//-----------------------------------------------------------------------------
// V12 Engine
// 
// Copyright (c) 2001 GarageGames.Com
// Portions Copyright (c) 2001 by Sierra Online, Inc.
//-----------------------------------------------------------------------------

#ifndef _GJK_H_
#define _GJK_H_

#ifndef _MMATH_H_
#include "Math/mMath.h"
#endif
#ifndef _TVECTOR_H_
#include "Core/tVector.h"
#endif

class Convex;
struct CollisionStateList;
struct Collision;

//----------------------------------------------------------------------------

struct CollisionState
{
   CollisionStateList* mLista;
   CollisionStateList* mListb;
   Convex* a;
   Convex* b;

   VectorF v;        // Vector between closest points
   F32 dist;         // v.len()

   // Temporary values
   Point3F p[4];     // support points of object A in local coordinates 
   Point3F q[4];     // support points of object B in local coordinates 
   VectorF y[4];     // support points of A - B in world coordinates

   S32 bits;         // identifies current simplex
   S32 all_bits;     // all_bits = bits | last_bit 
   F32 det[16][4];   // cached sub-determinants
   F32 dp[4][4];     // cached dot products

   S32 last;         // identifies last found support point
   S32 last_bit;     // last_bit = 1<<last

   //
   void compute_det();
   bool valid(int s);
   void compute_vector(int bits, VectorF& v);
   bool closest(VectorF& v);
   bool degenerate(const VectorF& w);
   void nextBit();
   void swap();
   void reset(const MatrixF& a2w, const MatrixF& b2w);

   CollisionState();
   ~CollisionState();

   void set(Convex* a,Convex* b,const MatrixF& a2w, const MatrixF& b2w);

   void getCollisionInfo(const MatrixF& mat, Collision* info);
   void getClosestPoints(Point3F& p1, Point3F& p2);
   bool intersect(const MatrixF& a2w, const MatrixF& b2w);
   F32 distance(const MatrixF& a2w, const MatrixF& b2w);
   F32 distanceBounded(const MatrixF& a2w, const MatrixF& b2w, const F32 dontCareDist,
                       const MatrixF* w2a = NULL, const MatrixF* _w2b = NULL);
   void render();
};


#endif