Torque3D/Engine/lib/opcode/OPC_Model.cpp

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/*
 *	OPCODE - Optimized Collision Detection
 *	Copyright (C) 2001 Pierre Terdiman
 *	Homepage: http://www.codercorner.com/Opcode.htm
 */
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/**
 *	Contains code for OPCODE models.
 *	\file		OPC_Model.cpp
 *	\author		Pierre Terdiman
 *	\date		March, 20, 2001
 */
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/**
 *	The main collision wrapper, for all trees. Supported trees are:
 *	- Normal trees (2*N-1 nodes, full size)
 *	- No-leaf trees (N-1 nodes, full size)
 *	- Quantized trees (2*N-1 nodes, half size)
 *	- Quantized no-leaf trees (N-1 nodes, half size)
 *
 *	Usage:
 *
 *	1) Create a static mesh interface using callbacks or pointers. (see OPC_MeshInterface.cpp).
 *	Keep it around in your app, since a pointer to this interface is saved internally and
 *	used until you release the collision structures.
 *
 *	2) Build a Model using a creation structure:
 *
 *	\code
 *		Model Sample;
 *
 *		OPCODECREATE OPCC;
 *		OPCC.IMesh			= ...;
 *		OPCC.Rules			= ...;
 *		OPCC.NoLeaf			= ...;
 *		OPCC.Quantized		= ...;
 *		OPCC.KeepOriginal	= ...;
 *		bool Status = Sample.Build(OPCC);
 *	\endcode
 *
 *	3) Create a tree collider and set it up:
 *
 *	\code
 *		AABBTreeCollider TC;
 *		TC.SetFirstContact(...);
 *		TC.SetFullBoxBoxTest(...);
 *		TC.SetFullPrimBoxTest(...);
 *		TC.SetTemporalCoherence(...);
 *	\endcode
 *
 *	4) Perform a collision query
 *
 *	\code
 *		// Setup cache
 *		static BVTCache ColCache;
 *		ColCache.Model0 = &Model0;
 *		ColCache.Model1 = &Model1;
 *
 *		// Collision query
 *		bool IsOk = TC.Collide(ColCache, World0, World1);
 *
 *		// Get collision status => if true, objects overlap
 *		BOOL Status = TC.GetContactStatus();
 *
 *		// Number of colliding pairs and list of pairs
 *		udword NbPairs = TC.GetNbPairs();
 *		const Pair* p = TC.GetPairs()
 *	\endcode
 *
 *	5) Stats
 *
 *	\code
 *		Model0.GetUsedBytes()	= number of bytes used for this collision tree
 *		TC.GetNbBVBVTests()		= number of BV-BV overlap tests performed during last query
 *		TC.GetNbPrimPrimTests()	= number of Triangle-Triangle overlap tests performed during last query
 *		TC.GetNbBVPrimTests()	= number of Triangle-BV overlap tests performed during last query
 *	\endcode
 *
 *	\class		Model
 *	\author		Pierre Terdiman
 *	\version	1.3
 *	\date		March, 20, 2001
*/
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#include "Opcode.h"

using namespace Opcode;

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/**
 *	Constructor.
 */
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Model::Model()
{
#ifdef __MESHMERIZER_H__	// Collision hulls only supported within ICE !
	mHull	= null;
#endif // __MESHMERIZER_H__
}

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/**
 *	Destructor.
 */
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Model::~Model()
{
	Release();
}

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/**
 *	Releases the model.
 */
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void Model::Release()
{
	ReleaseBase();
#ifdef __MESHMERIZER_H__	// Collision hulls only supported within ICE !
	DELETESINGLE(mHull);
#endif // __MESHMERIZER_H__
}

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/**
 *	Builds a collision model.
 *	\param		create		[in] model creation structure
 *	\return		true if success
 */
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bool Model::Build(const OPCODECREATE& create)
{
	// 1) Checkings
	if(!create.mIMesh || !create.mIMesh->IsValid())	return false;

	// For this model, we only support complete trees
	if(create.mSettings.mLimit!=1)	return SetIceError("OPCODE WARNING: supports complete trees only! Use mLimit = 1.\n", null);

	// Look for degenerate faces.
	udword NbDegenerate = create.mIMesh->CheckTopology();
	if(NbDegenerate)	Log("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 [Opcode 1.3, thanks Adam]

	// 1-1) Setup mesh interface automatically [Opcode 1.3]
	SetMeshInterface(create.mIMesh);

	// Special case for 1-triangle meshes [Opcode 1.3]
	udword NbTris = create.mIMesh->GetNbTriangles();
	if(NbTris==1)
	{
		// We don't need to actually create a tree here, since we'll only have a single triangle to deal with anyway.
		// It's a waste to use a "model" for this but at least it will work.
		mModelCode |= OPC_SINGLE_NODE;
		return true;
	}

	// 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.mSettings		= create.mSettings;
		TB.mNbPrimitives	= NbTris;
		if(!mSource->Build(&TB))	return false;
	}

	// 3) Create an optimized tree according to user-settings
	if(!CreateTree(create.mNoLeaf, create.mQuantized))	return false;

	// 3-2) Create optimized tree
	if(!mTree->Build(mSource))	return false;

	// 3-3) Delete generic tree if needed
	if(!create.mKeepOriginal)	DELETESINGLE(mSource);

#ifdef __MESHMERIZER_H__
	// 4) Convex hull
	if(create.mCollisionHull)
	{
		// Create hull
		mHull = new CollisionHull;
		CHECKALLOC(mHull);

		CONVEXHULLCREATE CHC;
		// ### doesn't work with strides
		CHC.NbVerts			= create.mIMesh->GetNbVertices();
		CHC.Vertices		= create.mIMesh->GetVerts();
		CHC.UnifyNormals	= true;
		CHC.ReduceVertices	= true;
		CHC.WordFaces		= false;
		mHull->Compute(CHC);
	}
#endif // __MESHMERIZER_H__

	return true;
}

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/**
 *	Gets the number of bytes used by the tree.
 *	\return		amount of bytes used
 */
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udword Model::GetUsedBytes() const
{
	if(!mTree)	return 0;
	return mTree->GetUsedBytes();
}