/*************************************************************************
 *                                                                       *
 * Open Dynamics Engine, Copyright (C) 2001-2003 Russell L. Smith.       *
 * All rights reserved.  Email: russ@q12.org   Web: www.q12.org          *
 *                                                                       *
 * This library is free software; you can redistribute it and/or         *
 * modify it under the terms of EITHER:                                  *
 *   (1) The GNU Lesser General Public License as published by the Free  *
 *       Software Foundation; either version 2.1 of the License, or (at  *
 *       your option) any later version. The text of the GNU Lesser      *
 *       General Public License is included with this library in the     *
 *       file LICENSE.TXT.                                               *
 *   (2) The BSD-style license that is included with this library in     *
 *       the file LICENSE-BSD.TXT.                                       *
 *                                                                       *
 * This library is distributed in the hope that it will be useful,       *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files    *
 * LICENSE.TXT and LICENSE-BSD.TXT for more details.                     *
 *                                                                       *
 *************************************************************************/

/*
 *	Triangle-Capsule(Capsule) collider by Alen Ladavac
 *  Ported to ODE by Nguyen Binh
 */

// NOTES from Nguyen Binh
//	14 Apr : Seem to be robust
//       There is a problem when you use original Step and set contact friction
//		surface.mu = dInfinity;
//		More description : 
//			When I dropped Capsule over the bunny ears, it seems to stuck
//			there for a while. I think the cause is when you set surface.mu = dInfinity;
//			the friction force is too high so it just hang the capsule there.
//			So the good cure for this is to set mu = around 1.5 (in my case)
//		For StepFast1, this become as solid as rock : StepFast1 just approximate 
//		friction force.

// NOTES from Croteam's Alen
//As a side note... there are some extra contacts that can be generated
//on the edge between two triangles, and if the capsule penetrates deeply into
//the triangle (usually happens with large mass or low FPS), some such
//contacts can in some cases push the capsule away from the edge instead of
//away from the two triangles. This shows up as capsule slowing down a bit
//when hitting an edge while sliding along a flat tesselated grid of
//triangles. This is only if capsule is standing upwards.

//Same thing can appear whenever a smooth object (e.g sphere) hits such an
//edge, and it needs to be solved as a special case probably. This is a
//problem we are looking forward to address soon.

#include <ode/collision.h>
#include <ode/rotation.h>
#include "config.h"
#include "matrix.h"
#include "odemath.h"
#include "collision_util.h"
#include "collision_trimesh_internal.h"
#include "util.h"


#if dTRIMESH_ENABLED

// OPCODE version
#if dTRIMESH_OPCODE

// largest number, double or float
#if defined(dSINGLE)
#define MAX_REAL	FLT_MAX
#define MIN_REAL	(-FLT_MAX)
#else
#define MAX_REAL	DBL_MAX
#define MIN_REAL	(-DBL_MAX)
#endif

// To optimize before send contacts to dynamic part
#define OPTIMIZE_CONTACTS 1

// dVector3
// r=a-b
#define SUBTRACT(a,b,r) dSubtractVectors3(r, a, b)


// dVector3
// a=b
#define SET(a,b) dCopyVector3(a, b)


// dMatrix3
// a=b
#define SETM(a,b) dCopyMatrix4x4(a, b)


// dVector3
// r=a+b
#define ADD(a,b,r) dAddVectors3(r, a, b)


// dMatrix3, int, dVector3
// v=column a from m
#define GETCOL(m,a,v) dGetMatrixColumn3(v, m, a)


// dVector4, dVector3
// distance between plane p and point v
#define POINTDISTANCE(p,v) dPointPlaneDistance(v, p)


// dVector4, dVector3, dReal
// construct plane from normal and d
#define CONSTRUCTPLANE(plane,normal,d) dConstructPlane(normal, d, plane)


// dVector3
// length of vector a
#define LENGTHOF(a) dCalcVectorLength3(a)


static inline dReal _length2OfVector3(dVector3 v)
{
    return dCalcVectorLengthSquare3(v);
}


// Local contacts data
typedef struct _sLocalContactData
{
    dVector3	vPos;
    dVector3	vNormal;
    dReal		fDepth;
    int			triIndex;
    int			nFlags; // 0 = filtered out, 1 = OK
}sLocalContactData;

struct sTrimeshCapsuleColliderData
{
    sTrimeshCapsuleColliderData(): m_gLocalContacts(NULL), m_ctContacts(0) { memset(m_vN, 0, sizeof(dVector3)); }

    void SetupInitialContext(dxTriMesh *TriMesh, dxGeom *Capsule, int flags, int skip);
    int TestCollisionForSingleTriangle(int ctContacts0, int Triint, dVector3 dv[3], 
        uint8 flags, bool &bOutFinishSearching);

#if OPTIMIZE_CONTACTS
    void _OptimizeLocalContacts();
#endif
    int	_ProcessLocalContacts(dContactGeom *contact, dxTriMesh *TriMesh, dxGeom *Capsule);

    static BOOL _cldClipEdgeToPlane(dVector3 &vEpnt0, dVector3 &vEpnt1, const dVector4& plPlane);
    BOOL _cldTestAxis(const dVector3 &v0, const dVector3 &v1, const dVector3 &v2, 
        dVector3 vAxis, int iAxis, BOOL bNoFlip = FALSE);
    BOOL _cldTestSeparatingAxesOfCapsule(const dVector3 &v0, const dVector3 &v1, 
        const dVector3 &v2, uint8 flags);
    void _cldTestOneTriangleVSCapsule(const dVector3 &v0, const dVector3 &v1, 
        const dVector3 &v2, uint8 flags);

    sLocalContactData   *m_gLocalContacts;
    unsigned int		m_ctContacts;

