summaryrefslogtreecommitdiff
path: root/thirdparty/bullet/src/LinearMath/btConvexHull.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'thirdparty/bullet/src/LinearMath/btConvexHull.cpp')
-rw-r--r--thirdparty/bullet/src/LinearMath/btConvexHull.cpp1167
1 files changed, 1167 insertions, 0 deletions
diff --git a/thirdparty/bullet/src/LinearMath/btConvexHull.cpp b/thirdparty/bullet/src/LinearMath/btConvexHull.cpp
new file mode 100644
index 0000000000..f8b79a1aba
--- /dev/null
+++ b/thirdparty/bullet/src/LinearMath/btConvexHull.cpp
@@ -0,0 +1,1167 @@
+/*
+Stan Melax Convex Hull Computation
+Copyright (c) 2003-2006 Stan Melax http://www.melax.com/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it freely,
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include <string.h>
+
+#include "btConvexHull.h"
+#include "btAlignedObjectArray.h"
+#include "btMinMax.h"
+#include "btVector3.h"
+
+
+
+
+
+//----------------------------------
+
+class int3
+{
+public:
+ int x,y,z;
+ int3(){};
+ int3(int _x,int _y, int _z){x=_x;y=_y;z=_z;}
+ const int& operator[](int i) const {return (&x)[i];}
+ int& operator[](int i) {return (&x)[i];}
+};
+
+
+//------- btPlane ----------
+
+
+inline btPlane PlaneFlip(const btPlane &plane){return btPlane(-plane.normal,-plane.dist);}
+inline int operator==( const btPlane &a, const btPlane &b ) { return (a.normal==b.normal && a.dist==b.dist); }
+inline int coplanar( const btPlane &a, const btPlane &b ) { return (a==b || a==PlaneFlip(b)); }
+
+
+//--------- Utility Functions ------
+
+btVector3 PlaneLineIntersection(const btPlane &plane, const btVector3 &p0, const btVector3 &p1);
+btVector3 PlaneProject(const btPlane &plane, const btVector3 &point);
+
+btVector3 ThreePlaneIntersection(const btPlane &p0,const btPlane &p1, const btPlane &p2);
+btVector3 ThreePlaneIntersection(const btPlane &p0,const btPlane &p1, const btPlane &p2)
+{
+ btVector3 N1 = p0.normal;
+ btVector3 N2 = p1.normal;
+ btVector3 N3 = p2.normal;
+
+ btVector3 n2n3; n2n3 = N2.cross(N3);
+ btVector3 n3n1; n3n1 = N3.cross(N1);
+ btVector3 n1n2; n1n2 = N1.cross(N2);
+
+ btScalar quotient = (N1.dot(n2n3));
+
+ btAssert(btFabs(quotient) > btScalar(0.000001));
+
+ quotient = btScalar(-1.) / quotient;
+ n2n3 *= p0.dist;
+ n3n1 *= p1.dist;
+ n1n2 *= p2.dist;
+ btVector3 potentialVertex = n2n3;
+ potentialVertex += n3n1;
+ potentialVertex += n1n2;
+ potentialVertex *= quotient;
+
+ btVector3 result(potentialVertex.getX(),potentialVertex.getY(),potentialVertex.getZ());
+ return result;
+
+}
+
+btScalar DistanceBetweenLines(const btVector3 &ustart, const btVector3 &udir, const btVector3 &vstart, const btVector3 &vdir, btVector3 *upoint=NULL, btVector3 *vpoint=NULL);
+btVector3 TriNormal(const btVector3 &v0, const btVector3 &v1, const btVector3 &v2);
+btVector3 NormalOf(const btVector3 *vert, const int n);
+
+
+btVector3 PlaneLineIntersection(const btPlane &plane, const btVector3 &p0, const btVector3 &p1)
+{
+ // returns the point where the line p0-p1 intersects the plane n&d
+ btVector3 dif;
+ dif = p1-p0;
+ btScalar dn= btDot(plane.normal,dif);
+ btScalar t = -(plane.dist+btDot(plane.normal,p0) )/dn;
+ return p0 + (dif*t);
+}
+
+btVector3 PlaneProject(const btPlane &plane, const btVector3 &point)
+{
+ return point - plane.normal * (btDot(point,plane.normal)+plane.dist);
+}
+
+btVector3 TriNormal(const btVector3 &v0, const btVector3 &v1, const btVector3 &v2)
+{
+ // return the normal of the triangle
+ // inscribed by v0, v1, and v2
+ btVector3 cp=btCross(v1-v0,v2-v1);
+ btScalar m=cp.length();
+ if(m==0) return btVector3(1,0,0);
+ return cp*(btScalar(1.0)/m);
+}
+
+
+btScalar DistanceBetweenLines(const btVector3 &ustart, const btVector3 &udir, const btVector3 &vstart, const btVector3 &vdir, btVector3 *upoint, btVector3 *vpoint)
+{
+ btVector3 cp;
+ cp = btCross(udir,vdir).normalized();
+
+ btScalar distu = -btDot(cp,ustart);
