[core] Added util::polygonIntersectsPolygon

2 files changed, 13 insertions, 20 deletions

diff --git a/src/mbgl/util/intersection_tests.cpp b/src/mbgl/util/intersection_tests.cpp
index a0feb8ec37..c580357298 100644
--- a/src/mbgl/util/intersection_tests.cpp
+++ b/src/mbgl/util/intersection_tests.cpp
@@ -16,14 +16,6 @@ bool polygonContainsPoint(const GeometryCoordinates& ring, const GeometryCoordin
     return c;
 }
 
-bool multiPolygonContainsPoint(const GeometryCollection& rings, const GeometryCoordinate& p) {
-    bool c = false;
-    for (auto& ring : rings) {
-        c = (c != polygonContainsPoint(ring, p));
-    }
-    return c;
-}
-
 // Code from http://stackoverflow.com/a/1501725/331379.
 float distToSegmentSquared(const GeometryCoordinate& p, const GeometryCoordinate& v, const GeometryCoordinate& w) {
     if (v == w) return util::distSqr<float>(p, v);
@@ -114,23 +106,23 @@ bool polygonIntersectsBufferedMultiLine(const GeometryCoordinates& polygon, cons
     return false;
 }
 
-bool polygonIntersectsMultiPolygon(const GeometryCoordinates& polygon, const GeometryCollection& multiPolygon) {
-    if (polygon.size() == 1) {
-        return multiPolygonContainsPoint(multiPolygon, polygon.at(0));
+bool polygonIntersectsPolygon(const GeometryCoordinates& polygonA, const GeometryCoordinates& polygonB) {
+    for (auto& p : polygonA) {
+        if (polygonContainsPoint(polygonB, p)) return true;
     }
 
-    for (auto& ring : multiPolygon) {
-        for (auto& p : ring) {
-            if (polygonContainsPoint(polygon, p)) return true;
-        }
+    for (auto& p : polygonB) {
+        if (polygonContainsPoint(polygonA, p)) return true;
     }
 
-    for (auto& p : polygon) {
-        if (multiPolygonContainsPoint(multiPolygon, p)) return true;
-    }
+    if (lineIntersectsLine(polygonA, polygonB)) return true;
 
-    for (auto& polygonB : multiPolygon) {
-        if (lineIntersectsLine(polygon, polygonB)) return true;
+    return false;
+}
+
+bool polygonIntersectsMultiPolygon(const GeometryCoordinates& polygon, const GeometryCollection& multiPolygon) {
+    for (auto& ring : multiPolygon) {
+        if (polygonIntersectsPolygon(polygon, ring)) return true;
     }
 
     return false;
diff --git a/src/mbgl/util/intersection_tests.hpp b/src/mbgl/util/intersection_tests.hpp
index 6adb3b5fdf..5bcb29c767 100644
--- a/src/mbgl/util/intersection_tests.hpp
+++ b/src/mbgl/util/intersection_tests.hpp
@@ -7,6 +7,7 @@ namespace util {
 
 bool polygonIntersectsBufferedMultiPoint(const GeometryCoordinates&, const GeometryCollection&, float radius);
 bool polygonIntersectsBufferedMultiLine(const GeometryCoordinates&, const GeometryCollection&, float radius);
+bool polygonIntersectsPolygon(const GeometryCoordinates&, const GeometryCoordinates&);
 bool polygonIntersectsMultiPolygon(const GeometryCoordinates&, const GeometryCollection&);
 
 } // namespace util