    // capsule data
    // real time data
    dMatrix3  m_mCapsuleRotation;
    dVector3   m_vCapsulePosition;
    dVector3   m_vCapsuleAxis;
    // static data
    dReal      m_vCapsuleRadius;
    dReal      m_fCapsuleSize;

    // mesh data
    // dMatrix4  mHullDstPl;
    dMatrix3   m_mTriMeshRot;
    dVector3   m_vTriMeshPos;
    dVector3   m_vE0, m_vE1, m_vE2;

    // global collider data
    dVector3 m_vNormal;
    dReal    m_fBestDepth;
    dReal    m_fBestCenter;
    dReal    m_fBestrt;
    int		m_iBestAxis;
    dVector3 m_vN;

    dVector3 m_vV0; 
    dVector3 m_vV1;
    dVector3 m_vV2;

    // ODE contact's specific
    unsigned int m_iFlags;
    int m_iStride;
};

// Capsule lie on axis number 3 = (Z axis)
static const int nCAPSULE_AXIS = 2;


#if OPTIMIZE_CONTACTS

// Use to classify contacts to be "near" in position
static const dReal fSameContactPositionEpsilon = REAL(0.0001); // 1e-4
// Use to classify contacts to be "near" in normal direction
static const dReal fSameContactNormalEpsilon = REAL(0.0001); // 1e-4

// If this two contact can be classified as "near"
inline int _IsNearContacts(sLocalContactData& c1,sLocalContactData& c2)
{
    int bPosNear = 0;
    int bSameDir = 0;
    dVector3	vDiff;

    // First check if they are "near" in position
    SUBTRACT(c1.vPos,c2.vPos,vDiff);
    if (  (dFabs(vDiff[0]) < fSameContactPositionEpsilon)
        &&(dFabs(vDiff[1]) < fSameContactPositionEpsilon)
        &&(dFabs(vDiff[2]) < fSameContactPositionEpsilon))
    {
        bPosNear = 1;
    }

    // Second check if they are "near" in normal direction
    SUBTRACT(c1.vNormal,c2.vNormal,vDiff);
    if (  (dFabs(vDiff[0]) < fSameContactNormalEpsilon)
        &&(dFabs(vDiff[1]) < fSameContactNormalEpsilon)
        &&(dFabs(vDiff[2]) < fSameContactNormalEpsilon) )
    {
        bSameDir = 1;
    }

    // Will be "near" if position and normal direction are "near"
    return (bPosNear && bSameDir);
}

inline int _IsBetter(sLocalContactData& c1,sLocalContactData& c2)
{
    // The not better will be throw away
    // You can change the selection criteria here
    return (c1.fDepth > c2.fDepth);
}

// iterate through gLocalContacts and filtered out "near contact"
void sTrimeshCapsuleColliderData::_OptimizeLocalContacts()
{
    int nContacts = m_ctContacts;

    for (int i = 0; i < nContacts-1; i++)
    {
        for (int j = i+1; j < nContacts; j++)
        {
            if (_IsNearContacts(m_gLocalContacts[i],m_gLocalContacts[j]))
            {
                // If they are seem to be the samed then filtered 
                // out the least penetrate one
                if (_IsBetter(m_gLocalContacts[j],m_gLocalContacts[i]))
                {
                    m_gLocalContacts[i].nFlags = 0; // filtered 1st contact
                }
                else
                {
                    m_gLocalContacts[j].nFlags = 0; // filtered 2nd contact
                }

                // NOTE
                // There is other way is to add two depth together but
                // it not work so well. Why???
            }
        }
    }
}
#endif // OPTIMIZE_CONTACTS

int	sTrimeshCapsuleColliderData::_ProcessLocalContacts(dContactGeom *contact,
                                                       dxTriMesh *TriMesh, dxGeom *Capsule)
{
#if OPTIMIZE_CONTACTS
    if (m_ctContacts > 1 && !(m_iFlags & CONTACTS_UNIMPORTANT))
    {
        // Can be optimized...
        _OptimizeLocalContacts();
    }
#endif		

    unsigned int iContact = 0;
    dContactGeom* Contact = 0;

    unsigned int nFinalContact = 0;

    for (iContact = 0; iContact < m_ctContacts; iContact ++)
    {
        // Ensure that we haven't created too many contacts
        if( nFinalContact >= (m_iFlags & NUMC_MASK)) 
        {
            break;
        }

        if (1 == m_gLocalContacts[iContact].nFlags)
        {
            Contact =  SAFECONTACT(m_iFlags, contact, nFinalContact, m_iStride);
            Contact->depth = m_gLocalContacts[iContact].fDepth;
            SET(Contact->normal,m_gLocalContacts[iContact].vNormal);
            SET(Contact->pos,m_gLocalContacts[iContact].vPos);
            Contact->g1 = TriMesh;
            Contact->g2 = Capsule;
            Contact->side1 = m_gLocalContacts[iContact].triIndex;
            Contact->side2 = -1;

            nFinalContact++;
        }
    }
    // debug
    //if (nFinalContact != m_ctContacts)
    //{
    //	printf("[Info] %d contacts generated,%d  filtered.\n",m_ctContacts,m_ctContacts-nFinalContact);
    //}

    return nFinalContact;
}

BOOL sTrimeshCapsuleColliderData::_cldClipEdgeToPlane( 
    dVector3 &vEpnt0, dVector3 &vEpnt1, const dVector4& plPlane)
{
    // calculate distance of edge points to plane
    dReal fDistance0 = POINTDISTANCE( plPlane, vEpnt0 );
    dReal fDistance1 = POINTDISTANCE( plPlane, vEpnt1 );