+ btScalar distv = -btDot(cp,vstart);
+ btScalar dist = (btScalar)fabs(distu-distv);
+ if(upoint)
+ {
+ btPlane plane;
+ plane.normal = btCross(vdir,cp).normalized();
+ plane.dist = -btDot(plane.normal,vstart);
+ *upoint = PlaneLineIntersection(plane,ustart,ustart+udir);
+ }
+ if(vpoint)
+ {
+ btPlane plane;
+ plane.normal = btCross(udir,cp).normalized();
+ plane.dist = -btDot(plane.normal,ustart);
+ *vpoint = PlaneLineIntersection(plane,vstart,vstart+vdir);
+ }
+ return dist;
+}
+
+
+
+
+
+
+
+#define COPLANAR (0)
+#define UNDER (1)
+#define OVER (2)
+#define SPLIT (OVER|UNDER)
+#define PAPERWIDTH (btScalar(0.001))
+
+btScalar planetestepsilon = PAPERWIDTH;
+
+
+
+typedef ConvexH::HalfEdge HalfEdge;
+
+ConvexH::ConvexH(int vertices_size,int edges_size,int facets_size)
+{
+ vertices.resize(vertices_size);
+ edges.resize(edges_size);
+ facets.resize(facets_size);
+}
+
+
+int PlaneTest(const btPlane &p, const btVector3 &v);
+int PlaneTest(const btPlane &p, const btVector3 &v) {
+ btScalar a = btDot(v,p.normal)+p.dist;
+ int flag = (a>planetestepsilon)?OVER:((a<-planetestepsilon)?UNDER:COPLANAR);
+ return flag;
+}
+
+int SplitTest(ConvexH &convex,const btPlane &plane);
+int SplitTest(ConvexH &convex,const btPlane &plane) {
+ int flag=0;
+ for(int i=0;i<convex.vertices.size();i++) {
+ flag |= PlaneTest(plane,convex.vertices[i]);
+ }
+ return flag;
+}
+
+class VertFlag
+{
+public:
+ unsigned char planetest;
+ unsigned char junk;
+ unsigned char undermap;
+ unsigned char overmap;
+};
+class EdgeFlag
+{
+public:
+ unsigned char planetest;
+ unsigned char fixes;
+ short undermap;
+ short overmap;
+};
+class PlaneFlag
+{
+public:
+ unsigned char undermap;
+ unsigned char overmap;
+};
+class Coplanar{
+public:
+ unsigned short ea;
+ unsigned char v0;
+ unsigned char v1;
+};
+
+
+
+
+
+
+
+
+template<class T>
+int maxdirfiltered(const T *p,int count,const T &dir,btAlignedObjectArray<int> &allow)
+{
+ btAssert(count);
+ int m=-1;
+ for(int i=0;i<count;i++)
+ if(allow[i])
+ {
+ if(m==-1 || btDot(p[i],dir)>btDot(p[m],dir))
+ m=i;
+ }
+ btAssert(m!=-1);
+ return m;
+}
+
+btVector3 orth(const btVector3 &v);
+btVector3 orth(const btVector3 &v)
+{
+ btVector3 a=btCross(v,btVector3(0,0,1));
+ btVector3 b=btCross(v,btVector3(0,1,0));
+ if (a.length() > b.length())
+ {
+ return a.normalized();
+ } else {
+ return b.normalized();
+ }
+}
+
+
+template<class T>
+int maxdirsterid(const T *p,int count,const T &dir,btAlignedObjectArray<int> &allow)
+{
+ int m=-1;
+ while(m==-1)
+ {
+ m = maxdirfiltered(p,count,dir,allow);
+ if(allow[m]==3) return m;
+ T u = orth(dir);
+ T v = btCross(u,dir);
+ int ma=-1;
+ for(btScalar x = btScalar(0.0) ; x<= btScalar(360.0) ; x+= btScalar(45.0))
+ {
+ btScalar s = btSin(SIMD_RADS_PER_DEG*(x));
+ btScalar c = btCos(SIMD_RADS_PER_DEG*(x));
+ int mb = maxdirfiltered(p,count,dir+(u*s+v*c)*btScalar(0.025),allow);
+ if(ma==m && mb==m)
+ {
+ allow[m]=3;
+ return m;
+ }
+ if(ma!=-1 && ma!=mb) // Yuck - this is really ugly
+ {
+ int mc = ma;
+ for(btScalar xx = x-btScalar(40.0) ; xx <= x ; xx+= btScalar(5.0))
+ {
+ btScalar s = btSin(SIMD_RADS_PER_DEG*(xx));
+ btScalar c = btCos(SIMD_RADS_PER_DEG*(xx));
+ int md = maxdirfiltered(p,count,dir+(u*s+v*c)*btScalar(0.025),allow);
+ if(mc==m && md==m)
+ {
+ allow[m]=3;
+ return m;
+ }
+ mc=md;
+ }
+ }
+ ma=mb;
+ }
+ allow[m]=0;
+ m=-1;
+ }
+ btAssert(0);
+ return m;
+}
+
+
+
+
+int operator ==(const int3 &a,const int3 &b);
+int operator ==(const int3 &a,const int3 &b)
+{
+ for(int i=0;i<3;i++)
+ {
+ if(a[i]!=b[i]) return 0;
+ }
+ return 1;
+}
+
+
+int above(btVector3* vertices,const int3& t, const btVector3 &p, btScalar epsilon);
+int above(btVector3* vertices,const int3& t, const btVector3 &p, btScalar epsilon)
+{
+ btVector3 n=TriNormal(vertices[t[0]],vertices[t[1]],vertices[t[2]]);
+ return (btDot(n,p-vertices[t[0]]) > epsilon); // EPSILON???
