blender-archive/source/blender/physics/intern/implicit.h

/*
 * ***** 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): Lukas Toenne
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef __BPH_IMPLICIT_H__
#define __BPH_IMPLICIT_H__

/** \file implicit.h
 *  \ingroup bph
 */

#include "stdio.h"

#include "BKE_collision.h"

#include "BLI_utildefines.h"

#ifdef __cplusplus
extern "C" {
#endif

//#define IMPLICIT_SOLVER_EIGEN
#define IMPLICIT_SOLVER_BLENDER

#define CLOTH_ROOT_FRAME /* enable use of root frame coordinate transform */

#define CLOTH_FORCE_GRAVITY
#define CLOTH_FORCE_DRAG
#define CLOTH_FORCE_SPRING_STRUCTURAL
#define CLOTH_FORCE_SPRING_BEND
#define CLOTH_FORCE_SPRING_GOAL
#define CLOTH_FORCE_EFFECTORS

//#define IMPLICIT_PRINT_SOLVER_INPUT_OUTPUT

//#define IMPLICIT_ENABLE_EIGEN_DEBUG

struct Implicit_Data;

BLI_INLINE void implicit_print_matrix_elem(float v)
{
    printf("%-8.3f", v);
}

/* ==== hash functions for debugging ==== */
BLI_INLINE unsigned int hash_int_2d(unsigned int kx, unsigned int ky)
{
#define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))

	unsigned int a, b, c;

	a = b = c = 0xdeadbeef + (2 << 2) + 13;
	a += kx;
	b += ky;

	c ^= b; c -= rot(b,14);
	a ^= c; a -= rot(c,11);
	b ^= a; b -= rot(a,25);
	c ^= b; c -= rot(b,16);
	a ^= c; a -= rot(c,4);
	b ^= a; b -= rot(a,14);
	c ^= b; c -= rot(b,24);

	return c;

#undef rot
}

BLI_INLINE int hash_vertex(int type, int vertex)
{
	return hash_int_2d((unsigned int)type, (unsigned int)vertex);
}

BLI_INLINE int hash_collpair(int type, CollPair *collpair)
{
	return hash_int_2d((unsigned int)type, hash_int_2d((unsigned int)collpair->face1, (unsigned int)collpair->face2));
}
/* ================ */

void BPH_mass_spring_set_root_motion(struct Implicit_Data *data, int index, const float loc[3], const float vel[3], float rot[3][3], const float angvel[3]);

void BPH_mass_spring_set_motion_state(struct Implicit_Data *data, int index, const float x[3], const float v[3]);
void BPH_mass_spring_set_position(struct Implicit_Data *data, int index, const float x[3]);
void BPH_mass_spring_set_velocity(struct Implicit_Data *data, int index, const float v[3]);
void BPH_mass_spring_get_motion_state(struct Implicit_Data *data, int index, float x[3], float v[3]);
void BPH_mass_spring_set_vertex_mass(struct Implicit_Data *data, int index, float mass);

int BPH_mass_spring_init_spring(struct Implicit_Data *data, int index, int v1, int v2);

void BPH_mass_spring_clear_constraints(struct Implicit_Data *data);
void BPH_mass_spring_add_constraint_ndof0(struct Implicit_Data *data, int index, const float dV[3]);
void BPH_mass_spring_add_constraint_ndof1(struct Implicit_Data *data, int index, const float c1[3], const float c2[3], const float dV[3]);
void BPH_mass_spring_add_constraint_ndof2(struct Implicit_Data *data, int index, const float c1[3], const float dV[3]);

bool BPH_mass_spring_solve(struct Implicit_Data *data, float dt);
void BPH_mass_spring_apply_result(struct Implicit_Data *data);

/* Clear the force vector at the beginning of the time step */
void BPH_mass_spring_force_clear(struct Implicit_Data *data);
/* Fictitious forces introduced by moving coordinate systems */
void BPH_mass_spring_force_reference_frame(struct Implicit_Data *data, int index);
/* Simple uniform gravity force */
void BPH_mass_spring_force_gravity(struct Implicit_Data *data, const float g[3]);
/* Global drag force (velocity damping) */
void BPH_mass_spring_force_drag(struct Implicit_Data *data, float drag);
/* Custom external force */
void BPH_mass_spring_force_extern(struct Implicit_Data *data, int i, const float f[3], float dfdx[3][3], float dfdv[3][3]);
/* Wind force, acting on a face */
void BPH_mass_spring_force_face_wind(struct Implicit_Data *data, int v1, int v2, int v3, int v4, const float (*winvec)[3]);
/* Wind force, acting on an edge */
void BPH_mass_spring_force_edge_wind(struct Implicit_Data *data, int v1, int v2, const float (*winvec)[3]);
/* Linear spring force between two points */
bool BPH_mass_spring_force_spring_linear(struct Implicit_Data *data, int i, int j, int spring_index, float restlen,
                                         float stiffness, float damping, bool no_compress, float clamp_force,
                                         float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);
/* Bending force, forming a triangle at the base of two structural springs */
bool BPH_mass_spring_force_spring_bending(struct Implicit_Data *data, int i, int j, int spring_index, float restlen,
                                          float kb, float cb,
                                          float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);
/* Global goal spring */
bool BPH_mass_spring_force_spring_goal(struct Implicit_Data *data, int i, int spring_index, const float goal_x[3], const float goal_v[3],
                                       float stiffness, float damping,
                                       float r_f[3], float r_dfdx[3][3], float r_dfdv[3][3]);

/* ======== Hair Volumetric Forces ======== */

struct HairVertexGrid;
struct HairColliderGrid;

struct HairVertexGrid *BPH_hair_volume_create_vertex_grid(const float gmin[3], const float gmax[3]);
void BPH_hair_volume_free_vertex_grid(struct HairVertexGrid *grid);

void BPH_hair_volume_add_vertex(struct HairVertexGrid *grid, const float x[3], const float v[3]);
void BPH_hair_volume_normalize_vertex_grid(struct HairVertexGrid *grid);
void BPH_hair_volume_vertex_grid_forces(struct HairVertexGrid *grid, const float x[3], const float v[3],
                                        float smoothfac, float pressurefac, float minpressure,
                                        float f[3], float dfdx[3][3], float dfdv[3][3]);

#ifdef __cplusplus
}
#endif

#endif