initial experimentation

src/slic3r/CMakeLists.txt

@@ -47,6 +47,7 @@ set(SLIC3R_GUI_SOURCES
     GUI/Gizmos/GLGizmoSlaSupports.hpp
     GUI/Gizmos/GLGizmoFdmSupports.cpp
     GUI/Gizmos/GLGizmoFdmSupports.hpp
+    GUI/Gizmos/Experiment.cpp
     GUI/Gizmos/GLGizmoFlatten.cpp
     GUI/Gizmos/GLGizmoFlatten.hpp
     GUI/Gizmos/GLGizmoCut.cpp

src/slic3r/GUI/Gizmos/Experiment.cpp

@@ -0,0 +1,77 @@
+#include "libslic3r/Model.hpp"
+
+#include <algorithm>
+
+#include "slic3r/GUI/GLCanvas3D.hpp"
+#include "slic3r/GUI/Gizmos/GLGizmoPainterBase.hpp"
+#include "libslic3r/TriangleSelector.hpp"
+
+namespace Slic3r::GUI {
+
+//TODO close in seprate namespace
+
+struct Triangle {
+    stl_triangle_vertex_indices indices;
+    Vec3f normal;
+    size_t index_in_its;
+    Vec3i neighbours;
+    float min_z;
+
+    //members updated during algorithm
+    size_t area { 0 };
+};
+
+struct SupportPlacerMesh {
+
+    indexed_triangle_set mesh;
+    std::vector<Triangle> triangles;
+    std::vector<size_t> triangle_indexes_by_z;
+
+    explicit SupportPlacerMesh(indexed_triangle_set &&mesh) :
+            mesh(mesh) {
+
+        auto neighbours = its_face_neighbors_par(mesh);
+
+        auto min_z_point = [](const size_t &t_index) {
+            const auto &t = triangles[t_index];
+            return std::min(mesh.vertices[t.indices.z()].z(),
+                    std::min(mesh.vertices[t.indices.x()].z(), mesh.vertices[t.indices.y()].z()));
+        };
+
+        for (size_t face_index = 0; face_index < mesh.indices; ++face_index) {
+            Vec3f normal = its_face_normal(mesh, face_index);
+            triangles.push_back(Triangle { mesh.indices[face_index], normal, face_index, neighbours[face_index],
+                    min_z_point(face_index) });
+            triangle_indexes_by_z.push_back(face_index);
+        }
+
+        std::sort(triangle_indexes_by_z.begin(), triangle_indexes_by_z.end(),
+                [&](const size_t &left, const size_t &right) {
+                    return triangles[left].min_z < triangles[right].min_z;
+                });
+    }
+
+    void assign_areas() {
+        size_t next_to_process = 0;
+        while (next_to_process < triangles.size()) {
+        if (triangles[next_to_process].area > 0){
+            //already done, skip
+            continue;
+        }
+
+
+
+    }
+}
+
+};
+
+void do_experimental_support_placement(indexed_triangle_set mesh,
+        const TriangleSelectorGUI *selector) {
+    SupportPlacerMesh support_placer { std::move(mesh) };
+
+    support_placer.assign_areas();
+
+}
+
+}

src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp

@@ -347,6 +347,12 @@ void GLGizmoFdmSupports::select_facets_by_angle(float threshold_deg, bool block)
 
         float dot_limit = limit.dot(down);
 
+
+        indexed_triangle_set mesh_triangles = mv->mesh().its;
+        its_transform(mesh_triangles, mi->get_matrix(true));
+        do_experimental_support_placement(std::move(mesh_triangles), m_triangle_selectors[mesh_id].get());
+
+        if (false) {
         // Now calculate dot product of vert_direction and facets' normals.
         int idx = 0;
         const indexed_triangle_set &its = mv->mesh().its;
@@ -357,6 +363,7 @@ void GLGizmoFdmSupports::select_facets_by_angle(float threshold_deg, bool block)
             }
             ++ idx;
         }
+        }
     }
 
     Plater::TakeSnapshot snapshot(wxGetApp().plater(), block ? _L("Block supports by angle")

src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.hpp

@@ -3,6 +3,8 @@
 
 #include "GLGizmoPainterBase.hpp"
 
+#include "Experiment.cpp"
+
 namespace Slic3r::GUI {
 
 class GLGizmoFdmSupports : public GLGizmoPainterBase