2 * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
6 * Resources: Box2D - Erin Catto
16 VG_STATIC
void rb_tangent_basis( v3f n
, v3f tx
, v3f ty
);
17 VG_STATIC bh_system bh_system_rigidbodies
;
23 * -----------------------------------------------------------------------------
25 * -----------------------------------------------------------------------------
29 k_rb_rate
= (1.0/VG_TIMESTEP_FIXED
),
30 k_rb_delta
= (1.0/k_rb_rate
),
32 k_damp_linear
= 0.1f
, /* scale velocity 1/(1+x) */
33 k_damp_angular
= 0.1f
, /* scale angular 1/(1+x) */
34 k_penetration_slop
= 0.01f
,
35 k_inertia_scale
= 8.0f
,
36 k_phys_baumgarte
= 0.2f
,
41 k_joint_correction
= 0.01f
,
42 k_joint_impulse
= 1.0f
,
43 k_joint_bias
= 0.08f
; /* positional joints */
45 VG_STATIC
void rb_register_cvar(void)
47 VG_VAR_F32( k_limit_bias
, flags
=VG_VAR_CHEAT
);
48 VG_VAR_F32( k_joint_bias
, flags
=VG_VAR_CHEAT
);
49 VG_VAR_F32( k_joint_correction
, flags
=VG_VAR_CHEAT
);
50 VG_VAR_F32( k_joint_impulse
, flags
=VG_VAR_CHEAT
);
54 * -----------------------------------------------------------------------------
55 * structure definitions
56 * -----------------------------------------------------------------------------
59 typedef struct rigidbody rigidbody
;
60 typedef struct rb_object rb_object
;
61 typedef struct contact rb_ct
;
62 typedef struct rb_sphere rb_sphere
;
63 typedef struct rb_capsule rb_capsule
;
64 typedef struct rb_scene rb_scene
;
85 /* inertia model and inverse world tensor */
88 m4x3f to_world
, to_local
;
96 k_rb_shape_sphere
= 1,
97 k_rb_shape_capsule
= 2,
103 struct rb_sphere sphere
;
104 struct rb_capsule capsule
;
105 struct rb_scene scene
;
110 VG_STATIC
struct contact
{
111 rigidbody
*rba
, *rbb
;
114 float p
, bias
, norm_impulse
, tangent_impulse
[2],
115 normal_mass
, tangent_mass
[2];
119 enum contact_type type
;
121 rb_contact_buffer
[256];
122 VG_STATIC
int rb_contact_count
= 0;
124 typedef struct rb_constr_pos rb_constr_pos
;
125 typedef struct rb_constr_swingtwist rb_constr_swingtwist
;
127 struct rb_constr_pos
{
128 rigidbody
*rba
, *rbb
;
132 struct rb_constr_swingtwist
{
133 rigidbody
*rba
, *rbb
;
135 v4f conevx
, conevy
; /* relative to rba */
136 v3f view_offset
, /* relative to rba */
137 coneva
, conevxb
;/* relative to rbb */
139 int tangent_violation
, axis_violation
;
140 v3f axis
, tangent_axis
, tangent_target
, axis_target
;
143 float tangent_mass
, axis_mass
;
146 struct rb_constr_spring
{
151 * -----------------------------------------------------------------------------
153 * -----------------------------------------------------------------------------
156 VG_STATIC
float sphere_volume( float radius
)
158 float r3
= radius
*radius
*radius
;
159 return (4.0f
/3.0f
) * VG_PIf
* r3
;
162 VG_STATIC
void rb_tangent_basis( v3f n
, v3f tx
, v3f ty
)
164 /* Compute tangent basis (box2d) */
165 if( fabsf( n
[0] ) >= 0.57735027f
){
177 v3_cross( n
, tx
, ty
);
181 * -----------------------------------------------------------------------------
183 * -----------------------------------------------------------------------------
186 VG_STATIC
void rb_debug_contact( rb_ct
*ct
)
189 v3_muladds( ct
->co
, ct
->n
, 0.05f
, p1
);
191 if( ct
->type
== k_contact_type_default
){
192 vg_line_pt3( ct
->co
, 0.0125f
, 0xff0000ff );
193 vg_line( ct
->co
, p1
, 0xffffffff );
195 else if( ct
->type
== k_contact_type_edge
){
196 vg_line_pt3( ct
->co
, 0.0125f
, 0xff00ffc0 );
197 vg_line( ct
->co
, p1
, 0xffffffff );
201 VG_STATIC
void debug_sphere( m4x3f m
, float radius
, u32 colour
)
203 v3f ly
= { 0.0f
, 0.0f
, radius
},
204 lx
= { 0.0f
, radius
, 0.0f
},
205 lz
= { 0.0f
, 0.0f
, radius
};
207 for( int i
=0; i
<16; i
++ ){
208 float t
= ((float)(i
+1) * (1.0f
/16.0f
)) * VG_PIf
* 2.0f
,
212 v3f py
= { s
*radius
, 0.0f
, c
*radius
},
213 px
= { s
*radius
, c
*radius
, 0.0f
},
214 pz
= { 0.0f
, s
*radius
, c
*radius
};
216 v3f p0
, p1
, p2
, p3
, p4
, p5
;
217 m4x3_mulv( m
, py
, p0
);
218 m4x3_mulv( m
, ly
, p1
);
219 m4x3_mulv( m
, px
, p2
);
220 m4x3_mulv( m
, lx
, p3
);
221 m4x3_mulv( m
, pz
, p4
);
222 m4x3_mulv( m
, lz
, p5
);
224 vg_line( p0
, p1
, colour
== 0x00? 0xff00ff00: colour
);
225 vg_line( p2
, p3
, colour
== 0x00? 0xff0000ff: colour
);
226 vg_line( p4
, p5
, colour
== 0x00? 0xffff0000: colour
);
234 VG_STATIC
void debug_capsule( m4x3f m
, float radius
, float h
, u32 colour
)
236 v3f ly
= { 0.0f
, 0.0f
, radius
},
237 lx
= { 0.0f
, radius
, 0.0f
},
238 lz
= { 0.0f
, 0.0f
, radius
};
240 float s0
= sinf(0.0f
)*radius
,
241 c0
= cosf(0.0f
)*radius
;
243 v3f p0
, p1
, up
, right
, forward
;
244 m3x3_mulv( m
, (v3f
){0.0f
,1.0f
,0.0f
}, up
);
245 m3x3_mulv( m
, (v3f
){1.0f
,0.0f
,0.0f
}, right
);
246 m3x3_mulv( m
, (v3f
){0.0f
,0.0f
,-1.0f
}, forward
);
247 v3_muladds( m
[3], up
, -h
*0.5f
+radius
, p0
);
248 v3_muladds( m
[3], up
, h
*0.5f
-radius
, p1
);
251 v3_muladds( p0
, right
, radius
, a0
);
252 v3_muladds( p1
, right
, radius
, a1
);
253 v3_muladds( p0
, forward
, radius
, b0
);
254 v3_muladds( p1
, forward
, radius
, b1
);
255 vg_line( a0
, a1
, colour
);
256 vg_line( b0
, b1
, colour
);
258 v3_muladds( p0
, right
, -radius
, a0
);
259 v3_muladds( p1
, right
, -radius
, a1
);
260 v3_muladds( p0
, forward
, -radius
, b0
);
261 v3_muladds( p1
, forward
, -radius
, b1
);
262 vg_line( a0
, a1
, colour
);
263 vg_line( b0
, b1
, colour
);
265 for( int i
=0; i
<16; i
++ ){
266 float t
= ((float)(i
+1) * (1.0f
/16.0f
)) * VG_PIf
* 2.0f
,
270 v3f e0
= { s0
, 0.0f
, c0
},
271 e1
= { s1
, 0.0f
, c1
},
272 e2
= { s0
, c0
, 0.0f
},
273 e3
= { s1
, c1
, 0.0f
},
274 e4
= { 0.0f
, c0
, s0
},
275 e5
= { 0.0f
, c1
, s1
};
277 m3x3_mulv( m
, e0
, e0
);
278 m3x3_mulv( m
, e1
, e1
);
279 m3x3_mulv( m
, e2
, e2
);
280 m3x3_mulv( m
, e3
, e3
);
281 m3x3_mulv( m
, e4
, e4
);
282 m3x3_mulv( m
, e5
, e5
);
284 v3_add( p0
, e0
, a0
);
285 v3_add( p0
, e1
, a1
);
286 v3_add( p1
, e0
, b0
);
287 v3_add( p1
, e1
, b1
);
289 vg_line( a0
, a1
, colour
);
290 vg_line( b0
, b1
, colour
);
293 v3_add( p0
, e2
, a0
);
294 v3_add( p0
, e3
, a1
);
295 v3_add( p0
, e4
, b0
);
296 v3_add( p0
, e5
, b1
);
299 v3_add( p1
, e2
, a0
);
300 v3_add( p1
, e3
, a1
);
301 v3_add( p1
, e4
, b0
);
302 v3_add( p1
, e5
, b1
);
305 vg_line( a0
, a1
, colour
);
306 vg_line( b0
, b1
, colour
);
313 VG_STATIC
void rb_object_debug( rb_object
*obj
, u32 colour
)
315 if( obj
->type
== k_rb_shape_box
){
316 v3f
*box
= obj
->rb
.bbx
;
317 vg_line_boxf_transformed( obj
->rb
.to_world
, obj
->rb
.bbx
, colour
);
319 else if( obj
->type
== k_rb_shape_sphere
){
320 debug_sphere( obj
->rb
.to_world
, obj
->inf
.sphere
.radius
, colour
);
322 else if( obj
->type
== k_rb_shape_capsule
){
324 float h
= obj
->inf
.capsule
.height
,
325 r
= obj
->inf
.capsule
.radius
;
327 debug_capsule( obj
->rb
.to_world
, r
, h
, colour
);
329 else if( obj
->type
== k_rb_shape_scene
){
330 vg_line_boxf( obj
->rb
.bbx
, colour
);
335 * -----------------------------------------------------------------------------
337 * -----------------------------------------------------------------------------
341 * Update world space bounding box based on local one
343 VG_STATIC
void rb_update_bounds( rigidbody
*rb
)
345 box_copy( rb
->bbx
, rb
->bbx_world
);
346 m4x3_transform_aabb( rb
->to_world
, rb
->bbx_world
);
350 * Commit transform to rigidbody. Updates matrices
352 VG_STATIC
void rb_update_transform( rigidbody
*rb
)
354 q_normalize( rb
->q
);
355 q_m3x3( rb
->q
, rb
->to_world
);
356 v3_copy( rb
->co
, rb
->to_world
[3] );
358 m4x3_invert_affine( rb
->to_world
, rb
->to_local
);
361 m3x3_mulv( rb
->to_world
, (v3f
){1.0f
,0.0f
, 0.0f
}, rb
->right
);
362 m3x3_mulv( rb
->to_world
, (v3f
){0.0f
,1.0f
, 0.0f
}, rb
->up
);
363 m3x3_mulv( rb
->to_world
, (v3f
){0.0f
,0.0f
,-1.0f
}, rb
->forward
);
366 m3x3_mul( rb
->iI
, rb
->to_local
, rb
->iIw
);
367 m3x3_mul( rb
->to_world
, rb
->iIw
, rb
->iIw
);
369 rb_update_bounds( rb
);
373 * Extrapolate rigidbody into a transform based on vg accumulator.
