Fix Geometry3D::get_closest_points_between_segments() returns NaN

Also fix:
- Geometry3D::get_closest_distance_between_segments() returning
  incorrect values.
- Test for Geometry3D::get_closest_distance_between_segments() testing for
  an incorrect value.

1 files changed, 2 insertions, 90 deletions

diff --git a/core/math/geometry_3d.h b/core/math/geometry_3d.h
index 59c56906f4..e5ace9db72 100644
--- a/core/math/geometry_3d.h
+++ b/core/math/geometry_3d.h
@@ -37,96 +37,8 @@
 
 class Geometry3D {
 public:
-	static void get_closest_points_between_segments(const Vector3 &p1, const Vector3 &p2, const Vector3 &q1, const Vector3 &q2, Vector3 &c1, Vector3 &c2) {
-// Do the function 'd' as defined by pb. I think it's a dot product of some sort.
-#define d_of(m, n, o, p) ((m.x - n.x) * (o.x - p.x) + (m.y - n.y) * (o.y - p.y) + (m.z - n.z) * (o.z - p.z))
-
-		// Calculate the parametric position on the 2 curves, mua and mub.
-		real_t mua = (d_of(p1, q1, q2, q1) * d_of(q2, q1, p2, p1) - d_of(p1, q1, p2, p1) * d_of(q2, q1, q2, q1)) / (d_of(p2, p1, p2, p1) * d_of(q2, q1, q2, q1) - d_of(q2, q1, p2, p1) * d_of(q2, q1, p2, p1));
-		real_t mub = (d_of(p1, q1, q2, q1) + mua * d_of(q2, q1, p2, p1)) / d_of(q2, q1, q2, q1);
-
-		// Clip the value between [0..1] constraining the solution to lie on the original curves.
-		if (mua < 0) {
-			mua = 0;
-		}
-		if (mub < 0) {
-			mub = 0;
-		}
-		if (mua > 1) {
-			mua = 1;
-		}
-		if (mub > 1) {
-			mub = 1;
-		}
-		c1 = p1.lerp(p2, mua);
-		c2 = q1.lerp(q2, mub);
-	}
-
-	static real_t get_closest_distance_between_segments(const Vector3 &p_from_a, const Vector3 &p_to_a, const Vector3 &p_from_b, const Vector3 &p_to_b) {
-		Vector3 u = p_to_a - p_from_a;
-		Vector3 v = p_to_b - p_from_b;
-		Vector3 w = p_from_a - p_to_a;
-		real_t a = u.dot(u); // Always >= 0
-		real_t b = u.dot(v);
-		real_t c = v.dot(v); // Always >= 0
-		real_t d = u.dot(w);
-		real_t e = v.dot(w);
-		real_t D = a * c - b * b; // Always >= 0
-		real_t sc, sN, sD = D; // sc = sN / sD, default sD = D >= 0
-		real_t tc, tN, tD = D; // tc = tN / tD, default tD = D >= 0
-
-		// Compute the line parameters of the two closest points.
-		if (D < (real_t)CMP_EPSILON) { // The lines are almost parallel.
-			sN = 0.0f; // Force using point P0 on segment S1
-			sD = 1.0f; // to prevent possible division by 0.0 later.
-			tN = e;
-			tD = c;
-		} else { // Get the closest points on the infinite lines
-			sN = (b * e - c * d);
-			tN = (a * e - b * d);
-			if (sN < 0.0f) { // sc < 0 => the s=0 edge is visible.
-				sN = 0.0f;
-				tN = e;
-				tD = c;
-			} else if (sN > sD) { // sc > 1 => the s=1 edge is visible.
-				sN = sD;
-				tN = e + b;
-				tD = c;
-			}
-		}
-
-		if (tN < 0.0f) { // tc < 0 => the t=0 edge is visible.
-			tN = 0.0f;
-			// Recompute sc for this edge.
-			if (-d < 0.0f) {
-				sN = 0.0f;
-			} else if (-d > a) {
-				sN = sD;
-			} else {
-				sN = -d;
-				sD = a;
-			}
-		} else if (tN > tD) { // tc > 1 => the t=1 edge is visible.
-			tN = tD;
-			// Recompute sc for this edge.
-			if ((-d + b) < 0.0f) {
-				sN = 0;
-			} else if ((-d + b) > a) {
-				sN = sD;
-			} else {
-				sN = (-d + b);
-				sD = a;
-			}
-		}
-		// Finally do the division to get sc and tc.
-		sc = (Math::is_zero_approx(sN) ? 0.0f : sN / sD);
-		tc = (Math::is_zero_approx(tN) ? 0.0f : tN / tD);
-
-		// Get the difference of the two closest points.
-		Vector3 dP = w + (sc * u) - (tc * v); // = S1(sc) - S2(tc)
-
-		return dP.length(); // Return the closest distance.
-	}
+	static void get_closest_points_between_segments(const Vector3 &p_p0, const Vector3 &p_p1, const Vector3 &p_q0, const Vector3 &p_q1, Vector3 &r_ps, Vector3 &r_qt);
+	static real_t get_closest_distance_between_segments(const Vector3 &p_p0, const Vector3 &p_p1, const Vector3 &p_q0, const Vector3 &p_q1);
 
 	static inline bool ray_intersects_triangle(const Vector3 &p_from, const Vector3 &p_dir, const Vector3 &p_v0, const Vector3 &p_v1, const Vector3 &p_v2, Vector3 *r_res = nullptr) {
 		Vector3 e1 = p_v1 - p_v0;