Refactored ForceImpl, lots of KernelImpl subclasses, and other related classes...

Refactored ForceImpl, lots of KernelImpl subclasses, and other related classes to avoid redundant calculations when requesting a State with both forces and energies

olla/include/openmm/kernels.h

@@ -82,36 +82,26 @@ public:
      */
     virtual void initialize(const System& system) = 0;
     /**
-     * This is called at the beginning of each force computation, before calcForces() has been called on
+     * This is called at the beginning of each force/energy computation, before calcForcesAndEnergy() has been called on
      * any ForceImpl.
      * 
      * @param context       the context in which to execute this kernel
+     * @param includeForce  true if forces should be computed
+     * @param includeEnergy true if potential energy should be computed
      */
-    virtual void beginForceComputation(ContextImpl& context) = 0;
+    virtual void beginComputation(ContextImpl& context, bool includeForce, bool includeEnergy) = 0;
     /**
-     * This is called at the end of each force computation, after calcForces() has been called on
-     * every ForceImpl.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void finishForceComputation(ContextImpl& context) = 0;
-    /**
-     * This is called at the beginning of each energy computation, before calcEnergy() has been called on
-     * any ForceImpl.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void beginEnergyComputation(ContextImpl& context) = 0;
-    /**
-     * This is called at the end of each energy computation, after calcEnergy() has been called on
+     * This is called at the end of each force/energy computation, after calcForcesAndEnergy() has been called on
      * every ForceImpl.
      *
      * @param context       the context in which to execute this kernel
+     * @param includeForce  true if forces should be computed
+     * @param includeEnergy true if potential energy should be computed
      * @return the potential energy of the system.  This value is added to all values returned by ForceImpls'
-     * calcEnergy() methods.  That is, each force kernel may <i>either</i> return its contribution to the
+     * calcForcesAndEnergy() methods.  That is, each force kernel may <i>either</i> return its contribution to the
      * energy directly, <i>or</i> add it to an internal buffer so that it will be included here.
      */
-    virtual double finishEnergyComputation(ContextImpl& context) = 0;
+    virtual double finishComputation(ContextImpl& context, bool includeForce, bool includeEnergy) = 0;
 };
 
 /**
@@ -235,18 +225,14 @@ public:
      */
     virtual void initialize(const System& system, const HarmonicBondForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     * 
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      * 
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the HarmonicBondForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -267,18 +253,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomBondForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the CustomBondForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -299,18 +281,14 @@ public:
      */
     virtual void initialize(const System& system, const HarmonicAngleForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     * 
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the HarmonicAngleForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -331,18 +309,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomAngleForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     *
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the CustomAngleForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -363,18 +337,14 @@ public:
      */
     virtual void initialize(const System& system, const PeriodicTorsionForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     * 
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the PeriodicTorsionForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -395,18 +365,14 @@ public:
      */
     virtual void initialize(const System& system, const RBTorsionForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     * 
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the RBTorsionForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -427,18 +393,14 @@ public:
      */
     virtual void initialize(const System& system, const CMAPTorsionForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the CMAPTorsionForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -459,18 +421,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomTorsionForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     *
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the CustomTorsionForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -498,18 +456,14 @@ public:
      */
     virtual void initialize(const System& system, const NonbondedForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     * 
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the NonbondedForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -535,18 +489,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomNonbondedForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     *
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the CustomNonbondedForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -567,18 +517,14 @@ public:
      */
     virtual void initialize(const System& system, const GBSAOBCForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     * 
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the GBSAOBCForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -600,18 +546,14 @@ public:
      */
     virtual void initialize(const System& system, const GBVIForce& force, const std::vector<double>& scaledRadii) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     * 
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the GBVIForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -637,18 +579,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomGBForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the CustomGBForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -669,18 +607,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomExternalForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
-     *
-     * @param context    the context in which to execute this kernel
-     * @return the potential energy due to the CustomExternalForce
-     */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**
@@ -706,18 +640,14 @@ public:
      */
     virtual void initialize(const System& system, const CustomHbondForce& force) = 0;
     /**
-     * Execute the kernel to calculate the forces.
-     *
-     * @param context    the context in which to execute this kernel
-     */
-    virtual void executeForces(ContextImpl& context) = 0;
-    /**
-     * Execute the kernel to calculate the energy.
+     * Execute the kernel to calculate the forces and/or energy.
      *
      * @param context        the context in which to execute this kernel
-     * @return the potential energy due to the CustomHbondForce
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy due to the force
      */
-    virtual double executeEnergy(ContextImpl& context) = 0;
+    virtual double execute(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
 };
 
