OPC_SphereCollider.cpp

Go to the documentation of this file.

/*
 *      OPCODE - Optimized Collision Detection
 *      Copyright (C) 2001 Pierre Terdiman
 *      Homepage: http://www.codercorner.com/Opcode.htm
 */





// Precompiled Header
#include "Stdafx.h"

using namespace Opcode;

#include "OPC_SphereAABBOverlap.h"
#include "OPC_SphereTriOverlap.h"

#define SET_CONTACT(prim_index, flag)                                                                   \
        /* Set contact status */                                                                                        \
        mFlags |= flag;                                                                                                         \
        mTouchedPrimitives->Add(prim_index);

#define SPHERE_PRIM(prim_index, flag)                                                                   \
        /* Request vertices from the app */                                                                     \
        VertexPointers VP;      mIMesh->GetTriangle(VP, prim_index);                    \
                                                                                                                                                \
        /* Perform sphere-tri overlap test */                                                           \
        if(SphereTriOverlap(*VP.Vertex[0], *VP.Vertex[1], *VP.Vertex[2]))       \
        {                                                                                                                                       \
                SET_CONTACT(prim_index, flag)                                                                   \
        }


SphereCollider::SphereCollider()
{
        mCenter.Zero();
        mRadius2 = 0.0f;
}


SphereCollider::~SphereCollider()
{
}


bool SphereCollider::Collide(SphereCache& cache, const Sphere& sphere, const Model& model, const Matrix4x4* worlds, const Matrix4x4* worldm)
{
        // Checkings
        if(!Setup(&model))      return false;

        // Init collision query
        if(InitQuery(cache, sphere, worlds, worldm))    return true;

        if(!model.HasLeafNodes())
        {
                if(model.IsQuantized())
                {
                        const AABBQuantizedNoLeafTree* Tree = (const AABBQuantizedNoLeafTree*)model.GetTree();

                        // Setup dequantization coeffs
                        mCenterCoeff    = Tree->mCenterCoeff;
                        mExtentsCoeff   = Tree->mExtentsCoeff;

                        // Perform collision query
                        if(SkipPrimitiveTests())        _CollideNoPrimitiveTest(Tree->GetNodes());
                        else                                            _Collide(Tree->GetNodes());
                }
                else
                {
                        const AABBNoLeafTree* Tree = (const AABBNoLeafTree*)model.GetTree();

                        // Perform collision query
                        if(SkipPrimitiveTests())        _CollideNoPrimitiveTest(Tree->GetNodes());
                        else                                            _Collide(Tree->GetNodes());
                }
        }
        else
        {
                if(model.IsQuantized())
                {
                        const AABBQuantizedTree* Tree = (const AABBQuantizedTree*)model.GetTree();

                        // Setup dequantization coeffs
                        mCenterCoeff    = Tree->mCenterCoeff;
                        mExtentsCoeff   = Tree->mExtentsCoeff;

                        // Perform collision query
                        if(SkipPrimitiveTests())        _CollideNoPrimitiveTest(Tree->GetNodes());
                        else                                            _Collide(Tree->GetNodes());
                }
                else
                {
                        const AABBCollisionTree* Tree = (const AABBCollisionTree*)model.GetTree();

                        // Perform collision query
                        if(SkipPrimitiveTests())        _CollideNoPrimitiveTest(Tree->GetNodes());
                        else                                            _Collide(Tree->GetNodes());
                }
        }
        return true;
}


BOOL SphereCollider::InitQuery(SphereCache& cache, const Sphere& sphere, const Matrix4x4* worlds, const Matrix4x4* worldm)
{
        // 1) Call the base method
        VolumeCollider::InitQuery();

        // 2) Compute sphere in model space:
        // - Precompute R^2
        mRadius2 = sphere.mRadius * sphere.mRadius;
        // - Compute center position
        mCenter = sphere.mCenter;
        // -> to world space
        if(worlds)      mCenter *= *worlds;
        // -> to model space
        if(worldm)
        {
                // Invert model matrix
                Matrix4x4 InvWorldM;
                InvertPRMatrix(InvWorldM, *worldm);

                mCenter *= InvWorldM;
        }

        // 3) Setup destination pointer
        mTouchedPrimitives = &cache.TouchedPrimitives;

