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// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// SPDX-FileCopyrightText: Copyright (c) 2008-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
// SPDX-License-Identifier: Apache-2.0
#ifndef GU_INTERSECTION_TETRAHEDRON_TETRAHEDRON_H
#define GU_INTERSECTION_TETRAHEDRON_TETRAHEDRON_H
#include "foundation/PxPlane.h"
#include "common/PxPhysXCommonConfig.h"
namespace physx
{
namespace Gu
{
struct Tetrahedron
{
PxVec3 verts[4];
PxPlane planes[4];
PxVec3 centroid;
};
PX_INLINE PX_CUDA_CALLABLE PxPlane createPlane(const PxVec3& pa, const PxVec3& pb, const PxVec3& pc, const PxVec3& pd)
{
PxPlane plane(pa, pb, pc);
PxReal distance = plane.distance(pd);
if (distance > 0.f)
{
plane.n = -plane.n;
plane.d = -plane.d;
}
return plane;
}
PX_INLINE PX_CUDA_CALLABLE void constructTetrahedron(const PxVec3& a, const PxVec3& b, const PxVec3& c, const PxVec3& d,
Tetrahedron& tet)
{
tet.verts[0] = a; tet.verts[1] = b; tet.verts[2] = c; tet.verts[3] = d;
tet.planes[0] = createPlane(a, b, c, d);
tet.planes[1] = createPlane(a, b, d, c);
tet.planes[2] = createPlane(a, c, d, b);
tet.planes[3] = createPlane(b, c, d, a);
tet.centroid = (a + b + c) * (1.f / 3.f);
}
PX_INLINE PX_CUDA_CALLABLE PxReal minProject(const PxPlane& plane, const Tetrahedron& tet)
{
/*return PxMin(plane.distance(tet.verts[0]), PxMin(plane.distance(tet.verts[1]),
PxMin(plane.distance(tet.verts[2]), plane.distance(tet.verts[3]))));*/
return PxMin(plane.n.dot(tet.verts[0]),PxMin(plane.n.dot(tet.verts[1]),
PxMin(plane.n.dot(tet.verts[2]), plane.n.dot(tet.verts[3])))) + plane.d;
}
PX_INLINE PX_CUDA_CALLABLE PxReal testSeparatingAxis(const PxVec3& axis, const Tetrahedron& tet0, const Tetrahedron& tet1)
{
PxReal min0, max0, min1, max1;
min0 = max0 = tet0.verts[0].dot(axis);
min1 = max1 = tet1.verts[0].dot(axis);
for (PxU32 i = 1; i < 4; ++i)
{
PxReal proj0 = tet0.verts[i].dot(axis);
PxReal proj1 = tet1.verts[i].dot(axis);
min0 = PxMin(proj0, min0);
max0 = PxMax(proj0, max0);
min1 = PxMin(proj1, min1);
max1 = PxMax(proj1, max1);
}
return PxMax(min1 - max0, min0 - max1);
}
template <bool TDoCross = true>
PX_INLINE PX_CUDA_CALLABLE PxReal satIntersect(const Tetrahedron& tet0, const Tetrahedron& tet1, const PxReal tolerance)
{
PxReal sep = minProject(tet0.planes[0], tet1);
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet0.planes[1], tet1));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet0.planes[2], tet1));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet0.planes[3], tet1));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet1.planes[0], tet0));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet1.planes[1], tet0));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet1.planes[2], tet0));
if (sep > tolerance)
return sep;
sep = PxMax(sep, minProject(tet1.planes[3], tet0));
if (sep > tolerance)
return sep;
if (TDoCross)
{
PxVec3 axes0[6];
PxVec3 axes1[6];
axes0[0] = tet0.verts[1] - tet0.verts[0];
axes0[1] = tet0.verts[2] - tet0.verts[0];
axes0[2] = tet0.verts[3] - tet0.verts[0];
axes0[3] = tet0.verts[2] - tet0.verts[1];
axes0[4] = tet0.verts[3] - tet0.verts[1];
axes0[5] = tet0.verts[3] - tet0.verts[2];
axes1[0] = tet1.verts[1] - tet1.verts[0];
axes1[1] = tet1.verts[2] - tet1.verts[0];
axes1[2] = tet1.verts[3] - tet1.verts[0];
axes1[3] = tet1.verts[2] - tet1.verts[1];
axes1[4] = tet1.verts[3] - tet1.verts[1];
axes1[5] = tet1.verts[3] - tet1.verts[2];
for (PxU32 i = 0; i < 6; ++i)
{
const PxVec3 axis0 = axes0[i];
for (PxU32 j = 0; j < 6; ++j)
{
const PxVec3 axis1 = axes1[j];
PxVec3 sepAxis = axis0.cross(axis1);
const PxReal magSq = sepAxis.magnitudeSquared();
if (magSq > 1e-5f)
{
sepAxis = sepAxis * (1.f / PxSqrt(magSq));
const PxReal tSep = testSeparatingAxis(sepAxis, tet0, tet1);
sep = PxMax(sep, tSep);
if (sep > tolerance)
return sep;
}
}
}
}
return sep;
}
} // namespace Gu
}
#endif