374 * Useful for rendering
376 VG_STATIC
void rb_extrapolate( rigidbody
*rb
, v3f co
, v4f q
)
378 float substep
= vg
.time_fixed_extrapolate
;
379 v3_muladds( rb
->co
, rb
->v
, k_rb_delta
*substep
, co
);
381 if( v3_length2( rb
->w
) > 0.0f
){
384 v3_copy( rb
->w
, axis
);
386 float mag
= v3_length( axis
);
387 v3_divs( axis
, mag
, axis
);
388 q_axis_angle( rotation
, axis
, mag
*k_rb_delta
*substep
);
389 q_mul( rotation
, rb
->q
, q
);
398 * Initialize rigidbody and calculate masses, inertia
400 VG_STATIC
void rb_init_object( rb_object
*obj
)
405 if( obj
->type
== k_rb_shape_box
){
407 v3_sub( obj
->rb
.bbx
[1], obj
->rb
.bbx
[0], dims
);
408 volume
= dims
[0]*dims
[1]*dims
[2];
410 else if( obj
->type
== k_rb_shape_sphere
){
411 volume
= sphere_volume( obj
->inf
.sphere
.radius
);
412 v3_fill( obj
->rb
.bbx
[0], -obj
->inf
.sphere
.radius
);
413 v3_fill( obj
->rb
.bbx
[1], obj
->inf
.sphere
.radius
);
415 else if( obj
->type
== k_rb_shape_capsule
){
416 float r
= obj
->inf
.capsule
.radius
,
417 h
= obj
->inf
.capsule
.height
;
418 volume
= sphere_volume( r
) + VG_PIf
* r
*r
* (h
- r
*2.0f
);
420 v3_fill( obj
->rb
.bbx
[0], -r
);
421 v3_fill( obj
->rb
.bbx
[1], r
);
422 obj
->rb
.bbx
[0][1] = -h
;
423 obj
->rb
.bbx
[1][1] = h
;
425 else if( obj
->type
== k_rb_shape_scene
){
427 box_copy( obj
->inf
.scene
.bh_scene
->nodes
[0].bbx
, obj
->rb
.bbx
);
431 obj
->rb
.inv_mass
= 0.0f
;
432 v3_zero( obj
->rb
.I
);
433 m3x3_zero( obj
->rb
.iI
);
436 float mass
= 2.0f
*volume
;
437 obj
->rb
.inv_mass
= 1.0f
/mass
;
440 v3_sub( obj
->rb
.bbx
[1], obj
->rb
.bbx
[0], extent
);
441 v3_muls( extent
, 0.5f
, extent
);
443 /* local intertia tensor */
444 float scale
= k_inertia_scale
;
445 float ex2
= scale
*extent
[0]*extent
[0],
446 ey2
= scale
*extent
[1]*extent
[1],
447 ez2
= scale
*extent
[2]*extent
[2];
449 obj
->rb
.I
[0] = ((1.0f
/12.0f
) * mass
* (ey2
+ez2
));
450 obj
->rb
.I
[1] = ((1.0f
/12.0f
) * mass
* (ex2
+ez2
));
451 obj
->rb
.I
[2] = ((1.0f
/12.0f
) * mass
* (ex2
+ey2
));
453 m3x3_identity( obj
->rb
.iI
);
454 obj
->rb
.iI
[0][0] = obj
->rb
.I
[0];
455 obj
->rb
.iI
[1][1] = obj
->rb
.I
[1];
456 obj
->rb
.iI
[2][2] = obj
->rb
.I
[2];
457 m3x3_inv( obj
->rb
.iI
, obj
->rb
.iI
);
460 rb_update_transform( &obj
->rb
);
463 VG_STATIC
void rb_iter( rigidbody
*rb
)
465 if( !vg_validf( rb
->v
[0] ) ||
466 !vg_validf( rb
->v
[1] ) ||
467 !vg_validf( rb
->v
[2] ) )
469 vg_fatal_error( "NaN velocity" );
472 v3f gravity
= { 0.0f
, -9.8f
, 0.0f
};
473 v3_muladds( rb
->v
, gravity
, k_rb_delta
, rb
->v
);
475 /* intergrate velocity */
476 v3_muladds( rb
->co
, rb
->v
, k_rb_delta
, rb
->co
);
477 v3_lerp( rb
->w
, (v3f
){0.0f
,0.0f
,0.0f
}, 0.0025f
, rb
->w
);
479 /* inegrate inertia */
480 if( v3_length2( rb
->w
) > 0.0f
)
484 v3_copy( rb
->w
, axis
);
486 float mag
= v3_length( axis
);
487 v3_divs( axis
, mag
, axis
);
488 q_axis_angle( rotation
, axis
, mag
*k_rb_delta
);
489 q_mul( rotation
, rb
->q
, rb
->q
);
493 v3_muls( rb
->v
, 1.0f
/(1.0f
+k_rb_delta
*k_damp_linear
), rb
->v
);
494 v3_muls( rb
->w
, 1.0f
/(1.0f
+k_rb_delta
*k_damp_angular
), rb
->w
);
499 * -----------------------------------------------------------------------------
500 * Boolean shape overlap functions
501 * -----------------------------------------------------------------------------
505 * Project AABB, and triangle interval onto axis to check if they overlap
507 VG_STATIC
int rb_box_triangle_interval( v3f extent
, v3f axis
, v3f tri
[3] )
511 r
= extent
[0] * fabsf(axis
[0]) +
512 extent
[1] * fabsf(axis
[1]) +
513 extent
[2] * fabsf(axis
[2]),
515 p0
= v3_dot( axis
, tri
[0] ),
516 p1
= v3_dot( axis
, tri
[1] ),
517 p2
= v3_dot( axis
, tri
[2] ),
519 e
= vg_maxf(-vg_maxf(p0
,vg_maxf(p1
,p2
)), vg_minf(p0
,vg_minf(p1
,p2
)));
521 if( e
> r
) return 0;
526 * Seperating axis test box vs triangle
528 VG_STATIC
int rb_box_triangle_sat( v3f extent
, v3f center
,
529 m4x3f to_local
, v3f tri_src
[3] )
533 for( int i
=0; i
<3; i
++ ){
534 m4x3_mulv( to_local
, tri_src
[i
], tri
[i
] );
535 v3_sub( tri
[i
], center
, tri
[i
] );
539 v3_sub( tri
[1], tri
[0], f0
);
540 v3_sub( tri
[2], tri
[1], f1
);
541 v3_sub( tri
[0], tri
[2], f2
);
545 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f0
, axis
[0] );
546 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f1
, axis
[1] );
547 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f2
, axis
[2] );
548 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f0
, axis
[3] );
549 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f1
, axis
[4] );
550 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f2
, axis
[5] );
551 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f0
, axis
[6] );
552 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f1
, axis
[7] );
553 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f2
, axis
[8] );
555 for( int i
=0; i
<9; i
++ )
556 if(!rb_box_triangle_interval( extent
, axis
[i
], tri
)) return 0;
559 if(!rb_box_triangle_interval( extent
, (v3f
){1.0f
,0.0f
,0.0f
}, tri
)) return 0;
560 if(!rb_box_triangle_interval( extent
, (v3f
){0.0f
,1.0f
,0.0f
}, tri
)) return 0;
561 if(!rb_box_triangle_interval( extent
, (v3f
){0.0f
,0.0f
,1.0f
}, tri
)) return 0;
564 v3_cross( f0
, f1
, n
);
565 if(!rb_box_triangle_interval( extent
, n
, tri
)) return 0;
571 * -----------------------------------------------------------------------------
573 * -----------------------------------------------------------------------------
576 VG_STATIC
int rb_manifold_apply_filtered( rb_ct
*man
, int len
)
580 for( int i
=0; i
<len
; i
++ ){
583 if( ct
->type
== k_contact_type_disabled
)
593 * Merge two contacts if they are within radius(r) of eachother
595 VG_STATIC
void rb_manifold_contact_weld( rb_ct
*ci
, rb_ct
*cj
, float r
)
597 if( v3_dist2( ci
->co
, cj
->co
) < r
*r
){
598 cj
->type
= k_contact_type_disabled
;
599 ci
->p
= (ci
->p
+ cj
->p
) * 0.5f
;
601 v3_add( ci
->co
, cj
->co
, ci
->co
);
602 v3_muls( ci
->co
, 0.5f
, ci
->co
);
605 v3_sub( ci
->rba
->co
, ci
->co
, delta
);
607 float c0
= v3_dot( ci
->n
, delta
),
608 c1
= v3_dot( cj
->n
, delta
);
610 if( c0
< 0.0f
|| c1
< 0.0f
){
612 ci
->type
= k_contact_type_disabled
;
616 v3_muls( ci
->n
, c0
, n
);
617 v3_muladds( n
, cj
->n
, c1
, n
);
627 VG_STATIC
void rb_manifold_filter_joint_edges( rb_ct
*man
, int len
, float r