    // if both points are behind the plane
    if ( fDistance0 < 0 && fDistance1 < 0 ) 
    {
        // do nothing
        return FALSE;
        // if both points in front of the plane
    } else if ( fDistance0 > 0 && fDistance1 > 0 ) 
    {
        // accept them
        return TRUE;
        // if we have edge/plane intersection
    } else if ((fDistance0 > 0 && fDistance1 < 0) || ( fDistance0 < 0 && fDistance1 > 0)) 
    {
        // find intersection point of edge and plane
        dVector3 vIntersectionPoint;
        vIntersectionPoint[0]= vEpnt0[0]-(vEpnt0[0]-vEpnt1[0])*fDistance0/(fDistance0-fDistance1);
        vIntersectionPoint[1]= vEpnt0[1]-(vEpnt0[1]-vEpnt1[1])*fDistance0/(fDistance0-fDistance1);
        vIntersectionPoint[2]= vEpnt0[2]-(vEpnt0[2]-vEpnt1[2])*fDistance0/(fDistance0-fDistance1);

        // clamp correct edge to intersection point
        if ( fDistance0 < 0 ) 
        {
            SET(vEpnt0,vIntersectionPoint);
        } else 
        {
            SET(vEpnt1,vIntersectionPoint);
        }
        return TRUE;
    }
    return TRUE;
}

BOOL sTrimeshCapsuleColliderData::_cldTestAxis(
    const dVector3 &/*v0*/,
    const dVector3 &/*v1*/,
    const dVector3 &/*v2*/, 
    dVector3 vAxis, 
    int iAxis,
    BOOL bNoFlip/* = FALSE*/) 
{

    // calculate length of separating axis vector
    dReal fL = LENGTHOF(vAxis);
    // if not long enough
    // TODO : dReal epsilon please
    if ( fL < REAL(1e-5) ) 
    {
        // do nothing
        //iLastOutAxis = 0;
        return TRUE;
    }

    // otherwise normalize it
    dNormalize3(vAxis);

    // project capsule on vAxis
    dReal frc = dFabs(dCalcVectorDot3(m_vCapsuleAxis,vAxis))*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius) + m_vCapsuleRadius;

    // project triangle on vAxis
    dReal afv[3];
    afv[0] = dCalcVectorDot3(m_vV0, vAxis);
    afv[1] = dCalcVectorDot3(m_vV1, vAxis);
    afv[2] = dCalcVectorDot3(m_vV2, vAxis);

    dReal fMin = MAX_REAL;
    dReal fMax = MIN_REAL;

    // for each vertex 
    for(int i=0; i<3; i++) 
    {
        // find minimum
        if (afv[i]<fMin) 
        {
            fMin = afv[i];
        }
        // find maximum
        if (afv[i]>fMax) 
        {
            fMax = afv[i];
        }
    }

    // find triangle's center of interval on axis
    dReal fCenter = (fMin+fMax)*REAL(0.5);
    // calculate triangles half interval 
    dReal fTriangleRadius = (fMax-fMin)*REAL(0.5);

    // if they do not overlap, 
    if (dFabs(fCenter) > ( frc + fTriangleRadius ))
    { 
        // exit, we have no intersection
        return FALSE; 
    }

    // calculate depth 
    dReal fDepth = dFabs(fCenter) - (frc+fTriangleRadius);

    // if greater then best found so far
    if ( fDepth > m_fBestDepth ) 
    {
        // remember depth
        m_fBestDepth  = fDepth;
        m_fBestCenter = fCenter;
        m_fBestrt     = fTriangleRadius;

        m_vNormal[0]     = vAxis[0];
        m_vNormal[1]     = vAxis[1];
        m_vNormal[2]     = vAxis[2];

        m_iBestAxis   = iAxis;

        // flip normal if interval is wrong faced
        if (fCenter<0 && !bNoFlip) 
        { 
            m_vNormal[0] = -m_vNormal[0];
            m_vNormal[1] = -m_vNormal[1];
            m_vNormal[2] = -m_vNormal[2];

            m_fBestCenter = -fCenter;
        }
    }

    return TRUE;
}

// helper for less key strokes
inline void _CalculateAxis(const dVector3& v1,
                           const dVector3& v2,
                           const dVector3& v3,
                           const dVector3& v4,
                           dVector3& r)
{
    dVector3 t1;
    dVector3 t2;

    SUBTRACT(v1,v2,t1);
    dCalcVectorCross3(t2,t1,v3);
    dCalcVectorCross3(r,t2,v4);
}

