Index: source/maths/BoundingSphere.h
===================================================================
--- source/maths/BoundingSphere.h
+++ source/maths/BoundingSphere.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,35 +18,18 @@
#ifndef INCLUDED_BOUNDINGSPHERE
#define INCLUDED_BOUNDINGSPHERE
-#include "maths/BoundingBoxAligned.h"
#include "maths/Vector3D.h"
+class BoundingBoxAligned;
+
class CBoundingSphere
{
-private:
- CVector3D m_Center;
- float m_Radius;
-
public:
CBoundingSphere() : m_Radius(0) { }
CBoundingSphere(const CVector3D& center, float radius) : m_Center(center), m_Radius(radius) { }
- /**
- * Construct a bounding sphere that encompasses a bounding box
- * swept through all possible rotations around the origin.
- */
- static CBoundingSphere FromSweptBox(const CBoundingBoxAligned& bbox)
- {
- float maxX = std::max(fabsf(bbox[0].X), fabsf(bbox[1].X));
- float maxY = std::max(fabsf(bbox[0].Y), fabsf(bbox[1].Y));
- float maxZ = std::max(fabsf(bbox[0].Z), fabsf(bbox[1].Z));
- float radius = sqrtf(maxX*maxX + maxY*maxY + maxZ*maxZ);
-
- return CBoundingSphere(CVector3D(0.f, 0.f, 0.f), radius);
- }
-
- const CVector3D& GetCenter()
+ const CVector3D& GetCenter() const
{
return m_Center;
}
@@ -57,21 +40,20 @@
}
/**
+ * Construct a bounding sphere that encompasses a bounding box
+ * swept through all possible rotations around the origin.
+ */
+ static CBoundingSphere FromSweptBox(const CBoundingBoxAligned& bbox);
+
+ /**
* Check if the ray, defined by an origin point and a direction unit vector
- * interesects with the sphere
+ * interesects with the sphere. The direction should be normalized.
*/
- bool RayIntersect(const CVector3D& origin, const CVector3D& dir) const
- {
- CVector3D v = m_Center - origin; // Vector v from the origin of the ray to the center of the sphere
- float pcLen = dir.Dot(v); // Length of the projection of v onto the direction vector of the ray
- if(pcLen <= 0)
- return false; // Sphere behind the ray
- // Get the shortest distance from the center of the sphere to the ray
- v = (dir * pcLen) - v;
- if (v.LengthSquared() > m_Radius * m_Radius)
- return false; // Distance to sphere center more than radius
- return true;
- }
+ bool RayIntersect(const CVector3D& origin, const CVector3D& dir) const;
+
+private:
+ CVector3D m_Center;
+ float m_Radius;
};
#endif // INCLUDED_BOUNDINGSPHERE
Index: source/maths/BoundingSphere.cpp
===================================================================
--- source/maths/BoundingSphere.cpp
+++ source/maths/BoundingSphere.cpp
@@ -0,0 +1,51 @@
+/* Copyright (C) 2018 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 0 A.D. is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with 0 A.D. If not, see .
+ */
+
+#include "precompiled.h"
+
+#include "maths/BoundingBoxAligned.h"
+#include "maths/BoundingSphere.h"
+
+CBoundingSphere CBoundingSphere::FromSweptBox(const CBoundingBoxAligned& bbox)
+{
+ float maxX = std::max(fabsf(bbox[0].X), fabsf(bbox[1].X));
+ float maxY = std::max(fabsf(bbox[0].Y), fabsf(bbox[1].Y));
+ float maxZ = std::max(fabsf(bbox[0].Z), fabsf(bbox[1].Z));
+
+ float radius = sqrtf(maxX*maxX + maxY*maxY + maxZ*maxZ);
+
+ return CBoundingSphere(CVector3D(0.f, 0.f, 0.f), radius);
+}
+
+bool CBoundingSphere::RayIntersect(const CVector3D& origin, const CVector3D& dir) const
+{
+ // Vector v from the origin of the ray to the center of the sphere
+ CVector3D v = m_Center - origin;
+ // Length of the projection of v onto the direction vector of the ray
+ float pcLen = dir.Dot(v);
+ if (pcLen <= 0)
+ {
+ if (v.LengthSquared() <= m_Radius * m_Radius)
+ return true; // Sphere inside the ray
+ return false; // Sphere behind the ray
+ }
+ // Get the shortest distance from the center of the sphere to the ray
+ v = (dir * pcLen) - v;
+ if (v.LengthSquared() > m_Radius * m_Radius)
+ return false; // Distance to sphere center more than radius
+ return true;
+}
Index: source/maths/tests/test_BoundingSphere.h
===================================================================
--- source/maths/tests/test_BoundingSphere.h
+++ source/maths/tests/test_BoundingSphere.h
@@ -0,0 +1,80 @@
+/* Copyright (C) 2018 Wildfire Games.