+}
+int hasedge(const int3 &t, int a,int b);
+int hasedge(const int3 &t, int a,int b)
+{
+ for(int i=0;i<3;i++)
+ {
+ int i1= (i+1)%3;
+ if(t[i]==a && t[i1]==b) return 1;
+ }
+ return 0;
+}
+int hasvert(const int3 &t, int v);
+int hasvert(const int3 &t, int v)
+{
+ return (t[0]==v || t[1]==v || t[2]==v) ;
+}
+int shareedge(const int3 &a,const int3 &b);
+int shareedge(const int3 &a,const int3 &b)
+{
+ int i;
+ for(i=0;i<3;i++)
+ {
+ int i1= (i+1)%3;
+ if(hasedge(a,b[i1],b[i])) return 1;
+ }
+ return 0;
+}
+
+class btHullTriangle;
+
+
+
+class btHullTriangle : public int3
+{
+public:
+ int3 n;
+ int id;
+ int vmax;
+ btScalar rise;
+ btHullTriangle(int a,int b,int c):int3(a,b,c),n(-1,-1,-1)
+ {
+ vmax=-1;
+ rise = btScalar(0.0);
+ }
+ ~btHullTriangle()
+ {
+ }
+ int &neib(int a,int b);
+};
+
+
+int &btHullTriangle::neib(int a,int b)
+{
+ static int er=-1;
+ int i;
+ for(i=0;i<3;i++)
+ {
+ int i1=(i+1)%3;
+ int i2=(i+2)%3;
+ if((*this)[i]==a && (*this)[i1]==b) return n[i2];
+ if((*this)[i]==b && (*this)[i1]==a) return n[i2];
+ }
+ btAssert(0);
+ return er;
+}
+void HullLibrary::b2bfix(btHullTriangle* s,btHullTriangle*t)
+{
+ int i;
+ for(i=0;i<3;i++)
+ {
+ int i1=(i+1)%3;
+ int i2=(i+2)%3;
+ int a = (*s)[i1];
+ int b = (*s)[i2];
+ btAssert(m_tris[s->neib(a,b)]->neib(b,a) == s->id);
+ btAssert(m_tris[t->neib(a,b)]->neib(b,a) == t->id);
+ m_tris[s->neib(a,b)]->neib(b,a) = t->neib(b,a);
+ m_tris[t->neib(b,a)]->neib(a,b) = s->neib(a,b);
+ }
+}
+
+void HullLibrary::removeb2b(btHullTriangle* s,btHullTriangle*t)
+{
+ b2bfix(s,t);
+ deAllocateTriangle(s);
+
+ deAllocateTriangle(t);
+}
+
+void HullLibrary::checkit(btHullTriangle *t)
+{
+ (void)t;
+
+ int i;
+ btAssert(m_tris[t->id]==t);
+ for(i=0;i<3;i++)
+ {
+ int i1=(i+1)%3;
+ int i2=(i+2)%3;
+ int a = (*t)[i1];
+ int b = (*t)[i2];
+
+ // release compile fix
+ (void)i1;
+ (void)i2;
+ (void)a;
+ (void)b;
+
+ btAssert(a!=b);
+ btAssert( m_tris[t->n[i]]->neib(b,a) == t->id);
+ }
+}
+
+btHullTriangle* HullLibrary::allocateTriangle(int a,int b,int c)
+{
+ void* mem = btAlignedAlloc(sizeof(btHullTriangle),16);
+ btHullTriangle* tr = new (mem)btHullTriangle(a,b,c);
+ tr->id = m_tris.size();
+ m_tris.push_back(tr);
+
+ return tr;
+}
+
+void HullLibrary::deAllocateTriangle(btHullTriangle* tri)
+{
+ btAssert(m_tris[tri->id]==tri);
+ m_tris[tri->id]=NULL;
+ tri->~btHullTriangle();
+ btAlignedFree(tri);
+}
+
+
+void HullLibrary::extrude(btHullTriangle *t0,int v)
+{
+ int3 t= *t0;
+ int n = m_tris.size();
+ btHullTriangle* ta = allocateTriangle(v,t[1],t[2]);
+ ta->n = int3(t0->n[0],n+1,n+2);
+ m_tris[t0->n[0]]->neib(t[1],t[2]) = n+0;
+ btHullTriangle* tb = allocateTriangle(v,t[2],t[0]);
+ tb->n = int3(t0->n[1],n+2,n+0);
+ m_tris[t0->n[1]]->neib(t[2],t[0]) = n+1;
+ btHullTriangle* tc = allocateTriangle(v,t[0],t[1]);
+ tc->n = int3(t0->n[2],n+0,n+1);
+ m_tris[t0->n[2]]->neib(t[0],t[1]) = n+2;
+ checkit(ta);
+ checkit(tb);
+ checkit(tc);
+ if(hasvert(*m_tris[ta->n[0]],v)) removeb2b(ta,m_tris[ta->n[0]]);
+ if(hasvert(*m_tris[tb->n[0]],v)) removeb2b(tb,m_tris[tb->n[0]]);
+ if(hasvert(*m_tris[tc->n[0]],v)) removeb2b(tc,m_tris[tc->n[0]]);
+ deAllocateTriangle(t0);
+
+}
+
+btHullTriangle* HullLibrary::extrudable(btScalar epsilon)
+{
+ int i;
+ btHullTriangle *t=NULL;
+ for(i=0;i<m_tris.size();i++)
+ {
+ if(!t || (m_tris[i] && t->rise<m_tris[i]->rise))
+ {
+ t = m_tris[i];
+ }
+ }
+ return (t->rise >epsilon)?t:NULL ;
+}
+
+
+
+
