1 files changed, 57 insertions, 0 deletions
diff --git a/Runtime/Geometry/Sphere.cpp b/Runtime/Geometry/Sphere.cpp
new file mode 100644
index 0000000..19ddb3c
--- /dev/null
+++ b/Runtime/Geometry/Sphere.cpp
@@ -0,0 +1,57 @@
+#include "UnityPrefix.h"
+#include "Sphere.h"
+
+Sphere MergeSpheres (const Sphere& inSphere0, const Sphere& inSphere1);
+float MergeSpheresRadius (const Sphere& inSphere0, const Sphere& inSphere1);
+
+void Sphere::Set (const Vector3f* inVertices, UInt32 inHowmany)
+{
+	m_Radius = 0.0F;
+	m_Center = Vector3f::zero;
+	UInt32 i;
+	for (i=0;i<inHowmany;i++)
+		m_Radius = std::max (m_Radius, SqrMagnitude (inVertices[i]));
+	m_Radius = sqrt (m_Radius);
+}
+
+
+Sphere MergeSpheres (const Sphere& inSphere0, const Sphere& inSphere1)
+{
+	Vector3f kCDiff = inSphere1.GetCenter() - inSphere0.GetCenter();
+	float fLSqr = SqrMagnitude (kCDiff);
+	float fRDiff = inSphere1.GetRadius() - inSphere0.GetRadius();
+
+	if (fRDiff*fRDiff >= fLSqr)
+	   return fRDiff >= 0.0 ? inSphere1 : inSphere0;
+
+	float fLength = sqrt (fLSqr);
+	const float fTolerance = 1.0e-06f;
+	Sphere kSphere;
+
+	if (fLength > fTolerance)
+	{
+	   float fCoeff = (fLength + fRDiff) / (2.0 * fLength);
+	   kSphere.GetCenter () = inSphere0.GetCenter () + fCoeff * kCDiff;
+	}
+	else
+	{
+	   kSphere.GetCenter () = inSphere0.GetCenter ();
+	}
+
+	kSphere.GetRadius () = 0.5F * (fLength + inSphere0.GetRadius () +  inSphere1.GetRadius ());
+
+	return kSphere;
+}
+
+float MergeSpheresRadius (const Sphere& inSphere0, const Sphere& inSphere1)
+{
+	Vector3f kCDiff = inSphere1.GetCenter() - inSphere0.GetCenter();
+	float fLSqr = SqrMagnitude (kCDiff);
+	float fRDiff = inSphere1.GetRadius () - inSphere0.GetRadius();
+
+	if (fRDiff*fRDiff >= fLSqr)
+	   return fRDiff >= 0.0 ? inSphere1.GetRadius () : inSphere0.GetRadius ();
+
+	float fLength = sqrt (fLSqr);
+	return 0.5F * (fLength + inSphere0.GetRadius () +  inSphere1.GetRadius ());
+}