diff --git a/src/libslic3r/CMakeLists.txt b/src/libslic3r/CMakeLists.txt
index 0a0062a75..443c81b48 100644
--- a/src/libslic3r/CMakeLists.txt
+++ b/src/libslic3r/CMakeLists.txt
@@ -201,6 +201,8 @@ set(SLIC3R_SOURCES
     Point.hpp
     Polygon.cpp
     Polygon.hpp
+    PolygonPointTest.cpp
+    PolygonPointTest.hpp
     MutablePolygon.cpp
     MutablePolygon.hpp
     PolygonTrimmer.cpp
diff --git a/src/libslic3r/PolygonPointTest.cpp b/src/libslic3r/PolygonPointTest.cpp
new file mode 100644
index 000000000..dcab9e87e
--- /dev/null
+++ b/src/libslic3r/PolygonPointTest.cpp
@@ -0,0 +1 @@
+#include "PolygonPointTest.hpp"
diff --git a/src/libslic3r/PolygonPointTest.hpp b/src/libslic3r/PolygonPointTest.hpp
new file mode 100644
index 000000000..79e6b4ab5
--- /dev/null
+++ b/src/libslic3r/PolygonPointTest.hpp
@@ -0,0 +1,73 @@
+#ifndef SRC_LIBSLIC3R_POLYGONPOINTTEST_HPP_
+#define SRC_LIBSLIC3R_POLYGONPOINTTEST_HPP_
+
+#include "libslic3r/Point.hpp"
+#include "libslic3r/EdgeGrid.hpp"
+
+namespace Slic3r {
+
+struct EdgeGridWrapper {
+    EdgeGridWrapper(coord_t resolution, ExPolygons ex_polys) :
+            ex_polys(ex_polys) {
+
+        grid.create(this->ex_polys, resolution);
+        grid.calculate_sdf();
+    }
+
+    bool signed_distance(const Point &point, coordf_t point_width, coordf_t &dist_out) const {
+        coordf_t tmp_dist_out;
+        bool found = grid.signed_distance(point, point_width, tmp_dist_out);
+        // decrease the distance by half of edge width of previous layer and half of flow width of current layer
+        dist_out = tmp_dist_out - point_width / 2;
+        return found;
+
+    }
+
+    EdgeGrid::Grid grid;
+    ExPolygons ex_polys;
+};
+
+class PolygonPointTest {
+public:
+    PolygonPointTest(const ExPolygons &ex_polygons) {
+        std::vector<Line> lines;
+        for (const auto &exp : ex_polygons) {
+            Lines contour = exp.contour.lines();
+            lines.insert(lines.end(), contour.begin(), contour.end());
+            for (const auto &hole : exp.holes) {
+                Lines hole_lines = hole.lines();
+                for (Line &line : hole_lines) {
+                    line.reverse(); // reverse hole lines, so that we can use normal to deduce where the object is
+                }
+                lines.insert(lines.end(), hole_lines.begin(), hole_lines.end());
+            }
+        }
+
+        std::vector<std::pair<size_t, bool>> sweeping_data(lines.size());
+        sweeping_data.reserve(lines.size() * 2);
+        for (int line_index = 0; line_index < lines.size(); ++line_index) {
+            sweeping_data[line_index].first = line_index;
+            sweeping_data[line_index].second = true;
+        }
+
+        const auto data_comparator = [&lines](const std::pair<size_t, bool> &left,
+                const std::pair<size_t, bool> &right) {
+            return std::min(lines[left.first].a.x(), lines[left.first].b.x())
+                    < std::min(lines[right.first].a.x(), lines[right.first].b.x());
+        };
+
+        std::make_heap(sweeping_data.begin(), sweeping_data.end(), data_comparator);
+        std::set<size_t> active_lines;
+
+        //TODO continue
+
+
+
+
+    }
+
+};
+
+}
+
+#endif /* SRC_LIBSLIC3R_POLYGONPOINTTEST_HPP_ */
diff --git a/src/libslic3r/SupportableIssuesSearch.cpp b/src/libslic3r/SupportableIssuesSearch.cpp
index 6510c3546..39ded7648 100644
--- a/src/libslic3r/SupportableIssuesSearch.cpp
+++ b/src/libslic3r/SupportableIssuesSearch.cpp
@@ -8,8 +8,8 @@
 #include <stack>
 
 #include "libslic3r/Layer.hpp"
-#include "libslic3r/EdgeGrid.hpp"
 #include "libslic3r/ClipperUtils.hpp"
+#include "PolygonPointTest.hpp"
 
 #define DEBUG_FILES
 
@@ -33,28 +33,6 @@ bool Issues::empty() const {
 
 namespace Impl {
 
-struct EdgeGridWrapper {
-    EdgeGridWrapper(coord_t edge_width, ExPolygons ex_polys) :
-            ex_polys(ex_polys), edge_width(edge_width) {
-
-        grid.create(this->ex_polys, edge_width);
-        grid.calculate_sdf();
-    }
-
-    bool signed_distance(const Point &point, coordf_t point_width, coordf_t &dist_out) const {
-        coordf_t tmp_dist_out;
-        bool found = grid.signed_distance(point, edge_width, tmp_dist_out);
-        // decrease the distance by half of edge width of previous layer and half of flow width of current layer
-        dist_out = tmp_dist_out - edge_width / 2 - point_width / 2;
-        return found;
-
-    }
-
-    EdgeGrid::Grid grid;
-    ExPolygons ex_polys;
-    coord_t edge_width;
-};
-
 #ifdef DEBUG_FILES
 void debug_export(Issues issues, std::string file_name) {
     Slic3r::CNumericLocalesSetter locales_setter;
@@ -194,7 +172,7 @@ Issues check_extrusion_entity_stability(const ExtrusionEntity *entity,
             }
 
             if (dist_from_prev_layer > max_allowed_dist_from_prev_layer) { //extrusion point is unsupported
-                unsupported_distance += (fpoint - prev_fpoint).norm(); // for algortihm simplicity, expect that the whole line between prev and current point is unsupported
+                unsupported_distance += (fpoint - prev_fpoint).norm(); // for algorithm simplicity, expect that the whole line between prev and current point is unsupported
 
                 if (!points.empty()) {
                     const Vec2f v1 = (fpoint - prev_fpoint).head<2>();