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blender-archive/source/blender/blenkernel/intern/collision.c

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C

/* collision.c
*
*
* ***** BEGIN GPL/BL DUAL 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. The Blender
* Foundation also sells licenses for use in proprietary software under
* the Blender License. See http://www.blender.org/BL/ for information
* about this.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* The Original Code is Copyright (C) Blender Foundation
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL/BL DUAL LICENSE BLOCK *****
*/
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "MEM_guardedalloc.h"
/* types */
#include "DNA_curve_types.h"
#include "DNA_object_types.h"
#include "DNA_object_force.h"
#include "DNA_cloth_types.h"
#include "DNA_key_types.h"
#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_lattice_types.h"
#include "DNA_scene_types.h"
#include "DNA_modifier_types.h"
#include "BLI_blenlib.h"
#include "BLI_arithb.h"
#include "BLI_edgehash.h"
#include "BLI_linklist.h"
#include "BKE_collisions.h"
#include "BKE_curve.h"
#include "BKE_deform.h"
#include "BKE_DerivedMesh.h"
#include "BKE_cdderivedmesh.h"
#include "BKE_displist.h"
#include "BKE_effect.h"
#include "BKE_global.h"
#include "BKE_mesh.h"
#include "BKE_object.h"
#include "BKE_cloth.h"
#include "BKE_modifier.h"
#include "BKE_utildefines.h"
#include "BKE_DerivedMesh.h"
#include "DNA_screen_types.h"
#include "BSE_headerbuttons.h"
#include "BIF_screen.h"
#include "BIF_space.h"
#include "mydevice.h"
#include "Bullet-C-Api.h"
// step is limited from 0 (frame start position) to 1 (frame end position)
void collision_move_object(CollisionModifierData *collmd, float step, float prevstep)
{
float tv[3] = {0,0,0};
unsigned int i = 0;
for ( i = 0; i < collmd->numverts; i++ )
{
VECSUB(tv, collmd->xnew[i].co, collmd->x[i].co);
VECADDS(collmd->current_x[i].co, collmd->x[i].co, tv, prevstep);
VECADDS(collmd->current_xnew[i].co, collmd->x[i].co, tv, step);
VECSUB(collmd->current_v[i].co, collmd->current_xnew[i].co, collmd->current_x[i].co);
}
}
/**
* gsl_poly_solve_cubic -
*
* copied from SOLVE_CUBIC.C --> GSL
*/
#define mySWAP(a,b) { float tmp = b ; b = a ; a = tmp ; }
int gsl_poly_solve_cubic (float a, float b, float c, float *x0, float *x1, float *x2)
{
float q = (a * a - 3 * b);
float r = (2 * a * a * a - 9 * a * b + 27 * c);
float Q = q / 9;
float R = r / 54;
float Q3 = Q * Q * Q;
float R2 = R * R;
float CR2 = 729 * r * r;
float CQ3 = 2916 * q * q * q;
if (R == 0 && Q == 0)
{
*x0 = - a / 3 ;
*x1 = - a / 3 ;
*x2 = - a / 3 ;
return 3 ;
}
else if (CR2 == CQ3)
{
/* this test is actually R2 == Q3, written in a form suitable
for exact computation with integers */
/* Due to finite precision some float roots may be missed, and
considered to be a pair of complex roots z = x +/- epsilon i
close to the real axis. */
float sqrtQ = sqrtf (Q);
if (R > 0)
{
*x0 = -2 * sqrtQ - a / 3;
*x1 = sqrtQ - a / 3;
*x2 = sqrtQ - a / 3;
}
else
{
*x0 = - sqrtQ - a / 3;
*x1 = - sqrtQ - a / 3;
*x2 = 2 * sqrtQ - a / 3;
}
return 3 ;
}
else if (CR2 < CQ3) /* equivalent to R2 < Q3 */
{
float sqrtQ = sqrtf (Q);
float sqrtQ3 = sqrtQ * sqrtQ * sqrtQ;
float theta = acosf (R / sqrtQ3);
float norm = -2 * sqrtQ;
*x0 = norm * cosf (theta / 3) - a / 3;
*x1 = norm * cosf ((theta + 2.0 * M_PI) / 3) - a / 3;
*x2 = norm * cosf ((theta - 2.0 * M_PI) / 3) - a / 3;
/* Sort *x0, *x1, *x2 into increasing order */
if (*x0 > *x1)
mySWAP(*x0, *x1) ;
if (*x1 > *x2)
{
mySWAP(*x1, *x2) ;
if (*x0 > *x1)
mySWAP(*x0, *x1) ;
}
return 3;
}
else
{
float sgnR = (R >= 0 ? 1 : -1);
float A = -sgnR * powf (fabs (R) + sqrtf (R2 - Q3), 1.0/3.0);
float B = Q / A ;
*x0 = A + B - a / 3;
return 1;
}
}
/**
* gsl_poly_solve_quadratic
*
* copied from GSL
*/
int gsl_poly_solve_quadratic (float a, float b, float c, float *x0, float *x1)
{
float disc = b * b - 4 * a * c;
if (disc > 0)
{