BOOL sTrimeshCapsuleColliderData::_cldTestSeparatingAxesOfCapsule(
    const dVector3 &v0,
    const dVector3 &v1,
    const dVector3 &v2,
    uint8 flags) 
{
    // calculate caps centers in absolute space
    dVector3 vCp0;
    vCp0[0] = m_vCapsulePosition[0] + m_vCapsuleAxis[0]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCp0[1] = m_vCapsulePosition[1] + m_vCapsuleAxis[1]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCp0[2] = m_vCapsulePosition[2] + m_vCapsuleAxis[2]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);

    dVector3 vCp1;
    vCp1[0] = m_vCapsulePosition[0] - m_vCapsuleAxis[0]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCp1[1] = m_vCapsulePosition[1] - m_vCapsuleAxis[1]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCp1[2] = m_vCapsulePosition[2] - m_vCapsuleAxis[2]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);

    // reset best axis
    m_iBestAxis = 0;
    // reset best depth
    m_fBestDepth  = -MAX_REAL;
    // reset separating axis vector
    dVector3 vAxis = {REAL(0.0),REAL(0.0),REAL(0.0),REAL(0.0)};

    // Epsilon value for checking axis vector length 
    const dReal fEpsilon = 1e-6f;

    // Translate triangle to Cc cord.
    SUBTRACT(v0, m_vCapsulePosition, m_vV0);
    SUBTRACT(v1, m_vCapsulePosition, m_vV1);
    SUBTRACT(v2, m_vCapsulePosition, m_vV2);

    // We begin to test for 19 separating axis now
    // I wonder does it help if we employ the method like ISA-GJK???
    // Or at least we should do experiment and find what axis will
    // be most likely to be separating axis to check it first.

    // Original
    // axis m_vN
    //vAxis = -m_vN;
    vAxis[0] = - m_vN[0];
    vAxis[1] = - m_vN[1];
    vAxis[2] = - m_vN[2];
    if (!_cldTestAxis(v0, v1, v2, vAxis, 1, TRUE)) 
    { 
        return FALSE; 
    }

    if (flags & dxTriMeshData::CUF_USE_FIRST_EDGE)
    {
        // axis CxE0 - Edge 0
        dCalcVectorCross3(vAxis,m_vCapsuleAxis,m_vE0);
        //vAxis = dCalcVectorCross3( m_vCapsuleAxis cross vE0 );
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 2)) { 
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_EDGE)
    {
        // axis CxE1 - Edge 1
        dCalcVectorCross3(vAxis,m_vCapsuleAxis,m_vE1);
        //vAxis = ( m_vCapsuleAxis cross m_vE1 );
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 3)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_EDGE)
    {
        // axis CxE2 - Edge 2
        //vAxis = ( m_vCapsuleAxis cross m_vE2 );
        dCalcVectorCross3(vAxis,m_vCapsuleAxis,m_vE2);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 4)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_FIRST_EDGE)
    {
        // first capsule point
        // axis ((Cp0-V0) x E0) x E0
        _CalculateAxis(vCp0,v0,m_vE0,m_vE0,vAxis);
        //	vAxis = ( ( vCp0-v0) cross vE0 ) cross vE0;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 5)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_EDGE)
    {
        // axis ((Cp0-V1) x E1) x E1
        _CalculateAxis(vCp0,v1,m_vE1,m_vE1,vAxis);
        //vAxis = ( ( vCp0-v1) cross vE1 ) cross vE1;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 6)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_EDGE)
    {
        // axis ((Cp0-V2) x E2) x E2
        _CalculateAxis(vCp0,v2,m_vE2,m_vE2,vAxis);
        //vAxis = ( ( vCp0-v2) cross vE2 ) cross vE2;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 7)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_FIRST_EDGE)
    {
        // second capsule point
        // axis ((Cp1-V0) x E0) x E0
        _CalculateAxis(vCp1,v0,m_vE0,m_vE0,vAxis);
        //vAxis = ( ( vCp1-v0 ) cross vE0 ) cross vE0;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 8)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_EDGE)
    {
        // axis ((Cp1-V1) x E1) x E1
        _CalculateAxis(vCp1,v1,m_vE1,m_vE1,vAxis);
        //vAxis = ( ( vCp1-v1 ) cross vE1 ) cross vE1;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 9)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_EDGE)
    {
        // axis ((Cp1-V2) x E2) x E2
        _CalculateAxis(vCp1,v2,m_vE2,m_vE2,vAxis);
        //vAxis = ( ( vCp1-v2 ) cross vE2 ) cross vE2;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 10)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_FIRST_VERTEX)
    {
        // first vertex on triangle
        // axis ((V0-Cp0) x C) x C
        _CalculateAxis(v0,vCp0,m_vCapsuleAxis,m_vCapsuleAxis,vAxis);
        //vAxis = ( ( v0-vCp0 ) cross m_vCapsuleAxis ) cross m_vCapsuleAxis;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 11)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_VERTEX)
    {
        // second vertex on triangle
        // axis ((V1-Cp0) x C) x C
        _CalculateAxis(v1,vCp0,m_vCapsuleAxis,m_vCapsuleAxis,vAxis);	
        //vAxis = ( ( v1-vCp0 ) cross vCapsuleAxis ) cross vCapsuleAxis;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 12)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_VERTEX)
    {
        // third vertex on triangle
        // axis ((V2-Cp0) x C) x C
        _CalculateAxis(v2,vCp0,m_vCapsuleAxis,m_vCapsuleAxis,vAxis);
        //vAxis = ( ( v2-vCp0 ) cross vCapsuleAxis ) cross vCapsuleAxis;
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 13)) {
                return FALSE;
            }
        }
    }