)
629 for( int i
=0; i
<len
-1; i
++ ){
631 if( ci
->type
!= k_contact_type_edge
)
634 for( int j
=i
+1; j
<len
; j
++ ){
636 if( cj
->type
!= k_contact_type_edge
)
639 rb_manifold_contact_weld( ci
, cj
, r
);
645 * Resolve overlapping pairs
649 VG_STATIC
void rb_manifold_filter_pairs( rb_ct
*man
, int len
, float r
)
651 for( int i
=0; i
<len
-1; i
++ ){
655 if( ci
->type
== k_contact_type_disabled
) continue;
657 for( int j
=i
+1; j
<len
; j
++ ){
660 if( cj
->type
== k_contact_type_disabled
) continue;
662 if( v3_dist2( ci
->co
, cj
->co
) < r
*r
){
663 cj
->type
= k_contact_type_disabled
;
664 v3_add( cj
->n
, ci
->n
, ci
->n
);
671 float n
= 1.0f
/((float)similar
+1.0f
);
672 v3_muls( ci
->n
, n
, ci
->n
);
675 if( v3_length2(ci
->n
) < 0.1f
*0.1f
)
676 ci
->type
= k_contact_type_disabled
;
678 v3_normalize( ci
->n
);
684 * Remove contacts that are facing away from A
686 VG_STATIC
void rb_manifold_filter_backface( rb_ct
*man
, int len
)
688 for( int i
=0; i
<len
; i
++ ){
690 if( ct
->type
== k_contact_type_disabled
)
694 v3_sub( ct
->co
, ct
->rba
->co
, delta
);
696 if( v3_dot( delta
, ct
->n
) > -0.001f
)
697 ct
->type
= k_contact_type_disabled
;
702 * Filter out duplicate coplanar results. Good for spheres.
704 VG_STATIC
void rb_manifold_filter_coplanar( rb_ct
*man
, int len
, float w
)
706 for( int i
=0; i
<len
; i
++ ){
708 if( ci
->type
== k_contact_type_disabled
||
709 ci
->type
== k_contact_type_edge
)
712 float d1
= v3_dot( ci
->co
, ci
->n
);
714 for( int j
=0; j
<len
; j
++ ){
719 if( cj
->type
== k_contact_type_disabled
)
722 float d2
= v3_dot( cj
->co
, ci
->n
),
725 if( fabsf( d
) <= w
){
726 cj
->type
= k_contact_type_disabled
;
733 * -----------------------------------------------------------------------------
735 * -----------------------------------------------------------------------------
741 * These do not automatically allocate contacts, an appropriately sized
742 * buffer must be supplied. The function returns the size of the manifold
743 * which was generated.
745 * The values set on the contacts are: n, co, p, rba, rbb
749 * By collecting the minimum(time) and maximum(time) pairs of points, we
750 * build a reduced and stable exact manifold.
753 * rx: minimum distance of these points
754 * dx: the delta between the two points
756 * pairs will only ammend these if they are creating a collision
758 typedef struct capsule_manifold capsule_manifold
;
759 struct capsule_manifold
767 * Expand a line manifold with a new pair. t value is the time along segment
768 * on the oriented object which created this pair.
770 VG_STATIC
void rb_capsule_manifold( v3f pa
, v3f pb
, float t
, float r
,
771 capsule_manifold
*manifold
)
774 v3_sub( pa
, pb
, delta
);
776 if( v3_length2(delta
) < r
*r
){
777 if( t
< manifold
->t0
){
778 v3_copy( delta
, manifold
->d0
);
783 if( t
> manifold
->t1
){
784 v3_copy( delta
, manifold
->d1
);
791 VG_STATIC
void rb_capsule_manifold_init( capsule_manifold
*manifold
)
793 manifold
->t0
= INFINITY
;
794 manifold
->t1
= -INFINITY
;
797 VG_STATIC
int rb_capsule__manifold_done( m4x3f mtx
, rb_capsule
*c
,
798 capsule_manifold
*manifold
,
802 v3_muladds( mtx
[3], mtx
[1], -c
->height
*0.5f
+c
->radius
, p0
);
803 v3_muladds( mtx
[3], mtx
[1], c
->height
*0.5f
-c
->radius
, p1
);
806 if( manifold
->t0
<= 1.0f
){
810 v3_muls( p0
, 1.0f
-manifold
->t0
, pa
);
811 v3_muladds( pa
, p1
, manifold
->t0
, pa
);
813 float d
= v3_length( manifold
->d0
);
814 v3_muls( manifold
->d0
, 1.0f
/d
, ct
->n
);
815 v3_muladds( pa
, ct
->n
, -c
->radius
, ct
->co
);
817 ct
->p
= manifold
->r0
- d
;
818 ct
->type
= k_contact_type_default
;
822 if( (manifold
->t1
>= 0.0f
) && (manifold
->t0
!= manifold
->t1
) ){
823 rb_ct
*ct
= buf
+count
;
826 v3_muls( p0
, 1.0f
-manifold
->t1
, pa
);
827 v3_muladds( pa
, p1
, manifold
->t1
, pa
);
829 float d
= v3_length( manifold
->d1
);
830 v3_muls( manifold
->d1
, 1.0f
/d
, ct
->n
);
831 v3_muladds( pa
, ct
->n
, -c
->radius
, ct
->co
);
833 ct
->p
= manifold
->r1
- d
;
834 ct
->type
= k_contact_type_default
;
844 vg_line( buf
[0].co
, buf
[1].co
, 0xff0000ff );
849 VG_STATIC
int rb_capsule_sphere( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
)
851 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
852 float h
= obja
->inf
.capsule
.height
,
853 ra
= obja
->inf
.capsule
.radius
,
854 rb
= objb
->inf
.sphere
.radius
;
857 v3_muladds( rba
->co
, rba
->to_world
[1], -h
*0.5f
+ra
, p0
);
858 v3_muladds( rba
->co
, rba
->to_world
[1], h
*0.5f
-ra
, p1
);
861 closest_point_segment( p0
, p1
, rbb
->co
, c
);
862 v3_sub( c
, rbb
->co
, delta
);
864 float d2
= v3_length2(delta
),
871 v3_muls( delta
, 1.0f
/d
, ct
->n
);
875 v3_muladds( c
, ct
->n
, -ra
, p0
);
876 v3_muladds( rbb
->co
, ct
->n
, rb
, p1
);
877 v3_add( p0
, p1
, ct
->co
);
878 v3_muls( ct
->co
, 0.5f
, ct
->co
);
882 ct
->type
= k_contact_type_default
;
890 VG_STATIC
int rb_capsule__capsule( m4x3f mtxA
, rb_capsule
*ca
,
891 m4x3f mtxB
, rb_capsule
*cb
, rb_ct
*buf
)
893 float ha
= ca
->height
,
900 v3_muladds( mtxA
[3], mtxA
[1], -ha
*0.5f
+ra
, p0
);
901 v3_muladds( mtxA
[3], mtxA
[1], ha
*0.5f
-ra
, p1
);
902 v3_muladds( mtxB
[3], mtxB
[1], -hb
*0.5f
+rb
, p2
);
903 v3_muladds( mtxB
[3], mtxB
[1], hb
*0.5f
-rb
, p3
);
905 capsule_manifold manifold
;
906 rb_capsule_manifold_init( &manifold
);
910 closest_segment_segment( p0
, p1
, p2
, p3
, &ta
, &tb
, pa
, pb
);
911 rb_capsule_manifold( pa
, pb
, ta
, r
, &manifold
);
913 ta
= closest_point_segment( p0
, p1
, p2
, pa
);
914 tb
= closest_point_segment( p0
, p1
, p3
, pb
);
915 rb_capsule_manifold( pa
, p2
, ta
, r
, &manifold
);
916 rb_capsule_manifold( pb
, p3
, tb
, r
, &manifold
);
918 closest_point_segment( p2
, p3
, p0
, pa
);
919 closest_point_segment( p2
, p3
, p1
, pb
);
920 rb_capsule_manifold( p0
, pa
, 0.0f
, r
, &manifold
);
921 rb_capsule_manifold( p1
, pb
, 1.0f
, r
, &manifold
);
923 return rb_capsule__manifold_done( mtxA
, ca
, &manifold
, buf
);
928 * Generates up to two contacts; optimised for the most stable manifold
930 VG_STATIC
int rb_capsule_box( rigidbody
*rba
, rigidbody
*rbb
, rb_ct
*buf
)
932 float h
= rba
->inf
.capsule
.height
,
933 r
= rba
->inf
.capsule
.radius
;
936 * Solving this in symetric local space of the cube saves us some time and a
937 * couple branches when it comes to the quad stage.