+int4 HullLibrary::FindSimplex(btVector3 *verts,int verts_count,btAlignedObjectArray<int> &allow)
+{
+ btVector3 basis[3];
+ basis[0] = btVector3( btScalar(0.01), btScalar(0.02), btScalar(1.0) );
+ int p0 = maxdirsterid(verts,verts_count, basis[0],allow);
+ int p1 = maxdirsterid(verts,verts_count,-basis[0],allow);
+ basis[0] = verts[p0]-verts[p1];
+ if(p0==p1 || basis[0]==btVector3(0,0,0))
+ return int4(-1,-1,-1,-1);
+ basis[1] = btCross(btVector3( btScalar(1),btScalar(0.02), btScalar(0)),basis[0]);
+ basis[2] = btCross(btVector3(btScalar(-0.02), btScalar(1), btScalar(0)),basis[0]);
+ if (basis[1].length() > basis[2].length())
+ {
+ basis[1].normalize();
+ } else {
+ basis[1] = basis[2];
+ basis[1].normalize ();
+ }
+ int p2 = maxdirsterid(verts,verts_count,basis[1],allow);
+ if(p2 == p0 || p2 == p1)
+ {
+ p2 = maxdirsterid(verts,verts_count,-basis[1],allow);
+ }
+ if(p2 == p0 || p2 == p1)
+ return int4(-1,-1,-1,-1);
+ basis[1] = verts[p2] - verts[p0];
+ basis[2] = btCross(basis[1],basis[0]).normalized();
+ int p3 = maxdirsterid(verts,verts_count,basis[2],allow);
+ if(p3==p0||p3==p1||p3==p2) p3 = maxdirsterid(verts,verts_count,-basis[2],allow);
+ if(p3==p0||p3==p1||p3==p2)
+ return int4(-1,-1,-1,-1);
+ btAssert(!(p0==p1||p0==p2||p0==p3||p1==p2||p1==p3||p2==p3));
+ if(btDot(verts[p3]-verts[p0],btCross(verts[p1]-verts[p0],verts[p2]-verts[p0])) <0) {btSwap(p2,p3);}
+ return int4(p0,p1,p2,p3);
+}
+
+int HullLibrary::calchullgen(btVector3 *verts,int verts_count, int vlimit)
+{
+ if(verts_count <4) return 0;
+ if(vlimit==0) vlimit=1000000000;
+ int j;
+ btVector3 bmin(*verts),bmax(*verts);
+ btAlignedObjectArray<int> isextreme;
+ isextreme.reserve(verts_count);
+ btAlignedObjectArray<int> allow;
+ allow.reserve(verts_count);
+
+ for(j=0;j<verts_count;j++)
+ {
+ allow.push_back(1);
+ isextreme.push_back(0);
+ bmin.setMin (verts[j]);
+ bmax.setMax (verts[j]);
+ }
+ btScalar epsilon = (bmax-bmin).length() * btScalar(0.001);
+ btAssert (epsilon != 0.0);
+
+
+ int4 p = FindSimplex(verts,verts_count,allow);
+ if(p.x==-1) return 0; // simplex failed
+
+
+
+ btVector3 center = (verts[p[0]]+verts[p[1]]+verts[p[2]]+verts[p[3]]) / btScalar(4.0); // a valid interior point
+ btHullTriangle *t0 = allocateTriangle(p[2],p[3],p[1]); t0->n=int3(2,3,1);
+ btHullTriangle *t1 = allocateTriangle(p[3],p[2],p[0]); t1->n=int3(3,2,0);
+ btHullTriangle *t2 = allocateTriangle(p[0],p[1],p[3]); t2->n=int3(0,1,3);
+ btHullTriangle *t3 = allocateTriangle(p[1],p[0],p[2]); t3->n=int3(1,0,2);
+ isextreme[p[0]]=isextreme[p[1]]=isextreme[p[2]]=isextreme[p[3]]=1;
+ checkit(t0);checkit(t1);checkit(t2);checkit(t3);
+
+ for(j=0;j<m_tris.size();j++)
+ {
+ btHullTriangle *t=m_tris[j];
+ btAssert(t);
+ btAssert(t->vmax<0);
+ btVector3 n=TriNormal(verts[(*t)[0]],verts[(*t)[1]],verts[(*t)[2]]);
+ t->vmax = maxdirsterid(verts,verts_count,n,allow);
+ t->rise = btDot(n,verts[t->vmax]-verts[(*t)[0]]);
+ }
+ btHullTriangle *te;
+ vlimit-=4;
+ while(vlimit >0 && ((te=extrudable(epsilon)) != 0))
+ {
+ //int3 ti=*te;
+ int v=te->vmax;
+ btAssert(v != -1);
+ btAssert(!isextreme[v]); // wtf we've already done this vertex
+ isextreme[v]=1;
+ //if(v==p0 || v==p1 || v==p2 || v==p3) continue; // done these already
+ j=m_tris.size();
+ while(j--) {
+ if(!m_tris[j]) continue;
+ int3 t=*m_tris[j];
+ if(above(verts,t,verts[v],btScalar(0.01)*epsilon))
+ {
+ extrude(m_tris[j],v);
+ }
+ }
+ // now check for those degenerate cases where we have a flipped triangle or a really skinny triangle
