/**
* Merge a set of faces removing the vertex index v.
* @param faces set of faces
* @param oldFaces set of old faces obtained from the merge
* @param newFaces set of new faces obtained from the merge
* @param vertices sequence of indexs (v1 ... vi = v ... vn) where :
* v is the current vertex to test,
* vj (j < i) are tested vertices,
* vk (k >= i) are vertices required to test to merge vj
* (so if a vertex vk can't be merged, the merge is not possible).
* @param v vertex index
* @return true if the merge is succesful, false otherwise
*/
bool BOP_Merge::mergeFaces(BOP_Faces &faces, BOP_Faces &oldFaces, BOP_Faces &newFaces, BOP_Indexs &vertices, BOP_Index v)
{
bool merged = false;
if (faces.size() == 2) {
// Merge a pair of faces into a new face without v
BOP_Face *faceI = faces[0];
BOP_Face *faceJ = faces[1];
BOP_Face *faceK = mergeFaces(faceI,faceJ,vertices,v);
if (faceK != NULL) {
newFaces.push_back(faceK);
oldFaces.push_back(faceI);
oldFaces.push_back(faceJ);
merged = true;
}
else merged = false;
}
else if (faces.size() == 4) {
// Merge two pair of faces into a new pair without v
// First we try to perform a simplify merge to avoid more pending vertices
// (for example, if we have two triangles and two quads it will be better
// to do 3+4 and 3+4 than 3+3 and 4+4)
BOP_Face *oldFace1 = faces[0];
BOP_Face *oldFace2, *newFace1;
unsigned int indexJ = 1;
while (indexJ < faces.size() && !merged) {
oldFace2 = faces[indexJ];
newFace1 = mergeFaces(oldFace1,oldFace2,v);
if (newFace1 != NULL) merged = true;
else indexJ++;
}
if (merged) {
// Merge the other pair of faces
unsigned int indexK, indexL;
if (indexJ == 1) {indexK = 2;indexL = 3;}
else if (indexJ == 2) {indexK = 1;indexL = 3;}
else {indexK = 1;indexL = 2;}
BOP_Face *oldFace3 = faces[indexK];
BOP_Face *oldFace4 = faces[indexL];
unsigned int oldSize = vertices.size();
BOP_Face *newFace2 = mergeFaces(oldFace3,oldFace4,vertices,v);
if (newFace2 != NULL) {
newFaces.push_back(newFace1);
newFaces.push_back(newFace2);
oldFaces.push_back(oldFace1);
oldFaces.push_back(oldFace2);
oldFaces.push_back(oldFace3);
oldFaces.push_back(oldFace4);
merged = true;
}
else {
// Undo all changes
delete newFace1;
merged = false;
unsigned int count = vertices.size() - oldSize;
if (count != 0)
vertices.erase(vertices.end() - count, vertices.end());
}
}
if (!merged) {
// Try a complete merge
merged = true;
while (faces.size()>0 && merged) {
indexJ = 1;
BOP_Face *faceI = faces[0];
merged = false;
while (indexJ < faces.size()) {
BOP_Face *faceJ = faces[indexJ];
BOP_Face *faceK = mergeFaces(faceI,faceJ,vertices,v);
if (faceK != NULL) {
// faceK = faceI + faceJ and it does not include v!
faces.erase(faces.begin()+indexJ,faces.begin()+(indexJ+1));
faces.erase(faces.begin(),faces.begin()+1);
newFaces.push_back(faceK);
oldFaces.push_back(faceI);
oldFaces.push_back(faceJ);
merged = true;
break;
}
else indexJ++;
}
}
}
}
else merged = false; // there are N=1 or N=3 or N>4 faces!
// Return merge result
return merged;
}
/**
* Simplifies a mesh, merging the faces with the specified vertices.
* @param mergeVertices vertices to test
* @return true if a face merge was performed
*/
bool BOP_Merge::mergeFaces(BOP_Indexs &mergeVertices)
{
// Check size > 0!
if (mergeVertices.size() == 0) return false;
// New faces added by merge
BOP_Faces newFaces;
// Old faces removed by merge
BOP_Faces oldFaces;
// Get the first vertex index and add it to
// the current pending vertices to merge
BOP_Index v = mergeVertices[0];
BOP_Indexs pendingVertices;
pendingVertices.push_back(v);
// Get faces with index v that come from the same original face
BOP_LFaces facesByOriginalFace;
getFaces(facesByOriginalFace,v);
bool merged = true;
// Check it has any unbroken face
if (facesByOriginalFace.size()==0) {
// v has not any unbroken face (so it's a new BROKEN vertex)
(m_mesh->getVertex(v))->setTAG(BROKEN);
merged = false;
}
// Merge vertex faces
const BOP_IT_LFaces facesEnd = facesByOriginalFace.end();
for(BOP_IT_LFaces facesByOriginalFaceX = facesByOriginalFace.begin();
(facesByOriginalFaceX != facesEnd)&&merged;
facesByOriginalFaceX++) {
merged = mergeFaces((*facesByOriginalFaceX),oldFaces,newFaces,pendingVertices,v);
}
// Check if the are some pendingVertices to merge
if (pendingVertices.size() > 1 && merged) {
// There are pending vertices that we need to merge in order to merge v ...
for(unsigned int i=1;i<pendingVertices.size() && merged;i++)
merged = mergeFaces(oldFaces,newFaces,pendingVertices,pendingVertices[i]);
}
// If merge was succesful ...
if (merged) {
// Set old faces to BROKEN...
const BOP_IT_Faces oldFacesEnd = oldFaces.end();
for(BOP_IT_Faces face=oldFaces.begin();face!=oldFacesEnd;face++)
(*face)->setTAG(BROKEN);
// ... and add merged faces (that are the new merged faces without pending vertices)
const BOP_IT_Faces newFacesEnd = newFaces.end();
for(BOP_IT_Faces newFace=newFaces.begin();newFace!=newFacesEnd;newFace++) {
m_mesh->addFace(*newFace);
// Also, add new face vertices to the queue of vertices to merge if they weren't
for(BOP_Index i = 0;i<(*newFace)->size();i++) {
BOP_Index vertexIndex = (*newFace)->getVertex(i);
if (vertexIndex >= m_firstVertex && !containsIndex(mergeVertices,vertexIndex))
mergeVertices.push_back(vertexIndex);
}
}
// Set the merged vertices to BROKEN ...
const BOP_IT_Indexs pendingEnd = pendingVertices.end();
for(BOP_IT_Indexs pendingVertex = pendingVertices.begin(); pendingVertex != pendingEnd;pendingVertex++) {
BOP_Index pV = *pendingVertex;
m_mesh->getVertex(pV)->setTAG(BROKEN);
// ... and remove them from mergeVertices queue
const BOP_IT_Indexs mergeEnd = mergeVertices.end();
for(BOP_IT_Indexs mergeVertex = mergeVertices.begin(); mergeVertex != mergeEnd;mergeVertex++) {
BOP_Index mV = *mergeVertex;
if (mV == pV) {
mergeVertices.erase(mergeVertex);
break;
}
}
}
}
else {
// The merge was not succesful, remove the vertex frome merge vertices queue
mergeVertices.erase(mergeVertices.begin());
// free the not used newfaces
const BOP_IT_Faces newFacesEnd = newFaces.end();
for(BOP_IT_Faces newFace=newFaces.begin();newFace!=newFacesEnd;newFace++) {
delete (*newFace);
}
}
// Invoke mergeFaces and return the merge result
return (mergeFaces(mergeVertices) || merged);
}
