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XCEngine/engine/third_party/physx/source/geomutils/src/common/GuMeshAnalysis.cpp

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6.7 KiB
C++

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2008-2025 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
#include "foundation/PxVec3.h"
#include "foundation/PxArray.h"
#include "GuMeshAnalysis.h"
using namespace physx;
using namespace Gu;
PX_FORCE_INLINE PxU64 key(PxI32 a, PxI32 b)
{
if (a < b)
return ((PxU64(a)) << 32) | (PxU64(b));
else
return ((PxU64(b)) << 32) | (PxU64(a));
}
#define INITIAL_VALUE -3
const static PxU32 neighborEdges[3][2] = { { 0, 1 }, { 2, 0 }, { 1, 2 } };
//const static PxU32 triTip[3] = { 2, 1, 0 };
bool MeshAnalyzer::buildTriangleAdjacency(const Triangle* tris, PxU32 numTriangles, PxArray<PxI32>& result, PxHashMap<PxU64, PxI32>& edges)
{
PxU32 l = 4 * numTriangles; //Still factor 4 - waste one entry per triangle to get a power of 2 which allows for bit shift usage instead of modulo
result.clear();
result.resize(l, -1);
for (PxU32 i = 3; i < l; i += 4)
result[i] = INITIAL_VALUE; //Mark the fields that get never accessed because they are just not used, this is useful for debugging
edges.clear();
for (PxU32 i = 0; i < numTriangles; ++i)
{
const Triangle& tri = tris[i];
if (tri[0] < 0)
continue;
for (PxU32 j = 0; j < 3; ++j)
{
PxU64 edge = key(tri[neighborEdges[j][0]], tri[neighborEdges[j][1]]);
if (const PxPair<const PxU64, PxI32>* ptr = edges.find(edge))
{
if (ptr->second < 0)
return false; //Edge shared by more than 2 triangles
if (result[4 * i + j] == -4 || result[ptr->second] == -4)
{
result[4 * i + j] = -4; //Mark as non-manifold edge
result[ptr->second] = -4;
}
else
{
if (result[4 * i + j] != -1 || result[ptr->second] != -1)
{
result[4 * i + j] = -4; //Mark as non-manifold edge
result[ptr->second] = -4;
}
result[4 * i + j] = ptr->second;
result[ptr->second] = 4 * i + j;
}
edges.erase(ptr->first);
edges.insert(edge, -1); //Mark as processed
}
else
edges.insert(edge, 4 * i + j);
}
}
return true;
}
PxI32 indexOf(const Triangle& tri, PxI32 node)
{
if (tri[0] == node) return 0;
if (tri[1] == node) return 1;
if (tri[2] == node) return 2;
return 0xFFFFFFFF;
}
bool MeshAnalyzer::checkConsistentTriangleOrientation(const Triangle* tris, PxU32 numTriangles)
{
PxArray<bool> flip;
PxHashMap<PxU64, PxI32> edges;
PxArray<PxArray<PxU32>> connectedTriangleGroups;
if (!buildConsistentTriangleOrientationMap(tris, numTriangles, flip, edges, connectedTriangleGroups))
return false;
for (PxU32 i = 0; i < flip.size(); ++i)
{
if (flip[i])
return false;
}
return true;
}
bool MeshAnalyzer::buildConsistentTriangleOrientationMap(const Triangle* tris, PxU32 numTriangles, PxArray<bool>& flip,
PxHashMap<PxU64, PxI32>& edges, PxArray<PxArray<PxU32>>& connectedTriangleGroups)
{
PxArray<PxI32> adj;
if (!buildTriangleAdjacency(tris, numTriangles, adj, edges))
return false;
PxU32 l = numTriangles;
PxArray<bool> done;
done.resize(l, false);
flip.clear();
flip.resize(l, false);
PxU32 seedIndex = 0;
PxArray<PxI32> stack;
while (true)
{
if (stack.size() == 0)
{
while (seedIndex < done.size() && done[seedIndex])
++seedIndex;
if (seedIndex == done.size())
break;
done[seedIndex] = true;
flip[seedIndex] = false;
stack.pushBack(seedIndex);
PxArray<PxU32> currentGroup;
currentGroup.pushBack(seedIndex);
connectedTriangleGroups.pushBack(currentGroup);
}
PxI32 index = stack.popBack();
bool f = flip[index];
const Triangle& tri = tris[index];
for (PxU32 i = 0; i < 3; ++i)
{
if (adj[4 * index + i] >= 0 && !done[adj[4 * index + i] >> 2])
{
PxI32 neighborTriIndex = adj[4 * index + i] >> 2;
done[neighborTriIndex] = true;
connectedTriangleGroups[connectedTriangleGroups.size() - 1].pushBack(neighborTriIndex);
const Triangle& neighborTri = tris[neighborTriIndex];
PxI32 j = indexOf(neighborTri, tri[neighborEdges[i][0]]);
flip[neighborTriIndex] = (neighborTri[(j + 1) % 3] == tri[neighborEdges[i][1]]) != f;
stack.pushBack(neighborTriIndex);
}
}
}
return true;
}
bool MeshAnalyzer::makeTriOrientationConsistent(Triangle* tris, PxU32 numTriangles, bool invertOrientation)
{
PxHashMap<PxU64, PxI32> edges;
PxArray<bool> flipTriangle;
PxArray<PxArray<PxU32>> connectedTriangleGroups;
if (!buildConsistentTriangleOrientationMap(tris, numTriangles, flipTriangle, edges, connectedTriangleGroups))
return false;
for (PxU32 i = 0; i < flipTriangle.size(); ++i)
{
Triangle& t = tris[i];
if (flipTriangle[i] != invertOrientation)
PxSwap(t[0], t[1]);
}
return true;
}
bool MeshAnalyzer::checkMeshWatertightness(const Triangle* tris, PxU32 numTriangles, bool treatInconsistentWindingAsNonWatertight)
{
PxArray<bool> flip;
PxHashMap<PxU64, PxI32> edges;
PxArray<PxArray<PxU32>> connectedTriangleGroups;
if (!MeshAnalyzer::buildConsistentTriangleOrientationMap(tris, numTriangles, flip, edges, connectedTriangleGroups))
return false;
if (treatInconsistentWindingAsNonWatertight)
{
for (PxU32 i = 0; i < flip.size(); ++i)
{
if (flip[i])
return false;
}
}
for (PxHashMap<PxU64, PxI32>::Iterator iter = edges.getIterator(); !iter.done(); ++iter)
{
if (iter->second >= 0)
return false;
}
return true;
}