/**
 * BKE_cloth.h
 *
 * $Id$
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): Daniel Genrich
 *
 * ***** END GPL LICENSE BLOCK *****
 */
#ifndef BKE_CLOTH_H
#define BKE_CLOTH_H

#include <float.h>

struct Object;
struct ListBase;
struct Scene;
struct MFace;
struct DerivedMesh;
struct ClothModifierData;
struct CollisionTree;

// this is needed for inlining behaviour
#if defined _WIN32
#   define DO_INLINE __inline
#elif defined (__sgi)
#   define DO_INLINE
#elif defined (__sun) || defined (__sun__)
#   define DO_INLINE
#else
#   define DO_INLINE static inline
#endif

#define CLOTH_MAX_THREAD 2

/* goal defines */
#define SOFTGOALSNAP  0.999f

/* This is approximately the smallest number that can be
* represented by a float, given its precision. */
#define ALMOST_ZERO		FLT_EPSILON

/* Bits to or into the ClothVertex.flags. */
#define CLOTH_VERT_FLAG_PINNED 1
#define CLOTH_VERT_FLAG_COLLISION 2
#define CLOTH_VERT_FLAG_PINNED_EM 3

/**
* This structure describes a cloth object against which the
* simulation can run.
*
* The m and n members of this structure represent the assumed
* rectangular ordered grid for which the original paper is written.
* At some point they need to disappear and we need to determine out
* own connectivity of the mesh based on the actual edges in the mesh.
*
**/
typedef struct Cloth
{
	struct ClothVertex	*verts;			/* The vertices that represent this cloth. */
	struct	LinkNode	*springs;		/* The springs connecting the mesh. */
	unsigned int		numverts;		/* The number of verts == m * n. */
	unsigned int		numsprings;		/* The count of springs. */
	unsigned int		numfaces;
	unsigned char 		old_solver_type;	/* unused, only 1 solver here */
	unsigned char 		pad2;
	short 			pad3;
	struct BVHTree		*bvhtree;			/* collision tree for this cloth object */
	struct BVHTree 		*bvhselftree;			/* collision tree for this cloth object */
	struct MFace 		*mfaces;
	struct Implicit_Data	*implicit; 		/* our implicit solver connects to this pointer */
	struct Implicit_Data	*implicitEM; 		/* our implicit solver connects to this pointer */
	struct EdgeHash 	*edgehash; 		/* used for selfcollisions */
} Cloth;

/**
 * The definition of a cloth vertex.
 */
typedef struct ClothVertex
{
	int	flags;		/* General flags per vertex.		*/
	float	v [3];		/* The velocity of the point.		*/
	float	xconst [3];	/* constrained position			*/
	float	x [3];		/* The current position of this vertex.	*/
	float 	xold [3];	/* The previous position of this vertex.*/
	float	tx [3];		/* temporary position */
	float 	txold [3];	/* temporary old position */
	float 	tv[3];		/* temporary "velocity", mostly used as tv = tx-txold */
	float 	mass;		/* mass / weight of the vertex		*/
	float 	goal;		/* goal, from SB			*/
	float	impulse[3];	/* used in collision.c */
	float	*xrest;		/* temporary valid for building springs */
	unsigned int impulse_count; /* same as above */
	float 	avg_spring_len; /* average length of connected springs */
	float 	struct_stiff;
	float	bend_stiff;
	float 	shear_stiff;
	int 	spring_count; /* how many springs attached? */
}
ClothVertex;

/**
 * The definition of a spring.
 */
typedef struct ClothSpring
{
	int	ij;		/* Pij from the paper, one end of the spring.	*/
	int	kl;		/* Pkl from the paper, one end of the spring.	*/
	float	restlen;	/* The original length of the spring.	*/
	int	matrix_index; 	/* needed for implicit solver (fast lookup) */
	int	type;		/* types defined in BKE_cloth.h ("springType") */
	int	flags; 		/* defined in BKE_cloth.h, e.g. deactivated due to tearing */
	float dfdx[3][3];
	float dfdv[3][3];
	float f[3];
	float 	stiffness;	/* stiffness factor from the vertex groups */
	float editrestlen;
}
ClothSpring;