 /**

openmmapi/include/openmm/internal/AndersenThermostatImpl.h

@@ -51,11 +51,9 @@ public:
         return owner;
     }
     void updateContextState(ContextImpl& context);
-    void calcForces(ContextImpl& context) {
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy) {
         // This force doesn't apply forces to particles.
-    }
-    double calcEnergy(ContextImpl& context) {
-        return 0.0; // This force doesn't contribute to the potential energy.
+        return 0.0;
     }
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();

openmmapi/include/openmm/internal/CMAPTorsionForceImpl.h

@@ -55,8 +55,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/CMMotionRemoverImpl.h

@@ -50,7 +50,7 @@ public:
         return owner;
     }
     void updateContextState(ContextImpl& context);
-    void calcForces(ContextImpl& context) {
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy) {
         // This force doesn't apply forces to particles.
     }
     double calcEnergy(ContextImpl& context) {

openmmapi/include/openmm/internal/ContextImpl.h

@@ -164,18 +164,18 @@ public:
      */
     void applyConstraints(double tol);
     /**
-     * Recalculate all of the forces in the system.  After calling this, use getForces() to retrieve
-     * the forces that were calculated.
+     * Recalculate all of the forces in the system and/or the potential energy of the system (in kJ/mol).
+     * After calling this, use getForces() to retrieve the forces that were calculated.
+     *
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
+     * @return the potential energy of the system, or 0 if includeEnergy is false
      */
-    void calcForces();
+    double calcForcesAndEnergy(bool includeForces, bool includeEnergy);
     /**
      * Calculate the kinetic energy of the system (in kJ/mol).
      */
     double calcKineticEnergy();
-    /**
-     * Calculate the potential energy of the system (in kJ/mol).
-     */
-    double calcPotentialEnergy();
     /**
      * This should be called at the start of each time step.  It calls updateContextState() on each
      * ForceImpl in the system, allowing them to modify the values of state variables.

openmmapi/include/openmm/internal/CustomAngleForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
 private:

openmmapi/include/openmm/internal/CustomBondForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
     std::vector<std::pair<int, int> > getBondedParticles() const;

openmmapi/include/openmm/internal/CustomExternalForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
 private:

openmmapi/include/openmm/internal/CustomGBForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
 private:

openmmapi/include/openmm/internal/CustomHbondForceImpl.h

@@ -59,8 +59,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
     /**

openmmapi/include/openmm/internal/CustomNonbondedForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
 private:

openmmapi/include/openmm/internal/CustomTorsionForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters();
     std::vector<std::string> getKernelNames();
 private:

openmmapi/include/openmm/internal/ForceImpl.h

@@ -76,22 +76,16 @@ public:
      */
     virtual void updateContextState(ContextImpl& context) = 0;
     /**
-     * Calculate the force on each particle generated by this ForceImpl.  The forces should be <i>added</i>
-     * to the values already present in the array that is passed in.  If this ForceImpl does not generate
-     * any new forces, it should simply return without modifying the array.
-     * 
-     * @param context     the context in which the system is being simulated
-     * @param forces      new forces should be added to the value already stored in this
-     */
-    virtual void calcForces(ContextImpl& context) = 0;
-    /**
-     * Calculate this ForceImpl's contribution to the potential energy of the system.
+     * Calculate the force on each particle generated by this ForceImpl and/or this ForceImpl's
+     * contribution to the potential energy of the system.
      * 
      * @param context        the context in which the system is being simulated
+     * @param includeForces  true if forces should be calculated
+     * @param includeEnergy  true if the energy should be calculated
      * @return this force's contribution to the potential energy of the system, or 0 if this
-     * force does not contribute to potential energy
+     * force does not contribute to potential energy (or if includeEnergy is false)
      */
-    virtual double calcEnergy(ContextImpl& context) = 0;
+    virtual double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy) = 0;
     /**
      * Get a map containing the default values for all adjustable parameters defined by this ForceImpl.  These
      * parameters and their default values will automatically be added to the Context.

openmmapi/include/openmm/internal/GBSAOBCForceImpl.h

@@ -53,8 +53,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/GBVIForceImpl.h

@@ -62,8 +62,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/HarmonicAngleForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/HarmonicBondForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/MonteCarloBarostatImpl.h

@@ -52,7 +52,7 @@ public:
         return owner;
     }
     void updateContextState(ContextImpl& context);
-    void calcForces(ContextImpl& context) {
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy) {
         // This force doesn't apply forces to particles.
     }
     double calcEnergy(ContextImpl& context) {

openmmapi/include/openmm/internal/NonbondedForceImpl.h

@@ -58,8 +58,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }

openmmapi/include/openmm/internal/PeriodicTorsionForceImpl.h

@@ -56,8 +56,7 @@ public:
     void updateContextState(ContextImpl& context) {
         // This force field doesn't update the state directly.
     }
-    void calcForces(ContextImpl& context);
-    double calcEnergy(ContextImpl& context);
+    double calcForcesAndEnergy(ContextImpl& context, bool includeForces, bool includeEnergy);
     std::map<std::string, double> getDefaultParameters() {
         return std::map<std::string, double>(); // This force field doesn't define any parameters.
     }