        // 4) Special case: 1-triangle meshes [Opcode 1.3]
        if(mCurrentModel && mCurrentModel->HasSingleNode())
        {
                if(!SkipPrimitiveTests())
                {
                        // We simply perform the BV-Prim overlap test each time. We assume single triangle has index 0.
                        mTouchedPrimitives->Reset();

                        // Perform overlap test between the unique triangle and the sphere (and set contact status if needed)
                        SPHERE_PRIM(udword(0), OPC_CONTACT)

                        // Return immediately regardless of status
                        return TRUE;
                }
        }

        // 5) Check temporal coherence :
        if(TemporalCoherenceEnabled())
        {
                // Here we use temporal coherence
                // => check results from previous frame before performing the collision query
                if(FirstContactEnabled())
                {
                        // We're only interested in the first contact found => test the unique previously touched face
                        if(mTouchedPrimitives->GetNbEntries())
                        {
                                // Get index of previously touched face = the first entry in the array
                                udword PreviouslyTouchedFace = mTouchedPrimitives->GetEntry(0);

                                // Then reset the array:
                                // - if the overlap test below is successful, the index we'll get added back anyway
                                // - if it isn't, then the array should be reset anyway for the normal query
                                mTouchedPrimitives->Reset();

                                // Perform overlap test between the cached triangle and the sphere (and set contact status if needed)
                                SPHERE_PRIM(PreviouslyTouchedFace, OPC_TEMPORAL_CONTACT)

                                // Return immediately if possible
                                if(GetContactStatus())  return TRUE;
                        }
                        // else no face has been touched during previous query
                        // => we'll have to perform a normal query
                }
                else
                {
                        // We're interested in all contacts =>test the new real sphere N(ew) against the previous fat sphere P(revious):
                        float r = sqrtf(cache.FatRadius2) - sphere.mRadius;
                        if(IsCacheValid(cache) && cache.Center.SquareDistance(mCenter) < r*r)
                        {
                                // - if N is included in P, return previous list
                                // => we simply leave the list (mTouchedFaces) unchanged

                                // Set contact status if needed
                                if(mTouchedPrimitives->GetNbEntries())  mFlags |= OPC_TEMPORAL_CONTACT;

                                // In any case we don't need to do a query
                                return TRUE;
                        }
                        else
                        {
                                // - else do the query using a fat N

                                // Reset cache since we'll about to perform a real query
                                mTouchedPrimitives->Reset();

                                // Make a fat sphere so that coherence will work for subsequent frames
                                mRadius2 *= cache.FatCoeff;
//                              mRadius2 = (sphere.mRadius * cache.FatCoeff)*(sphere.mRadius * cache.FatCoeff);

                                // Update cache with query data (signature for cached faces)
                                cache.Center = mCenter;
                                cache.FatRadius2 = mRadius2;
                        }
                }
        }
        else
        {
                // Here we don't use temporal coherence => do a normal query
                mTouchedPrimitives->Reset();
        }

        return FALSE;
}


bool SphereCollider::Collide(SphereCache& cache, const Sphere& sphere, const AABBTree* tree)
{
        // This is typically called for a scene tree, full of -AABBs-, not full of triangles.
        // So we don't really have "primitives" to deal with. Hence it doesn't work with
        // "FirstContact" + "TemporalCoherence".
        ASSERT( !(FirstContactEnabled() && TemporalCoherenceEnabled()) );

        // Checkings
        if(!tree)       return false;

        // Init collision query
        if(InitQuery(cache, sphere))    return true;

