2 * Copyright (C) 2021-2023 Mt.ZERO Software, Harry Godden - All Rights Reserved
6 * Resources: Box2D - Erin Catto
10 #include "vg/vg_console.h"
16 static bh_system bh_system_rigidbodies
;
22 * -----------------------------------------------------------------------------
24 * -----------------------------------------------------------------------------
28 k_rb_rate
= (1.0/VG_TIMESTEP_FIXED
),
29 k_rb_delta
= (1.0/k_rb_rate
),
31 k_damp_linear
= 0.1f
, /* scale velocity 1/(1+x) */
32 k_damp_angular
= 0.1f
, /* scale angular 1/(1+x) */
33 k_penetration_slop
= 0.01f
,
34 k_inertia_scale
= 8.0f
,
35 k_phys_baumgarte
= 0.2f
,
40 k_joint_correction
= 0.01f
,
41 k_joint_impulse
= 1.0f
,
42 k_joint_bias
= 0.08f
; /* positional joints */
44 static void rb_register_cvar(void){
45 VG_VAR_F32( k_limit_bias
, flags
=VG_VAR_CHEAT
);
46 VG_VAR_F32( k_joint_bias
, flags
=VG_VAR_CHEAT
);
47 VG_VAR_F32( k_joint_correction
, flags
=VG_VAR_CHEAT
);
48 VG_VAR_F32( k_joint_impulse
, flags
=VG_VAR_CHEAT
);
52 * -----------------------------------------------------------------------------
53 * structure definitions
54 * -----------------------------------------------------------------------------
57 typedef struct rigidbody rigidbody
;
58 typedef struct rb_object rb_object
;
59 typedef struct contact rb_ct
;
60 typedef struct rb_sphere rb_sphere
;
61 typedef struct rb_capsule rb_capsule
;
62 typedef struct rb_scene rb_scene
;
83 /* inertia model and inverse world tensor */
86 m4x3f to_world
, to_local
;
94 k_rb_shape_sphere
= 1,
95 k_rb_shape_capsule
= 2,
101 struct rb_sphere sphere
;
102 struct rb_capsule capsule
;
103 struct rb_scene scene
;
108 VG_STATIC
struct contact
{
109 rigidbody
*rba
, *rbb
;
112 float p
, bias
, norm_impulse
, tangent_impulse
[2],
113 normal_mass
, tangent_mass
[2];
117 enum contact_type type
;
119 rb_contact_buffer
[256];
120 VG_STATIC
int rb_contact_count
= 0;
122 typedef struct rb_constr_pos rb_constr_pos
;
123 typedef struct rb_constr_swingtwist rb_constr_swingtwist
;
125 struct rb_constr_pos
{
126 rigidbody
*rba
, *rbb
;
130 struct rb_constr_swingtwist
{
131 rigidbody
*rba
, *rbb
;
133 v4f conevx
, conevy
; /* relative to rba */
134 v3f view_offset
, /* relative to rba */
135 coneva
, conevxb
;/* relative to rbb */
137 int tangent_violation
, axis_violation
;
138 v3f axis
, tangent_axis
, tangent_target
, axis_target
;
141 float tangent_mass
, axis_mass
;
145 * -----------------------------------------------------------------------------
147 * -----------------------------------------------------------------------------
150 VG_STATIC
void rb_debug_contact( rb_ct
*ct
){
152 v3_muladds( ct
->co
, ct
->n
, 0.05f
, p1
);
154 if( ct
->type
== k_contact_type_default
){
155 vg_line_point( ct
->co
, 0.0125f
, 0xff0000ff );
156 vg_line( ct
->co
, p1
, 0xffffffff );
158 else if( ct
->type
== k_contact_type_edge
){
159 vg_line_point( ct
->co
, 0.0125f
, 0xff00ffc0 );
160 vg_line( ct
->co
, p1
, 0xffffffff );
165 VG_STATIC
void rb_object_debug( rb_object
*obj
, u32 colour
){
166 if( obj
->type
== k_rb_shape_box
){
167 v3f
*box
= obj
->rb
.bbx
;
168 vg_line_boxf_transformed( obj
->rb
.to_world
, obj
->rb
.bbx
, colour
);
170 else if( obj
->type
== k_rb_shape_sphere
){
171 vg_line_sphere( obj
->rb
.to_world
, obj
->inf
.sphere
.radius
, colour
);
173 else if( obj
->type
== k_rb_shape_capsule
){
175 float h
= obj
->inf
.capsule
.height
,
176 r
= obj
->inf
.capsule
.radius
;
178 vg_line_capsule( obj
->rb
.to_world
, r
, h
, colour
);
180 else if( obj
->type
== k_rb_shape_scene
){
181 vg_line_boxf( obj
->rb
.bbx
, colour
);
186 * -----------------------------------------------------------------------------
188 * -----------------------------------------------------------------------------
192 * Update world space bounding box based on local one
194 VG_STATIC
void rb_update_bounds( rigidbody
*rb
){
195 box_init_inf( rb
->bbx_world
);
196 m4x3_expand_aabb_aabb( rb
->to_world
, rb
->bbx_world
, rb
->bbx
);
200 * Commit transform to rigidbody. Updates matrices
202 VG_STATIC
void rb_update_transform( rigidbody
*rb
)
204 q_normalize( rb
->q
);
205 q_m3x3( rb
->q
, rb
->to_world
);
206 v3_copy( rb
->co
, rb
->to_world
[3] );
208 m4x3_invert_affine( rb
->to_world
, rb
->to_local
);
209 m3x3_mul( rb
->iI
, rb
->to_local
, rb
->iIw
);
210 m3x3_mul( rb
->to_world
, rb
->iIw
, rb
->iIw
);
212 rb_update_bounds( rb
);
216 * Extrapolate rigidbody into a transform based on vg accumulator.