    // Test as separating axes direction vectors between each triangle
    // edge and each capsule's cap center

    if (flags & dxTriMeshData::CUF_USE_FIRST_VERTEX)
    {
        // first triangle vertex and first capsule point
        //vAxis = v0 - vCp0;
        SUBTRACT(v0,vCp0,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 14)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_VERTEX)
    {
        // second triangle vertex and first capsule point
        //vAxis = v1 - vCp0;
        SUBTRACT(v1,vCp0,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 15)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_VERTEX)
    {
        // third triangle vertex and first capsule point
        //vAxis = v2 - vCp0;
        SUBTRACT(v2,vCp0,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 16)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_FIRST_VERTEX)
    {
        // first triangle vertex and second capsule point
        //vAxis = v0 - vCp1;
        SUBTRACT(v0,vCp1,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 17)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_SECOND_VERTEX)
    {
        // second triangle vertex and second capsule point
        //vAxis = v1 - vCp1;
        SUBTRACT(v1,vCp1,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 18)) {
                return FALSE;
            }
        }
    }

    if (flags & dxTriMeshData::CUF_USE_THIRD_VERTEX)
    {
        // third triangle vertex and second capsule point
        //vAxis = v2 - vCp1;
        SUBTRACT(v2,vCp1,vAxis);
        if (_length2OfVector3( vAxis ) > fEpsilon) {
            if (!_cldTestAxis(v0, v1, v2, vAxis, 19)) {
                return FALSE;
            }
        }
    }

    return TRUE;
}

// test one mesh triangle on intersection with capsule
void sTrimeshCapsuleColliderData::_cldTestOneTriangleVSCapsule(
    const dVector3 &v0, const dVector3 &v1, const dVector3 &v2,
    uint8 flags)
{
    // calculate edges
    SUBTRACT(v1,v0,m_vE0);
    SUBTRACT(v2,v1,m_vE1);
    SUBTRACT(v0,v2,m_vE2);

    dVector3	_minus_vE0;
    SUBTRACT(v0,v1,_minus_vE0);

    // calculate poly normal
    dCalcVectorCross3(m_vN,m_vE1,_minus_vE0);

    // Even though all triangles might be initially valid, 
    // a triangle may degenerate into a segment after applying 
    // space transformation.
    if (!dSafeNormalize3(m_vN))
    {
        return;
    }

    // create plane from triangle
    dReal plDistance = -dCalcVectorDot3(v0,m_vN);
    dVector4 plTrianglePlane;
    CONSTRUCTPLANE(plTrianglePlane,m_vN,plDistance);

    // calculate capsule distance to plane
    dReal fDistanceCapsuleCenterToPlane = POINTDISTANCE(plTrianglePlane,m_vCapsulePosition);

    // Capsule must be over positive side of triangle
    if (fDistanceCapsuleCenterToPlane < 0 /* && !bDoubleSided*/) 
    {
        // if not don't generate contacts
        return;
    }

    dVector3 vPnt0, vPnt1, vPnt2;
    SET	(vPnt0,v0);

    if (fDistanceCapsuleCenterToPlane < 0)
    {
        SET	(vPnt1,v2);
        SET	(vPnt2,v1);
    }
    else
    {
        SET	(vPnt1,v1);
        SET	(vPnt2,v2);
    }

    // do intersection test and find best separating axis
    if (!_cldTestSeparatingAxesOfCapsule(vPnt0, vPnt1, vPnt2, flags))
    {
        // if not found do nothing
        return;
    }

    // if best separation axis is not found
    if (m_iBestAxis == 0 ) 
    {
        // this should not happen (we should already exit in that case)
        dIASSERT(FALSE);
        // do nothing
        return;
    }

    // calculate caps centers in absolute space
    dVector3 vCposTrans;
    vCposTrans[0] = m_vCapsulePosition[0] + m_vNormal[0]*m_vCapsuleRadius;
    vCposTrans[1] = m_vCapsulePosition[1] + m_vNormal[1]*m_vCapsuleRadius;
    vCposTrans[2] = m_vCapsulePosition[2] + m_vNormal[2]*m_vCapsuleRadius;

    dVector3 vCEdgePoint0;
    vCEdgePoint0[0]  = vCposTrans[0] + m_vCapsuleAxis[0]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCEdgePoint0[1]  = vCposTrans[1] + m_vCapsuleAxis[1]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCEdgePoint0[2]  = vCposTrans[2] + m_vCapsuleAxis[2]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);

    dVector3 vCEdgePoint1;
    vCEdgePoint1[0] = vCposTrans[0] - m_vCapsuleAxis[0]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCEdgePoint1[1] = vCposTrans[1] - m_vCapsuleAxis[1]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);
    vCEdgePoint1[2] = vCposTrans[2] - m_vCapsuleAxis[2]*(m_fCapsuleSize*REAL(0.5)-m_vCapsuleRadius);