+ j=m_tris.size();
+ while(j--)
+ {
+ if(!m_tris[j]) continue;
+ if(!hasvert(*m_tris[j],v)) break;
+ int3 nt=*m_tris[j];
+ if(above(verts,nt,center,btScalar(0.01)*epsilon) || btCross(verts[nt[1]]-verts[nt[0]],verts[nt[2]]-verts[nt[1]]).length()< epsilon*epsilon*btScalar(0.1) )
+ {
+ btHullTriangle *nb = m_tris[m_tris[j]->n[0]];
+ btAssert(nb);btAssert(!hasvert(*nb,v));btAssert(nb->id<j);
+ extrude(nb,v);
+ j=m_tris.size();
+ }
+ }
+ j=m_tris.size();
+ while(j--)
+ {
+ btHullTriangle *t=m_tris[j];
+ if(!t) continue;
+ if(t->vmax>=0) break;
+ btVector3 n=TriNormal(verts[(*t)[0]],verts[(*t)[1]],verts[(*t)[2]]);
+ t->vmax = maxdirsterid(verts,verts_count,n,allow);
+ if(isextreme[t->vmax])
+ {
+ t->vmax=-1; // already done that vertex - algorithm needs to be able to terminate.
+ }
+ else
+ {
+ t->rise = btDot(n,verts[t->vmax]-verts[(*t)[0]]);
+ }
+ }
+ vlimit --;
+ }
+ return 1;
+}
+
+int HullLibrary::calchull(btVector3 *verts,int verts_count, TUIntArray& tris_out, int &tris_count,int vlimit)
+{
+ int rc=calchullgen(verts,verts_count, vlimit) ;
+ if(!rc) return 0;
+ btAlignedObjectArray<int> ts;
+ int i;
+
+ for(i=0;i<m_tris.size();i++)
+ {
+ if(m_tris[i])
+ {
+ for(int j=0;j<3;j++)
+ ts.push_back((*m_tris[i])[j]);
+ deAllocateTriangle(m_tris[i]);
+ }
+ }
+ tris_count = ts.size()/3;
+ tris_out.resize(ts.size());
+
+ for (i=0;i<ts.size();i++)
+ {
+ tris_out[i] = static_cast<unsigned int>(ts[i]);
+ }
+ m_tris.resize(0);
+
+ return 1;
+}
+
+
+
+
+
+bool HullLibrary::ComputeHull(unsigned int vcount,const btVector3 *vertices,PHullResult &result,unsigned int vlimit)
+{
+
+ int tris_count;
+ int ret = calchull( (btVector3 *) vertices, (int) vcount, result.m_Indices, tris_count, static_cast<int>(vlimit) );
+ if(!ret) return false;
+ result.mIndexCount = (unsigned int) (tris_count*3);
+ result.mFaceCount = (unsigned int) tris_count;
+ result.mVertices = (btVector3*) vertices;
+ result.mVcount = (unsigned int) vcount;
+ return true;
+
+}
+
+
+void ReleaseHull(PHullResult &result);
+void ReleaseHull(PHullResult &result)
+{
+ if ( result.m_Indices.size() )
+ {
+ result.m_Indices.clear();
+ }
+
+ result.mVcount = 0;
+ result.mIndexCount = 0;
+ result.mVertices = 0;
+}
+
+
+//*********************************************************************
+//*********************************************************************
+//******** HullLib header
+//*********************************************************************
+//*********************************************************************
+
+//*********************************************************************
+//*********************************************************************
+//******** HullLib implementation
+//*********************************************************************
+//*********************************************************************
+
+HullError HullLibrary::CreateConvexHull(const HullDesc &desc, // describes the input request
+ HullResult &result) // contains the resulst
+{
+ HullError ret = QE_FAIL;
+
+
+ PHullResult hr;
+
+ unsigned int vcount = desc.mVcount;
+ if ( vcount < 8 ) vcount = 8;
+
+ btAlignedObjectArray<btVector3> vertexSource;
+ vertexSource.resize(static_cast<int>(vcount));
+
+ btVector3 scale;
+
+ unsigned int ovcount;
+
+ bool ok = CleanupVertices(desc.mVcount,desc.mVertices, desc.mVertexStride, ovcount, &vertexSource[0], desc.mNormalEpsilon, scale ); // normalize point cloud, remove duplicates!
