blender/extern/bullet/Bullet/NarrowPhaseCollision/VoronoiSimplexSolver.cpp

593 lines
16 KiB
C++

/*
* Copyright (c) 2005 Erwin Coumans http://www.erwincoumans.com
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies.
* Erwin Coumans makes no representations about the suitability
* of this software for any purpose.
* It is provided "as is" without express or implied warranty.
*
Elsevier CDROM license agreements grants nonexclusive license to use the software
for any purpose, commercial or non-commercial as long as the following credit is included
identifying the original source of the software:
Parts of the source are "from the book Real-Time Collision Detection by
Christer Ericson, published by Morgan Kaufmann Publishers,
(c) 2005 Elsevier Inc."
*/
#include "VoronoiSimplexSolver.h"
#include <assert.h>
#include <stdio.h>
#define VERTA 0
#define VERTB 1
#define VERTC 2
#define VERTD 3
#define CATCH_DEGENERATE_TETRAHEDRON 1
void VoronoiSimplexSolver::removeVertex(int index)
{
assert(m_numVertices>0);
m_numVertices--;
m_simplexVectorW[index] = m_simplexVectorW[m_numVertices];
m_simplexPointsP[index] = m_simplexPointsP[m_numVertices];
m_simplexPointsQ[index] = m_simplexPointsQ[m_numVertices];
}
void VoronoiSimplexSolver::ReduceVertices (const UsageBitfield& usedVerts)
{
if ((numVertices() >= 4) && (!usedVerts.usedVertexD))
removeVertex(3);
if ((numVertices() >= 3) && (!usedVerts.usedVertexC))
removeVertex(2);
if ((numVertices() >= 2) && (!usedVerts.usedVertexB))
removeVertex(1);
if ((numVertices() >= 1) && (!usedVerts.usedVertexA))
removeVertex(0);
}
//clear the simplex, remove all the vertices
void VoronoiSimplexSolver::reset()
{
m_cachedValidClosest = false;
m_numVertices = 0;
m_needsUpdate = true;
m_lastW = SimdVector3(1e30f,1e30f,1e30f);
m_cachedBC.Reset();
}
//add a vertex
void VoronoiSimplexSolver::addVertex(const SimdVector3& w, const SimdPoint3& p, const SimdPoint3& q)
{
m_lastW = w;
m_needsUpdate = true;
m_simplexVectorW[m_numVertices] = w;
m_simplexPointsP[m_numVertices] = p;
m_simplexPointsQ[m_numVertices] = q;
m_numVertices++;
}
bool VoronoiSimplexSolver::UpdateClosestVectorAndPoints()
{
if (m_needsUpdate)
{
m_cachedBC.Reset();
m_needsUpdate = false;
switch (numVertices())
{
case 0:
m_cachedValidClosest = false;
break;
case 1:
{
m_cachedP1 = m_simplexPointsP[0];
m_cachedP2 = m_simplexPointsQ[0];
m_cachedV = m_cachedP1-m_cachedP2; //== m_simplexVectorW[0]
m_cachedBC.Reset();
m_cachedBC.SetBarycentricCoordinates(1.f,0.f,0.f,0.f);
m_cachedValidClosest = m_cachedBC.IsValid();
break;
};
case 2:
{
//closest point origin from line segment
const SimdVector3& from = m_simplexVectorW[0];
const SimdVector3& to = m_simplexVectorW[1];
SimdVector3 nearest;
SimdVector3 p (0.f,0.f,0.f);
SimdVector3 diff = p - from;
SimdVector3 v = to - from;
float t = v.dot(diff);
if (t > 0) {
float dotVV = v.dot(v);
if (t < dotVV) {
t /= dotVV;
diff -= t*v;
m_cachedBC.m_usedVertices.usedVertexA = true;
m_cachedBC.m_usedVertices.usedVertexB = true;
} else {
t = 1;
diff -= v;
//reduce to 1 point
m_cachedBC.m_usedVertices.usedVertexB = true;
}
} else
{
t = 0;
//reduce to 1 point
m_cachedBC.m_usedVertices.usedVertexA = true;
}
m_cachedBC.SetBarycentricCoordinates(1-t,t);
nearest = from + t*v;
m_cachedP1 = m_simplexPointsP[0] + t * (m_simplexPointsP[1] - m_simplexPointsP[0]);
m_cachedP2 = m_simplexPointsQ[0] + t * (m_simplexPointsQ[1] - m_simplexPointsQ[0]);
m_cachedV = m_cachedP1 - m_cachedP2;
ReduceVertices(m_cachedBC.m_usedVertices);
m_cachedValidClosest = m_cachedBC.IsValid();
break;
}
case 3:
{
//closest point origin from triangle
SimdVector3 p (0.f,0.f,0.f);
const SimdVector3& a = m_simplexVectorW[0];
const SimdVector3& b = m_simplexVectorW[1];
