CHull * ConvexBuilder::canMerge(CHull *a,CHull *b)
{
if ( !a->overlap(*b) ) return 0; // if their AABB's (with a little slop) don't overlap, then return.
CHull *ret = 0;
// ok..we are going to combine both meshes into a single mesh
// and then we are going to compute the concavity...
VertexLookup vc = Vl_createVertexLookup();
UintVector indices;
getMesh( *a->mResult, vc, indices );
getMesh( *b->mResult, vc, indices );
unsigned int vcount = Vl_getVcount(vc);
const float *vertices = Vl_getVertices(vc);
unsigned int tcount = indices.size()/3;
//don't do anything if hull is empty
if (!tcount)
{
Vl_releaseVertexLookup (vc);
return 0;
}
HullResult hresult;
HullLibrary hl;
HullDesc desc;
desc.SetHullFlag(QF_TRIANGLES);
desc.mVcount = vcount;
desc.mVertices = vertices;
desc.mVertexStride = sizeof(float)*3;
HullError hret = hl.CreateConvexHull(desc,hresult);
if ( hret == QE_OK )
{
float combineVolume = computeMeshVolume( hresult.mOutputVertices, hresult.mNumFaces, hresult.mIndices );
float sumVolume = a->mVolume + b->mVolume;
float percent = (sumVolume*100) / combineVolume;
if ( percent >= (100.0f-MERGE_PERCENT) )
{
ConvexResult cr(hresult.mNumOutputVertices, hresult.mOutputVertices, hresult.mNumFaces, hresult.mIndices);
ret = new CHull(cr);
}
}
Vl_releaseVertexLookup(vc);
return ret;
}
void addTri(VertexLookup vl,UintVector &list,const Vector3d &p1,const Vector3d &p2,const Vector3d &p3)
{
unsigned int i1 = Vl_getIndex(vl, p1.Ptr() );
unsigned int i2 = Vl_getIndex(vl, p2.Ptr() );
unsigned int i3 = Vl_getIndex(vl, p3.Ptr() );
// do *not* process degenerate triangles!
if ( i1 != i2 && i1 != i3 && i2 != i3 )
{
list.push_back(i1);
list.push_back(i2);
list.push_back(i3);
}
}
void ConvexBuilder::getMesh(const ConvexResult &cr,VertexLookup vc,UintVector &indices)
{
unsigned int *src = cr.mHullIndices;
for (unsigned int i=0; i<cr.mHullTcount; i++)
{
unsigned int i1 = *src++;
unsigned int i2 = *src++;
unsigned int i3 = *src++;
const float *p1 = &cr.mHullVertices[i1*3];
const float *p2 = &cr.mHullVertices[i2*3];
const float *p3 = &cr.mHullVertices[i3*3];
i1 = Vl_getIndex(vc,p1);
i2 = Vl_getIndex(vc,p2);
i3 = Vl_getIndex(vc,p3);
#if 0
bool duplicate = false;
unsigned int tcount = indices.size()/3;
for (unsigned int j=0; j<tcount; j++)
{
unsigned int ci1 = indices[j*3+0];
unsigned int ci2 = indices[j*3+1];
unsigned int ci3 = indices[j*3+2];
if ( isDuplicate(i1,i2,i3, ci1, ci2, ci3 ) )
{
duplicate = true;
break;
}
}
if ( !duplicate )
{
indices.push_back(i1);
indices.push_back(i2);
indices.push_back(i3);
}
#endif
}
}
void calcConvexDecomposition(unsigned int vcount,
const float *vertices,
unsigned int tcount,
const unsigned int *indices,
ConvexDecompInterface *callback,
float masterVolume,
unsigned int depth)
{
float plane[4];
bool split = false;
if ( depth < MAXDEPTH )
{
float volume;
float c = computeConcavity( vcount, vertices, tcount, indices, callback, plane, volume );
if ( depth == 0 )
{
masterVolume = volume;
}
float percent = (c*100.0f)/masterVolume;
if ( percent > CONCAVE_PERCENT ) // if great than 5% of the total volume is concave, go ahead and keep splitting.