// some macro enhancements for vector treatment
#define VECADDADD(v1,v2,v3) 	{*(v1)+= *(v2) + *(v3); *(v1+1)+= *(v2+1) + *(v3+1); *(v1+2)+= *(v2+2) + *(v3+2);}
#define VECSUBADD(v1,v2,v3) 	{*(v1)-= *(v2) + *(v3); *(v1+1)-= *(v2+1) + *(v3+1); *(v1+2)-= *(v2+2) + *(v3+2);}
#define VECADDSUB(v1,v2,v3) 	{*(v1)+= *(v2) - *(v3); *(v1+1)+= *(v2+1) - *(v3+1); *(v1+2)+= *(v2+2) - *(v3+2);}
#define VECSUBADDSS(v1,v2,aS,v3,bS) 	{*(v1)-= *(v2)*aS + *(v3)*bS; *(v1+1)-= *(v2+1)*aS + *(v3+1)*bS; *(v1+2)-= *(v2+2)*aS + *(v3+2)*bS;}
#define VECADDSUBSS(v1,v2,aS,v3,bS) 	{*(v1)+= *(v2)*aS - *(v3)*bS; *(v1+1)+= *(v2+1)*aS - *(v3+1)*bS; *(v1+2)+= *(v2+2)*aS - *(v3+2)*bS;}
#define VECADDSS(v1,v2,aS,v3,bS) 	{*(v1)= *(v2)*aS + *(v3)*bS; *(v1+1)= *(v2+1)*aS + *(v3+1)*bS; *(v1+2)= *(v2+2)*aS + *(v3+2)*bS;}
#define VECADDS(v1,v2,v3,bS) 	{*(v1)= *(v2) + *(v3)*bS; *(v1+1)= *(v2+1) + *(v3+1)*bS; *(v1+2)= *(v2+2) + *(v3+2)*bS;}
#define VECSUBMUL(v1,v2,aS) 	{*(v1)-= *(v2) * aS; *(v1+1)-= *(v2+1) * aS; *(v1+2)-= *(v2+2) * aS;}
#define VECSUBS(v1,v2,v3,bS) 	{*(v1)= *(v2) - *(v3)*bS; *(v1+1)= *(v2+1) - *(v3+1)*bS; *(v1+2)= *(v2+2) - *(v3+2)*bS;}
#define VECSUBSB(v1,v2, v3,bS) 	{*(v1)= (*(v2)- *(v3))*bS; *(v1+1)= (*(v2+1) - *(v3+1))*bS; *(v1+2)= (*(v2+2) - *(v3+2))*bS;}
#define VECMULS(v1,aS) 	{*(v1)*= aS; *(v1+1)*= aS; *(v1+2)*= *aS;}
#define VECADDMUL(v1,v2,aS) 	{*(v1)+= *(v2) * aS; *(v1+1)+= *(v2+1) * aS; *(v1+2)+= *(v2+2) * aS;}

/* SIMULATION FLAGS: goal flags,.. */
/* These are the bits used in SimSettings.flags. */
typedef enum
{
	CLOTH_SIMSETTINGS_FLAG_COLLOBJ = ( 1 << 2 ),// object is only collision object, no cloth simulation is done
	CLOTH_SIMSETTINGS_FLAG_GOAL = ( 1 << 3 ), 	// we have goals enabled
	CLOTH_SIMSETTINGS_FLAG_TEARING = ( 1 << 4 ),// true if tearing is enabled
	CLOTH_SIMSETTINGS_FLAG_SCALING = ( 1 << 8 ), /* is advanced scaling active? */
	CLOTH_SIMSETTINGS_FLAG_CCACHE_EDIT = (1 << 12),	/* edit cache in editmode */
	CLOTH_SIMSETTINGS_FLAG_NO_SPRING_COMPRESS = (1 << 13) /* don't allow spring compression */
} CLOTH_SIMSETTINGS_FLAGS;