        // Perform collision query
        _Collide(tree);

        return true;
}


inline_ BOOL SphereCollider::SphereContainsBox(const Point& bc, const Point& be)
{
        // I assume if all 8 box vertices are inside the sphere, so does the whole box.
        // Sounds ok but maybe there's a better way?
        Point p;
        p.x=bc.x+be.x; p.y=bc.y+be.y; p.z=bc.z+be.z;    if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x-be.x;                                                                  if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x+be.x; p.y=bc.y-be.y;                                   if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x-be.x;                                                                  if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x+be.x; p.y=bc.y+be.y; p.z=bc.z-be.z;    if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x-be.x;                                                                  if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x+be.x; p.y=bc.y-be.y;                                   if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;
        p.x=bc.x-be.x;                                                                  if(mCenter.SquareDistance(p)>=mRadius2) return FALSE;

        return TRUE;
}

#define TEST_BOX_IN_SPHERE(center, extents)     \
        if(SphereContainsBox(center, extents))  \
        {                                                                               \
                /* Set contact status */                        \
                mFlags |= OPC_CONTACT;                          \
                _Dump(node);                                            \
                return;                                                         \
        }


void SphereCollider::_Collide(const AABBCollisionNode* node)
{
        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))       return;

        TEST_BOX_IN_SPHERE(node->mAABB.mCenter, node->mAABB.mExtents)

        if(node->IsLeaf())
        {
                SPHERE_PRIM(node->GetPrimitive(), OPC_CONTACT)
        }
        else
        {
                _Collide(node->GetPos());

                if(ContactFound()) return;

                _Collide(node->GetNeg());
        }
}


void SphereCollider::_CollideNoPrimitiveTest(const AABBCollisionNode* node)
{
        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))       return;

        TEST_BOX_IN_SPHERE(node->mAABB.mCenter, node->mAABB.mExtents)

        if(node->IsLeaf())
        {
                SET_CONTACT(node->GetPrimitive(), OPC_CONTACT)
        }
        else
        {
                _CollideNoPrimitiveTest(node->GetPos());

                if(ContactFound()) return;

                _CollideNoPrimitiveTest(node->GetNeg());
        }
}


void SphereCollider::_Collide(const AABBQuantizedNode* node)
{
        // Dequantize box
        const QuantizedAABB& Box = node->mAABB;
        const Point Center(float(Box.mCenter[0]) * mCenterCoeff.x, float(Box.mCenter[1]) * mCenterCoeff.y, float(Box.mCenter[2]) * mCenterCoeff.z);
        const Point Extents(float(Box.mExtents[0]) * mExtentsCoeff.x, float(Box.mExtents[1]) * mExtentsCoeff.y, float(Box.mExtents[2]) * mExtentsCoeff.z);

        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(Center, Extents)) return;

        TEST_BOX_IN_SPHERE(Center, Extents)

        if(node->IsLeaf())
        {
                SPHERE_PRIM(node->GetPrimitive(), OPC_CONTACT)
        }
        else
        {
                _Collide(node->GetPos());

                if(ContactFound()) return;

                _Collide(node->GetNeg());
        }
}


void SphereCollider::_CollideNoPrimitiveTest(const AABBQuantizedNode* node)
{
        // Dequantize box
        const QuantizedAABB& Box = node->mAABB;
        const Point Center(float(Box.mCenter[0]) * mCenterCoeff.x, float(Box.mCenter[1]) * mCenterCoeff.y, float(Box.mCenter[2]) * mCenterCoeff.z);
        const Point Extents(float(Box.mExtents[0]) * mExtentsCoeff.x, float(Box.mExtents[1]) * mExtentsCoeff.y, float(Box.mExtents[2]) * mExtentsCoeff.z);

        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(Center, Extents)) return;

        TEST_BOX_IN_SPHERE(Center, Extents)

        if(node->IsLeaf())
        {
                SET_CONTACT(node->GetPrimitive(), OPC_CONTACT)
        }
        else
        {
                _CollideNoPrimitiveTest(node->GetPos());

                if(ContactFound()) return;

                _CollideNoPrimitiveTest(node->GetNeg());
        }
}


void SphereCollider::_Collide(const AABBNoLeafNode* node)
{
        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))       return;

