Upgrade Wagyu to cfc895 and use its Sutherland-Hodgman implementation

mapbox/geometry/wagyu/quick_clip.hpp

@@ -0,0 +1,137 @@
+#pragma once
+
+#include <mapbox/geometry/box.hpp>
+#include <mapbox/geometry/multi_polygon.hpp>
+#include <mapbox/geometry/polygon.hpp>
+#include <mapbox/geometry/wagyu/wagyu.hpp>
+
+#include <experimental/optional>
+
+template <typename T>
+using optional_linear_ring = std::experimental::optional<mapbox::geometry::linear_ring<T>>;
+
+namespace mapbox {
+namespace geometry {
+namespace wagyu {
+namespace quick_clip {
+
+template <typename T>
+mapbox::geometry::point<T> intersect(mapbox::geometry::point<T> a,
+                                     mapbox::geometry::point<T> b,
+                                     size_t edge,
+                                     mapbox::geometry::box<T> const& box) {
+    switch (edge) {
+    case 0:
+        return mapbox::geometry::point<T>(
+            static_cast<T>(a.x + static_cast<double>(b.x - a.x) * (box.min.y - a.y) / (b.y - a.y)),
+            box.min.y);
+
+    case 1:
+        return mapbox::geometry::point<T>(
+            box.max.x,
+            static_cast<T>(a.y + static_cast<double>(b.y - a.y) * (box.max.x - a.x) / (b.x - a.x)));
+
+    case 2:
+        return mapbox::geometry::point<T>(
+            static_cast<T>(a.x + static_cast<double>(b.x - a.x) * (box.max.y - a.y) / (b.y - a.y)),
+            box.max.y);
+
+    default: // case 3
+        return mapbox::geometry::point<T>(
+            box.min.x,
+            static_cast<T>(a.y + static_cast<double>(b.y - a.y) * (box.min.x - a.x) / (b.x - a.x)));
+    }
+}
+
+template <typename T>
+bool inside(mapbox::geometry::point<T> p, size_t edge, mapbox::geometry::box<T> const& b) {
+    switch (edge) {
+    case 0:
+        return p.y > b.min.y;
+
+    case 1:
+        return p.x < b.max.x;
+
+    case 2:
+        return p.y < b.max.y;
+
+    default: // case 3
+        return p.x > b.min.x;
+    }
+}
+
+template <typename T>
+optional_linear_ring<T> quick_lr_clip(mapbox::geometry::linear_ring<T> const& ring,
+                                      mapbox::geometry::box<T> const& b) {
+    mapbox::geometry::linear_ring<T> out = ring;
+
+    for (size_t edge = 0; edge < 4; edge++) {
+        if (out.size() > 0) {
+            mapbox::geometry::linear_ring<T> in = out;
+            mapbox::geometry::point<T> S = in[in.size() - 1];
+            out.resize(0);
+
+            for (size_t e = 0; e < in.size(); e++) {
+                mapbox::geometry::point<T> E = in[e];
+
+                if (inside(E, edge, b)) {
+                    if (!inside(S, edge, b)) {
+                        out.push_back(intersect(S, E, edge, b));
+                    }
+                    out.push_back(E);
+                } else if (inside(S, edge, b)) {
+                    out.push_back(intersect(S, E, edge, b));
+                }
+
+                S = E;
+            }
+        }
+    }
+
+    if (out.size() < 3) {
+        return optional_linear_ring<T>();
+    }
+    // Close the ring if the first/last point was outside
+    if (out[0] != out[out.size() - 1]) {
+        out.push_back(out[0]);
+    }
+    return optional_linear_ring<T>(std::move(out));
+}
+}
+
+template <typename T>
+mapbox::geometry::multi_polygon<T> clip(mapbox::geometry::polygon<T> const& poly,
+                                        mapbox::geometry::box<T> const& b,
+                                        fill_type subject_fill_type) {
+    mapbox::geometry::multi_polygon<T> result;
+    wagyu<T> clipper;
+    for (auto const& lr : poly) {
+        auto new_lr = quick_clip::quick_lr_clip(lr, b);
+        if (new_lr) {
+            clipper.add_ring(*new_lr, polygon_type_subject);
+        }
+    }
+    clipper.execute(clip_type_union, result, subject_fill_type, fill_type_even_odd);
+    return result;
+}
+
+template <typename T>
+mapbox::geometry::multi_polygon<T> clip(mapbox::geometry::multi_polygon<T> const& mp,
+                                        mapbox::geometry::box<T> const& b,
+                                        fill_type subject_fill_type) {
+    mapbox::geometry::multi_polygon<T> result;
+    wagyu<T> clipper;
+    for (auto const& poly : mp) {
+        for (auto const& lr : poly) {
+            auto new_lr = quick_clip::quick_lr_clip(lr, b);
+            if (new_lr) {
+                clipper.add_ring(*new_lr, polygon_type_subject);
+            }
+        }
+    }
+    clipper.execute(clip_type_union, result, subject_fill_type, fill_type_even_odd);
+    return result;
+}
+}
+}
+}

mapbox/geometry/wagyu/ring_util.hpp

@@ -485,15 +485,15 @@ bool first_is_bottom_point(const_point_ptr<T> btmPt1, const_point_ptr<T> btmPt2)
 
 template <typename T>
 point_ptr<T> get_bottom_point(point_ptr<T> pp) {
-    point_ptr<T> dups = 0;
+    point_ptr<T> dups = nullptr;
     point_ptr<T> p = pp->next;
     while (p != pp) {
         if (p->y > pp->y) {
             pp = p;
-            dups = 0;
+            dups = nullptr;
         } else if (p->y == pp->y && p->x <= pp->x) {
             if (p->x < pp->x) {
-                dups = 0;
+                dups = nullptr;
                 pp = p;
             } else {
                 if (p->next != pp && p->prev != pp) {