Adding some wilson loop support

lib/qcd/action/gauge/GaugeActionBase.h

@@ -0,0 +1,20 @@
+#ifndef QCD_GAUGE_ACTION_BASE
+#define QCD_GAUGE_ACTION_BASE
+namespace Grid {
+namespace QCD{
+
+template<class GaugeField>
+class GaugeActionBase { // derive this from TermInAction?
+
+ public:
+  virtual RealD S(const GaugeField &U)                        = 0;  // evaluate the action
+  virtual void  deriv(const GaugeField &U,GaugeField & dSdU ) = 0;  // evaluate the action derivative
+  virtual void  staple(const GaugeField &U,GaugeField & dSdU ) = 0;  // evaluate the action derivative
+  virtual void refresh(const GaugeField & ) {}; 
+  // Boundary conditions?
+  // Heatbath?
+  virtual ~GaugeActionBase() {};
+};
+
+}}
+#endif

lib/qcd/action/gauge/WilsonGaugeAction.h

@@ -0,0 +1,24 @@
+#ifndef QCD_WILSON_GAUGE_ACTION_H
+#define QCD_WILSON_GAUGE_ACTION_H
+
+////////////////////////////////////////////////////////////////////////
+// Wilson Gauge Action .. should I template the Nc etc..
+////////////////////////////////////////////////////////////////////////
+template<class GaugeField,class MatrixField>
+class WilsonGaugeAction : public GaugeActionBase<GaugeField> {
+ public:
+  virtual RealD S(const GaugeField &U) {
+    return WilsonLoops<MatrixField,GaugeField>::sumPlaquette(U);
+  };
+  virtual RealD deriv(GaugeField &U,GaugeField & dSdU ) {
+    WilsonLoops<MatrixField,GaugeField>::Staple(dSdU,U,mu);
+  };
+  virtual void  staple(const MatrixField &stap,GaugeField & U,int mu ) {
+    WilsonLoops<MatrixField,GaugeField>::Staple(stap,U,mu);
+  };
+};
+
+
+#endif
+
+#endif