/* COLLISION FLAGS */
typedef enum
{
	CLOTH_COLLSETTINGS_FLAG_ENABLED = ( 1 << 1 ), /* enables cloth - object collisions */
	CLOTH_COLLSETTINGS_FLAG_SELF = ( 1 << 2 ), /* enables selfcollisions */
} CLOTH_COLLISIONSETTINGS_FLAGS;

/* Spring types as defined in the paper.*/
typedef enum
{
	CLOTH_SPRING_TYPE_STRUCTURAL  = ( 1 << 1 ),
	CLOTH_SPRING_TYPE_SHEAR  = ( 1 << 2 ) ,
	CLOTH_SPRING_TYPE_BENDING  = ( 1 << 3 ),
	CLOTH_SPRING_TYPE_GOAL  = ( 1 << 4 ),
} CLOTH_SPRING_TYPES;

/* SPRING FLAGS */
typedef enum
{
	CLOTH_SPRING_FLAG_DEACTIVATE = ( 1 << 1 ),
	CLOTH_SPRING_FLAG_NEEDED = ( 1 << 2 ), // springs has values to be applied
} CLOTH_SPRINGS_FLAGS;


/////////////////////////////////////////////////
// collision.c
////////////////////////////////////////////////

// needed for implicit.c
int cloth_bvh_objcollision (struct Object *ob, struct ClothModifierData * clmd, float step, float dt );

////////////////////////////////////////////////


////////////////////////////////////////////////
// implicit.c
////////////////////////////////////////////////

// needed for cloth.c
int implicit_init ( struct Object *ob, struct ClothModifierData *clmd );
int implicit_free ( struct ClothModifierData *clmd );
int implicit_solver ( struct Object *ob, float frame, struct ClothModifierData *clmd, struct ListBase *effectors );
void implicit_set_positions ( struct ClothModifierData *clmd );

// globally needed
void clmdSetInterruptCallBack ( int ( *f ) ( void ) );
////////////////////////////////////////////////


/////////////////////////////////////////////////
// cloth.c
////////////////////////////////////////////////

// needed for modifier.c
void cloth_free_modifier_extern ( struct ClothModifierData *clmd );
void cloth_free_modifier ( struct Object *ob, struct ClothModifierData *clmd );
void cloth_init ( struct ClothModifierData *clmd );
struct DerivedMesh *clothModifier_do ( struct ClothModifierData *clmd, struct Scene *scene, struct Object *ob, struct DerivedMesh *dm, int useRenderParams, int isFinalCalc );

void cloth_update_normals ( ClothVertex *verts, int nVerts, struct MFace *face, int totface );
int cloth_uses_vgroup(struct ClothModifierData *clmd);

// needed for collision.c
void bvhtree_update_from_cloth ( struct ClothModifierData *clmd, int moving );
void bvhselftree_update_from_cloth ( struct ClothModifierData *clmd, int moving );

// needed for button_object.c
void cloth_clear_cache ( struct Object *ob, struct ClothModifierData *clmd, float framenr );

// needed for cloth.c
int cloth_add_spring ( struct ClothModifierData *clmd, unsigned int indexA, unsigned int indexB, float restlength, int spring_type);

////////////////////////////////////////////////


/* This enum provides the IDs for our solvers. */
// only one available in the moment
typedef enum
{
	CM_IMPLICIT = 0,
} CM_SOLVER_ID;


/* This structure defines how to call the solver.
*/
typedef struct
{
	char		*name;
	CM_SOLVER_ID	id;
	int	( *init ) ( struct Object *ob, struct ClothModifierData *clmd );
	int	( *solver ) ( struct Object *ob, float framenr, struct ClothModifierData *clmd, struct ListBase *effectors );
	int	( *free ) ( struct ClothModifierData *clmd );
}
CM_SOLVER_DEF;


#endif