{
split = true;
}
}
if ( depth >= MAXDEPTH || !split )
{
#if 1
HullResult result;
HullLibrary hl;
HullDesc desc;
desc.SetHullFlag(QF_TRIANGLES);
desc.mVcount = vcount;
desc.mVertices = vertices;
desc.mVertexStride = sizeof(float)*3;
HullError ret = hl.CreateConvexHull(desc,result);
if ( ret == QE_OK )
{
ConvexResult r(result.mNumOutputVertices, result.mOutputVertices, result.mNumFaces, result.mIndices);
callback->ConvexDecompResult(r);
}
#else
static unsigned int colors[8] =
{
0xFF0000,
0x00FF00,
0x0000FF,
0xFFFF00,
0x00FFFF,
0xFF00FF,
0xFFFFFF,
0xFF8040
};
static int count = 0;
count++;
if ( count == 8 ) count = 0;
assert( count >= 0 && count < 8 );
unsigned int color = colors[count];
const unsigned int *source = indices;
for (unsigned int i=0; i<tcount; i++)
{
unsigned int i1 = *source++;
unsigned int i2 = *source++;
unsigned int i3 = *source++;
FaceTri t(vertices, i1, i2, i3 );
callback->ConvexDebugTri( t.mP1.Ptr(), t.mP2.Ptr(), t.mP3.Ptr(), color );
}
#endif
return;
}
UintVector ifront;
UintVector iback;
VertexLookup vfront = Vl_createVertexLookup();
VertexLookup vback = Vl_createVertexLookup();
bool showmesh = false;
#if SHOW_MESH
showmesh = true;
#endif
if ( 0 )
{
showmesh = true;
for (float x=-1; x<1; x+=0.10f)
{
for (float y=0; y<1; y+=0.10f)
{
for (float z=-1; z<1; z+=0.04f)
{
float d = x*plane[0] + y*plane[1] + z*plane[2] + plane[3];
Vector3d p(x,y,z);
if ( d >= 0 )
callback->ConvexDebugPoint(p.Ptr(), 0.02f, 0x00FF00);
else
callback->ConvexDebugPoint(p.Ptr(), 0.02f, 0xFF0000);
}
}
}
}
if ( 1 )
{
// ok..now we are going to 'split' all of the input triangles against this plane!
const unsigned int *source = indices;
for (unsigned int i=0; i<tcount; i++)
{
unsigned int i1 = *source++;
unsigned int i2 = *source++;
unsigned int i3 = *source++;
FaceTri t(vertices, i1, i2, i3 );
Vector3d front[4];
Vector3d back[4];
unsigned int fcount=0;
unsigned int bcount=0;
PlaneTriResult result;
result = planeTriIntersection(plane,t.mP1.Ptr(),sizeof(Vector3d),0.00001f,front[0].Ptr(),fcount,back[0].Ptr(),bcount );
if( fcount > 4 || bcount > 4 )
{
result = planeTriIntersection(plane,t.mP1.Ptr(),sizeof(Vector3d),0.00001f,front[0].Ptr(),fcount,back[0].Ptr(),bcount );
}
switch ( result )
{
case PTR_FRONT:
assert( fcount == 3 );
if ( showmesh )
callback->ConvexDebugTri( front[0].Ptr(), front[1].Ptr(), front[2].Ptr(), 0x00FF00 );
#if MAKE_MESH
addTri( vfront, ifront, front[0], front[1], front[2] );
#endif
break;
case PTR_BACK:
assert( bcount == 3 );
if ( showmesh )
callback->ConvexDebugTri( back[0].Ptr(), back[1].Ptr(), back[2].Ptr(), 0xFFFF00 );
#if MAKE_MESH
addTri( vback, iback, back[0], back[1], back[2] );
#endif
break;
case PTR_SPLIT:
assert( fcount >= 3 && fcount <= 4);
assert( bcount >= 3 && bcount <= 4);
#if MAKE_MESH
addTri( vfront, ifront, front[0], front[1], front[2] );
addTri( vback, iback, back[0], back[1], back[2] );
if ( fcount == 4 )
{
addTri( vfront, ifront, front[0], front[2], front[3] );
}
if ( bcount == 4 )
{
addTri( vback, iback, back[0], back[2], back[3] );
}
#endif
if ( showmesh )
{
callback->ConvexDebugTri( front[0].Ptr(), front[1].Ptr(), front[2].Ptr(), 0x00D000 );
callback->ConvexDebugTri( back[0].Ptr(), back[1].Ptr(), back[2].Ptr(), 0xD0D000 );
if ( fcount == 4 )
{
callback->ConvexDebugTri( front[0].Ptr(), front[2].Ptr(), front[3].Ptr(), 0x00D000 );
}
if ( bcount == 4 )
{
callback->ConvexDebugTri( back[0].Ptr(), back[2].Ptr(), back[3].Ptr(), 0xD0D000 );
}
}
break;
}
}
unsigned int fsize = ifront.size()/3;
unsigned int bsize = iback.size()/3;
// ok... here we recursively call
if ( ifront.size() )
{
unsigned int vcount = Vl_getVcount(vfront);
const float *vertices = Vl_getVertices(vfront);
unsigned int tcount = ifront.size()/3;
calcConvexDecomposition(vcount, vertices, tcount, &ifront[0], callback, masterVolume, depth+1);
}
ifront.clear();
Vl_releaseVertexLookup(vfront);
if ( iback.size() )
{
unsigned int vcount = Vl_getVcount(vback);
const float *vertices = Vl_getVertices(vback);
unsigned int tcount = iback.size()/3;
calcConvexDecomposition(vcount, vertices, tcount, &iback[0], callback, masterVolume, depth+1);
}
iback.clear();
Vl_releaseVertexLookup(vback);
}
}