ENH: Adds time integrator class

Adds time integrator which only sets rules for finite difference in time.
Adds comments for DeformableObject class

Base/Scene/Object/imstkDeformableObject.cpp

@@ -22,6 +22,7 @@
 #include "imstkDeformableObject.h"
 
 namespace imstk {
+
 std::shared_ptr<Geometry>
 DeformableObject::getPhysicsGeometry() const
 {
@@ -33,4 +34,11 @@ DeformableObject::setPhysicsGeometry(std::shared_ptr<Geometry> geometry)
 {
     m_physicsGeometry = geometry;
 }
+
+int
+DeformableObject::getNumOfDOF() const
+{
+    return numDOF;
+}
+
 }

Base/Scene/Object/imstkDeformableObject.h

@@ -23,6 +23,7 @@
 #define imstkDeformableObject_h
 
 #include <memory>
+#include <string>
 
 #include "imstkCollidingObject.h"
 
@@ -31,25 +32,50 @@ namespace imstk {
 class Geometry;
 class GeometryMap;
 
+///
+/// \class DeformableObject
+///
+/// \brief Base class for scene objects that deform
+///
 class DeformableObject : public CollidingObject
 {
 public:
 
+    ///
+    /// \brief Constructor
+    ///
     DeformableObject(std::string name) : CollidingObject(name)
     {
         m_type = Type::Deformable;
     }
 
+    ///
+    /// \brief Destructor
+    ///
     ~DeformableObject() = default;
 
+    ///
+    /// \brief Returns the geometry used for Physics computations
+    ///
     std::shared_ptr<Geometry> getPhysicsGeometry() const;
+
+    ///
+    /// \brief Assigns the geometry used for Physics related computations
+    ///
     void setPhysicsGeometry(std::shared_ptr<Geometry> geometry);
 
+    ///
+    /// \brief Returns the number of degree of freedom
+    ///
+    int getNumOfDOF() const;
+
 protected:
 
-    std::shared_ptr<Geometry> m_physicsGeometry;          ///> Geometry for collisions
-    std::shared_ptr<GeometryMap> m_physicsToCollidingMap; ///> Maps transformations to colliding geometry
+    std::shared_ptr<Geometry> m_physicsGeometry;                ///> Geometry used for Physics
+    std::shared_ptr<GeometryMap> m_physicsToCollidingGeomMap;   ///> Maps transformations to colliding geometry
+    std::shared_ptr<GeometryMap> m_physicsToVisualGeomMap;      ///> Maps transformations to colliding geometry
 
+    int numDOF; ///> Number of degree of freedom of the body in the discretized model
 };
 
 }

Base/Scene/Object/imstkSceneObject.h

@@ -23,6 +23,7 @@
 #define imstkSceneObject_h
 
 #include <memory>
+#include <string>
 
 namespace imstk {
 

Base/Scene/Object/imstkTimeIntegrator.cpp

+/*=========================================================================
+
+Library: iMSTK
+
+Copyright (c) Kitware, Inc. & Center for Modeling, Simulation,
+& Imaging in Medicine, Rensselaer Polytechnic Institute.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0.txt
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+=========================================================================*/
+
+#include "imstkTimeIntegrator.h"
+
+namespace imstk {
+
+TimeIntegrator::TimeIntegrator(const timeIntegratorType type)
+{
+    this->setType(type);
+}
+
+void
+TimeIntegrator::setType(const timeIntegratorType type)
+{
+    this->m_type = type;
+    this->setCoefficients(type);
+}
+
+const Type&
+TimeIntegrator::getType() const
+{
+    return m_type;
+}
+
+void
+TimeIntegrator::setCoefficients(const timeIntegratorType type)
+{
+    switch (type) {
+    case timeIntegratorType::backwardEuler:
+        m_alpha = {1, 0, 0};
+        m_beta = {1, -1, 0};
+        m_gamma = {1, -2, -1};
+        break;
+
+    case timeIntegratorType::forwardEuler:
+    case timeIntegratorType::newmarkBeta:
+    case timeIntegratorType::centralDifference:
+        LOG(WARNING) << "Type of the time integrator not supported!";
+        break;
+
+    default:
+        LOG(WARNING) << "Type of the time integrator not identified!";
+        break;
+    }
+}
+
+}

Base/Scene/Object/imstkTimeIntegrator.h

+/*=========================================================================
+
+   Library: iMSTK
+
+   Copyright (c) Kitware, Inc. & Center for Modeling, Simulation,
+   & Imaging in Medicine, Rensselaer Polytechnic Institute.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0.txt
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+
+   =========================================================================*/
+
+#ifndef imstkTimeIntegrator_h
+#define imstkTimeIntegrator_h
+
+namespace imstk {
+
+///
+/// \class TimeIntegrator
+///
+/// \brief This class defines the time integrators of various types.
+/// It only sets the rules of how the velocity (or equivalent) and
+/// acceleration (or equivalent) of the present time in terms of
+/// positions (or equivalent) from previous time steps.
+///
+class TimeIntegrator
+{
+    enum class timeIntegratorType
+    {
+        forwardEuler,
+        backwardEuler,
+        newmarkBeta,
+        centralDifference
+    };
+
+public:
+    ///
+    /// \brief Constructor
+    ///
+    TimeIntegrator(const timeIntegratorType type);
+
+    ///
+    /// \brief Destructor
+    ///
+    ~TimeIntegrator() = default;
+
+    ///
+    /// \brief Set/Get type of the time integrator
+    ///
+    void setType(const timeIntegratorType type);
+    const Type& getType() const;
+
+    ///
+    /// \brief Set coefficients for a given time integrator type
+    ///
+    void setCoefficients(const timeIntegratorType type);
+
+protected:
+    timeIntegratorType m_type; ///> Type of the time integrator
+
+    // Coefficients of the time integrator
+    double m_alpha[3];
+    double m_gamma[3];
+    double m_beta[3];
+};
+
+}
+
+#endif // ifndef imstkTimeIntegrator_h