const SimdVector3& c = m_simplexVectorW[2];
ClosestPtPointTriangle(p,a,b,c,m_cachedBC);
m_cachedP1 = m_simplexPointsP[0] * m_cachedBC.m_barycentricCoords[0] +
m_simplexPointsP[1] * m_cachedBC.m_barycentricCoords[1] +
m_simplexPointsP[2] * m_cachedBC.m_barycentricCoords[2] +
m_simplexPointsP[3] * m_cachedBC.m_barycentricCoords[3];
m_cachedP2 = m_simplexPointsQ[0] * m_cachedBC.m_barycentricCoords[0] +
m_simplexPointsQ[1] * m_cachedBC.m_barycentricCoords[1] +
m_simplexPointsQ[2] * m_cachedBC.m_barycentricCoords[2] +
m_simplexPointsQ[3] * m_cachedBC.m_barycentricCoords[3];
m_cachedV = m_cachedP1-m_cachedP2;
ReduceVertices (m_cachedBC.m_usedVertices);
m_cachedValidClosest = m_cachedBC.IsValid();
break;
}
case 4:
{
SimdVector3 p (0.f,0.f,0.f);
const SimdVector3& a = m_simplexVectorW[0];
const SimdVector3& b = m_simplexVectorW[1];
const SimdVector3& c = m_simplexVectorW[2];
const SimdVector3& d = m_simplexVectorW[3];
bool hasSeperation = ClosestPtPointTetrahedron(p,a,b,c,d,m_cachedBC);
if (hasSeperation)
{
m_cachedP1 = m_simplexPointsP[0] * m_cachedBC.m_barycentricCoords[0] +
m_simplexPointsP[1] * m_cachedBC.m_barycentricCoords[1] +
m_simplexPointsP[2] * m_cachedBC.m_barycentricCoords[2] +
m_simplexPointsP[3] * m_cachedBC.m_barycentricCoords[3];
m_cachedP2 = m_simplexPointsQ[0] * m_cachedBC.m_barycentricCoords[0] +
m_simplexPointsQ[1] * m_cachedBC.m_barycentricCoords[1] +
m_simplexPointsQ[2] * m_cachedBC.m_barycentricCoords[2] +
m_simplexPointsQ[3] * m_cachedBC.m_barycentricCoords[3];
m_cachedV = m_cachedP1-m_cachedP2;
ReduceVertices (m_cachedBC.m_usedVertices);
} else
{
// printf("sub distance got penetration\n");
if (m_cachedBC.m_degenerate)
{
m_cachedValidClosest = false;
} else
{
m_cachedValidClosest = true;
//degenerate case == false, penetration = true + zero
m_cachedV.setValue(0.f,0.f,0.f);
}
break;
}
m_cachedValidClosest = m_cachedBC.IsValid();
//closest point origin from tetrahedron
break;
}
default:
{
m_cachedValidClosest = false;
}
};
}
return m_cachedValidClosest;
}
//return/calculate the closest vertex
bool VoronoiSimplexSolver::closest(SimdVector3& v)
{
bool succes = UpdateClosestVectorAndPoints();
v = m_cachedV;
return succes;
}
SimdScalar VoronoiSimplexSolver::maxVertex()
{
int i, numverts = numVertices();
SimdScalar maxV = 0.f;
for (i=0;i<numverts;i++)
{
SimdScalar curLen2 = m_simplexVectorW[i].length2();
if (maxV < curLen2)
maxV = curLen2;
}
return maxV;
}
//return the current simplex
int VoronoiSimplexSolver::getSimplex(SimdPoint3 *pBuf, SimdPoint3 *qBuf, SimdVector3 *yBuf) const
{
int i;
for (i=0;i<numVertices();i++)
{
yBuf[i] = m_simplexVectorW[i];
pBuf[i] = m_simplexPointsP[i];
qBuf[i] = m_simplexPointsQ[i];
}
return numVertices();
}
bool VoronoiSimplexSolver::inSimplex(const SimdVector3& w)
{
bool found = false;
int i, numverts = numVertices();
SimdScalar maxV = 0.f;
//w is in the current (reduced) simplex
for (i=0;i<numverts;i++)
{
if (m_simplexVectorW[i] == w)
found = true;
}
//check in case lastW is already removed
if (w == m_lastW)
return true;
return found;
}
void VoronoiSimplexSolver::backup_closest(SimdVector3& v)
{
v = m_cachedV;
}
bool VoronoiSimplexSolver::emptySimplex() const
{
return (numVertices() == 0);
}
void VoronoiSimplexSolver::compute_points(SimdPoint3& p1, SimdPoint3& p2)
{
UpdateClosestVectorAndPoints();
p1 = m_cachedP1;
p2 = m_cachedP2;
}
bool VoronoiSimplexSolver::ClosestPtPointTriangle(const SimdPoint3& p, const SimdPoint3& a, const SimdPoint3& b, const SimdPoint3& c,SubSimplexClosestResult& result)
{
result.m_usedVertices.reset();
// Check if P in vertex region outside A
SimdVector3 ab = b - a;
SimdVector3 ac = c - a;
SimdVector3 ap = p - a;
float d1 = ab.dot(ap);
float d2 = ac.dot(ap);
if (d1 <= 0.0f && d2 <= 0.0f)