    // transform capsule edge points into triangle space
    vCEdgePoint0[0] -= vPnt0[0];
    vCEdgePoint0[1] -= vPnt0[1];
    vCEdgePoint0[2] -= vPnt0[2];

    vCEdgePoint1[0] -= vPnt0[0];
    vCEdgePoint1[1] -= vPnt0[1];
    vCEdgePoint1[2] -= vPnt0[2];

    dVector4 plPlane;
    dVector3 _minus_vN;
    _minus_vN[0] = -m_vN[0];
    _minus_vN[1] = -m_vN[1];
    _minus_vN[2] = -m_vN[2];
    // triangle plane
    CONSTRUCTPLANE(plPlane,_minus_vN,0);
    //plPlane = Plane4f( -m_vN, 0);

    if (!_cldClipEdgeToPlane( vCEdgePoint0, vCEdgePoint1, plPlane )) 
    { 
        return; 
    }

    // plane with edge 0
    dVector3 vTemp;
    dCalcVectorCross3(vTemp,m_vN,m_vE0);
    CONSTRUCTPLANE(plPlane, vTemp, REAL(1e-5));
    if (!_cldClipEdgeToPlane( vCEdgePoint0, vCEdgePoint1, plPlane ))
    { 
        return; 
    }

    dCalcVectorCross3(vTemp,m_vN,m_vE1);
    CONSTRUCTPLANE(plPlane, vTemp, -(dCalcVectorDot3(m_vE0,vTemp)-REAL(1e-5)));
    if (!_cldClipEdgeToPlane( vCEdgePoint0, vCEdgePoint1, plPlane )) 
    { 
        return; 
    }

    dCalcVectorCross3(vTemp,m_vN,m_vE2);
    CONSTRUCTPLANE(plPlane, vTemp, REAL(1e-5));
    if (!_cldClipEdgeToPlane( vCEdgePoint0, vCEdgePoint1, plPlane )) { 
        return; 
    }

    // return capsule edge points into absolute space
    vCEdgePoint0[0] += vPnt0[0];
    vCEdgePoint0[1] += vPnt0[1];
    vCEdgePoint0[2] += vPnt0[2];

    vCEdgePoint1[0] += vPnt0[0];
    vCEdgePoint1[1] += vPnt0[1];
    vCEdgePoint1[2] += vPnt0[2];

    // calculate depths for both contact points
    SUBTRACT(vCEdgePoint0,m_vCapsulePosition,vTemp);
    dReal fDepth0 = dCalcVectorDot3(vTemp,m_vNormal) - (m_fBestCenter-m_fBestrt);
    SUBTRACT(vCEdgePoint1,m_vCapsulePosition,vTemp);
    dReal fDepth1 = dCalcVectorDot3(vTemp,m_vNormal) - (m_fBestCenter-m_fBestrt);

    // clamp depths to zero
    if (fDepth0 < 0) 
    {
        fDepth0 = 0.0f;
    }

    if (fDepth1 < 0 ) 
    {
        fDepth1 = 0.0f;
    }

    // Cached contacts's data
    // contact 0
    dIASSERT(m_ctContacts < (m_iFlags & NUMC_MASK)); // Do not call function if there is no room to store result
    m_gLocalContacts[m_ctContacts].fDepth = fDepth0;
    SET(m_gLocalContacts[m_ctContacts].vNormal,m_vNormal);
    SET(m_gLocalContacts[m_ctContacts].vPos,vCEdgePoint0);
    m_gLocalContacts[m_ctContacts].nFlags = 1;
    m_ctContacts++;

    if (m_ctContacts < (m_iFlags & NUMC_MASK)) {
        // contact 1
        m_gLocalContacts[m_ctContacts].fDepth = fDepth1;
        SET(m_gLocalContacts[m_ctContacts].vNormal,m_vNormal);
        SET(m_gLocalContacts[m_ctContacts].vPos,vCEdgePoint1);
        m_gLocalContacts[m_ctContacts].nFlags = 1;
        m_ctContacts++;
    }
}

void sTrimeshCapsuleColliderData::SetupInitialContext(dxTriMesh *TriMesh, dxGeom *Capsule, 
                                                      int flags, int skip)
{
    const dMatrix3* pRot = (const dMatrix3*)dGeomGetRotation(Capsule);
    memcpy(m_mCapsuleRotation, pRot, sizeof(dMatrix3));

    const dVector3* pDst = (const dVector3*)dGeomGetPosition(Capsule);
    memcpy(m_vCapsulePosition, pDst, sizeof(dVector3));

    m_vCapsuleAxis[0] = m_mCapsuleRotation[0*4 + nCAPSULE_AXIS];
    m_vCapsuleAxis[1] = m_mCapsuleRotation[1*4 + nCAPSULE_AXIS];
    m_vCapsuleAxis[2] = m_mCapsuleRotation[2*4 + nCAPSULE_AXIS];

    // Get size of Capsule
    dGeomCapsuleGetParams(Capsule, &m_vCapsuleRadius, &m_fCapsuleSize);
    m_fCapsuleSize += 2*m_vCapsuleRadius;

    const dMatrix3* pTriRot = (const dMatrix3*)dGeomGetRotation(TriMesh);
    memcpy(m_mTriMeshRot, pTriRot, sizeof(dMatrix3));

    const dVector3* pTriPos = (const dVector3*)dGeomGetPosition(TriMesh);
    memcpy(m_vTriMeshPos, pTriPos, sizeof(dVector3));

    // global info for contact creation
    m_iStride			=skip;
    m_iFlags			=flags;