        TEST_BOX_IN_SPHERE(node->mAABB.mCenter, node->mAABB.mExtents)

        if(node->HasPosLeaf())  { SPHERE_PRIM(node->GetPosPrimitive(), OPC_CONTACT) }
        else                                    _Collide(node->GetPos());

        if(ContactFound()) return;

        if(node->HasNegLeaf())  { SPHERE_PRIM(node->GetNegPrimitive(), OPC_CONTACT) }
        else                                    _Collide(node->GetNeg());
}


void SphereCollider::_CollideNoPrimitiveTest(const AABBNoLeafNode* node)
{
        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(node->mAABB.mCenter, node->mAABB.mExtents))       return;

        TEST_BOX_IN_SPHERE(node->mAABB.mCenter, node->mAABB.mExtents)

        if(node->HasPosLeaf())  { SET_CONTACT(node->GetPosPrimitive(), OPC_CONTACT) }
        else                                    _CollideNoPrimitiveTest(node->GetPos());

        if(ContactFound()) return;

        if(node->HasNegLeaf())  { SET_CONTACT(node->GetNegPrimitive(), OPC_CONTACT) }
        else                                    _CollideNoPrimitiveTest(node->GetNeg());
}


void SphereCollider::_Collide(const AABBQuantizedNoLeafNode* node)
{
        // Dequantize box
        const QuantizedAABB& Box = node->mAABB;
        const Point Center(float(Box.mCenter[0]) * mCenterCoeff.x, float(Box.mCenter[1]) * mCenterCoeff.y, float(Box.mCenter[2]) * mCenterCoeff.z);
        const Point Extents(float(Box.mExtents[0]) * mExtentsCoeff.x, float(Box.mExtents[1]) * mExtentsCoeff.y, float(Box.mExtents[2]) * mExtentsCoeff.z);

        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(Center, Extents)) return;

        TEST_BOX_IN_SPHERE(Center, Extents)

        if(node->HasPosLeaf())  { SPHERE_PRIM(node->GetPosPrimitive(), OPC_CONTACT) }
        else                                    _Collide(node->GetPos());

        if(ContactFound()) return;

        if(node->HasNegLeaf())  { SPHERE_PRIM(node->GetNegPrimitive(), OPC_CONTACT) }
        else                                    _Collide(node->GetNeg());
}


void SphereCollider::_CollideNoPrimitiveTest(const AABBQuantizedNoLeafNode* node)
{
        // Dequantize box
        const QuantizedAABB& Box = node->mAABB;
        const Point Center(float(Box.mCenter[0]) * mCenterCoeff.x, float(Box.mCenter[1]) * mCenterCoeff.y, float(Box.mCenter[2]) * mCenterCoeff.z);
        const Point Extents(float(Box.mExtents[0]) * mExtentsCoeff.x, float(Box.mExtents[1]) * mExtentsCoeff.y, float(Box.mExtents[2]) * mExtentsCoeff.z);

        // Perform Sphere-AABB overlap test
        if(!SphereAABBOverlap(Center, Extents)) return;

        TEST_BOX_IN_SPHERE(Center, Extents)

        if(node->HasPosLeaf())  { SET_CONTACT(node->GetPosPrimitive(), OPC_CONTACT) }
        else                                    _CollideNoPrimitiveTest(node->GetPos());

        if(ContactFound()) return;

        if(node->HasNegLeaf())  { SET_CONTACT(node->GetNegPrimitive(), OPC_CONTACT) }
        else                                    _CollideNoPrimitiveTest(node->GetNeg());
}


void SphereCollider::_Collide(const AABBTreeNode* node)
{
        // Perform Sphere-AABB overlap test
        Point Center, Extents;
        node->GetAABB()->GetCenter(Center);
        node->GetAABB()->GetExtents(Extents);
        if(!SphereAABBOverlap(Center, Extents)) return;

        if(node->IsLeaf() || SphereContainsBox(Center, Extents))
        {
                mFlags |= OPC_CONTACT;
                mTouchedPrimitives->Add(node->GetPrimitives(), node->GetNbPrimitives());
        }
        else
        {
                _Collide(node->GetPos());
                _Collide(node->GetNeg());
        }
}