if (b == 0)
{
float r = fabs (0.5 * sqrtf (disc) / a);
*x0 = -r;
*x1 = r;
}
else
{
float sgnb = (b > 0 ? 1 : -1);
float temp = -0.5 * (b + sgnb * sqrtf (disc));
float r1 = temp / a ;
float r2 = c / temp ;
if (r1 < r2)
{
*x0 = r1 ;
*x1 = r2 ;
}
else
{
*x0 = r2 ;
*x1 = r1 ;
}
}
return 2;
}
else if (disc == 0)
{
*x0 = -0.5 * b / a ;
*x1 = -0.5 * b / a ;
return 2 ;
}
else
{
return 0;
}
}
/*
* See Bridson et al. "Robust Treatment of Collision, Contact and Friction for Cloth Animation"
* page 4, left column
*/
int collisions_get_collision_time(float a[3], float b[3], float c[3], float d[3], float e[3], float f[3], float solution[3])
{
int num_sols = 0;
float g = -a[2] * c[1] * e[0] + a[1] * c[2] * e[0] +
a[2] * c[0] * e[1] - a[0] * c[2] * e[1] -
a[1] * c[0] * e[2] + a[0] * c[1] * e[2];
float h = -b[2] * c[1] * e[0] + b[1] * c[2] * e[0] - a[2] * d[1] * e[0] +
a[1] * d[2] * e[0] + b[2] * c[0] * e[1] - b[0] * c[2] * e[1] +
a[2] * d[0] * e[1] - a[0] * d[2] * e[1] - b[1] * c[0] * e[2] +
b[0] * c[1] * e[2] - a[1] * d[0] * e[2] + a[0] * d[1] * e[2] -
a[2] * c[1] * f[0] + a[1] * c[2] * f[0] + a[2] * c[0] * f[1] -
a[0] * c[2] * f[1] - a[1] * c[0] * f[2] + a[0] * c[1] * f[2];
float i = -b[2] * d[1] * e[0] + b[1] * d[2] * e[0] +
b[2] * d[0] * e[1] - b[0] * d[2] * e[1] -
b[1] * d[0] * e[2] + b[0] * d[1] * e[2] -
b[2] * c[1] * f[0] + b[1] * c[2] * f[0] -
a[2] * d[1] * f[0] + a[1] * d[2] * f[0] +
b[2] * c[0] * f[1] - b[0] * c[2] * f[1] +
a[2] * d[0] * f[1] - a[0] * d[2] * f[1] -
b[1] * c[0] * f[2] + b[0] * c[1] * f[2] -
a[1] * d[0] * f[2] + a[0] * d[1] * f[2];
float j = -b[2] * d[1] * f[0] + b[1] * d[2] * f[0] +
b[2] * d[0] * f[1] - b[0] * d[2] * f[1] -
b[1] * d[0] * f[2] + b[0] * d[1] * f[2];
// Solve cubic equation to determine times t1, t2, t3, when the collision will occur.
if(ABS(j) > ALMOST_ZERO)
{
i /= j;
h /= j;
g /= j;
num_sols = gsl_poly_solve_cubic(i, h, g, &solution[0], &solution[1], &solution[2]);
}
else if(ABS(i) > ALMOST_ZERO)
{
num_sols = gsl_poly_solve_quadratic(i, h, g, &solution[0], &solution[1]);
solution[2] = -1.0;
}
else if(ABS(h) > ALMOST_ZERO)
{
solution[0] = -g / h;
solution[1] = solution[2] = -1.0;
num_sols = 1;
}
else if(ABS(g) > ALMOST_ZERO)
{
solution[0] = 0;
solution[1] = solution[2] = -1.0;
num_sols = 1;
}
// Discard negative solutions
if ((num_sols >= 1) && (solution[0] < 0))
{
--num_sols;
solution[0] = solution[num_sols];
}
if ((num_sols >= 2) && (solution[1] < 0))
{
--num_sols;
solution[1] = solution[num_sols];
}
if ((num_sols == 3) && (solution[2] < 0))
{
--num_sols;
}
// Sort
if (num_sols == 2)
{
if (solution[0] > solution[1])
{
double tmp = solution[0];
solution[0] = solution[1];
solution[1] = tmp;
}
}
else if (num_sols == 3)
{
// Bubblesort
if (solution[0] > solution[1]) {
double tmp = solution[0]; solution[0] = solution[1]; solution[1] = tmp;
}
if (solution[1] > solution[2]) {
double tmp = solution[1]; solution[1] = solution[2]; solution[2] = tmp;
}
if (solution[0] > solution[1]) {
double tmp = solution[0]; solution[0] = solution[1]; solution[1] = tmp;
}
}
return num_sols;
}
// w3 is not perfect
void collisions_compute_barycentric (float pv[3], float p1[3], float p2[3], float p3[3], float *w1, float *w2, float *w3)
{
double tempV1[3], tempV2[3], tempV4[3];
double a,b,c,d,e,f;
VECSUB (tempV1, p1, p3);
VECSUB (tempV2, p2, p3);
VECSUB (tempV4, pv, p3);
a = INPR (tempV1, tempV1);
b = INPR (tempV1, tempV2);
c = INPR (tempV2, tempV2);
e = INPR (tempV1, tempV4);
f = INPR (tempV2, tempV4);
d = (a * c - b * b);
if (ABS(d) < ALMOST_ZERO) {
*w1 = *w2 = *w3 = 1.0 / 3.0;
return;
}
w1[0] = (float)((e * c - b * f) / d);
if(w1[0] < 0)
w1[0] = 0;
w2[0] = (float)((f - b * (double)w1[0]) / c);
if(w2[0] < 0)
w2[0] = 0;
w3[0] = 1.0f - w1[0] - w2[0];
}
DO_INLINE void interpolateOnTriangle(float to[3], float v1[3], float v2[3], float v3[3], double w1, double w2, double w3)
{
to[0] = to[1] = to[2] = 0;
VECADDMUL(to, v1, w1);
VECADDMUL(to, v2, w2);
VECADDMUL(to, v3, w3);
}