/*************************************************************************
 *                                                                       *
 * 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.                     *
 *                                                                       *
 *************************************************************************/

// TriMesh code by Erwin de Vries.

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

#if dTRIMESH_ENABLED

#include "collision_util.h"
#include "collision_trimesh_internal.h"

#if dTRIMESH_OPCODE
int dCollideRTL(dxGeom* g1, dxGeom* RayGeom, int Flags, dContactGeom* Contacts, int Stride){
    dIASSERT (Stride >= (int)sizeof(dContactGeom));
    dIASSERT (g1->type == dTriMeshClass);
    dIASSERT (RayGeom->type == dRayClass);
    dIASSERT ((Flags & NUMC_MASK) >= 1);

    dxTriMesh* TriMesh = (dxTriMesh*)g1;

    const dVector3& TLPosition = *(const dVector3*)dGeomGetPosition(TriMesh);
    const dMatrix3& TLRotation = *(const dMatrix3*)dGeomGetRotation(TriMesh);

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

    dReal Length = dGeomRayGetLength(RayGeom);

    int FirstContact = dGeomRayGetFirstContact(RayGeom);
    int BackfaceCull = dGeomRayGetBackfaceCull(RayGeom);
    int ClosestHit = dGeomRayGetClosestHit(RayGeom);

    Collider.SetFirstContact(FirstContact != 0);
    Collider.SetClosestHit(ClosestHit != 0);
    Collider.SetCulling(BackfaceCull != 0);
    Collider.SetMaxDist(Length);

    dVector3 Origin, Direction;
    dGeomRayGet(RayGeom, Origin, Direction);

    /* Make Ray */
    Ray WorldRay;
    WorldRay.mOrig.x = Origin[0];
    WorldRay.mOrig.y = Origin[1];
    WorldRay.mOrig.z = Origin[2];
    WorldRay.mDir.x = Direction[0];
    WorldRay.mDir.y = Direction[1];
    WorldRay.mDir.z = Direction[2];

    /* Intersect */
    Matrix4x4 amatrix;
    int TriCount = 0;
    if (Collider.Collide(WorldRay, TriMesh->Data->BVTree, &MakeMatrix(TLPosition, TLRotation, amatrix))) {
        TriCount = pccColliderCache->Faces.GetNbFaces();
    }

    if (TriCount == 0) {
        return 0;
    }

    const CollisionFace* Faces = pccColliderCache->Faces.GetFaces();

    int OutTriCount = 0;
    for (int i = 0; i < TriCount; i++) {
        if (TriMesh->RayCallback == null ||
            TriMesh->RayCallback(TriMesh, RayGeom, Faces[i].mFaceID,
            Faces[i].mU, Faces[i].mV)) {
                const int& TriIndex = Faces[i].mFaceID;
                if (!Callback(TriMesh, RayGeom, TriIndex)) {
                    continue;
                }

                dContactGeom* Contact = SAFECONTACT(Flags, Contacts, OutTriCount, Stride);

                dVector3 dv[3];
                FetchTriangle(TriMesh, TriIndex, TLPosition, TLRotation, dv);

                dVector3 vu;
                vu[0] = dv[1][0] - dv[0][0];
                vu[1] = dv[1][1] - dv[0][1];
                vu[2] = dv[1][2] - dv[0][2];
                vu[3] = REAL(0.0);

                dVector3 vv;
                vv[0] = dv[2][0] - dv[0][0];
                vv[1] = dv[2][1] - dv[0][1];
                vv[2] = dv[2][2] - dv[0][2];
                vv[3] = REAL(0.0);

                dCalcVectorCross3(Contact->normal, vv, vu);	// Reversed

                // Even though all triangles might be initially valid, 
                // a triangle may degenerate into a segment after applying 
                // space transformation.
                if (dSafeNormalize3(Contact->normal))
                {
                    // No sense to save on single type conversion in algorithm of this size.
                    // If there would be a custom typedef for distance type it could be used 
                    // instead of dReal. However using float directly is the loss of abstraction 
                    // and possible loss of precision in future.
                    /*float*/ dReal T = Faces[i].mDistance;
                    Contact->pos[0] = Origin[0] + (Direction[0] * T);
                    Contact->pos[1] = Origin[1] + (Direction[1] * T);
                    Contact->pos[2] = Origin[2] + (Direction[2] * T);
                    Contact->pos[3] = REAL(0.0);

                    Contact->depth = T;
                    Contact->g1 = TriMesh;
                    Contact->g2 = RayGeom;
                    Contact->side1 = TriIndex;
                    Contact->side2 = -1;

                    OutTriCount++;

                    // Putting "break" at the end of loop prevents unnecessary checks on first pass and "continue"
                    if (OutTriCount >= (Flags & NUMC_MASK)) {
                        break;
                    }
                }
        }
    }
    return OutTriCount;
}
#endif // dTRIMESH_OPCODE

#if dTRIMESH_GIMPACT
int dCollideRTL(dxGeom* g1, dxGeom* RayGeom, int Flags, dContactGeom* Contacts, int Stride)
{
    dIASSERT (Stride >= (int)sizeof(dContactGeom));
    dIASSERT (g1->type == dTriMeshClass);
    dIASSERT (RayGeom->type == dRayClass);
    dIASSERT ((Flags & NUMC_MASK) >= 1);

    dxTriMesh* TriMesh = (dxTriMesh*)g1;

    dReal Length = dGeomRayGetLength(RayGeom);
    int FirstContact, BackfaceCull;
    dGeomRayGetParams(RayGeom, &FirstContact, &BackfaceCull);
    int ClosestHit = dGeomRayGetClosestHit(RayGeom);
    dVector3 Origin, Direction;
    dGeomRayGet(RayGeom, Origin, Direction);

    char intersect=0;
    GIM_TRIANGLE_RAY_CONTACT_DATA contact_data;

    if(ClosestHit)
    {
        intersect = gim_trimesh_ray_closest_collisionODE(&TriMesh->m_collision_trimesh,Origin,Direction,Length,&contact_data);
    }
    else
    {
        intersect = gim_trimesh_ray_collisionODE(&TriMesh->m_collision_trimesh,Origin,Direction,Length,&contact_data);
    }

    if(intersect == 0)
    {
        return 0;
    }


    if(!TriMesh->RayCallback || 
        TriMesh->RayCallback(TriMesh, RayGeom, contact_data.m_face_id, contact_data.u , contact_data.v))
    {
        dContactGeom* Contact = &( Contacts[ 0 ] );
        VEC_COPY(Contact->pos,contact_data.m_point);
        VEC_COPY(Contact->normal,contact_data.m_normal);
        Contact->depth = contact_data.tparam;
        Contact->g1 = TriMesh;
        Contact->g2 = RayGeom;
        Contact->side1 = contact_data.m_face_id;
        Contact->side2 = -1;
        return 1;
    }

    return 0;
}
#endif  // dTRIMESH_GIMPACT

#endif // dTRIMESH_ENABLED