+
+ if ( ok )
+ {
+
+
+// if ( 1 ) // scale vertices back to their original size.
+ {
+ for (unsigned int i=0; i<ovcount; i++)
+ {
+ btVector3& v = vertexSource[static_cast<int>(i)];
+ v[0]*=scale[0];
+ v[1]*=scale[1];
+ v[2]*=scale[2];
+ }
+ }
+
+ ok = ComputeHull(ovcount,&vertexSource[0],hr,desc.mMaxVertices);
+
+ if ( ok )
+ {
+
+ // re-index triangle mesh so it refers to only used vertices, rebuild a new vertex table.
+ btAlignedObjectArray<btVector3> vertexScratch;
+ vertexScratch.resize(static_cast<int>(hr.mVcount));
+
+ BringOutYourDead(hr.mVertices,hr.mVcount, &vertexScratch[0], ovcount, &hr.m_Indices[0], hr.mIndexCount );
+
+ ret = QE_OK;
+
+ if ( desc.HasHullFlag(QF_TRIANGLES) ) // if he wants the results as triangle!
+ {
+ result.mPolygons = false;
+ result.mNumOutputVertices = ovcount;
+ result.m_OutputVertices.resize(static_cast<int>(ovcount));
+ result.mNumFaces = hr.mFaceCount;
+ result.mNumIndices = hr.mIndexCount;
+
+ result.m_Indices.resize(static_cast<int>(hr.mIndexCount));
+
+ memcpy(&result.m_OutputVertices[0], &vertexScratch[0], sizeof(btVector3)*ovcount );
+
+ if ( desc.HasHullFlag(QF_REVERSE_ORDER) )
+ {
+
+ const unsigned int *source = &hr.m_Indices[0];
+ unsigned int *dest = &result.m_Indices[0];
+
+ for (unsigned int i=0; i<hr.mFaceCount; i++)
+ {
+ dest[0] = source[2];
+ dest[1] = source[1];
+ dest[2] = source[0];
+ dest+=3;
+ source+=3;
+ }
+
+ }
+ else
+ {
+ memcpy(&result.m_Indices[0], &hr.m_Indices[0], sizeof(unsigned int)*hr.mIndexCount);
+ }
+ }
+ else
+ {
+ result.mPolygons = true;
+ result.mNumOutputVertices = ovcount;
+ result.m_OutputVertices.resize(static_cast<int>(ovcount));
+ result.mNumFaces = hr.mFaceCount;
+ result.mNumIndices = hr.mIndexCount+hr.mFaceCount;
+ result.m_Indices.resize(static_cast<int>(result.mNumIndices));
+ memcpy(&result.m_OutputVertices[0], &vertexScratch[0], sizeof(btVector3)*ovcount );
+
+// if ( 1 )
+ {
+ const unsigned int *source = &hr.m_Indices[0];
+ unsigned int *dest = &result.m_Indices[0];
+ for (unsigned int i=0; i<hr.mFaceCount; i++)
+ {
+ dest[0] = 3;
+ if ( desc.HasHullFlag(QF_REVERSE_ORDER) )
+ {
+ dest[1] = source[2];
+ dest[2] = source[1];
+ dest[3] = source[0];
+ }
+ else
+ {
+ dest[1] = source[0];
+ dest[2] = source[1];
+ dest[3] = source[2];
+ }
+
+ dest+=4;
+ source+=3;
+ }
+ }
+ }
+ ReleaseHull(hr);
+ }
+ }
+
+ return ret;
+}
+
+
+
+HullError HullLibrary::ReleaseResult(HullResult &result) // release memory allocated for this result, we are done with it.
+{
+ if ( result.m_OutputVertices.size())
+ {
+ result.mNumOutputVertices=0;
+ result.m_OutputVertices.clear();
+ }
+ if ( result.m_Indices.size() )
+ {
+ result.mNumIndices=0;
+ result.m_Indices.clear();
+ }
+ return QE_OK;
+}
+
+
+static void addPoint(unsigned int &vcount,btVector3 *p,btScalar x,btScalar y,btScalar z)
+{
+ // XXX, might be broken
+ btVector3& dest = p[vcount];
+ dest[0] = x;
+ dest[1] = y;
+ dest[2] = z;
+ vcount++;
+}
+
+btScalar GetDist(btScalar px,btScalar py,btScalar pz,const btScalar *p2);
+btScalar GetDist(btScalar px,btScalar py,btScalar pz,const btScalar *p2)
+{
+
+ btScalar dx = px - p2[0];
+ btScalar dy = py - p2[1];
+ btScalar dz = pz - p2[2];
+
+ return dx*dx+dy*dy+dz*dz;
+}
+
+
+
+bool HullLibrary::CleanupVertices(unsigned int svcount,
+ const btVector3 *svertices,
+ unsigned int stride,
+ unsigned int &vcount, // output number of vertices
+ btVector3 *vertices, // location to store the results.
