WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/libslic3r/Polyline.cpp

@@ -0,0 +1,256 @@
+#include "BoundingBox.hpp"
+#include "Polyline.hpp"
+#include "ExPolygon.hpp"
+#include "ExPolygonCollection.hpp"
+#include "Line.hpp"
+#include "Polygon.hpp"
+#include <iostream>
+#include <utility>
+
+namespace Slic3r {
+
+Polyline::operator Polylines() const
+{
+    Polylines polylines;
+    polylines.push_back(*this);
+    return polylines;
+}
+
+Polyline::operator Line() const
+{
+    if (this->points.size() > 2) 
+        throw std::invalid_argument("Can't convert polyline with more than two points to a line");
+    return Line(this->points.front(), this->points.back());
+}
+
+Point
+Polyline::last_point() const
+{
+    return this->points.back();
+}
+
+Point
+Polyline::leftmost_point() const
+{
+    Point p = this->points.front();
+    for (Points::const_iterator it = this->points.begin() + 1; it != this->points.end(); ++it) {
+        if ((*it)(0) < p(0)) p = *it;
+    }
+    return p;
+}
+
+Lines
+Polyline::lines() const
+{
+    Lines lines;
+    if (this->points.size() >= 2) {
+        lines.reserve(this->points.size() - 1);
+        for (Points::const_iterator it = this->points.begin(); it != this->points.end()-1; ++it) {
+            lines.push_back(Line(*it, *(it + 1)));
+        }
+    }
+    return lines;
+}
+
+// removes the given distance from the end of the polyline
+void Polyline::clip_end(double distance)
+{
+    while (distance > 0) {
+        Vec2d  last_point = this->last_point().cast<double>();
+        this->points.pop_back();
+        if (this->points.empty())
+            break;
+        Vec2d  v    = this->last_point().cast<double>() - last_point;
+        double lsqr = v.squaredNorm();
+        if (lsqr > distance * distance) {
+            this->points.emplace_back((last_point + v * (distance / sqrt(lsqr))).cast<coord_t>());
+            return;
+        }
+        distance -= sqrt(lsqr);
+    }
+}
+
+// removes the given distance from the start of the polyline
+void Polyline::clip_start(double distance)
+{
+    this->reverse();
+    this->clip_end(distance);
+    if (this->points.size() >= 2)
+        this->reverse();
+}
+
+void Polyline::extend_end(double distance)
+{
+    // relocate last point by extending the last segment by the specified length
+    Vec2d v = (this->points.back() - *(this->points.end() - 2)).cast<double>().normalized();
+    this->points.back() += (v * distance).cast<coord_t>();
+}
+
+void Polyline::extend_start(double distance)
+{
+    // relocate first point by extending the first segment by the specified length
+    Vec2d v = (this->points.front() - this->points[1]).cast<double>().normalized();
+    this->points.front() += (v * distance).cast<coord_t>();
+}
+
+/* this method returns a collection of points picked on the polygon contour
+   so that they are evenly spaced according to the input distance */
+Points Polyline::equally_spaced_points(double distance) const
+{
+    Points points;
+    points.emplace_back(this->first_point());
+    double len = 0;
+    
+    for (Points::const_iterator it = this->points.begin() + 1; it != this->points.end(); ++it) {
+        Vec2d  p1 = (it-1)->cast<double>();
+        Vec2d  v  = it->cast<double>() - p1;
+        double segment_length = v.norm();
+        len += segment_length;
+        if (len < distance)
+            continue;
+        if (len == distance) {
+            points.emplace_back(*it);
+            len = 0;
+            continue;
+        }
+        double take = segment_length - (len - distance);  // how much we take of this segment
+        points.emplace_back((p1 + v * (take / v.norm())).cast<coord_t>());
+        -- it;
+        len = - take;
+    }
+    return points;
+}
+
+void Polyline::simplify(double tolerance)
+{
+    this->points = MultiPoint::_douglas_peucker(this->points, tolerance);
+}
+
+/* This method simplifies all *lines* contained in the supplied area */
