/osgAnimation/VertexInfluence.cpp
index 9c9e178ba..3038e8374 100644
--- a/src/osgAnimation/VertexInfluence.cpp
+++ b/src/osgAnimation/VertexInfluence.cpp
@@ -20,3 +20,85 @@
 
 using namespace osgAnimation;
 
+struct invweight_ordered
+{
+    inline bool operator() (const BoneWeight& bw1, const BoneWeight& bw2)
+    {
+        if (bw1.getWeight() > bw2.getWeight())return true;
+        if (bw1.getWeight() < bw2.getWeight())return false;
+        return(bw1.getBoneName()<bw2.getBoneName());
+    }
+};
+
+void VertexInfluenceMap::normalize(unsigned int numvert) {
+
+    typedef std::pair<float, std::vector<float*> > PerVertWeights;
+    std::vector<PerVertWeights > localstore;
+    localstore.resize(numvert);
+    for(VertexInfluenceMap::iterator mapit=this->begin(); mapit!=this->end(); ++mapit) {
+        BoneInfluenceList &curvecinf=mapit->second;
+        for(BoneInfluenceList::iterator curinf=curvecinf.begin(); curinf!=curvecinf.end(); ++curinf) {
+            IndexWeight& inf=*curinf;
+            localstore[inf.first].first+=inf.second;
+            localstore[inf.first].second.push_back(&inf.second);
+
+        }
+    }
+    unsigned int vertid=0;
+    for(std::vector<PerVertWeights >::iterator itvert=localstore.begin(); itvert!=localstore.end(); ++itvert, ++vertid) {
+        PerVertWeights & weights=*itvert;
+        if(weights.first< 1e-4)
+        {
+            OSG_WARN << "VertexInfluenceMap::normalize warning the vertex " <<vertid << " seems to have 0 weight, skip normalize for this vertex" << std::endl;
+        }
+        else
+        {
+            float mult = 1.0/weights.first;
+            for (std::vector<float*>::iterator itf =weights.second.begin(); itf!=weights.second.end(); ++itf)
+                **itf*=mult;
+        }
+    }
+
+}
+///remove weakest influences in order to fit targetted numbonepervertex
+void VertexInfluenceMap::cullInfluenceCountPerVertex(unsigned int numbonepervertex,float minweight, bool renormalize) {
+
+    typedef std::set<BoneWeight,invweight_ordered >  BoneWeightOrdered;
+    std::map<int,BoneWeightOrdered > tempVec2Bones;
+    for(VertexInfluenceMap::iterator mapit=this->begin(); mapit!=this->end(); ++mapit) {
+        BoneInfluenceList &curvecinf=mapit->second;
+        for(BoneInfluenceList::iterator curinf=curvecinf.begin(); curinf!=curvecinf.end(); ++curinf) {
+            IndexWeight& inf=*curinf;
+            if( curvecinf.getBoneName().empty()) {
+                OSG_WARN << "VertexInfluenceSet::buildVertex2BoneList warning vertex " << inf.first << " is not assigned to a bone" << std::endl;
+            }
+            else if(inf.second>minweight)tempVec2Bones[inf.first].insert(BoneWeight(curvecinf.getBoneName(), inf.second));
+        }
+    }
+    this->clear();
+    for( std::map<int,BoneWeightOrdered >::iterator mapit=tempVec2Bones.begin(); mapit!=tempVec2Bones.end(); ++mapit) {
+        BoneWeightOrdered& bwset=mapit->second;
+        unsigned int newsize=numbonepervertex<bwset.size()?numbonepervertex:bwset.size();
+        float sum=0;
+        while(bwset.size()>newsize)bwset.erase(*bwset.rbegin());
+        if(renormalize){
+            for(BoneWeightOrdered::iterator bwit=bwset.begin(); bwit!=bwset.end(); ++bwit)
+                sum+=bwit->getWeight();
+            if(sum>1e-4){
+                sum=1.0f/sum;
+                for(BoneWeightOrdered::iterator bwit=bwset.begin(); bwit!=bwset.end(); ++bwit) {
+                    BoneInfluenceList & inf= (*this)[bwit->getBoneName()];
+                    inf.setBoneName(bwit->getBoneName());
+                    inf.push_back(IndexWeight(mapit->first, bwit->getWeight()*sum));
+                }
+            }
+        }else{
+            for(BoneWeightOrdered::iterator bwit=bwset.begin(); bwit!=bwset.end(); ++bwit) {
+                BoneInfluenceList & inf= (*this)[bwit->getBoneName()];
+                inf.setBoneName(bwit->getBoneName());
+                inf.push_back(IndexWeight(mapit->first,bwit->getWeight()));
+            }
+
+        }
+    }
+}