feat(IspointInside): check if a point is inside a polygon

include/geode/geometry/is_point_inside.hpp

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019 - 2026 Geode-solutions
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#pragma once
+
+#include <geode/geometry/basic_objects/polygon.hpp>
+#include <geode/geometry/common.hpp>
+#include <geode/geometry/point.hpp>
+
+namespace geode
+{
+    /*!
+     * Find if point is inside a polygon.
+     * @param[in] point The point to rotate.
+     * @param[in] axis Axis for the rotation (not null but not necessary
+     * normalized).
+     * @param[in] angle Rotation angle expresses in radians.
+     */
+    [[nodiscard]] bool opengeode_geometry_api is_point_inside_polygon(
+        const Point2D& point, absl::Span< const Point2D > polygon_points );
+
+} // namespace geode

src/geode/geometry/CMakeLists.txt

@@ -47,6 +47,7 @@ add_geode_library(
         "information.cpp"
         "intersection.cpp"
         "intersection_detection.cpp"
+        "is_point_inside.cpp"
         "mensuration.cpp"
         "nn_search.cpp"
         "normal_frame_transform.cpp"
@@ -86,6 +87,7 @@ add_geode_library(
         "information.hpp"
         "intersection.hpp"
         "intersection_detection.hpp"
+        "is_point_inside.hpp"
         "mensuration.hpp"
         "nn_search.hpp"
         "normal_frame_transform.hpp"

src/geode/geometry/is_point_inside.cpp

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2019 - 2026 Geode-solutions
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include <geode/geometry/is_point_inside.hpp>
+
+#include <geode/basic/logger.hpp>
+
+namespace
+{
+    double is_left( const geode::Point2D& p0,
+        const geode::Point2D& p1,
+        const geode::Point2D& p2 )
+    {
+        return ( p1.value( 0 ) - p0.value( 0 ) )
+                   * ( p2.value( 1 ) - p0.value( 1 ) )
+               - ( p2.value( 0 ) - p0.value( 0 ) )
+                     * ( p1.value( 1 ) - p0.value( 1 ) );
+    }
+} // namespace
+
+namespace geode
+{
+    bool opengeode_geometry_api is_point_inside_polygon(
+        const Point2D& point, absl::Span< const Point2D > polygon_points )
+    {
+        double widing_number{ 0 };
+        DEBUG( "is_point_inside_polygon" );
+        SDEBUG( point );
+        for( const auto polygon_vertex :
+            geode::Range{ 0, polygon_points.size() } )
+        {
+            const auto v0 = polygon_points[polygon_vertex];
+            const auto next_polygon_vertex =
+                ( polygon_vertex + 1 ) % polygon_points.size();
+            const auto v1 = polygon_points[next_polygon_vertex];
+            SDEBUG( v0 );
+            SDEBUG( v1 );
+            if( v0.value( 1 ) <= point.value( 1 ) )
+            {
+                if( v1.value( 1 ) > point.value( 1 ) )
+                {
+                    if( is_left( v0, v1, point ) > 0 )
+                    {
+                        DEBUG( "widing_number++" );
+                        widing_number++;
+                    }
+                }
+            }
+            else
+            {
+                if( v1.value( 1 ) <= point.value( 1 ) )
+                {
+                    if( is_left( v0, v1, point ) < 0 )
+                    {
+                        DEBUG( "widing_number--" );
+                        widing_number--;
+                    }
+                }
+            }
+        }
+        DEBUG( widing_number );
+        return widing_number != 0;
+    }
+} // namespace geode