+ btScalar normalepsilon,
+ btVector3& scale)
+{
+ if ( svcount == 0 ) return false;
+
+ m_vertexIndexMapping.resize(0);
+
+
+#define EPSILON btScalar(0.000001) /* close enough to consider two btScalaring point numbers to be 'the same'. */
+
+ vcount = 0;
+
+ btScalar recip[3]={0.f,0.f,0.f};
+
+ if ( scale )
+ {
+ scale[0] = 1;
+ scale[1] = 1;
+ scale[2] = 1;
+ }
+
+ btScalar bmin[3] = { FLT_MAX, FLT_MAX, FLT_MAX };
+ btScalar bmax[3] = { -FLT_MAX, -FLT_MAX, -FLT_MAX };
+
+ const char *vtx = (const char *) svertices;
+
+// if ( 1 )
+ {
+ for (unsigned int i=0; i<svcount; i++)
+ {
+ const btScalar *p = (const btScalar *) vtx;
+
+ vtx+=stride;
+
+ for (int j=0; j<3; j++)
+ {
+ if ( p[j] < bmin[j] ) bmin[j] = p[j];
+ if ( p[j] > bmax[j] ) bmax[j] = p[j];
+ }
+ }
+ }
+
+ btScalar dx = bmax[0] - bmin[0];
+ btScalar dy = bmax[1] - bmin[1];
+ btScalar dz = bmax[2] - bmin[2];
+
+ btVector3 center;
+
+ center[0] = dx*btScalar(0.5) + bmin[0];
+ center[1] = dy*btScalar(0.5) + bmin[1];
+ center[2] = dz*btScalar(0.5) + bmin[2];
+
+ if ( dx < EPSILON || dy < EPSILON || dz < EPSILON || svcount < 3 )
+ {
+
+ btScalar len = FLT_MAX;
+
+ if ( dx > EPSILON && dx < len ) len = dx;
+ if ( dy > EPSILON && dy < len ) len = dy;
+ if ( dz > EPSILON && dz < len ) len = dz;
+
+ if ( len == FLT_MAX )
+ {
+ dx = dy = dz = btScalar(0.01); // one centimeter
+ }
+ else
+ {
+ if ( dx < EPSILON ) dx = len * btScalar(0.05); // 1/5th the shortest non-zero edge.
+ if ( dy < EPSILON ) dy = len * btScalar(0.05);
+ if ( dz < EPSILON ) dz = len * btScalar(0.05);
+ }
+
+ btScalar x1 = center[0] - dx;
+ btScalar x2 = center[0] + dx;
+
+ btScalar y1 = center[1] - dy;
+ btScalar y2 = center[1] + dy;
+
+ btScalar z1 = center[2] - dz;
+ btScalar z2 = center[2] + dz;
+
+ addPoint(vcount,vertices,x1,y1,z1);
+ addPoint(vcount,vertices,x2,y1,z1);
+ addPoint(vcount,vertices,x2,y2,z1);
+ addPoint(vcount,vertices,x1,y2,z1);
+ addPoint(vcount,vertices,x1,y1,z2);
+ addPoint(vcount,vertices,x2,y1,z2);
+ addPoint(vcount,vertices,x2,y2,z2);
+ addPoint(vcount,vertices,x1,y2,z2);
+
+ return true; // return cube
+
+
+ }
+ else
+ {
+ if ( scale )
+ {
+ scale[0] = dx;
+ scale[1] = dy;
+ scale[2] = dz;
+
+ recip[0] = 1 / dx;
+ recip[1] = 1 / dy;
+ recip[2] = 1 / dz;
+
+ center[0]*=recip[0];
+ center[1]*=recip[1];
+ center[2]*=recip[2];
+
+ }
+
+ }
+
+
+
+ vtx = (const char *) svertices;
+
+ for (unsigned int i=0; i<svcount; i++)
+ {
+ const btVector3 *p = (const btVector3 *)vtx;
+ vtx+=stride;
+
+ btScalar px = p->getX();
+ btScalar py = p->getY();
+ btScalar pz = p->getZ();
+
+ if ( scale )
+ {
+ px = px*recip[0]; // normalize
+ py = py*recip[1]; // normalize
+ pz = pz*recip[2]; // normalize
+ }
+
+// if ( 1 )
+ {
+ unsigned int j;
+
+ for (j=0; j<vcount; j++)
+ {
+ /// XXX might be broken
+ btVector3& v = vertices[j];
+
+ btScalar x = v[0];
+ btScalar y = v[1];
+ btScalar z = v[2];
+
+ btScalar dx = btFabs(x - px );
+ btScalar dy = btFabs(y - py );
+ btScalar dz = btFabs(z - pz );
+
+ if ( dx < normalepsilon && dy < normalepsilon && dz < normalepsilon )
+ {
+ // ok, it is close enough to the old one
+ // now let us see if it is further from the center of the point cloud than the one we already recorded.
+ // in which case we keep this one instead.