940 v3_add( rbb
->bbx
[0], rbb
->bbx
[1], centroid
);
941 v3_muls( centroid
, 0.5f
, centroid
);
944 v3_sub( rbb
->bbx
[0], centroid
, bbx
[0] );
945 v3_sub( rbb
->bbx
[1], centroid
, bbx
[1] );
947 v3f pc
, p0w
, p1w
, p0
, p1
;
948 v3_muladds( rba
->co
, rba
->up
, -h
*0.5f
+r
, p0w
);
949 v3_muladds( rba
->co
, rba
->up
, h
*0.5f
-r
, p1w
);
951 m4x3_mulv( rbb
->to_local
, p0w
, p0
);
952 m4x3_mulv( rbb
->to_local
, p1w
, p1
);
953 v3_sub( p0
, centroid
, p0
);
954 v3_sub( p1
, centroid
, p1
);
955 v3_add( p0
, p1
, pc
);
956 v3_muls( pc
, 0.5f
, pc
);
959 * Finding an appropriate quad to collide lines with
962 v3_div( pc
, bbx
[1], region
);
965 if( (fabsf(region
[0]) > fabsf(region
[1])) &&
966 (fabsf(region
[0]) > fabsf(region
[2])) )
968 float px
= vg_signf(region
[0]) * bbx
[1][0];
969 v3_copy( (v3f
){ px
, bbx
[0][1], bbx
[0][2] }, quad
[0] );
970 v3_copy( (v3f
){ px
, bbx
[1][1], bbx
[0][2] }, quad
[1] );
971 v3_copy( (v3f
){ px
, bbx
[1][1], bbx
[1][2] }, quad
[2] );
972 v3_copy( (v3f
){ px
, bbx
[0][1], bbx
[1][2] }, quad
[3] );
974 else if( fabsf(region
[1]) > fabsf(region
[2]) )
976 float py
= vg_signf(region
[1]) * bbx
[1][1];
977 v3_copy( (v3f
){ bbx
[0][0], py
, bbx
[0][2] }, quad
[0] );
978 v3_copy( (v3f
){ bbx
[1][0], py
, bbx
[0][2] }, quad
[1] );
979 v3_copy( (v3f
){ bbx
[1][0], py
, bbx
[1][2] }, quad
[2] );
980 v3_copy( (v3f
){ bbx
[0][0], py
, bbx
[1][2] }, quad
[3] );
984 float pz
= vg_signf(region
[2]) * bbx
[1][2];
985 v3_copy( (v3f
){ bbx
[0][0], bbx
[0][1], pz
}, quad
[0] );
986 v3_copy( (v3f
){ bbx
[1][0], bbx
[0][1], pz
}, quad
[1] );
987 v3_copy( (v3f
){ bbx
[1][0], bbx
[1][1], pz
}, quad
[2] );
988 v3_copy( (v3f
){ bbx
[0][0], bbx
[1][1], pz
}, quad
[3] );
991 capsule_manifold manifold
;
992 rb_capsule_manifold_init( &manifold
);
995 closest_point_aabb( p0
, bbx
, c0
);
996 closest_point_aabb( p1
, bbx
, c1
);
999 v3_sub( c0
, p0
, d0
);
1000 v3_sub( c1
, p1
, d1
);
1001 v3_sub( p1
, p0
, da
);
1007 if( v3_dot( da
, d0
) <= 0.01f
)
1008 rb_capsule_manifold( p0
, c0
, 0.0f
, r
, &manifold
);
1010 if( v3_dot( da
, d1
) >= -0.01f
)
1011 rb_capsule_manifold( p1
, c1
, 1.0f
, r
, &manifold
);
1013 for( int i
=0; i
<4; i
++ )
1020 closest_segment_segment( p0
, p1
, quad
[i0
], quad
[i1
], &ta
, &tb
, ca
, cb
);
1021 rb_capsule_manifold( ca
, cb
, ta
, r
, &manifold
);
1025 * Create final contacts based on line manifold
1027 m3x3_mulv( rbb
->to_world
, manifold
.d0
, manifold
.d0
);
1028 m3x3_mulv( rbb
->to_world
, manifold
.d1
, manifold
.d1
);
1035 for( int i
=0; i
<4; i
++ )
1041 v3_add( quad
[i0
], centroid
, q0
);
1042 v3_add( quad
[i1
], centroid
, q1
);
1044 m4x3_mulv( rbb
->to_world
, q0
, q0
);
1045 m4x3_mulv( rbb
->to_world
, q1
, q1
);
1047 vg_line( q0
, q1
, 0xffffffff );
1051 return rb_capsule_manifold_done( rba
, rbb
, &manifold
, buf
);
1055 VG_STATIC
int rb_sphere_box( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
)
1058 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
1060 closest_point_obb( rba
->co
, rbb
->bbx
, rbb
->to_world
, rbb
->to_local
, co
);
1061 v3_sub( rba
->co
, co
, delta
);
1063 float d2
= v3_length2(delta
),
1064 r
= obja
->inf
.sphere
.radius
;
1070 if( d2
<= 0.0001f
){
1071 v3_sub( rba
->co
, rbb
->co
, delta
);
1074 * some extra testing is required to find the best axis to push the
1075 * object back outside the box. Since there isnt a clear seperating
1076 * vector already, especially on really high aspect boxes.
1078 float lx
= v3_dot( rbb
->to_world
[0], delta
),
1079 ly
= v3_dot( rbb
->to_world
[1], delta
),
1080 lz
= v3_dot( rbb
->to_world
[2], delta
),
1081 px
= rbb
->bbx
[1][0] - fabsf(lx
),
1082 py
= rbb
->bbx
[1][1] - fabsf(ly
),
1083 pz
= rbb
->bbx
[1][2] - fabsf(lz
);
1085 if( px
< py
&& px
< pz
)
1086 v3_muls( rbb
->to_world
[0], vg_signf(lx
), ct
->n
);
1088 v3_muls( rbb
->to_world
[1], vg_signf(ly
), ct
->n
);
1090 v3_muls( rbb
->to_world
[2], vg_signf(lz
), ct
->n
);
1092 v3_muladds( rba
->co
, ct
->n
, -r
, ct
->co
);
1097 v3_muls( delta
, 1.0f
/d
, ct
->n
);
1099 v3_copy( co
, ct
->co
);
1104 ct
->type
= k_contact_type_default
;
1111 VG_STATIC
int rb_sphere_sphere( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
)
1113 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
1115 v3_sub( rba
->co
, rbb
->co
, delta
);
1117 float d2
= v3_length2(delta
),
1118 r
= obja
->inf
.sphere
.radius
+ objb
->inf
.sphere
.radius
;
1121 float d
= sqrtf(d2
);
1124 v3_muls( delta
, 1.0f
/d
, ct
->n
);
1127 v3_muladds( rba
->co
, ct
->n
,-obja
->inf
.sphere
.radius
, p0
);
1128 v3_muladds( rbb
->co
, ct
->n
, objb
->inf
.sphere
.radius
, p1
);
1129 v3_add( p0
, p1
, ct
->co
);
1130 v3_muls( ct
->co
, 0.5f
, ct
->co
);
1131 ct
->type
= k_contact_type_default
;
1141 //#define RIGIDBODY_DYNAMIC_MESH_EDGES
1144 __attribute__ ((deprecated
))
1145 VG_STATIC
int rb_sphere_triangle( rigidbody
*rba
, rigidbody
*rbb
,
1146 v3f tri
[3], rb_ct
*buf
)
1150 #ifdef RIGIDBODY_DYNAMIC_MESH_EDGES
1151 closest_on_triangle_1( rba
->co
, tri
, co
);
1153 enum contact_type type
= closest_on_triangle_1( rba
->co
, tri
, co
);
1156 v3_sub( rba
->co
, co
, delta
);
1158 float d2
= v3_length2( delta
),
1159 r
= rba
->inf
.sphere
.radius
;
1166 v3_sub( tri
[2], tri
[0], ab
);
1167 v3_sub( tri
[1], tri
[0], ac
);
1168 v3_cross( ac
, ab
, tn
);
1169 v3_copy( tn
, ct
->n
);
1171 if( v3_length2( ct
->n
) <= 0.00001f
)
1173 vg_error( "Zero area triangle!\n" );
1177 v3_normalize( ct
->n
);
1179 float d
= sqrtf(d2
);
1181 v3_copy( co
, ct
->co
);
1193 VG_STATIC
int rb_sphere__triangle( m4x3f mtxA
, rb_sphere
*b
,
1194 v3f tri
[3], rb_ct
*buf
)
1197 enum contact_type type
= closest_on_triangle_1( mtxA
[3], tri
, co
);
1199 v3_sub( mtxA
[3], co
, delta
);
1201 float d2
= v3_length2( delta
),
1208 v3_sub( tri
[2], tri
[0], ab
);
1209 v3_sub( tri
[1], tri
[0], ac
);
1210 v3_cross( ac
, ab
, tn
);
1211 v3_copy( tn
, ct
->n
);
1213 if( v3_length2( ct
->n
) <= 0.00001f
){
1214 vg_error( "Zero area triangle!\n" );
1218 v3_normalize( ct
->n
);
1220 float d
= sqrtf(d2
);
1222 v3_copy( co
, ct
->co
);
1231 VG_STATIC
int rb_sphere__scene( m4x3f mtxA
, rb_sphere
*b
,
1232 m4x3f mtxB
, rb_scene
*s
, rb_ct
*buf
)
1234 scene_context
*sc
= s
->bh_scene
->user
;
1238 float r
= b
->radius