217 * Useful for rendering
219 VG_STATIC
void rb_extrapolate( rigidbody
*rb
, v3f co
, v4f q
)
221 float substep
= vg
.time_fixed_extrapolate
;
222 v3_muladds( rb
->co
, rb
->v
, k_rb_delta
*substep
, co
);
224 if( v3_length2( rb
->w
) > 0.0f
){
227 v3_copy( rb
->w
, axis
);
229 float mag
= v3_length( axis
);
230 v3_divs( axis
, mag
, axis
);
231 q_axis_angle( rotation
, axis
, mag
*k_rb_delta
*substep
);
232 q_mul( rotation
, rb
->q
, q
);
241 * Initialize rigidbody and calculate masses, inertia
243 VG_STATIC
void rb_init_object( rb_object
*obj
){
247 if( obj
->type
== k_rb_shape_box
){
249 v3_sub( obj
->rb
.bbx
[1], obj
->rb
.bbx
[0], dims
);
250 volume
= dims
[0]*dims
[1]*dims
[2];
252 else if( obj
->type
== k_rb_shape_sphere
){
253 volume
= vg_sphere_volume( obj
->inf
.sphere
.radius
);
254 v3_fill( obj
->rb
.bbx
[0], -obj
->inf
.sphere
.radius
);
255 v3_fill( obj
->rb
.bbx
[1], obj
->inf
.sphere
.radius
);
257 else if( obj
->type
== k_rb_shape_capsule
){
258 float r
= obj
->inf
.capsule
.radius
,
259 h
= obj
->inf
.capsule
.height
;
260 volume
= vg_sphere_volume( r
) + VG_PIf
* r
*r
* (h
- r
*2.0f
);
262 v3_fill( obj
->rb
.bbx
[0], -r
);
263 v3_fill( obj
->rb
.bbx
[1], r
);
264 obj
->rb
.bbx
[0][1] = -h
;
265 obj
->rb
.bbx
[1][1] = h
;
267 else if( obj
->type
== k_rb_shape_scene
){
269 box_copy( obj
->inf
.scene
.bh_scene
->nodes
[0].bbx
, obj
->rb
.bbx
);
273 obj
->rb
.inv_mass
= 0.0f
;
274 v3_zero( obj
->rb
.I
);
275 m3x3_zero( obj
->rb
.iI
);
278 float mass
= 2.0f
*volume
;
279 obj
->rb
.inv_mass
= 1.0f
/mass
;
282 v3_sub( obj
->rb
.bbx
[1], obj
->rb
.bbx
[0], extent
);
283 v3_muls( extent
, 0.5f
, extent
);
285 /* local intertia tensor */
286 float scale
= k_inertia_scale
;
287 float ex2
= scale
*extent
[0]*extent
[0],
288 ey2
= scale
*extent
[1]*extent
[1],
289 ez2
= scale
*extent
[2]*extent
[2];
291 obj
->rb
.I
[0] = ((1.0f
/12.0f
) * mass
* (ey2
+ez2
));
292 obj
->rb
.I
[1] = ((1.0f
/12.0f
) * mass
* (ex2
+ez2
));
293 obj
->rb
.I
[2] = ((1.0f
/12.0f
) * mass
* (ex2
+ey2
));
295 m3x3_identity( obj
->rb
.iI
);
296 obj
->rb
.iI
[0][0] = obj
->rb
.I
[0];
297 obj
->rb
.iI
[1][1] = obj
->rb
.I
[1];
298 obj
->rb
.iI
[2][2] = obj
->rb
.I
[2];
299 m3x3_inv( obj
->rb
.iI
, obj
->rb
.iI
);
302 rb_update_transform( &obj
->rb
);
305 VG_STATIC
void rb_iter( rigidbody
*rb
){
306 if( !vg_validf( rb
->v
[0] ) ||
307 !vg_validf( rb
->v
[1] ) ||
308 !vg_validf( rb
->v
[2] ) )
310 vg_fatal_error( "NaN velocity" );
313 v3f gravity
= { 0.0f
, -9.8f
, 0.0f
};
314 v3_muladds( rb
->v
, gravity
, k_rb_delta
, rb
->v
);
316 /* intergrate velocity */
317 v3_muladds( rb
->co
, rb
->v
, k_rb_delta
, rb
->co
);
318 v3_lerp( rb
->w
, (v3f
){0.0f
,0.0f
,0.0f
}, 0.0025f
, rb
->w
);
320 /* inegrate inertia */
321 if( v3_length2( rb
->w
) > 0.0f
)
325 v3_copy( rb
->w
, axis
);
327 float mag
= v3_length( axis
);
328 v3_divs( axis
, mag
, axis
);
329 q_axis_angle( rotation
, axis
, mag
*k_rb_delta
);
330 q_mul( rotation
, rb
->q
, rb