{
result.m_closestPointOnSimplex = a;
result.m_usedVertices.usedVertexA = true;
result.SetBarycentricCoordinates(1,0,0);
return true;// a; // barycentric coordinates (1,0,0)
}
// Check if P in vertex region outside B
SimdVector3 bp = p - b;
float d3 = ab.dot(bp);
float d4 = ac.dot(bp);
if (d3 >= 0.0f && d4 <= d3)
{
result.m_closestPointOnSimplex = b;
result.m_usedVertices.usedVertexB = true;
result.SetBarycentricCoordinates(0,1,0);
return true; // b; // barycentric coordinates (0,1,0)
}
// Check if P in edge region of AB, if so return projection of P onto AB
float vc = d1*d4 - d3*d2;
if (vc <= 0.0f && d1 >= 0.0f && d3 <= 0.0f) {
float v = d1 / (d1 - d3);
result.m_closestPointOnSimplex = a + v * ab;
result.m_usedVertices.usedVertexA = true;
result.m_usedVertices.usedVertexB = true;
result.SetBarycentricCoordinates(1-v,v,0);
return true;
//return a + v * ab; // barycentric coordinates (1-v,v,0)
}
// Check if P in vertex region outside C
SimdVector3 cp = p - c;
float d5 = ab.dot(cp);
float d6 = ac.dot(cp);
if (d6 >= 0.0f && d5 <= d6)
{
result.m_closestPointOnSimplex = c;
result.m_usedVertices.usedVertexC = true;
result.SetBarycentricCoordinates(0,0,1);
return true;//c; // barycentric coordinates (0,0,1)
}
// Check if P in edge region of AC, if so return projection of P onto AC
float vb = d5*d2 - d1*d6;
if (vb <= 0.0f && d2 >= 0.0f && d6 <= 0.0f) {
float w = d2 / (d2 - d6);
result.m_closestPointOnSimplex = a + w * ac;
result.m_usedVertices.usedVertexA = true;
result.m_usedVertices.usedVertexC = true;
result.SetBarycentricCoordinates(1-w,0,w);
return true;
//return a + w * ac; // barycentric coordinates (1-w,0,w)
}
// Check if P in edge region of BC, if so return projection of P onto BC
float va = d3*d6 - d5*d4;
if (va <= 0.0f && (d4 - d3) >= 0.0f && (d5 - d6) >= 0.0f) {
float w = (d4 - d3) / ((d4 - d3) + (d5 - d6));
result.m_closestPointOnSimplex = b + w * (c - b);
result.m_usedVertices.usedVertexB = true;
result.m_usedVertices.usedVertexC = true;
result.SetBarycentricCoordinates(0,1-w,w);
return true;
// return b + w * (c - b); // barycentric coordinates (0,1-w,w)
}
// P inside face region. Compute Q through its barycentric coordinates (u,v,w)
float denom = 1.0f / (va + vb + vc);
float v = vb * denom;
float w = vc * denom;
result.m_closestPointOnSimplex = a + ab * v + ac * w;
result.m_usedVertices.usedVertexA = true;
result.m_usedVertices.usedVertexB = true;
result.m_usedVertices.usedVertexC = true;
result.SetBarycentricCoordinates(1-v-w,v,w);
return true;
// return a + ab * v + ac * w; // = u*a + v*b + w*c, u = va * denom = 1.0f - v - w
}
/// Test if point p and d lie on opposite sides of plane through abc
int VoronoiSimplexSolver::PointOutsideOfPlane(const SimdPoint3& p, const SimdPoint3& a, const SimdPoint3& b, const SimdPoint3& c, const SimdPoint3& d)
{
SimdVector3 normal = (b-a).cross(c-a);
float signp = (p - a).dot(normal); // [AP AB AC]
float signd = (d - a).dot( normal); // [AD AB AC]
#ifdef CATCH_DEGENERATE_TETRAHEDRON
if (signd * signd < (1e-4f * 1e-4f))
{
// printf("affine dependent/degenerate\n");//
return -1;
}
#endif
// Points on opposite sides if expression signs are opposite
return signp * signd < 0.f;
}
bool VoronoiSimplexSolver::ClosestPtPointTetrahedron(const SimdPoint3& p, const SimdPoint3& a, const SimdPoint3& b, const SimdPoint3& c, const SimdPoint3& d, SubSimplexClosestResult& finalResult)
{
SubSimplexClosestResult tempResult;
// Start out assuming point inside all halfspaces, so closest to itself
finalResult.m_closestPointOnSimplex = p;
finalResult.m_usedVertices.reset();
finalResult.m_usedVertices.usedVertexA = true;
finalResult.m_usedVertices.usedVertexB = true;
finalResult.m_usedVertices.usedVertexC = true;