+ 0.1f
;
1240 v3_sub( mtxA
[3], (v3f
){ r
,r
,r
}, box
[0] );
1241 v3_add( mtxA
[3], (v3f
){ r
,r
,r
}, box
[1] );
1245 bh_iter_init_box( 0, &it
, box
);
1247 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
1248 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
1251 for( int j
=0; j
<3; j
++ )
1252 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
1254 buf
[ count
].element_id
= ptri
[0];
1256 vg_line( tri
[0],tri
[1],0x70ff6000 );
1257 vg_line( tri
[1],tri
[2],0x70ff6000 );
1258 vg_line( tri
[2],tri
[0],0x70ff6000 );
1260 int contact
= rb_sphere__triangle( mtxA
, b
, tri
, &buf
[count
] );
1264 vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" );
1272 VG_STATIC
int rb_box__scene( m4x3f mtxA
, boxf bbx
,
1273 m4x3f mtxB
, rb_scene
*s
, rb_ct
*buf
)
1276 scene_context
*sc
= s
->bh_scene
->user
;
1280 v3_sub( bbx
[1], bbx
[0], extent
);
1281 v3_muls( extent
, 0.5f
, extent
);
1282 v3_add( bbx
[0], extent
, center
);
1284 float r
= v3_length(extent
);
1286 v3_fill( world_bbx
[0], -r
);
1287 v3_fill( world_bbx
[1], r
);
1288 for( int i
=0; i
<2; i
++ ){
1289 v3_add( center
, world_bbx
[i
], world_bbx
[i
] );
1290 v3_add( mtxA
[3], world_bbx
[i
], world_bbx
[i
] );
1294 m4x3_invert_affine( mtxA
, to_local
);
1297 bh_iter_init_box( 0, &it
, world_bbx
);
1301 vg_line_boxf( world_bbx
, VG__RED
);
1303 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
1304 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
1306 for( int j
=0; j
<3; j
++ )
1307 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
1309 if( rb_box_triangle_sat( extent
, center
, to_local
, tri
) ){
1310 vg_line(tri
[0],tri
[1],0xff50ff00 );
1311 vg_line(tri
[1],tri
[2],0xff50ff00 );
1312 vg_line(tri
[2],tri
[0],0xff50ff00 );
1315 vg_line(tri
[0],tri
[1],0xff0000ff );
1316 vg_line(tri
[1],tri
[2],0xff0000ff );
1317 vg_line(tri
[2],tri
[0],0xff0000ff );
1322 v3_sub( tri
[1], tri
[0], v0
);
1323 v3_sub( tri
[2], tri
[0], v1
);
1324 v3_cross( v0
, v1
, n
);
1327 /* find best feature */
1328 float best
= v3_dot( mtxA
[0], n
);
1331 for( int i
=1; i
<3; i
++ ){
1332 float c
= v3_dot( mtxA
[i
], n
);
1334 if( fabsf(c
) > fabsf(best
) ){
1343 float px
= best
> 0.0f
? bbx
[0][0]: bbx
[1][0];
1344 manifold
[0][0] = px
;
1345 manifold
[0][1] = bbx
[0][1];
1346 manifold
[0][2] = bbx
[0][2];
1347 manifold
[1][0] = px
;
1348 manifold
[1][1] = bbx
[1][1];
1349 manifold
[1][2] = bbx
[0][2];
1350 manifold
[2][0] = px
;
1351 manifold
[2][1] = bbx
[1][1];
1352 manifold
[2][2] = bbx
[1][2];
1353 manifold
[3][0] = px
;
1354 manifold
[3][1] = bbx
[0][1];
1355 manifold
[3][2] = bbx
[1][2];
1357 else if( axis
== 1 ){
1358 float py
= best
> 0.0f
? bbx
[0][1]: bbx
[1][1];
1359 manifold
[0][0] = bbx
[0][0];
1360 manifold
[0][1] = py
;
1361 manifold
[0][2] = bbx
[0][2];
1362 manifold
[1][0] = bbx
[1][0];
1363 manifold
[1][1] = py
;
1364 manifold
[1][2] = bbx
[0][2];
1365 manifold
[2][0] = bbx
[1][0];
1366 manifold
[2][1] = py
;
1367 manifold
[2][2] = bbx
[1][2];
1368 manifold
[3][0] = bbx
[0][0];
1369 manifold
[3][1] = py
;
1370 manifold
[3][2] = bbx
[1][2];
1373 float pz
= best
> 0.0f
? bbx
[0][2]: bbx
[1][2];
1374 manifold
[0][0] = bbx
[0][0];
1375 manifold
[0][1] = bbx
[0][1];
1376 manifold
[0][2] = pz
;
1377 manifold
[1][0] = bbx
[1][0];
1378 manifold
[1][1] = bbx
[0][1];
1379 manifold
[1][2] = pz
;
1380 manifold
[2][0] = bbx
[1][0];
1381 manifold
[2][1] = bbx
[1][1];
1382 manifold
[2][2] = pz
;
1383 manifold
[3][0] = bbx
[0][0];
1384 manifold
[3][1] = bbx
[1][1];
1385 manifold
[3][2] = pz
;
1388 for( int j
=0; j
<4; j
++ )
1389 m4x3_mulv( mtxA
, manifold
[j
], manifold
[j
] );
1391 vg_line( manifold
[0], manifold
[1], 0xffffffff );
1392 vg_line( manifold
[1], manifold
[2], 0xffffffff );
1393 vg_line( manifold
[2], manifold
[3], 0xffffffff );
1394 vg_line( manifold
[3], manifold
[0], 0xffffffff );
1396 for( int j
=0; j
<4; j
++ ){
1397 rb_ct
*ct
= buf
+count
;
1399 v3_copy( manifold
[j
], ct
->co
);
1400 v3_copy( n
, ct
->n
);
1402 float l0
= v3_dot( tri
[0], n
),
1403 l1
= v3_dot( manifold
[j
], n
);
1405 ct
->p
= (l0
-l1
)*0.5f
;
1409 ct
->type
= k_contact_type_default
;
1419 scene
*sc
= s
->bh_scene
->user
;
1423 v3_sub( bbx
[1], bbx
[0], extent
);
1424 v3_muls( extent
, 0.5f
, extent
);
1425 v3_add( bbx
[0], extent
, center
);
1427 float r
= v3_length(extent
);
1429 v3_fill( world_bbx
[0], -r
);
1430 v3_fill( world_bbx
[1], r
);
1431 for( int i
=0; i
<2; i
++ ){
1432 v3_add( center
, world_bbx
[i
], world_bbx
[i
] );
1433 v3_add( mtxA
[3], world_bbx
[i
], world_bbx
[i
] );
1437 m4x3_invert_affine( mtxA
, to_local
);
1440 bh_iter_init( 0, &it
);
1444 vg_line_boxf( world_bbx
, VG__RED
);
1446 while( bh_next( s
->bh_scene
, &it
, world_bbx
, &idx
) ){
1447 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
1449 for( int j
=0; j
<3; j
++ )
1450 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
1452 vg_line( tri
[0],tri
[1],VG__BLACK
);
1453 vg_line( tri
[1],tri
[2],VG__BLACK
);
1454 vg_line( tri
[2],tri
[0],VG__BLACK
);
1457 u32 clip_length
= 0;
1463 VG_STATIC
int rb_capsule__triangle( m4x3f mtxA
, rb_capsule
*c
,
1464 v3f tri
[3], rb_ct
*buf
)
1467 v3_muladds( mtxA
[3], mtxA
[1], -c
->height
*0.5f
+c
->radius
, p0w
);
1468 v3_muladds( mtxA
[3], mtxA
[1], c
->height
*0.5f
-c
->radius
, p1w
);
1470 capsule_manifold manifold
;
1471 rb_capsule_manifold_init( &manifold
);
1474 closest_on_triangle_1( p0w
, tri
, c0
);
1475 closest_on_triangle_1( p1w
, tri
, c1
);
1478 v3_sub( c0
, p0w
, d0
);
1479 v3_sub( c1
, p1w
, d1
);
1480 v3_sub( p1w
, p0w
, da
);
1486 if( v3_dot( da
, d0
) <= 0.01f
)
1487 rb_capsule_manifold( p0w
, c0
, 0.0f
, c
->radius
, &manifold
);
1489 if( v3_dot( da
, d1
) >= -0.01f
)
1490 rb_capsule_manifold( p1w
, c1
, 1.0f
, c
->radius
, &manifold
);
1492 for( int i
=0; i
<3; i
++ ){
1498 closest_segment_segment( p0w
, p1w
, tri
[i0
], tri
[i1
], &ta
, &tb
, ca
, cb
);
1499 rb_capsule_manifold( ca
, cb
, ta
, c
->radius
, &manifold
);
1503 v3_sub( tri
[1], tri
[0], v0
);
1504 v3_sub( tri
[2], tri
[0], v1
);
1505 v3_cross( v0
, v1
, n
);
1508 int count
= rb_capsule__manifold_done( mtxA
, c
, &manifold
, buf
);
1509 for( int i
=0; i
<count
; i
++ )
1510 v3_copy( n
, buf
[i
].n
);
1515 /* mtxB is defined only for tradition; it is not used currently */