->q
);
334 v3_muls( rb
->v
, 1.0f
/(1.0f
+k_rb_delta
*k_damp_linear
), rb
->v
);
335 v3_muls( rb
->w
, 1.0f
/(1.0f
+k_rb_delta
*k_damp_angular
), rb
->w
);
340 * -----------------------------------------------------------------------------
341 * Boolean shape overlap functions
342 * -----------------------------------------------------------------------------
346 * Project AABB, and triangle interval onto axis to check if they overlap
348 VG_STATIC
int rb_box_triangle_interval( v3f extent
, v3f axis
, v3f tri
[3] ){
351 r
= extent
[0] * fabsf(axis
[0]) +
352 extent
[1] * fabsf(axis
[1]) +
353 extent
[2] * fabsf(axis
[2]),
355 p0
= v3_dot( axis
, tri
[0] ),
356 p1
= v3_dot( axis
, tri
[1] ),
357 p2
= v3_dot( axis
, tri
[2] ),
359 e
= vg_maxf(-vg_maxf(p0
,vg_maxf(p1
,p2
)), vg_minf(p0
,vg_minf(p1
,p2
)));
361 if( e
> r
) return 0;
366 * Seperating axis test box vs triangle
368 VG_STATIC
int rb_box_triangle_sat( v3f extent
, v3f center
,
369 m4x3f to_local
, v3f tri_src
[3] ){
372 for( int i
=0; i
<3; i
++ ){
373 m4x3_mulv( to_local
, tri_src
[i
], tri
[i
] );
374 v3_sub( tri
[i
], center
, tri
[i
] );
378 v3_sub( tri
[1], tri
[0], f0
);
379 v3_sub( tri
[2], tri
[1], f1
);
380 v3_sub( tri
[0], tri
[2], f2
);
384 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f0
, axis
[0] );
385 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f1
, axis
[1] );
386 v3_cross( (v3f
){1.0f
,0.0f
,0.0f
}, f2
, axis
[2] );
387 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f0
, axis
[3] );
388 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f1
, axis
[4] );
389 v3_cross( (v3f
){0.0f
,1.0f
,0.0f
}, f2
, axis
[5] );
390 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f0
, axis
[6] );
391 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f1
, axis
[7] );
392 v3_cross( (v3f
){0.0f
,0.0f
,1.0f
}, f2
, axis
[8] );
394 for( int i
=0; i
<9; i
++ )
395 if(!rb_box_triangle_interval( extent
, axis
[i
], tri
)) return 0;
398 if(!rb_box_triangle_interval( extent
, (v3f
){1.0f
,0.0f
,0.0f
}, tri
)) return 0;
399 if(!rb_box_triangle_interval( extent
, (v3f
){0.0f
,1.0f
,0.0f
}, tri
)) return 0;
400 if(!rb_box_triangle_interval( extent
, (v3f
){0.0f
,0.0f
,1.0f
}, tri
)) return 0;
403 v3_cross( f0
, f1
, n
);
404 if(!rb_box_triangle_interval( extent
, n
, tri
)) return 0;
410 * -----------------------------------------------------------------------------
412 * -----------------------------------------------------------------------------
415 VG_STATIC
int rb_manifold_apply_filtered( rb_ct
*man
, int len
){
418 for( int i
=0; i
<len
; i
++ ){
421 if( ct
->type
== k_contact_type_disabled
)
431 * Merge two contacts if they are within radius(r) of eachother
433 VG_STATIC
void rb_manifold_contact_weld( rb_ct
*ci
, rb_ct
*cj
, float r
){
434 if( v3_dist2( ci
->co
, cj
->co
) < r
*r
){
435 cj
->type
= k_contact_type_disabled
;
436 ci
->p
= (ci
->p
+ cj
->p
) * 0.5f
;
438 v3_add( ci
->co
, cj
->co
, ci
->co
);
439 v3_muls( ci
->co