+template <class T>
+void Polyline::simplify_by_visibility(const T &area)
+{
+    Points &pp = this->points;
+    
+    size_t s = 0;
+    bool did_erase = false;
+    for (size_t i = s+2; i < pp.size(); i = s + 2) {
+        if (area.contains(Line(pp[s], pp[i]))) {
+            pp.erase(pp.begin() + s + 1, pp.begin() + i);
+            did_erase = true;
+        } else {
+            ++s;
+        }
+    }
+    if (did_erase)
+        this->simplify_by_visibility(area);
+}
+template void Polyline::simplify_by_visibility<ExPolygon>(const ExPolygon &area);
+template void Polyline::simplify_by_visibility<ExPolygonCollection>(const ExPolygonCollection &area);
+
+void Polyline::split_at(const Point &point, Polyline* p1, Polyline* p2) const
+{
+    if (this->points.empty()) return;
+    
+    // find the line to split at
+    size_t line_idx = 0;
+    Point p = this->first_point();
+    double min = (p - point).cast<double>().norm();
+    Lines lines = this->lines();
+    for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
+        Point p_tmp = point.projection_onto(*line);
+        if ((p_tmp - point).cast<double>().norm() < min) {
+	        p = p_tmp;
+	        min = (p - point).cast<double>().norm();
+	        line_idx = line - lines.begin();
+        }
+    }
+    
+    // create first half
+    p1->points.clear();
+    for (Lines::const_iterator line = lines.begin(); line != lines.begin() + line_idx + 1; ++line)
+        if (line->a != p) 
+            p1->points.push_back(line->a);
+    // we add point instead of p because they might differ because of numerical issues
+    // and caller might want to rely on point belonging to result polylines
+    p1->points.push_back(point);
+    
+    // create second half
+    p2->points.clear();
+    p2->points.push_back(point);
+    for (Lines::const_iterator line = lines.begin() + line_idx; line != lines.end(); ++line) {
+        p2->points.push_back(line->b);
+    }
+}
+
+bool Polyline::is_straight() const
+{
+    // Check that each segment's direction is equal to the line connecting
+    // first point and last point. (Checking each line against the previous
+    // one would cause the error to accumulate.)
+    double dir = Line(this->first_point(), this->last_point()).direction();
+    for (const auto &line: this->lines())
+        if (! line.parallel_to(dir))
+            return false;
+    return true;
+}
+
+BoundingBox get_extents(const Polyline &polyline)
+{
+    return polyline.bounding_box();
+}
+
+BoundingBox get_extents(const Polylines &polylines)
+{
+    BoundingBox bb;
+    if (! polylines.empty()) {
+        bb = polylines.front().bounding_box();
+        for (size_t i = 1; i < polylines.size(); ++ i)
+            bb.merge(polylines[i]);
+    }
+    return bb;
+}
+
+bool remove_degenerate(Polylines &polylines)
+{
+    bool modified = false;
+    size_t j = 0;
+    for (size_t i = 0; i < polylines.size(); ++ i) {
+        if (polylines[i].points.size() >= 2) {
+            if (j < i) 
+                std::swap(polylines[i].points, polylines[j].points);
+            ++ j;
+        } else
+            modified = true;
+    }
+    if (j < polylines.size())
+        polylines.erase(polylines.begin() + j, polylines.end());
+    return modified;
+}
+
+ThickLines ThickPolyline::thicklines() const
+{
+    ThickLines lines;
+    if (this->points.size() >= 2) {
+        lines.reserve(this->points.size() - 1);
+        for (size_t i = 0; i + 1 < this->points.size(); ++ i)
+            lines.emplace_back(this->points[i], this->points[i + 1], this->width[2 * i], this->width[2 * i + 1]);
+    }
+    return lines;
+}
+
+Lines3 Polyline3::lines() const
+{
+    Lines3 lines;
+    if (points.size() >= 2)
+    {
+        lines.reserve(points.size() - 1);
+        for (Points3::const_iterator it = points.begin(); it != points.end() - 1; ++it)
+        {
+            lines.emplace_back(*it, *(it + 1));
+        }
+    }
+    return lines;
+}
+
+}