bool HybridModel::Build(const OPCODECREATE& create)
{
// 1) Checkings
if(!create.mIMesh || !create.mIMesh->IsValid()) return false;
// Look for degenerate faces.
udword NbDegenerate = create.mIMesh->CheckTopology();
if(NbDegenerate) OpcodeLog("OPCODE WARNING: found %d degenerate faces in model! Collision might report wrong results!\n", NbDegenerate);
// We continue nonetheless....
Release(); // Make sure previous tree has been discarded
// 1-1) Setup mesh interface automatically
SetMeshInterface(create.mIMesh);
bool Status = false;
AABBTree* LeafTree = null;
Internal Data;
// 2) Build a generic AABB Tree.
mSource = new AABBTree;
CHECKALLOC(mSource);
// 2-1) Setup a builder. Our primitives here are triangles from input mesh,
// so we use an AABBTreeOfTrianglesBuilder.....
{
AABBTreeOfTrianglesBuilder TB;
TB.mIMesh = create.mIMesh;
TB.mNbPrimitives = create.mIMesh->GetNbTriangles();
TB.mSettings = create.mSettings;
TB.mSettings.mLimit = 16; // ### Hardcoded, but maybe we could let the user choose 8 / 16 / 32 ...
if(!mSource->Build(&TB)) goto FreeAndExit;
}
// 2-2) Here's the trick : create *another* AABB tree using the leaves of the first one (which are boxes, this time)
struct Local
{
// A callback to count leaf nodes
static bool CountLeaves(const AABBTreeNode* current, udword depth, void* user_data)
{
if(current->IsLeaf())
{
Internal* Data = (Internal*)user_data;
Data->mNbLeaves++;
}
return true;
}
// A callback to setup leaf nodes in our internal structures
static bool SetupLeafData(const AABBTreeNode* current, udword depth, void* user_data)
{
if(current->IsLeaf())
{
Internal* Data = (Internal*)user_data;
// Get current leaf's box
Data->mLeaves[Data->mNbLeaves] = *current->GetAABB();
// Setup leaf data
udword Index = (size_t(current->GetPrimitives()) - size_t(Data->mBase)) / sizeof(size_t);
Data->mTriangles[Data->mNbLeaves].SetData(current->GetNbPrimitives(), Index);
Data->mNbLeaves++;
}
return true;
}
};
// Walk the tree & count number of leaves
Data.mNbLeaves = 0;
mSource->Walk(Local::CountLeaves, &Data);
mNbLeaves = Data.mNbLeaves; // Keep track of it
// Special case for 1-leaf meshes
if(mNbLeaves==1)
{
mModelCode |= OPC_SINGLE_NODE;
Status = true;
goto FreeAndExit;
}
// Allocate our structures
Data.mLeaves = new IceMaths::AABB[Data.mNbLeaves];
CHECKALLOC(Data.mLeaves);
mTriangles = new LeafTriangles[Data.mNbLeaves];
CHECKALLOC(mTriangles);
// Walk the tree again & setup leaf data
Data.mTriangles = mTriangles;
Data.mBase = mSource->GetIndices();
Data.mNbLeaves = 0; // Reset for incoming walk
mSource->Walk(Local::SetupLeafData, &Data);
// Handle source indices
{
bool MustKeepIndices = true;
if(create.mCanRemap)
{
// We try to get rid of source indices (saving more ram!) by reorganizing triangle arrays...
// Remap can fail when we use callbacks => keep track of indices in that case (it still
// works, only using more memory)
if(create.mIMesh->RemapClient(mSource->GetNbPrimitives(), mSource->GetIndices()))
{
MustKeepIndices = false;
}
}
if(MustKeepIndices)
{
// Keep track of source indices (from vanilla tree)
mNbPrimitives = mSource->GetNbPrimitives();
mIndices = new udword[mNbPrimitives];
CopyMemory(mIndices, mSource->GetIndices(), mNbPrimitives*sizeof(udword));
}
}
// Now, create our optimized tree using previous leaf nodes
LeafTree = new AABBTree;
CHECKALLOC(LeafTree);
{
AABBTreeOfAABBsBuilder TB; // Now using boxes !
TB.mSettings = create.mSettings;
TB.mSettings.mLimit = 1; // We now want a complete tree so that we can "optimize" it
TB.mNbPrimitives = Data.mNbLeaves;
TB.mAABBArray = Data.mLeaves;
if(!LeafTree->Build(&TB)) goto FreeAndExit;
}
// 3) Create an optimized tree according to user-settings
if(!CreateTree(create.mNoLeaf, create.mQuantized)) goto FreeAndExit;
// 3-2) Create optimized tree
if(!mTree->Build(LeafTree)) goto FreeAndExit;
// Finally ok...
Status = true;
FreeAndExit: // Allow me this one...
DELETESINGLE(LeafTree);
// 3-3) Delete generic tree if needed
if(!create.mKeepOriginal) DELETESINGLE(mSource);
return Status;
}