1516 VG_STATIC
int rb_capsule__scene( m4x3f mtxA
, rb_capsule
*c
,
1517 m4x3f mtxB
, rb_scene
*s
,
1523 v3_sub( mtxA
[3], (v3f
){ c
->height
, c
->height
, c
->height
}, bbx
[0] );
1524 v3_add( mtxA
[3], (v3f
){ c
->height
, c
->height
, c
->height
}, bbx
[1] );
1526 scene_context
*sc
= s
->bh_scene
->user
;
1529 bh_iter_init_box( 0, &it
, bbx
);
1531 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
1532 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
1535 for( int j
=0; j
<3; j
++ )
1536 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
1538 buf
[ count
].element_id
= ptri
[0];
1540 int contact
= rb_capsule__triangle( mtxA
, c
, tri
, &buf
[count
] );
1544 vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
1552 VG_STATIC
int rb_global_has_space( void )
1554 if( rb_contact_count
+ 16 > vg_list_size(rb_contact_buffer
) )
1560 VG_STATIC rb_ct
*rb_global_buffer( void )
1562 return &rb_contact_buffer
[ rb_contact_count
];
1566 * -----------------------------------------------------------------------------
1568 * -----------------------------------------------------------------------------
1571 VG_STATIC
void rb_solver_reset(void)
1573 rb_contact_count
= 0;
1576 VG_STATIC rb_ct
*rb_global_ct(void)
1578 return rb_contact_buffer
+ rb_contact_count
;
1581 VG_STATIC
void rb_prepare_contact( rb_ct
*ct
, float timestep
)
1583 ct
->bias
= -0.2f
* (timestep
*3600.0f
)
1584 * vg_minf( 0.0f
, -ct
->p
+k_penetration_slop
);
1586 rb_tangent_basis( ct
->n
, ct
->t
[0], ct
->t
[1] );
1587 ct
->norm_impulse
= 0.0f
;
1588 ct
->tangent_impulse
[0] = 0.0f
;
1589 ct
->tangent_impulse
[1] = 0.0f
;
1592 /* calculate total move. manifold should belong to ONE object only */
1593 VG_STATIC
void rb_depenetrate( rb_ct
*manifold
, int len
, v3f dt
)
1597 for( int j
=0; j
<7; j
++ )
1599 for( int i
=0; i
<len
; i
++ )
1601 struct contact
*ct
= &manifold
[i
];
1603 float resolved_amt
= v3_dot( ct
->n
, dt
),
1604 remaining
= (ct
->p
-k_penetration_slop
) - resolved_amt
,
1605 apply
= vg_maxf( remaining
, 0.0f
) * 0.4f
;
1607 v3_muladds( dt
, ct
->n
, apply
, dt
);
1613 * Initializing things like tangent vectors
1615 VG_STATIC
void rb_presolve_contacts( rb_ct
*buffer
, int len
)
1617 for( int i
=0; i
<len
; i
++ ){
1618 rb_ct
*ct
= &buffer
[i
];
1619 rb_prepare_contact( ct
, k_rb_delta
);
1621 v3f ra
, rb
, raCn
, rbCn
, raCt
, rbCt
;
1622 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1623 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1624 v3_cross( ra
, ct
->n
, raCn
);
1625 v3_cross( rb
, ct
->n
, rbCn
);
1627 /* orient inverse inertia tensors */
1629 m3x3_mulv( ct
->rba
->iIw
, raCn
, raCnI
);
1630 m3x3_mulv( ct
->rbb
->iIw
, rbCn
, rbCnI
);
1632 ct
->normal_mass
= ct
->rba
->inv_mass
+ ct
->rbb
->inv_mass
;
1633 ct
->normal_mass
+= v3_dot( raCn
, raCnI
);
1634 ct
->normal_mass
+= v3_dot( rbCn
, rbCnI
);
1635 ct
->normal_mass
= 1.0f
/ct
->normal_mass
;
1637 for( int j
=0; j
<2; j
++ ){
1639 v3_cross( ct
->t
[j
], ra
, raCt
);
1640 v3_cross( ct
->t
[j
], rb
, rbCt
);
1641 m3x3_mulv( ct
->rba
->iIw
, raCt
, raCtI
);
1642 m3x3_mulv( ct
->rbb
->iIw
, rbCt
, rbCtI
);
1644 ct
->tangent_mass
[j
] = ct
->rba
->inv_mass
+ ct
->rbb
->inv_mass
;
1645 ct
->tangent_mass
[j
] += v3_dot( raCt
, raCtI
);
1646 ct
->tangent_mass
[j
] += v3_dot( rbCt
, rbCtI
);
1647 ct
->tangent_mass
[j
] = 1.0f
/ct
->tangent_mass
[j
];
1650 rb_debug_contact( ct
);
1655 * Creates relative contact velocity vector
1657 VG_STATIC
void rb_rcv( rigidbody
*rba
, rigidbody
*rbb
, v3f ra
, v3f rb
, v3f rv
)
1660 v3_cross( rba
->w
, ra
, rva
);
1661 v3_add( rba
->v
, rva
, rva
);
1662 v3_cross( rbb
->w
, rb
, rvb
);
1663 v3_add( rbb
->v
, rvb
, rvb
);
1665 v3_sub( rva
, rvb
, rv
);
1668 VG_STATIC
void rb_contact_restitution( rb_ct
*ct
, float cr
)
1671 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1672 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1673 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1675 float v
= v3_dot( rv
, ct
->n
);
1678 ct
->bias
+= -cr
* v
;
1683 * Apply impulse to object
1685 VG_STATIC
void rb_linear_impulse( rigidbody
*rb
, v3f delta
, v3f impulse
)
1688 v3_muladds( rb
->v
, impulse
, rb
->inv_mass
, rb
->v
);
1690 /* Angular velocity */
1692 v3_cross( delta
, impulse
, wa
);
1694 m3x3_mulv( rb
->iIw
, wa
, wa
);
1695 v3_add( rb
->w
, wa
, rb
->w
);
1699 * One iteration to solve the contact constraint
1701 VG_STATIC
void rb_solve_contacts( rb_ct
*buf
, int len
)
1703 for( int i
=0; i
<len
; i
++ ){
1704 struct contact
*ct
= &buf
[i
];
1707 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1708 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1709 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1712 for( int j
=0; j
<2; j
++ ){
1713 float f
= k_friction
* ct
->norm_impulse
,
1714 vt
= v3_dot( rv
, ct
->t
[j
] ),
1715 lambda
= ct
->tangent_mass
[j
] * -vt
;
1717 float temp
= ct
->tangent_impulse
[j
];
1718 ct
->tangent_impulse
[j
] = vg_clampf( temp
+ lambda
, -f
, f
);
1719 lambda
= ct
->tangent_impulse
[j
] - temp
;
1722 v3_muls( ct
->t
[j
], lambda
, impulse
);
1723 rb_linear_impulse( ct
->rba
, ra
, impulse
);
1725 v3_muls( ct
->t
[j
], -lambda
, impulse
);
1726 rb_linear_impulse( ct
->rbb
, rb
, impulse
);
1730 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1731 float vn
= v3_dot( rv
, ct
->n
),
1732 lambda
= ct
->normal_mass
* (-vn
+ ct
->bias
);
1734 float temp
= ct
->norm_impulse
;
1735 ct
->norm_impulse
= vg_maxf( temp
+ lambda
, 0.0f
);
1736 lambda
= ct
->norm_impulse
- temp
;
1739 v3_muls( ct
->n
, lambda
, impulse
);
1740 rb_linear_impulse( ct
->rba
, ra
, impulse
);
1742 v3_muls( ct
->n
, -lambda
, impulse
);
1743 rb_linear_impulse( ct
->rbb
, rb
, impulse
);
1748 * -----------------------------------------------------------------------------
1750 * -----------------------------------------------------------------------------
1753 VG_STATIC
void rb_debug_position_constraints( rb_constr_pos
*buffer
, int len
)
1755 for( int i
=0; i
<len
; i
++ ){
1756 rb_constr_pos
*constr
= &buffer
[i
];
1757 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
1760 m3x3_mulv( rba
->to_world
, constr
->lca
, wca
);
1761 m3x3_mulv( rbb
->to_world
, constr
->lcb
, wcb
);
1764 v3_add( wca
, rba
->co
, p0