    // reset contact counter
    m_ctContacts = 0;	

    // reset best depth
    m_fBestDepth  = - MAX_REAL;
    m_fBestCenter = 0;
    m_fBestrt     = 0;

    // reset collision normal
    m_vNormal[0] = REAL(0.0);
    m_vNormal[1] = REAL(0.0);
    m_vNormal[2] = REAL(0.0);
}

int sTrimeshCapsuleColliderData::TestCollisionForSingleTriangle(int ctContacts0, 
                                                                int Triint, dVector3 dv[3], uint8 flags, bool &bOutFinishSearching)
{
    // test this triangle
    _cldTestOneTriangleVSCapsule(dv[0],dv[1],dv[2], flags);

    // fill-in tri index for generated contacts
    for (; ctContacts0 < (int)m_ctContacts; ctContacts0++)
        m_gLocalContacts[ctContacts0].triIndex = Triint;

    // Putting "break" at the end of loop prevents unnecessary checks on first pass and "continue"
    bOutFinishSearching = (m_ctContacts >= (m_iFlags & NUMC_MASK));

    return ctContacts0;
}


static void dQueryCCTLPotentialCollisionTriangles(OBBCollider &Collider, 
                                                  const sTrimeshCapsuleColliderData &cData, dxTriMesh *TriMesh, dxGeom *Capsule,
                                                  OBBCache &BoxCache)
{
    Matrix4x4 MeshMatrix;
    const dVector3 vZeroVector3 = { REAL(0.0), };
    MakeMatrix(vZeroVector3, cData.m_mTriMeshRot, MeshMatrix);

    const dVector3 &vCapsulePos = cData.m_vCapsulePosition;
    const dMatrix3 &mCapsuleRot = cData.m_mCapsuleRotation;

    dVector3 vCapsuleOffsetPos;
    dSubtractVectors3(vCapsuleOffsetPos, vCapsulePos, cData.m_vTriMeshPos);

    const dReal fCapsuleRadius = cData.m_vCapsuleRadius, fCapsuleHalfAxis = cData.m_fCapsuleSize * REAL(0.5);

    OBB obbCapsule;
    obbCapsule.mCenter.Set(vCapsuleOffsetPos[0], vCapsuleOffsetPos[1], vCapsuleOffsetPos[2]);
    obbCapsule.mExtents.Set(
        0 == nCAPSULE_AXIS ? fCapsuleHalfAxis : fCapsuleRadius,
        1 == nCAPSULE_AXIS ? fCapsuleHalfAxis : fCapsuleRadius,
        2 == nCAPSULE_AXIS ? fCapsuleHalfAxis : fCapsuleRadius);
    obbCapsule.mRot.Set(
        mCapsuleRot[0], mCapsuleRot[4], mCapsuleRot[8],
        mCapsuleRot[1], mCapsuleRot[5], mCapsuleRot[9],
        mCapsuleRot[2], mCapsuleRot[6], mCapsuleRot[10]);

    // TC results
    if (TriMesh->getDoTC(dxTriMesh::TTC_BOX)) {
        dxTriMesh::BoxTC* BoxTC = 0;
        const int iBoxCacheSize = TriMesh->m_BoxTCCache.size();
        for (int i = 0; i != iBoxCacheSize; i++){
            if (TriMesh->m_BoxTCCache[i].Geom == Capsule){
                BoxTC = &TriMesh->m_BoxTCCache[i];
                break;
            }
        }
        if (!BoxTC){
            TriMesh->m_BoxTCCache.push(dxTriMesh::BoxTC());

            BoxTC = &TriMesh->m_BoxTCCache[TriMesh->m_BoxTCCache.size() - 1];
            BoxTC->Geom = Capsule;
            BoxTC->FatCoeff = 1.0f;
        }

        // Intersect
        Collider.SetTemporalCoherence(true);
        Collider.Collide(*BoxTC, obbCapsule, TriMesh->retrieveMeshBVTreeRef(), null, &MeshMatrix);
    }
    else {
        Collider.SetTemporalCoherence(false);
        Collider.Collide(BoxCache, obbCapsule, TriMesh->retrieveMeshBVTreeRef(), null, &MeshMatrix);
    }
}

// capsule - trimesh by CroTeam
// Ported by Nguyem Binh
int dCollideCCTL(dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip)
{
    dIASSERT (skip >= (int)sizeof(dContactGeom));
    dIASSERT (o1->type == dTriMeshClass);
    dIASSERT (o2->type == dCapsuleClass);
    dIASSERT ((flags & NUMC_MASK) >= 1);

    int nContactCount = 0;

    dxTriMesh *TriMesh = (dxTriMesh*)o1;
    dxGeom *Capsule = o2;

    sTrimeshCapsuleColliderData cData;
    cData.SetupInitialContext(TriMesh, Capsule, flags, skip);

    const unsigned uiTLSKind = TriMesh->getParentSpaceTLSKind();
    dIASSERT(uiTLSKind == Capsule->getParentSpaceTLSKind()); // The colliding spaces must use matching cleanup method
    TrimeshCollidersCache *pccColliderCache = GetTrimeshCollidersCache(uiTLSKind);
    OBBCollider& Collider = pccColliderCache->m_OBBCollider;