HybridSphereCollider::HybridSphereCollider()
{
}


HybridSphereCollider::~HybridSphereCollider()
{
}

bool HybridSphereCollider::Collide(SphereCache& cache, const Sphere& sphere, const HybridModel& model, const Matrix4x4* worlds, const Matrix4x4* worldm)
{
        // We don't want primitive tests here!
        mFlags |= OPC_NO_PRIMITIVE_TESTS;

        // Checkings
        if(!Setup(&model))      return false;

        // Init collision query
        if(InitQuery(cache, sphere, worlds, worldm))    return true;

        // Special case for 1-leaf trees
        if(mCurrentModel && mCurrentModel->HasSingleNode())
        {
                // Here we're supposed to perform a normal query, except our tree has a single node, i.e. just a few triangles
                udword Nb = mIMesh->GetNbTriangles();

                // Loop through all triangles
                for(udword i=0;i<Nb;i++)
                {
                        SPHERE_PRIM(i, OPC_CONTACT)
                }
                return true;
        }

        // Override destination array since we're only going to get leaf boxes here
        mTouchedBoxes.Reset();
        mTouchedPrimitives = &mTouchedBoxes;

        // Now, do the actual query against leaf boxes
        if(!model.HasLeafNodes())
        {
                if(model.IsQuantized())
                {
                        const AABBQuantizedNoLeafTree* Tree = (const AABBQuantizedNoLeafTree*)model.GetTree();

                        // Setup dequantization coeffs
                        mCenterCoeff    = Tree->mCenterCoeff;
                        mExtentsCoeff   = Tree->mExtentsCoeff;

                        // Perform collision query - we don't want primitive tests here!
                        _CollideNoPrimitiveTest(Tree->GetNodes());
                }
                else
                {
                        const AABBNoLeafTree* Tree = (const AABBNoLeafTree*)model.GetTree();

                        // Perform collision query - we don't want primitive tests here!
                        _CollideNoPrimitiveTest(Tree->GetNodes());
                }
        }
        else
        {
                if(model.IsQuantized())
                {
                        const AABBQuantizedTree* Tree = (const AABBQuantizedTree*)model.GetTree();

                        // Setup dequantization coeffs
                        mCenterCoeff    = Tree->mCenterCoeff;
                        mExtentsCoeff   = Tree->mExtentsCoeff;

                        // Perform collision query - we don't want primitive tests here!
                        _CollideNoPrimitiveTest(Tree->GetNodes());
                }
                else
                {
                        const AABBCollisionTree* Tree = (const AABBCollisionTree*)model.GetTree();

                        // Perform collision query - we don't want primitive tests here!
                        _CollideNoPrimitiveTest(Tree->GetNodes());
                }
        }

        // We only have a list of boxes so far
        if(GetContactStatus())
        {
                // Reset contact status, since it currently only reflects collisions with leaf boxes
                Collider::InitQuery();

                // Change dest container so that we can use built-in overlap tests and get collided primitives
                cache.TouchedPrimitives.Reset();
                mTouchedPrimitives = &cache.TouchedPrimitives;

                // Read touched leaf boxes
                udword Nb = mTouchedBoxes.GetNbEntries();
                const udword* Touched = mTouchedBoxes.GetEntries();

                const LeafTriangles* LT = model.GetLeafTriangles();
                const udword* Indices = model.GetIndices();

                // Loop through touched leaves
                while(Nb--)
                {
                        const LeafTriangles& CurrentLeaf = LT[*Touched++];

                        // Each leaf box has a set of triangles
                        udword NbTris = CurrentLeaf.GetNbTriangles();
                        if(Indices)
                        {
                                const udword* T = &Indices[CurrentLeaf.GetTriangleIndex()];

                                // Loop through triangles and test each of them
                                while(NbTris--)
                                {
                                        udword TriangleIndex = *T++;
                                        SPHERE_PRIM(TriangleIndex, OPC_CONTACT)
                                }
                        }
                        else
                        {
                                udword BaseIndex = CurrentLeaf.GetTriangleIndex();

                                // Loop through triangles and test each of them
                                while(NbTris--)
                                {
                                        udword TriangleIndex = BaseIndex++;
                                        SPHERE_PRIM(TriangleIndex, OPC_CONTACT)
                                }
                        }
                }
        }

        return true;
}