+
+ btScalar dist1 = GetDist(px,py,pz,center);
+ btScalar dist2 = GetDist(v[0],v[1],v[2],center);
+
+ if ( dist1 > dist2 )
+ {
+ v[0] = px;
+ v[1] = py;
+ v[2] = pz;
+
+ }
+
+ break;
+ }
+ }
+
+ if ( j == vcount )
+ {
+ btVector3& dest = vertices[vcount];
+ dest[0] = px;
+ dest[1] = py;
+ dest[2] = pz;
+ vcount++;
+ }
+ m_vertexIndexMapping.push_back(j);
+ }
+ }
+
+ // ok..now make sure we didn't prune so many vertices it is now invalid.
+// if ( 1 )
+ {
+ btScalar bmin[3] = { FLT_MAX, FLT_MAX, FLT_MAX };
+ btScalar bmax[3] = { -FLT_MAX, -FLT_MAX, -FLT_MAX };
+
+ for (unsigned int i=0; i<vcount; i++)
+ {
+ const btVector3& p = vertices[i];
+ for (int j=0; j<3; j++)
+ {
+ if ( p[j] < bmin[j] ) bmin[j] = p[j];
+ if ( p[j] > bmax[j] ) bmax[j] = p[j];
+ }
+ }
+
+ btScalar dx = bmax[0] - bmin[0];
+ btScalar dy = bmax[1] - bmin[1];
+ btScalar dz = bmax[2] - bmin[2];
+
+ if ( dx < EPSILON || dy < EPSILON || dz < EPSILON || vcount < 3)
+ {
+ btScalar cx = dx*btScalar(0.5) + bmin[0];
+ btScalar cy = dy*btScalar(0.5) + bmin[1];
+ btScalar cz = dz*btScalar(0.5) + bmin[2];
+
+ btScalar len = FLT_MAX;
+
+ if ( dx >= EPSILON && dx < len ) len = dx;
+ if ( dy >= EPSILON && dy < len ) len = dy;
+ if ( dz >= EPSILON && dz < len ) len = dz;
+
+ if ( len == FLT_MAX )
+ {
+ dx = dy = dz = btScalar(0.01); // one centimeter
+ }
+ else
+ {
+ if ( dx < EPSILON ) dx = len * btScalar(0.05); // 1/5th the shortest non-zero edge.
+ if ( dy < EPSILON ) dy = len * btScalar(0.05);
+ if ( dz < EPSILON ) dz = len * btScalar(0.05);
+ }
+
+ btScalar x1 = cx - dx;
+ btScalar x2 = cx + dx;
+
+ btScalar y1 = cy - dy;
+ btScalar y2 = cy + dy;
+
+ btScalar z1 = cz - dz;
+ btScalar z2 = cz + dz;
+
+ vcount = 0; // add box
+
+ addPoint(vcount,vertices,x1,y1,z1);
+ addPoint(vcount,vertices,x2,y1,z1);
+ addPoint(vcount,vertices,x2,y2,z1);
+ addPoint(vcount,vertices,x1,y2,z1);
+ addPoint(vcount,vertices,x1,y1,z2);
+ addPoint(vcount,vertices,x2,y1,z2);
+ addPoint(vcount,vertices,x2,y2,z2);
+ addPoint(vcount,vertices,x1,y2,z2);
+
+ return true;
+ }
+ }
+
+ return true;
+}
+
+void HullLibrary::BringOutYourDead(const btVector3* verts,unsigned int vcount, btVector3* overts,unsigned int &ocount,unsigned int *indices,unsigned indexcount)
+{
+ btAlignedObjectArray<int>tmpIndices;
+ tmpIndices.resize(m_vertexIndexMapping.size());
+ int i;
+
+ for (i=0;i<m_vertexIndexMapping.size();i++)
+ {
+ tmpIndices[i] = m_vertexIndexMapping[i];
+ }
+
+ TUIntArray usedIndices;
+ usedIndices.resize(static_cast<int>(vcount));
+ memset(&usedIndices[0],0,sizeof(unsigned int)*vcount);
+
+ ocount = 0;
+
+ for (i=0; i<int (indexcount); i++)
+ {
+ unsigned int v = indices[i]; // original array index
+
+ btAssert( v >= 0 && v < vcount );
+
+ if ( usedIndices[static_cast<int>(v)] ) // if already remapped
+ {
+ indices[i] = usedIndices[static_cast<int>(v)]-1; // index to new array
+ }
+ else
+ {
+
+ indices[i] = ocount; // new index mapping
+
+ overts[ocount][0] = verts[v][0]; // copy old vert to new vert array
+ overts[ocount][1] = verts[v][1];
+ overts[ocount][2] = verts[v][2];
+
+ for (int k=0;k<m_vertexIndexMapping.size();k++)
+ {
+ if (tmpIndices[k]==int(v))
+ m_vertexIndexMapping[k]=ocount;
+ }
+
+ ocount++; // increment output vert count
+
+ btAssert( ocount >=0 && ocount <= vcount );
+
+ usedIndices[static_cast<int>(v)] = ocount; // assign new index remapping
+
+
+ }
+ }
+
+
+}