Initial release

src/libslic3r/Arachne/utils/PolygonsPointIndex.hpp

@@ -0,0 +1,178 @@
+//Copyright (c) 2018 Ultimaker B.V.
+//CuraEngine is released under the terms of the AGPLv3 or higher.
+
+#ifndef UTILS_POLYGONS_POINT_INDEX_H
+#define UTILS_POLYGONS_POINT_INDEX_H
+
+#include <vector>
+
+#include "../../Point.hpp"
+#include "../../Polygon.hpp"
+
+
+namespace Slic3r::Arachne
+{
+
+// Identity function, used to be able to make templated algorithms where the input is sometimes points, sometimes things that contain or can be converted to points.
+inline const Point &make_point(const Point &p) { return p; }
+
+/*!
+ * A class for iterating over the points in one of the polygons in a \ref Polygons object
+ */
+template<typename Paths>
+class PathsPointIndex
+{
+public:
+    /*!
+     * The polygons into which this index is indexing.
+     */
+    const Paths* polygons; // (pointer to const polygons)
+
+    unsigned int poly_idx; //!< The index of the polygon in \ref PolygonsPointIndex::polygons
+
+    unsigned int point_idx; //!< The index of the point in the polygon in \ref PolygonsPointIndex::polygons
+
+    /*!
+     * Constructs an empty point index to no polygon.
+     *
+     * This is used as a placeholder for when there is a zero-construction
+     * needed. Since the `polygons` field is const you can't ever make this
+     * initialisation useful.
+     */
+    PathsPointIndex() : polygons(nullptr), poly_idx(0), point_idx(0) {}
+
+    /*!
+     * Constructs a new point index to a vertex of a polygon.
+     * \param polygons The Polygons instance to which this index points.
+     * \param poly_idx The index of the sub-polygon to point to.
+     * \param point_idx The index of the vertex in the sub-polygon.
+     */
+    PathsPointIndex(const Paths *polygons, unsigned int poly_idx, unsigned int point_idx) : polygons(polygons), poly_idx(poly_idx), point_idx(point_idx) {}
+
+    /*!
+     * Copy constructor to copy these indices.
+     */
+    PathsPointIndex(const PathsPointIndex& original) = default;
+
+    Point p() const
+    {
+        if (!polygons)
+            return {0, 0};
+
+        return make_point((*polygons)[poly_idx][point_idx]);
+    }
+
+    /*!
+     * \brief Returns whether this point is initialised.
+     */
+    bool initialized() const { return polygons; }
+
+    /*!
+     * Get the polygon to which this PolygonsPointIndex refers
+     */
+    const Polygon &getPolygon() const { return (*polygons)[poly_idx]; }
+
+    /*!
+     * Test whether two iterators refer to the same polygon in the same polygon list.
+     *
+     * \param other The PolygonsPointIndex to test for equality
+     * \return Wether the right argument refers to the same polygon in the same ListPolygon as the left argument.
+     */
+    bool operator==(const PathsPointIndex &other) const
+    {
+        return polygons == other.polygons && poly_idx == other.poly_idx && point_idx == other.point_idx;
+    }
+    bool operator!=(const PathsPointIndex &other) const
+    {
+        return !(*this == other);
+    }
+    bool operator<(const PathsPointIndex &other) const
+    {
+        return this->p() < other.p();
+    }
+    PathsPointIndex &operator=(const PathsPointIndex &other)
+    {
+        polygons  = other.polygons;
+        poly_idx  = other.poly_idx;
+        point_idx = other.point_idx;
+        return *this;
+    }
+    //! move the iterator forward (and wrap around at the end)
+    PathsPointIndex &operator++()
+    {
+        point_idx = (point_idx + 1) % (*polygons)[poly_idx].size();
+        return *this;
+    }
+    //! move the iterator backward (and wrap around at the beginning)
+    PathsPointIndex &operator--()
+    {
+        if (point_idx == 0)
+            point_idx = (*polygons)[poly_idx].size();
+        point_idx--;
+        return *this;
+    }
+    //! move the iterator forward (and wrap around at the end)
+    PathsPointIndex next() const
+    {
+        PathsPointIndex ret(*this);
+        ++ret;
+        return ret;
+    }
+    //! move the iterator backward (and wrap around at the beginning)
+    PathsPointIndex prev() const
+    {
+        PathsPointIndex ret(*this);
+        --ret;
+        return ret;
+    }
+};
+
+using PolygonsPointIndex = PathsPointIndex<Polygons>;
+
+/*!
+ * Locator to extract a line segment out of a \ref PolygonsPointIndex
+ */
+struct PolygonsPointIndexSegmentLocator
+{
+    std::pair<Point, Point> operator()(const PolygonsPointIndex &val) const
+    {
+        const Polygon &poly           = (*val.polygons)[val.poly_idx];
+        Point          start          = poly[val.point_idx];
+        unsigned int   next_point_idx = (val.point_idx + 1) % poly.size();
+        Point          end            = poly[next_point_idx];
+        return std::pair<Point, Point>(start, end);
+    }
+};
+
+/*!
+ * Locator of a \ref PolygonsPointIndex
+ */
+template<typename Paths>
+struct PathsPointIndexLocator
+{
+    Point operator()(const PathsPointIndex<Paths>& val) const
+    {
+        return make_point(val.p());
+    }
+};
+
+}//namespace Slic3r::Arachne
+
+namespace std
+{
+/*!
+ * Hash function for \ref PolygonsPointIndex
+ */
+template <>
+struct hash<Slic3r::Arachne::PolygonsPointIndex>
+{
+    size_t operator()(const Slic3r::Arachne::PolygonsPointIndex& lpi) const
+    {
+        return Slic3r::PointHash{}(lpi.p());
+    }
+};
+}//namespace std
+
+
+
+#endif//UTILS_POLYGONS_POINT_INDEX_H