Port bugfixes 2.2.4 (#102)

* more microoptimizations

* one more microoptimization

* fix infinite loops, simplify hole elimination

Co-Authored-By: Juha Laukala <104564021+JuhaLaukala@users.noreply.github.com>

* minor cleanup in findHoleBridge

Co-authored-by: Juha Laukala <104564021+JuhaLaukala@users.noreply.github.com>

Author: kkaefer

include/mapbox/earcut.hpp

@@ -177,9 +177,9 @@ void Earcut<N>::operator()(const Polygon& points) {
             p = p->next;
         } while (p != outerNode);
 
-        // minX, minY and size are later used to transform coords into integers for z-order calculation
+        // minX, minY and inv_size are later used to transform coords into integers for z-order calculation
         inv_size = std::max<double>(maxX - minX, maxY - minY);
-        inv_size = inv_size != .0 ? (1. / inv_size) : .0;
+        inv_size = inv_size != .0 ? (32767. / inv_size) : .0;
     }
 
     earcutLinked(outerNode);
@@ -443,7 +443,6 @@ Earcut<N>::eliminateHoles(const Polygon& points, Node* outerNode) {
     // process holes from left to right
     for (size_t i = 0; i < queue.size(); i++) {
         outerNode = eliminateHole(queue[i], outerNode);
-        outerNode = filterPoints(outerNode, outerNode->next);
     }
 
     return outerNode;
@@ -461,11 +460,10 @@ Earcut<N>::eliminateHole(Node* hole, Node* outerNode) {
     Node* bridgeReverse = splitPolygon(bridge, hole);
 
     // filter collinear points around the cuts
-    Node* filteredBridge = filterPoints(bridge, bridge->next);
     filterPoints(bridgeReverse, bridgeReverse->next);
 
     // Check if input node was removed by the filtering
-    return outerNode == bridge ? filteredBridge : outerNode;
+    return filterPoints(bridge, bridge->next);
 }
 
 // David Eberly's algorithm for finding a bridge between hole and outer polygon
@@ -485,20 +483,15 @@ Earcut<N>::findHoleBridge(Node* hole, Node* outerNode) {
           double x = p->x + (hy - p->y) * (p->next->x - p->x) / (p->next->y - p->y);
           if (x <= hx && x > qx) {
             qx = x;
-            if (x == hx) {
-                if (hy == p->y) return p;
-                if (hy == p->next->y) return p->next;
-            }
             m = p->x < p->next->x ? p : p->next;
+            if (x == hx) return m; // hole touches outer segment; pick leftmost endpoint
           }
         }
         p = p->next;
     } while (p != outerNode);
 
     if (!m) return 0;
 
-    if (hx == qx) return m; // hole touches outer segment; pick leftmost endpoint
-
     // look for points inside the triangle of hole Vertex, segment intersection and endpoint;
     // if there are no points found, we have a valid connection;
     // otherwise choose the Vertex of the minimum angle with the ray as connection Vertex
@@ -628,8 +621,8 @@ Earcut<N>::sortLinked(Node* list) {
 template <typename N>
 int32_t Earcut<N>::zOrder(const double x_, const double y_) {
     // coords are transformed into non-negative 15-bit integer range
-    int32_t x = static_cast<int32_t>(32767.0 * (x_ - minX) * inv_size);
-    int32_t y = static_cast<int32_t>(32767.0 * (y_ - minY) * inv_size);
+    int32_t x = static_cast<int32_t>((x_ - minX) * inv_size);
+    int32_t y = static_cast<int32_t>((y_ - minY) * inv_size);
 
     x = (x | (x << 8)) & 0x00FF00FF;
     x = (x | (x << 4)) & 0x0F0F0F0F;
@@ -662,9 +655,9 @@ Earcut<N>::getLeftmost(Node* start) {
 // check if a point lies within a convex triangle
 template <typename N>
 bool Earcut<N>::pointInTriangle(double ax, double ay, double bx, double by, double cx, double cy, double px, double py) const {
-    return (cx - px) * (ay - py) - (ax - px) * (cy - py) >= 0 &&
-           (ax - px) * (by - py) - (bx - px) * (ay - py) >= 0 &&
-           (bx - px) * (cy - py) - (cx - px) * (by - py) >= 0;
+    return (cx - px) * (ay - py) >= (ax - px) * (cy - py) &&
+           (ax - px) * (by - py) >= (bx - px) * (ay - py) &&
+           (bx - px) * (cy - py) >= (cx - px) * (by - py);
 }
 
 // check if a diagonal between two polygon nodes is valid (lies in polygon interior)

test/fixtures/filtered_bridge_jhl.cpp

@@ -0,0 +1,17 @@
+// This file is auto-generated, manual changes will be lost if the code is regenerated.
+
+#include "geometries.hpp"
+
+namespace mapbox {
+namespace fixtures {
+
+static const Fixture<short> filtered_bridge_jhl("filtered_bridge_jhl", 25, 1e-14, 0.000001, {
+    {{22,14},{17,12},{5,12},{0,12},{0,0},{22,0}},
+    {{9,4},{10,4},{10,3},{9,3}},
+    {{6,9},{7,9},{7,8},{6,8}},
+    {{7,10},{17,10},{17,5},{8,5}},
+    {{13,4},{14,4},{14,3},{13,3}},
+});
+
+}
+}

test/fixtures/infinite_loop_jhl.cpp

@@ -0,0 +1,14 @@
+// This file is auto-generated, manual changes will be lost if the code is regenerated.
+
+#include "geometries.hpp"
+
+namespace mapbox {
+namespace fixtures {
+
+static const Fixture<double> infinite_loop_jhl("infinite_loop_jhl", 0, 1e-14, Infinity, {
+    {{-1,2},{0,0},{2,-1}},
+    {{2,-1},{0,1e-28},{-1,2}},
+});
+
+}
+}

test/fixtures/issue142.cpp

@@ -0,0 +1,14 @@
+// This file is auto-generated, manual changes will be lost if the code is regenerated.
+
+#include "geometries.hpp"
+
+namespace mapbox {
+namespace fixtures {
+
+static const Fixture<double> issue142("issue142", 4, 0.12754968037146489, 8.53067013, {
+    {{5.62675358811389,31.94879819160804},{-16.369709114391867,28.341954255099814},{-10.786562672455382,-1.2779295357476745},{10.819423740334923,2.069348113719755}},
+    {{3.220439475288522,4.197526331591453},{5.024815373142793,1.1716264034331543},{10.819423740334923,2.069348113719755},{5.62675358811389,31.94879819160804},{-16.369709114391867,28.341954255099814},{-10.786562672455382,-1.2779295357476745},{-6.833718161055838,-0.6655405509524673},{-8.602352370111433,2.142874784407777},{-5.34630560403934,6.768689248602321},{-1.4053749889060216,7.453573097663546}},
+});
+
+}
+}

test/fixtures/issue149.cpp

@@ -0,0 +1,14 @@
+// This file is auto-generated, manual changes will be lost if the code is regenerated.
+
+#include "geometries.hpp"
+
+namespace mapbox {
+namespace fixtures {
+
+static const Fixture<short> issue149("issue149", 2, 1e-14, 0.000001, {
+    {{1888,5504},{1872,5504},{1872,5536},{1856,5536},{1856,5520},{1840,5520},{1840,5504},{1856,5504},{1856,5520},{1872,5520},{1872,5504},{1888,5504}},
+    {{1856,5520},{1856,5536},{1872,5536},{1872,5520}},
+});
+
+}
+}