/Users/frarees/Desktop/rv1/source/inc/Field.h

#ifndef __FIELD_H__
#define __FIELD_H__


//
// Field.h: Force field header file
//
// Fields are allocated from a static linked list of available fields.
// When a field is created, a field from the empty list is transferred
// to the active field list. When a field is deleted, it is moved from
// the active list to the empty list.
//
// The fields apply an impulse to particles. The field impulses must be
// applied before any collision response is calculated.
//

#ifndef _PSX
#define MAX_FIELDS  128
#else 
#define MAX_FIELDS  16
#endif

#define FIELD_PARENT_NONE -1

enum {
  FIELD_PRIORITY_MAX = 0,
  FIELD_PRIORITY_MIN
};


typedef struct LinearParamsStruct {
  VEC Size;
  VEC Dir;
  REAL  Mag;
  REAL  Damping;
} LINEAR_FIELD_PARAMS;

typedef struct LinearTwistParamsStruct {
  VEC Size;
  VEC Dir;
  REAL  Mag;
  REAL  Damping;
  VEC Torque;
} LINEARTWIST_FIELD_PARAMS;

typedef struct VelocityParamsStruct {
  VEC Size;
  VEC Dir;
  REAL  Mag;
} VELOCITY_FIELD_PARAMS;

typedef struct SphericalParamsStruct {
  REAL  RadStart, RadEnd;         // Start and end radii squared
  REAL  GradStart, GradEnd;         // Start and end gradient
} SPHERICAL_FIELD_PARAMS;

typedef struct CylindricalParamsStruct {
  VEC Dir;
  REAL  RadStart, RadEnd;         // Start and end radii squared
  REAL  GradStart, GradEnd;         // Start and end gradient
} CYLINDRICAL_FIELD_PARAMS;

typedef struct OrientationParamsStruct {
  VEC Size;
  VEC Dir;
  REAL  Mag;
  REAL  Damping;
} ORIENTATION_FIELD_PARAMS;

typedef struct LocalParamsStruct {
  VEC Size;
  VEC *DirPtr;
  REAL  Mag;
  REAL  Damping;
} LOCAL_FIELD_PARAMS;

typedef struct VortexParamsStruct {
  VEC Size;
  VEC Dir;
  REAL  Mag;
  REAL  RMin;
  REAL  RMax;
} VORTEX_FIELD_PARAMS;

typedef struct FieldDataStruct {
  long ObjectID;
  long Priority;
  VEC *Pos;
  VEC *Vel;
  VEC *AngVel;
  MAT *Mat;
  QUATERNION *Quat;
  REAL Mass;
} FIELD_DATA;

typedef struct ForceFieldStruct {
  long  Status;
  long  Type;
  long  ParentID;
  long  Priority;

  VEC *PosPtr;                // World position of centre of force field
  MAT *MatPtr;                // World matrix of field
  BBOX  BBox;                 // Local axis-aligned bounding box
  union ForceFieldParamsUnion {
    LINEAR_FIELD_PARAMS     LinearParams;
    LINEARTWIST_FIELD_PARAMS  LinearTwistParams;
    LOCAL_FIELD_PARAMS      LocalParams;
    VELOCITY_FIELD_PARAMS   VelocityParams;
    SPHERICAL_FIELD_PARAMS    SphericalParams;
    CYLINDRICAL_FIELD_PARAMS  CylindricalParams;
    ORIENTATION_FIELD_PARAMS  OrientationParams;
    VORTEX_FIELD_PARAMS     VortexParams;
  } Params;
  bool  (*FieldCollTest)(struct ForceFieldStruct *field, VEC *pos); // Check if pos is in field area of effect  
  void  (*AddFieldImpulse)(struct ForceFieldStruct *field, FIELD_DATA *data, VEC *imp, VEC *angImp);  // Apply impulse to particle or body from field

  struct ForceFieldStruct *Prev;
  struct ForceFieldStruct *Next;

} FORCE_FIELD;



/*#define FIELD_OWNS_POS  1
#define FIELD_OWNS_MAT  2

#define SetFieldOwnsPos(field)  ((field)->Status |= FIELD_OWNS_POS)
#define DoesFieldOwnPos(field)  ((field)->Statuc & FIELD_OWNS_POS)
#define SetFieldOwnsMat(field)  ((field)->Status |= FIELD_OWNS_MAT)
#define DoesFieldOwnMat(field)  ((field)->Statuc & FIELD_OWNS_MAT)*/

#define FieldPriorityTest(fieldPriority, objectPriority) ((objectPriority) >= (fieldPriority))

#define FIELD_LINEAR  0
#define FIELD_SPHERICAL 1
#define FIELD_VELOCITY  2
#define FIELD_ORIENTATION 4
#define FIELD_VORTEX  8
#define FIELD_LOCAL   16
#define FIELD_LINEARTWIST 32

//
// GLOBAL FUNCTIONS
//

extern void FreeForceFields();
extern void InitFields(void);
extern void RemoveField(FORCE_FIELD *field);
extern FORCE_FIELD *FirstField(void);
extern FORCE_FIELD *NextField(FORCE_FIELD *field);
extern void AllFieldImpulses(FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddLinearField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag, REAL damping);
extern bool LinearFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void LinearFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddLinearTwistField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag, VEC *torque, REAL damping);
extern bool LinearTwistFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void LinearTwistFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddLocalField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag, REAL damping);
extern bool LocalFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void LocalFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddVelocityField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag);
extern bool VelocityFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void VelocityFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddSphericalField(long parentID, long priority, VEC *posPtr, REAL rStart, REAL rEnd, REAL gStart, REAL gEnd);
extern bool SphericalFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void SphericalFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddCylindricalField(long parentID, long priority, VEC *posPtr, VEC *dir, REAL rStart, REAL rEnd, REAL gStart, REAL gEnd);
extern bool CylindricalFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void CylindricalFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddVortexField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag, REAL rMin, REAL rMax);
extern bool VortexFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void VortexFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);

extern FORCE_FIELD *AddOrientationField(long parentID, long priority, VEC *posPtr, MAT *matPtr, BBOX *bBox, VEC *size, VEC *dir, REAL mag, REAL damping);
extern bool OrientationFieldCollTest(FORCE_FIELD *field, VEC *pos);
extern void OrientationFieldImpulse(FORCE_FIELD *field, FIELD_DATA *data, VEC *imp, VEC *angImp);


//
// GLOBALS
//

extern int FLD_NForceFields;
extern REAL FLD_Gravity;
extern BBOX FLD_GlobalBBox;
extern VEC FLD_GlobalSize;
extern FORCE_FIELD  *FLD_GravityField;
#endif

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