    // Will it be better to use LSS here? -> confirm Pierre.
    dQueryCCTLPotentialCollisionTriangles(Collider, cData, 
        TriMesh, Capsule, pccColliderCache->m_DefaultBoxCache);

    if (Collider.GetContactStatus()) 
    {
        // Retrieve data
        int TriCount = Collider.GetNbTouchedPrimitives();

        if (TriCount != 0)
        {
            const int* Triangles = (const int*)Collider.GetTouchedPrimitives();

            if (TriMesh->m_ArrayCallback != null)
            {
                TriMesh->m_ArrayCallback(TriMesh, Capsule, Triangles, TriCount);
            }

            // allocate buffer for local contacts on stack
            cData.m_gLocalContacts = (sLocalContactData*)dALLOCA16(sizeof(sLocalContactData)*(cData.m_iFlags & NUMC_MASK));

            unsigned int ctContacts0 = cData.m_ctContacts;

            const uint8 *useFlags = TriMesh->retrieveMeshSmartUseFlags();

            // loop through all intersecting triangles
            for (int i = 0; i < TriCount; i++)
            {
                const int Triint = Triangles[i];
                if (!TriMesh->invokeCallback(Capsule, Triint)) continue;

                dVector3 dv[3];
                TriMesh->fetchMeshTriangle(dv, Triint, cData.m_vTriMeshPos, cData.m_mTriMeshRot);

                uint8 flags = useFlags != NULL ? useFlags[Triint] : (uint8)dxTriMeshData::CUF__USE_ALL_COMPONENTS;

                bool bFinishSearching;
                ctContacts0 = cData.TestCollisionForSingleTriangle(ctContacts0, Triint, dv, flags, bFinishSearching);

                if (bFinishSearching) 
                {
                    break;
                }
            }

            if (cData.m_ctContacts != 0)
            {
                nContactCount = cData._ProcessLocalContacts(contact, TriMesh, Capsule);
            }
        }
    }

    return nContactCount;
}


#endif


// GIMPACT version
#if dTRIMESH_GIMPACT

#include "gimpact_contact_export_helper.h"
#include "gimpact_gim_contact_accessor.h"

#define nCAPSULE_AXIS 2

// capsule - trimesh  By francisco leon
int dCollideCCTL(dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip)
{
    dIASSERT (skip >= (int)sizeof(dContactGeom));
    dIASSERT (o1->type == dTriMeshClass);
    dIASSERT (o2->type == dCapsuleClass);
    dIASSERT ((flags & NUMC_MASK) >= 1);

    dxTriMesh* TriMesh = (dxTriMesh*)o1;
    dxGeom*	   gCylinder = o2;

    //Get capsule params
    dMatrix3  mCapsuleRotation;
    dVector3   vCapsulePosition;
    dVector3   vCapsuleAxis;
    dReal      vCapsuleRadius;
    dReal      fCapsuleSize;
    dMatrix3* pRot = (dMatrix3*) dGeomGetRotation(gCylinder);
    memcpy(mCapsuleRotation,pRot,sizeof(dMatrix3));
    dVector3* pDst = (dVector3*)dGeomGetPosition(gCylinder);
    memcpy(vCapsulePosition,pDst,sizeof(dVector3));
    //Axis
    vCapsuleAxis[0] = mCapsuleRotation[0*4 + nCAPSULE_AXIS];
    vCapsuleAxis[1] = mCapsuleRotation[1*4 + nCAPSULE_AXIS];
    vCapsuleAxis[2] = mCapsuleRotation[2*4 + nCAPSULE_AXIS];
    // Get size of CCylinder
    dGeomCCylinderGetParams(gCylinder,&vCapsuleRadius,&fCapsuleSize);
    fCapsuleSize*=0.5f;
    //Set Capsule params
    GIM_CAPSULE_DATA capsule;

    capsule.m_radius = vCapsuleRadius;
    VEC_SCALE(capsule.m_point1,fCapsuleSize,vCapsuleAxis);
    VEC_SUM(capsule.m_point1,vCapsulePosition,capsule.m_point1);
    VEC_SCALE(capsule.m_point2,-fCapsuleSize,vCapsuleAxis);
    VEC_SUM(capsule.m_point2,vCapsulePosition,capsule.m_point2);


    //Create contact list
    GDYNAMIC_ARRAY trimeshcontacts;
    GIM_CREATE_CONTACT_LIST(trimeshcontacts);

    //Collide trimeshe vs capsule
    gim_trimesh_capsule_collision(&TriMesh->m_collision_trimesh,&capsule,&trimeshcontacts);


    if(trimeshcontacts.m_size == 0)
    {
        GIM_DYNARRAY_DESTROY(trimeshcontacts);
        return 0;
    }

    GIM_CONTACT * ptrimeshcontacts = GIM_DYNARRAY_POINTER(GIM_CONTACT,trimeshcontacts);
    unsigned contactcount = trimeshcontacts.m_size;

    dxGIMCContactAccessor contactaccessor(ptrimeshcontacts, TriMesh, gCylinder, -1);
    contactcount = dxGImpactContactsExportHelper::ExportMaxDepthGImpactContacts(contactaccessor, contactcount, flags, contact, skip);

    GIM_DYNARRAY_DESTROY(trimeshcontacts);

    return (int)contactcount;
}


#endif // dTRIMESH_GIMPACT


#endif // dTRIMESH_ENABLED
