make weakening patches settable from cfg file

dune/tectonic/factories/strikeslipfactory.cc

@@ -2,6 +2,9 @@
 #include "config.h"
 #endif
 
+#include <vector>
+#include <regex>
+
 #include <dune/fufem/geometry/convexpolyhedron.hh>
 
 #include <dune/contact/projections/normalprojection.hh>
@@ -14,6 +17,34 @@
 
 #include "strikeslipfactory.hh"
 
+template <class HostGridType, class VectorTEMPLATE>
+std::vector<double> StrikeSlipFactory<HostGridType, VectorTEMPLATE>::parsePatchString(const std::string& patch_str) {
+    std::vector<double> res;
+
+    std::string str = patch_str;
+    std::regex my_regex("[0-9]+\\.[0-9]+");
+
+    double lower = 0.0;
+    std::smatch match;
+    while (std::regex_search(str, match, my_regex)) {
+        double newVal = atof(match[0].str().c_str());
+
+        if (newVal <= lower) {
+            DUNE_THROW(Dune::Exception, "Invalid patches object in .cfg file: Interval boundaries are expected in ascending order.");
+        }
+        lower = newVal;
+
+        res.push_back(newVal);
+        str = match.suffix();
+    }
+
+    if (res.size() % 2 != 0) {
+        DUNE_THROW(Dune::Exception, "Invalid patches object in .cfg file: An even number of doubles representing a sequence of intervals is expected.");
+    }
+
+    return res;
+}
+
 template <class HostGridType, class VectorTEMPLATE>
 void StrikeSlipFactory<HostGridType, VectorTEMPLATE>::setBodies() {
     // set up cuboid geometries
@@ -35,10 +66,24 @@ void StrikeSlipFactory<HostGridType, VectorTEMPLATE>::setBodies() {
         //triangleGeometries_[1]->addWeakeningPatch(frictionParset, origins[1], {origins[1][0] + lengths[1], origins[1][1], 0});
 #elif MY_DIM == 2
         triangleGeometries_[0] = std::make_shared<TriangleGeometry>(origin, lengths[0], heights[0]);
-        triangleGeometries_[0]->addWeakeningPatch(frictionParset, triangleGeometries_[0]->A(), triangleGeometries_[0]->C());
-
         triangleGeometries_[1] = std::make_shared<TriangleGeometry>(triangleGeometries_[0]->C(), -lengths[1], -heights[1]);
-        triangleGeometries_[1]->addWeakeningPatch(frictionParset, triangleGeometries_[1]->A(), triangleGeometries_[1]->C());
+
+        // parse weakening patches
+        using Patches = std::vector<std::array<double, 2> >;
+        std::string patches_str = this->parset_.template get<std::string>("boundary.friction.weakening.patches");
+
+        auto patches = parsePatchString(patches_str);
+        for (size_t i=0; i<patches.size(); i++) {
+            auto start1 = triangleGeometries_[1]->C() + patches[i]*(triangleGeometries_[1]->A() - triangleGeometries_[1]->C());
+            auto end1 = triangleGeometries_[1]->C() + patches[i+1]*(triangleGeometries_[1]->A() - triangleGeometries_[1]->C());
+            triangleGeometries_[1]->addWeakeningPatch(frictionParset, start1, end1);
+
+            auto start0 = triangleGeometries_[0]->A() + patches[i]*(triangleGeometries_[0]->C() - triangleGeometries_[0]->A());
+            auto end0 = triangleGeometries_[0]->A() + patches[i+1]*(triangleGeometries_[0]->C() - triangleGeometries_[0]->A());
+            triangleGeometries_[0]->addWeakeningPatch(frictionParset, start0, end0);
+            i++;
+        }
+
 #else
 #error CuboidGeometry only supports 2D and 3D!"
 #endif

dune/tectonic/factories/strikeslipfactory.hh

@@ -81,6 +81,8 @@ template <class HostGridType, class VectorType> class StrikeSlipFactory : public
             return {0, 0, 1};
         #endif
     }
+
+    std::vector<double> parsePatchString(const std::string& patch_str);
 };
 #endif