[fuseCut] add struct for advanced geometry intersection function

alicevision · Jul 13, 2020 · e6dd5f7 · e6dd5f7
1 parent d770fde
commit e6dd5f7
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diff --git a/src/aliceVision/fuseCut/DelaunayGraphCut.cpp b/src/aliceVision/fuseCut/DelaunayGraphCut.cpp
@@ -2984,5 +2984,47 @@ void DelaunayGraphCut::leaveLargestFullSegmentOnly()
     ALICEVISION_LOG_DEBUG("Largest full segment only done.");
 }
 
+DelaunayGraphCut::GeometryIntersection DelaunayGraphCut::lineIntersectTriangle(const Point3d& originPt, const Point3d& DirVec, const Facet& facet, Point3d& intersectPt, const float epsilon)
+{
+    const VertexIndex AvertexIndex = getVertexIndex(facet, 0);
+    const VertexIndex BvertexIndex = getVertexIndex(facet, 1);
+    const VertexIndex CvertexIndex = getVertexIndex(facet, 2);
+
+    // const std::array<const Point3d*, 3> facetPoints = getFacetsPoints(facet);
+    const Point3d* A = &_verticesCoords[AvertexIndex];
+    const Point3d* B = &_verticesCoords[BvertexIndex];
+    const Point3d* C = &_verticesCoords[CvertexIndex];
+
+    const Point2d triangleUv = getLineTriangleIntersectBarycCoords(&intersectPt, A, B, C, &originPt, &DirVec);
+    const float u = triangleUv.x; // A to C
+    const float v = triangleUv.y; // A to B
+
+    if(v > -epsilon && v < epsilon) // along A C edge
+    {
+        if(u > -epsilon && u < epsilon)
+            return GeometryIntersection(AvertexIndex); // vertex A
+        if(u > 1-epsilon && u < 1 + epsilon)
+            return GeometryIntersection(CvertexIndex); // vertex C
+
+        return GeometryIntersection(Edge(AvertexIndex, CvertexIndex)); // edge AC
+    }
+
+    if(u > -epsilon && u < epsilon) // along A B edge
+    {
+        if(v > 1 - epsilon && v < 1 + epsilon)
+            return GeometryIntersection(BvertexIndex); // vertex B
+
+        return GeometryIntersection(Edge(AvertexIndex, BvertexIndex)); // edge AB
+    }
+
+    if(u + v > 1 - epsilon && u + v < 1 + epsilon)
+        return GeometryIntersection(Edge(BvertexIndex, CvertexIndex)); // edge BC
+
+    if(u + v < 1.0f - epsilon)
+        return GeometryIntersection(facet);
+
+    return GeometryIntersection(); // Return none
+}
+
 } // namespace fuseCut
 } // namespace aliceVision
diff --git a/src/aliceVision/fuseCut/DelaunayGraphCut.hpp b/src/aliceVision/fuseCut/DelaunayGraphCut.hpp
@@ -75,6 +75,51 @@ class DelaunayGraphCut
         VertexIndex localVertexIndex = GEO::NO_VERTEX;
     };
 
+    struct Edge
+    {
+        Edge() = default;
+        Edge(VertexIndex v0_, VertexIndex v1_)
+            : v0{v0_}
+            , v1{v1_}
+        {}
+
+        VertexIndex v0 = GEO::NO_VERTEX;
+        VertexIndex v1 = GEO::NO_VERTEX;
+    };
+
+    enum class EGeometryType
+    {
+        Vertex,
+        Edge,
+        Facet,
+        None
+    };
+
+    struct GeometryIntersection
+    {
+        union
+        {
+            Facet facet;
+            VertexIndex vertex;
+            Edge edge;
+        };
+        GeometryIntersection() {}
+        GeometryIntersection(const Facet& f)
+            : facet{f}
+            , type{EGeometryType::Facet}
+        {}
+        GeometryIntersection(const VertexIndex& v)
+            : vertex{v}
+            , type{EGeometryType::Vertex}
+        {}
+        GeometryIntersection(const Edge& e)
+            : edge{e}
+            , type{EGeometryType::Edge}
+        {}
+
+        EGeometryType type = EGeometryType::None;
+    };
+
     mvsUtils::MultiViewParams* mp;
 
     GEO::Delaunay_var _tetrahedralization;
@@ -363,6 +408,9 @@ class DelaunayGraphCut
     void leaveLargestFullSegmentOnly();
 
     mesh::Mesh* createMesh(bool filterHelperPointsTriangles = true);
+
+    GeometryIntersection lineIntersectTriangle(const Point3d& originPt, const Point3d& DirVec, const Facet& facet,
+                                               Point3d& intersectPt, const float epsilon);
 };
 
 } // namespace fuseCut