);
1765 v3_add( wcb
, rbb
->co
, p1
);
1766 vg_line_pt3( p0
, 0.0025f
, 0xff000000 );
1767 vg_line_pt3( p1
, 0.0025f
, 0xffffffff );
1768 vg_line2( p0
, p1
, 0xff000000, 0xffffffff );
1772 VG_STATIC
void rb_presolve_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1777 for( int i
=0; i
<len
; i
++ ){
1778 rb_constr_swingtwist
*st
= &buf
[ i
];
1780 v3f vx
, vy
, va
, vxb
, axis
, center
;
1782 m3x3_mulv( st
->rba
->to_world
, st
->conevx
, vx
);
1783 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
1784 m3x3_mulv( st
->rba
->to_world
, st
->conevy
, vy
);
1785 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
1786 m4x3_mulv( st
->rba
->to_world
, st
->view_offset
, center
);
1787 v3_cross( vy
, vx
, axis
);
1789 /* Constraint violated ? */
1790 float fx
= v3_dot( vx
, va
), /* projection world */
1791 fy
= v3_dot( vy
, va
),
1792 fn
= v3_dot( va
, axis
),
1794 rx
= st
->conevx
[3], /* elipse radii */
1797 lx
= fx
/rx
, /* projection local (fn==lz) */
1800 st
->tangent_violation
= ((lx
*lx
+ ly
*ly
) > fn
*fn
) || (fn
<= 0.0f
);
1801 if( st
->tangent_violation
){
1802 /* Calculate a good position and the axis to solve on */
1803 v2f closest
, tangent
,
1804 p
= { fx
/fabsf(fn
), fy
/fabsf(fn
) };
1806 closest_point_elipse( p
, (v2f
){rx
,ry
}, closest
);
1807 tangent
[0] = -closest
[1] / (ry
*ry
);
1808 tangent
[1] = closest
[0] / (rx
*rx
);
1809 v2_normalize( tangent
);
1812 v3_muladds( axis
, vx
, closest
[0], v0
);
1813 v3_muladds( v0
, vy
, closest
[1], v0
);
1816 v3_muls( vx
, tangent
[0], v1
);
1817 v3_muladds( v1
, vy
, tangent
[1], v1
);
1819 v3_copy( v0
, st
->tangent_target
);
1820 v3_copy( v1
, st
->tangent_axis
);
1822 /* calculate mass */
1824 m3x3_mulv( st
->rba
->iIw
, st
->tangent_axis
, aIw
);
1825 m3x3_mulv( st
->rbb
->iIw
, st
->tangent_axis
, bIw
);
1826 st
->tangent_mass
= 1.0f
/ (v3_dot( st
->tangent_axis
, aIw
) +
1827 v3_dot( st
->tangent_axis
, bIw
));
1829 float angle
= v3_dot( va
, st
->tangent_target
);
1833 v3_cross( vy
, va
, refaxis
); /* our default rotation */
1834 v3_normalize( refaxis
);
1836 float angle
= v3_dot( refaxis
, vxb
);
1837 st
->axis_violation
= fabsf(angle
) < st
->conet
;
1839 if( st
->axis_violation
){
1841 v3_cross( refaxis
, vxb
, dir_test
);
1843 if( v3_dot(dir_test
, va
) < 0.0f
)
1844 st
->axis_violation
= -st
->axis_violation
;
1846 float newang
= (float)st
->axis_violation
* acosf(st
->conet
-0.0001f
);
1849 v3_cross( va
, refaxis
, refaxis_up
);
1850 v3_muls( refaxis_up
, sinf(newang
), st
->axis_target
);
1851 v3_muladds( st
->axis_target
, refaxis
, -cosf(newang
), st
->axis_target
);
1853 /* calculate mass */
1854 v3_copy( va
, st
->axis
);
1856 m3x3_mulv( st
->rba
->iIw
, st
->axis
, aIw
);
1857 m3x3_mulv( st
->rbb
->iIw
, st
->axis
, bIw
);
1858 st
->axis_mass
= 1.0f
/ (v3_dot( st
->axis
, aIw
) +
1859 v3_dot( st
->axis
, bIw
));
1864 VG_STATIC
void rb_debug_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1869 for( int i
=0; i
<len
; i
++ ){
1870 rb_constr_swingtwist
*st
= &buf
[ i
];
1872 v3f vx
, vxb
, vy
, va
, axis
, center
;
1874 m3x3_mulv( st
->rba
->to_world
, st
->conevx
, vx
);
1875 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
1876 m3x3_mulv( st
->rba
->to_world
, st
->conevy
, vy
);
1877 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
1878 m4x3_mulv( st
->rba
->to_world
, st
->view_offset
, center
);
1879 v3_cross( vy
, vx
, axis
);
1881 float rx
= st
->conevx
[3], /* elipse radii */
1885 v3_muladds( center
, va
, size
, p1
);
1886 vg_line( center
, p1
, 0xffffffff );
1887 vg_line_pt3( p1
, 0.00025f
, 0xffffffff );
1889 if( st
->tangent_violation
){
1890 v3_muladds( center
, st
->tangent_target
, size
, p0
);
1892 vg_line( center
, p0
, 0xff00ff00 );
1893 vg_line_pt3( p0
, 0.00025f
, 0xff00ff00 );
1894 vg_line( p1
, p0
, 0xff000000 );
1897 for( int x
=0; x
<32; x
++ ){
1898 float t0
= ((float)x
* (1.0f
/32.0f
)) * VG_TAUf
,
1899 t1
= (((float)x
+1.0f
) * (1.0f
/32.0f
)) * VG_TAUf
,
1906 v3_muladds( axis
, vx
, c0
*rx
, v0
);
1907 v3_muladds( v0
, vy
, s0
*ry
, v0
);
1908 v3_muladds( axis
, vx
, c1
*rx
, v1
);
1909 v3_muladds( v1
, vy
, s1
*ry
, v1
);
1914 v3_muladds( center
, v0
, size
, p0
);
1915 v3_muladds( center
, v1
, size
, p1
);
1917 u32 col0r
= fabsf(c0
) * 255.0f
,
1918 col0g
= fabsf(s0
) * 255.0f
,
1919 col1r
= fabsf(c1
) * 255.0f
,
1920 col1g
= fabsf(s1
) * 255.0f
,
1921 col
= st
->tangent_violation
? 0xff0000ff: 0xff000000,
1922 col0
= col
| (col0r
<<16) | (col0g
<< 8),
1923 col1
= col
| (col1r
<<16) | (col1g
<< 8);
1925 vg_line2( center
, p0
, VG__NONE
, col0
);
1926 vg_line2( p0
, p1
, col0
, col1
);
1930 v3_muladds( center
, va
, size
, p0
);
1931 v3_muladds( p0
, vxb
, size
, p1
);
1933 vg_line( p0
, p1
, 0xff0000ff );
1935 if( st
->axis_violation
){
1936 v3_muladds( p0
, st
->axis_target
, size
*1.25f
, p1
);
1937 vg_line( p0
, p1
, 0xffffff00 );
1938 vg_line_pt3( p1
, 0.0025f
, 0xffffff80 );
1942 v3_cross( vy
, va
, refaxis
); /* our default rotation */
1943 v3_normalize( refaxis
);
1945 v3_cross( va
, refaxis
, refaxis_up
);
1946 float newang
= acosf(st
->conet
-0.0001f
);
1948 v3_muladds( p0
, refaxis_up
, sinf(newang
)*size
, p1
);
1949 v3_muladds( p1
, refaxis
, -cosf(newang
)*size
, p1
);
1950 vg_line( p0
, p1
, 0xff000000 );
1952 v3_muladds( p0
, refaxis_up
, sinf(-newang
)*size
, p1
);
1953 v3_muladds( p1
, refaxis
, -cosf(-newang
)*size
, p1
);
1954 vg_line( p0
, p1
, 0xff404040 );
1959 * Solve a list of positional constraints
1961 VG_STATIC
void rb_solve_position_constraints( rb_constr_pos
*buf
, int len
)
1963 for( int i
=0; i
<len
; i
++ ){
1964 rb_constr_pos
*constr
= &buf
[i
];
1965 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
1968 m3x3_mulv( rba
->to_world
, constr
->lca
, wa
);
1969 m3x3_mulv( rbb
->to_world
, constr
->lcb
, wb
);
1971 m3x3f ssra
, ssrat
, ssrb
, ssrbt
;
1973 m3x3_skew_symetric( ssrat
, wa
);
1974 m3x3_skew_symetric( ssrbt
, wb
);
1975 m3x3_transpose( ssrat
, ssra
);
1976 m3x3_transpose( ssrbt
, ssrb
);
1978 v3f b
, b_wa
, b_wb
, b_a
, b_b
;
1979 m3x3_mulv( ssra
, rba
->w
, b_wa
);
1980 m3x3_mulv( ssrb
, rbb
->w
, b_wb
);
1981 v3_add( rba
->v
, b_wa
, b
);
1982 v3_sub( b
, rbb
->v
, b
);
1983 v3_sub( b
, b_wb
, b
);
1984 v3_muls( b
, -1.0f
, b
);
