Added missing PCK::aligned_3d predicate for points with expansion_nt

as coordinates.
BrunoLevy · Nov 7, 2023 · 8abdaea · 8abdaea
1 parent 8c0ec94
commit 8abdaea
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Showing 3 changed files with 26 additions and 2 deletions.
diff --git a/src/lib/geogram/mesh/mesh_surface_intersection.cpp b/src/lib/geogram/mesh/mesh_surface_intersection.cpp
@@ -633,7 +633,6 @@ namespace GEO {
         // Sanity check
         if(false) {
             Attribute<bool> selected(mesh_.facets.attributes(), "selection");
-
             for(index_t t: mesh_.facets) {
                 if(PCK::aligned_3d(
                        exact_vertex(mesh_.facets.vertex(t,0)),

diff --git a/src/lib/geogram/numerics/exact_geometry.cpp b/src/lib/geogram/numerics/exact_geometry.cpp
@@ -526,6 +526,20 @@ namespace GEO {
             geo_assert(Nz.sign() != ZERO);        
             return 2;
         }
+
+        bool aligned_3d(
+            const vec3HE& p0, const vec3HE& p1, const vec3HE& p2
+        ) {
+            // TODO: filter if need be
+            vec3HE U = p1-p0;
+            vec3HE V = p2-p0;
+            return (
+                det2x2(U.x,V.x,U.y,V.y).sign() == ZERO &&
+                det2x2(U.y,V.y,U.z,V.z).sign() == ZERO &&
+                det2x2(U.z,V.z,U.x,V.x).sign() == ZERO 
+            );
+        }
+
     }
 
 /*****************************************************************/

diff --git a/src/lib/geogram/numerics/exact_geometry.h b/src/lib/geogram/numerics/exact_geometry.h
@@ -327,7 +327,18 @@ namespace GEO {
         coord_index_t GEOGRAM_API triangle_normal_axis(
             const vec3& p1, const vec3& p2, const vec3& p3
         );
-
+
+        /**
+         * \brief Tests whether three 3d points are aligned
+         * \param(in] p0 , p1 , p2  the three points, 
+         *  in homogeneous coordinates, represented in exact form. 
+         * \retval true if the three points are aligned (or if two
+         *  of them or more are identical)
+         * \retval false otherwise
+         */
+        bool GEOGRAM_API aligned_3d(
+            const vec3HE& p0, const vec3HE& p1, const vec3HE& p2
+        );
     }
 
     /************************************************************************/