Remap filament for pre-colored models (#10303)

* Add a new feature to allow users to remap filament for a pre-painted model.

* Fix the color issues to support the theme

* clean up code

* Fix broken freetype-2.12.1.tar.gz link

src/libslic3r/TriangleSelector.cpp

@@ -3,6 +3,8 @@
 
 #include <boost/container/small_vector.hpp>
 #include <boost/log/trivial.hpp>
+#include <cstddef>
+#include <tbb/parallel_for.h>
 
 #ifndef NDEBUG
 //    #define EXPENSIVE_DEBUG_CHECKS
@@ -1256,6 +1258,22 @@ void TriangleSelector::garbage_collect()
     m_free_vertices_head = -1;
 }
 
+void TriangleSelector::remap_triangle_state(const EnforcerBlockerStateMap& state_map)
+{
+    if (m_triangles.empty())
+        return;
+
+    tbb::parallel_for(tbb::blocked_range<size_t>(0, m_triangles.size()), [this, &state_map](const tbb::blocked_range<size_t>& range) {
+        for (size_t i = range.begin(); i != range.end(); ++i) {
+            Triangle& tr = m_triangles[i];
+            if (tr.valid()) {
+                const auto current_state = static_cast<size_t>(tr.get_state());
+                tr.set_state(state_map[current_state]);
+            }
+        }
+    });
+}
+
 TriangleSelector::TriangleSelector(const TriangleMesh& mesh, float edge_limit)
     : m_mesh{mesh}, m_neighbors(its_face_neighbors(mesh.its)), m_face_normals(its_face_normals(mesh.its)), m_edge_limit(edge_limit)
 {

src/libslic3r/TriangleSelector.hpp

@@ -37,6 +37,9 @@ enum class EnforcerBlockerType : int8_t {
     ExtruderMax = Extruder16
 };
 
+// Type alias for the state mapping array to improve code readability
+using EnforcerBlockerStateMap = std::array<EnforcerBlockerType, (size_t)EnforcerBlockerType::ExtruderMax + 1>;
+
 // Following class holds information about selected triangles. It also has power
 // to recursively subdivide the triangles and make the selection finer.
 class TriangleSelector
@@ -344,6 +347,10 @@ public:
     // Remove all unnecessary data.
     void garbage_collect();
 
+    // Orca: remap the state of triangles according to the state_map
+    void remap_triangle_state(const EnforcerBlockerStateMap& state_map);
+
+
     // Store the division trees in compact form (a long stream of bits for each triangle of the original mesh).
     // First vector contains pairs of (triangle index, first bit in the second vector).
     TriangleSplittingData serialize() const;
@@ -416,10 +423,17 @@ protected:
         // or index of a vertex shared by the two split edges (for number_of_splits == 2).
         // For number_of_splits == 3, special_side_idx is always zero.
         char special_side_idx { 0 };
-        EnforcerBlockerType state;
         bool m_selected_by_seed_fill : 1;
         // Is this triangle valid or marked to be removed?
         bool m_valid : 1;
+
+        // Orca:
+        // IMPORTANT: `state` is intentionally placed after all other small members
+        // to prevent compilers from packing it in a way that would create
+        // data races during parallel processing. A write to `state` could
+        // otherwise become a non-atomic read-modify-write on a memory word
+        // that also contains other (bit-field) members, causing race conditions.
+        EnforcerBlockerType state;
     };
 
     struct Vertex {