1987 m3x3_diagonal( invMa
, rba
->inv_mass
);
1988 m3x3_diagonal( invMb
, rbb
->inv_mass
);
1991 m3x3_mul( ssra
, rba
->iIw
, ia
);
1992 m3x3_mul( ia
, ssrat
, ia
);
1993 m3x3_mul( ssrb
, rbb
->iIw
, ib
);
1994 m3x3_mul( ib
, ssrbt
, ib
);
1997 m3x3_add( invMa
, ia
, cma
);
1998 m3x3_add( invMb
, ib
, cmb
);
2001 m3x3_add( cma
, cmb
, A
);
2003 /* Solve Ax = b ( A^-1*b = x ) */
2006 m3x3_inv( A
, invA
);
2007 m3x3_mulv( invA
, b
, impulse
);
2009 v3f delta_va
, delta_wa
, delta_vb
, delta_wb
;
2011 m3x3_mul( rba
->iIw
, ssrat
, iwa
);
2012 m3x3_mul( rbb
->iIw
, ssrbt
, iwb
);
2014 m3x3_mulv( invMa
, impulse
, delta_va
);
2015 m3x3_mulv( invMb
, impulse
, delta_vb
);
2016 m3x3_mulv( iwa
, impulse
, delta_wa
);
2017 m3x3_mulv( iwb
, impulse
, delta_wb
);
2019 v3_add( rba
->v
, delta_va
, rba
->v
);
2020 v3_add( rba
->w
, delta_wa
, rba
->w
);
2021 v3_sub( rbb
->v
, delta_vb
, rbb
->v
);
2022 v3_sub( rbb
->w
, delta_wb
, rbb
->w
);
2026 VG_STATIC
void rb_solve_swingtwist_constraints( rb_constr_swingtwist
*buf
,
2031 for( int i
=0; i
<len
; i
++ ){
2032 rb_constr_swingtwist
*st
= &buf
[ i
];
2034 if( !st
->axis_violation
)
2037 float rv
= v3_dot( st
->axis
, st
->rbb
->w
) -
2038 v3_dot( st
->axis
, st
->rba
->w
);
2040 if( rv
* (float)st
->axis_violation
> 0.0f
)
2043 v3f impulse
, wa
, wb
;
2044 v3_muls( st
->axis
, rv
*st
->axis_mass
, impulse
);
2045 m3x3_mulv( st
->rba
->iIw
, impulse
, wa
);
2046 v3_add( st
->rba
->w
, wa
, st
->rba
->w
);
2048 v3_muls( impulse
, -1.0f
, impulse
);
2049 m3x3_mulv( st
->rbb
->iIw
, impulse
, wb
);
2050 v3_add( st
->rbb
->w
, wb
, st
->rbb
->w
);
2052 float rv2
= v3_dot( st
->axis
, st
->rbb
->w
) -
2053 v3_dot( st
->axis
, st
->rba
->w
);
2056 for( int i
=0; i
<len
; i
++ ){
2057 rb_constr_swingtwist
*st
= &buf
[ i
];
2059 if( !st
->tangent_violation
)
2062 float rv
= v3_dot( st
->tangent_axis
, st
->rbb
->w
) -
2063 v3_dot( st
->tangent_axis
, st
->rba
->w
);
2068 v3f impulse
, wa
, wb
;
2069 v3_muls( st
->tangent_axis
, rv
*st
->tangent_mass
, impulse
);
2070 m3x3_mulv( st
->rba
->iIw
, impulse
, wa
);
2071 v3_add( st
->rba
->w
, wa
, st
->rba
->w
);
2073 v3_muls( impulse
, -1.0f
, impulse
);
2074 m3x3_mulv( st
->rbb
->iIw
, impulse
, wb
);
2075 v3_add( st
->rbb
->w
, wb
, st
->rbb
->w
);
2077 float rv2
= v3_dot( st
->tangent_axis
, st
->rbb
->w
) -
2078 v3_dot( st
->tangent_axis
, st
->rba
->w
);
2082 VG_STATIC
void rb_solve_constr_angle( rigidbody
*rba
, rigidbody
*rbb
,
2085 m3x3f ssra
, ssrb
, ssrat
, ssrbt
;
2088 m3x3_skew_symetric( ssrat
, ra
);
2089 m3x3_skew_symetric( ssrbt
, rb
);
2090 m3x3_transpose( ssrat
, ssra
);
2091 m3x3_transpose( ssrbt
, ssrb
);
2093 m3x3_mul( ssra
, rba
->iIw
, cma
);
2094 m3x3_mul( cma
, ssrat
, cma
);
2095 m3x3_mul( ssrb
, rbb
->iIw
, cmb
);
2096 m3x3_mul( cmb
, ssrbt
, cmb
);
2099 m3x3_add( cma
, cmb
, A
);
2100 m3x3_inv( A
, invA
);
2103 m3x3_mulv( ssra
, rba
->w
, b_wa
);
2104 m3x3_mulv( ssrb
, rbb
->w
, b_wb
);
2105 v3_add( b_wa
, b_wb
, b
);
2109 m3x3_mulv( invA
, b
, impulse
);
2111 v3f delta_wa
, delta_wb
;
2113 m3x3_mul( rba
->iIw
, ssrat
, iwa
);
2114 m3x3_mul( rbb
->iIw
, ssrbt
, iwb
);
2115 m3x3_mulv( iwa
, impulse
, delta_wa
);
2116 m3x3_mulv( iwb
, impulse
, delta_wb
);
2117 v3_add( rba
->w
, delta_wa
, rba
->w
);
2118 v3_sub( rbb
->w
, delta_wb
, rbb
->w
);
2122 * Correct position constraint drift errors
2123 * [ 0.0 <= amt <= 1.0 ]: the correction amount
2125 VG_STATIC
void rb_correct_position_constraints( rb_constr_pos
*buf
, int len
,
2128 for( int i
=0; i
<len
; i
++ ){
2129 rb_constr_pos
*constr
= &buf
[i
];
2130 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
2133 m3x3_mulv( rba
->to_world
, constr
->lca
, p0
);
2134 m3x3_mulv( rbb
->to_world
, constr
->lcb
, p1
);
2135 v3_add( rba
->co
, p0
, p0
);
2136 v3_add( rbb
->co
, p1
, p1
);
2137 v3_sub( p1
, p0
, d
);
2139 v3_muladds( rbb
->co
, d
, -1.0f
* amt
, rbb
->co
);
2140 rb_update_transform( rbb
);
2144 VG_STATIC
void rb_correct_swingtwist_constraints( rb_constr_swingtwist
*buf
,
2145 int len
, float amt
)
2147 for( int i
=0; i
<len
; i
++ ){
2148 rb_constr_swingtwist
*st
= &buf
[i
];
2150 if( !st
->tangent_violation
)
2154 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
2156 float angle
= v3_dot( va
, st
->tangent_target
);
2158 if( fabsf(angle
) < 0.9999f
){
2160 v3_cross( va
, st
->tangent_target
, axis
);
2163 q_axis_angle( correction
, axis
, acosf(angle
) * amt
);
2164 q_mul( correction
, st
->rbb
->q
, st
->rbb
->q
);
2165 rb_update_transform( st
->rbb
);
2169 for( int i
=0; i
<len
; i
++ ){
2170 rb_constr_swingtwist
*st
= &buf
[i
];
2172 if( !st
->axis_violation
)
2176 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
2178 float angle
= v3_dot( vxb
, st
->axis_target
);
2180 if( fabsf(angle
) < 0.9999f
){
2182 v3_cross( vxb
, st
->axis_target
, axis
);
2185 q_axis_angle( correction
, axis
, acosf(angle
) * amt
);
2186 q_mul( correction
, st
->rbb
->q
, st
->rbb
->q
);
2187 rb_update_transform( st
->rbb
);
2192 VG_STATIC
void rb_correct_contact_constraints( rb_ct
*buf
, int len
, float amt
)
2194 for( int i
=0; i
<len
; i
++ ){
2195 rb_ct
*ct
= &buf
[i
];
2196 rigidbody
*rba
= ct
->rba
,
2199 float mass_total
= 1.0f
/ (rba
->inv_mass
+ rbb
->inv_mass
);
2201 v3_muladds( rba
->co
, ct
->n
, -mass_total
* rba
->inv_mass
, rba
->co
);
2202 v3_muladds( rbb
->co
, ct
->n
, mass_total
* rbb
->inv_mass
, rbb
->co
);
2211 VG_STATIC
void rb_effect_simple_bouyency( rigidbody
*ra
, v4f plane
,
2212 float amt
, float drag
)
2215 float depth
= v3_dot( plane
, ra
->co
) - plane
[3],
2216 lambda
= vg_clampf( -depth
, 0.0f
, 1.0f
) * amt
;
2218 v3_muladds( ra
->v
, plane
, lambda
* k_rb_delta
, ra
->v
);
2221 v3_muls( ra
->v
, 1.0f
-(drag
*k_rb_delta
), ra
->v
);
2224 /* apply a spring&dampener force to match ra(worldspace) on rigidbody, to
2227 VG_STATIC
void rb_effect_spring_target_vector( rigidbody
*rba
, v3f ra
, v3f rt
,
2228 float spring
, float dampening
,
2231 float d
= v3_dot( rt
, ra
);
2232 float a
= vg_signf( d
) * acosf( vg_clampf( d
, -1.0f
, 1.0f
) );
2235 v3_cross( rt
, ra
, axis
);
2237 float Fs
= -a
* spring
,
2238 Fd
= -v3_dot( rba
->w
, axis
) * dampening
;
2240 v3_muladds( rba
->w
, axis
, (Fs
+Fd
) * timestep
, rba
->w
);
2243 #endif /* RIGIDBODY_H */