From 727a39823c4a6ed8e8b2686fa69f3a867d78b818 Mon Sep 17 00:00:00 2001
From: Thomas Fischer <thomas.fischer@ufz.de>
Date: Thu, 28 Jul 2016 16:38:15 +0200
Subject: [PATCH] [MaL] Impl. of isPointInTriangleXY().
---
MathLib/GeometricBasics.cpp | 25 +++++++++++++++++++++++++
MathLib/GeometricBasics.h | 7 +++++++
2 files changed, 32 insertions(+)
diff --git a/MathLib/GeometricBasics.cpp b/MathLib/GeometricBasics.cpp
index a90c5bf86f0..255564779e7 100644
--- a/MathLib/GeometricBasics.cpp
+++ b/MathLib/GeometricBasics.cpp
@@ -169,6 +169,31 @@ bool barycentricPointInTriangle(MathLib::Point3d const& p,
return true;
}
+bool isPointInTriangleXY(MathLib::Point3d const& p,
+ MathLib::Point3d const& a,
+ MathLib::Point3d const& b,
+ MathLib::Point3d const& c)
+{
+ // criterion: p-a = u0 * (b-a) + u1 * (c-a); 0 <= u0, u1 <= 1, u0+u1 <= 1
+ MathLib::DenseMatrix<double> mat(2, 2);
+ mat(0, 0) = b[0] - a[0];
+ mat(0, 1) = c[0] - a[0];
+ mat(1, 0) = b[1] - a[1];
+ mat(1, 1) = c[1] - a[1];
+ double y[2] = {p[0] - a[0], p[1] - a[1]};
+
+ MathLib::GaussAlgorithm<MathLib::DenseMatrix<double>, double*> gauss;
+ gauss.solve(mat, y, true);
+
+ // check if u0 and u1 fulfills the condition
+ if (0 <= y[0] && y[0] <= 1 && 0 <= y[1] && y[1] <= 1 && y[0] + y[1] <= 1)
+ {
+ return true;
+ }
+ return false;
+
+}
+
bool dividedByPlane(const MathLib::Point3d& a, const MathLib::Point3d& b,
const MathLib::Point3d& c, const MathLib::Point3d& d)
{
diff --git a/MathLib/GeometricBasics.h b/MathLib/GeometricBasics.h
index 80a5783e559..e87d8b553aa 100644
--- a/MathLib/GeometricBasics.h
+++ b/MathLib/GeometricBasics.h
@@ -154,6 +154,13 @@ bool barycentricPointInTriangle(
double eps_pnt_out_of_plane = std::numeric_limits<float>::epsilon(),
double eps_pnt_out_of_tri = std::numeric_limits<float>::epsilon());
+/// Checks if the point \f$p'\f$ is in the triangle defined by the points
+/// \f$a', b', c'\f$, where the \f$p', a', b', c' \f$ are the orthogonal
+/// projections to the \f$x\f$-\f$y\f$ plane of the points \f$p, a, b, c\f$,
+/// respectively.
+bool isPointInTriangleXY(MathLib::Point3d const& p, MathLib::Point3d const& a,
+MathLib::Point3d const& b, MathLib::Point3d const& c);
+
/**
* Checks if a and b can be placed on a plane such that c and d lie on different
* sides of said plane. (In 2D space this checks if c and d are on different
--
GitLab