finalResult.m_usedVertices.usedVertexD = true;
int pointOutsideABC = PointOutsideOfPlane(p, a, b, c, d);
int pointOutsideACD = PointOutsideOfPlane(p, a, c, d, b);
int pointOutsideADB = PointOutsideOfPlane(p, a, d, b, c);
int pointOutsideBDC = PointOutsideOfPlane(p, b, d, c, a);
if (pointOutsideABC < 0 || pointOutsideACD < 0 || pointOutsideADB < 0 || pointOutsideBDC < 0)
{
finalResult.m_degenerate = true;
return false;
}
if (!pointOutsideABC && !pointOutsideACD && !pointOutsideADB && !pointOutsideBDC)
{
return false;
}
float bestSqDist = FLT_MAX;
// If point outside face abc then compute closest point on abc
if (pointOutsideABC)
{
ClosestPtPointTriangle(p, a, b, c,tempResult);
SimdPoint3 q = tempResult.m_closestPointOnSimplex;
float sqDist = (q - p).dot( q - p);
// Update best closest point if (squared) distance is less than current best
if (sqDist < bestSqDist) {
bestSqDist = sqDist;
finalResult.m_closestPointOnSimplex = q;
//convert result bitmask!
finalResult.m_usedVertices.reset();
finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA;
finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexB;
finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexC;
finalResult.SetBarycentricCoordinates(
tempResult.m_barycentricCoords[VERTA],
tempResult.m_barycentricCoords[VERTB],
tempResult.m_barycentricCoords[VERTC],
0
);
}
}
// Repeat test for face acd
if (pointOutsideACD)
{
ClosestPtPointTriangle(p, a, c, d,tempResult);
SimdPoint3 q = tempResult.m_closestPointOnSimplex;
//convert result bitmask!
float sqDist = (q - p).dot( q - p);
if (sqDist < bestSqDist)
{
bestSqDist = sqDist;
finalResult.m_closestPointOnSimplex = q;
finalResult.m_usedVertices.reset();
finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA;
finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexB;
finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexC;
finalResult.SetBarycentricCoordinates(
tempResult.m_barycentricCoords[VERTA],
0,
tempResult.m_barycentricCoords[VERTB],
tempResult.m_barycentricCoords[VERTC]
);
}
}
// Repeat test for face adb
if (pointOutsideADB)
{
ClosestPtPointTriangle(p, a, d, b,tempResult);
SimdPoint3 q = tempResult.m_closestPointOnSimplex;
//convert result bitmask!
float sqDist = (q - p).dot( q - p);
if (sqDist < bestSqDist)
{
bestSqDist = sqDist;
finalResult.m_closestPointOnSimplex = q;
finalResult.m_usedVertices.reset();
finalResult.m_usedVertices.usedVertexA = tempResult.m_usedVertices.usedVertexA;
finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexB;
finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexC;
finalResult.SetBarycentricCoordinates(
tempResult.m_barycentricCoords[VERTA],
tempResult.m_barycentricCoords[VERTC],
0,
tempResult.m_barycentricCoords[VERTB]
);
}
}
// Repeat test for face bdc
if (pointOutsideBDC)
{
ClosestPtPointTriangle(p, b, d, c,tempResult);
SimdPoint3 q = tempResult.m_closestPointOnSimplex;
//convert result bitmask!
float sqDist = (q - p).dot( q - p);
if (sqDist < bestSqDist)
{
bestSqDist = sqDist;
finalResult.m_closestPointOnSimplex = q;
finalResult.m_usedVertices.reset();
finalResult.m_usedVertices.usedVertexB = tempResult.m_usedVertices.usedVertexA;
finalResult.m_usedVertices.usedVertexD = tempResult.m_usedVertices.usedVertexB;
finalResult.m_usedVertices.usedVertexC = tempResult.m_usedVertices.usedVertexC;
finalResult.SetBarycentricCoordinates(
0,
tempResult.m_barycentricCoords[VERTA],
tempResult.m_barycentricCoords[VERTC],
tempResult.m_barycentricCoords[VERTB]
);
}
}
//help! we ended up full !
if (finalResult.m_usedVertices.usedVertexA &&
finalResult.m_usedVertices.usedVertexB &&
finalResult.m_usedVertices.usedVertexC &&
finalResult.m_usedVertices.usedVertexD)
{
return true;
}
return true;
}