deformable code refactor

src/BulletSoftBody/btDeformableLagrangianForce.h

@@ -0,0 +1,63 @@
+//
+//  btDeformableLagrangianForce.h
+//  BulletSoftBody
+//
+//  Created by Xuchen Han on 7/1/19.
+//
+
+#ifndef BT_DEFORMABLE_LAGRANGIAN_FORCE_H
+#define BT_DEFORMABLE_LAGRANGIAN_FORCE_H
+
+#include "btSoftBody.h"
+#include <unordered_map>
+
+class btDeformableLagrangianForce
+{
+public:
+    using TVStack = btAlignedObjectArray<btVector3>;
+    const btAlignedObjectArray<btSoftBody *>& m_softBodies;
+    std::unordered_map<btSoftBody::Node *, size_t> m_indices;
+    
+    btDeformableLagrangianForce(const btAlignedObjectArray<btSoftBody *>& softBodies)
+    : m_softBodies(softBodies)
+    {
+    }
+    
+    virtual ~btDeformableLagrangianForce(){}
+    
+    virtual void addScaledImplicitForce(btScalar scale, TVStack& force) = 0;
+    
+    virtual void addScaledForceDifferential(btScalar scale, const TVStack& dv, TVStack& df) = 0;
+    
+    virtual void addScaledExplicitForce(btScalar scale, TVStack& force) = 0;
+    
+    virtual void reinitialize(bool nodeUpdated)
+    {
+        if (nodeUpdated)
+            updateId();
+    }
+    
+    virtual void updateId()
+    {
+        size_t index = 0;
+        for (int i = 0; i < m_softBodies.size(); ++i)
+        {
+            btSoftBody* psb = m_softBodies[i];
+            for (int j = 0; j < psb->m_nodes.size(); ++j)
+            {
+                m_indices[&(psb->m_nodes[j])] = index++;
+            }
+        }
+    }
+    
+    virtual int getNumNodes()
+    {
+        int numNodes = 0;
+        for (int i = 0; i < m_softBodies.size(); ++i)
+        {
+            numNodes += m_softBodies[i]->m_nodes.size();
+        }
+        return numNodes;
+    }
+};
+#endif /* BT_DEFORMABLE_LAGRANGIAN_FORCE */