+ * This file is part of 0 A.D.
+ *
+ * 0 A.D. is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 0 A.D. is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with 0 A.D. If not, see .
+ */
+
+#include "lib/self_test.h"
+
+#include "maths/BoundingBoxAligned.h"
+#include "maths/BoundingSphere.h"
+
+#include
+
+class TestBoundingSphere : public CxxTest::TestSuite
+{
+public:
+ void test_basic()
+ {
+ CBoundingBoxAligned indentityAABB(CVector3D(-1.0f, -1.0f, -1.0f), CVector3D(1.0f, 1.0f, 1.0f));
+ CBoundingSphere bs1 = CBoundingSphere::FromSweptBox(indentityAABB);
+ // The radius should be equal to the length of diagonal in an identity cube.
+ TS_ASSERT_DELTA(bs1.GetRadius(), sqrtf(3.0f), 1e-5);
+ TS_ASSERT_EQUALS(bs1.GetCenter(), CVector3D(0.0f, 0.0f, 0.0f));
+
+ CBoundingBoxAligned translatedAABB;
+ CVector3D translate(1.0f, 2.0f, 3.0f);
+ indentityAABB.Translate(translate, translatedAABB);
+ CBoundingSphere bs2 = CBoundingSphere::FromSweptBox(translatedAABB);
+ CVector3D farVertex = translate + CVector3D(1.0f, 1.0f, 1.0f);
+ TS_ASSERT_DELTA(bs2.GetRadius(), farVertex.Length(), 1e-5);
+ TS_ASSERT_EQUALS(bs2.GetCenter(), CVector3D(0.0f, 0.0f, 0.0f));
+ }
+
+ void check_intersections(const CVector3D& pivot)
+ {
+ // Axis aligned rays for different axis.
+ CBoundingSphere bs1(pivot, 1.0f);
+ for (size_t i = 0; i < 3; ++i)
+ {
+ CVector3D origin = pivot, direction;
+ origin[i] += 2.0f;
+ direction[i] = 1.0f;
+ TS_ASSERT_EQUALS(bs1.RayIntersect(origin, -direction), true);
+ TS_ASSERT_EQUALS(bs1.RayIntersect(origin, direction), false);
+ }
+
+ // Rays inside bounding spheres.
+ CBoundingSphere bs2(pivot, 10.0f);
+ TS_ASSERT_EQUALS(bs2.RayIntersect(pivot + CVector3D(0.0f, 1.0f, 0.0f), CVector3D(0.0f, 1.0f, 0.0f)), true);
+ TS_ASSERT_EQUALS(bs2.RayIntersect(pivot - CVector3D(0.0f, 1.0f, 0.0f), CVector3D(0.0f, 1.0f, 0.0f)), true);
+
+ CBoundingSphere bs3(pivot, 2.0f);
+ TS_ASSERT_EQUALS(bs3.RayIntersect(pivot + CVector3D(-4.0f, -2.0f, -4.0f), CVector3D(1.0f, 1.0f, 1.0f).Normalized()), true);
+ TS_ASSERT_EQUALS(bs3.RayIntersect(pivot + CVector3D(-4.0f, -1.0f, -4.0f), CVector3D(1.0f, 1.0f, 1.0f).Normalized()), false);
+ }
+
+ void test_intersections()
+ {
+ // Initial positions of bounding spheres.
+ CVector3D pivots[] = {
+ CVector3D(0.0f, 0.0f, 0.0f),
+ CVector3D(1.0f, 2.0f, 3.0f),
+ CVector3D(-10.0f, 0.5f, 3.0f)
+ };
+
+ for (const CVector3D& pivot : pivots)
+ check_intersections(pivot);
+ }
+};