, 0.5f
, ci
->co
);
442 v3_sub( ci
->rba
->co
, ci
->co
, delta
);
444 float c0
= v3_dot( ci
->n
, delta
),
445 c1
= v3_dot( cj
->n
, delta
);
447 if( c0
< 0.0f
|| c1
< 0.0f
){
449 ci
->type
= k_contact_type_disabled
;
453 v3_muls( ci
->n
, c0
, n
);
454 v3_muladds( n
, cj
->n
, c1
, n
);
464 VG_STATIC
void rb_manifold_filter_joint_edges( rb_ct
*man
, int len
, float r
){
465 for( int i
=0; i
<len
-1; i
++ ){
467 if( ci
->type
!= k_contact_type_edge
)
470 for( int j
=i
+1; j
<len
; j
++ ){
472 if( cj
->type
!= k_contact_type_edge
)
475 rb_manifold_contact_weld( ci
, cj
, r
);
481 * Resolve overlapping pairs
483 VG_STATIC
void rb_manifold_filter_pairs( rb_ct
*man
, int len
, float r
){
484 for( int i
=0; i
<len
-1; i
++ ){
488 if( ci
->type
== k_contact_type_disabled
) continue;
490 for( int j
=i
+1; j
<len
; j
++ ){
493 if( cj
->type
== k_contact_type_disabled
) continue;
495 if( v3_dist2( ci
->co
, cj
->co
) < r
*r
){
496 cj
->type
= k_contact_type_disabled
;
497 v3_add( cj
->n
, ci
->n
, ci
->n
);
504 float n
= 1.0f
/((float)similar
+1.0f
);
505 v3_muls( ci
->n
, n
, ci
->n
);
508 if( v3_length2(ci
->n
) < 0.1f
*0.1f
)
509 ci
->type
= k_contact_type_disabled
;
511 v3_normalize( ci
->n
);
517 * Remove contacts that are facing away from A
519 VG_STATIC
void rb_manifold_filter_backface( rb_ct
*man
, int len
){
520 for( int i
=0; i
<len
; i
++ ){
522 if( ct
->type
== k_contact_type_disabled
)
526 v3_sub( ct
->co
, ct
->rba
->co
, delta
);
528 if( v3_dot( delta
, ct
->n
) > -0.001f
)
529 ct
->type
= k_contact_type_disabled
;
534 * Filter out duplicate coplanar results. Good for spheres.
536 VG_STATIC
void rb_manifold_filter_coplanar( rb_ct
*man
, int len
, float w
){
537 for( int i
=0; i
<len
; i
++ ){
539 if( ci
->type
== k_contact_type_disabled
||
540 ci
->type
== k_contact_type_edge
)
543 float d1
= v3_dot( ci
->co
, ci
->n
);
545 for( int j
=0; j
<len
; j
++ ){
550 if( cj
->type
== k_contact_type_disabled
)
553 float d2
= v3_dot( cj
->co
, ci
->n
),
556 if( fabsf( d
) <= w
){
557 cj
->type
= k_contact_type_disabled
;
564 * -----------------------------------------------------------------------------
566 * -----------------------------------------------------------------------------
572 * These do not automatically allocate contacts, an appropriately sized
573 * buffer must be supplied. The function returns the size of the manifold
574 * which was generated.
576 * The values set on the contacts are: n, co, p, rba, rbb
580 * By collecting the minimum(time) and maximum(time) pairs of points, we
581 * build a reduced and stable exact manifold.
584 * rx: minimum distance of these points
585 * dx: the delta between the two points
587 * pairs will only ammend these if they are creating a collision
589 typedef struct capsule_manifold capsule_manifold
;
590 struct capsule_manifold
{
597 * Expand a line manifold with a new pair. t value is the time along segment
598 * on the oriented object which created this pair.
600 VG_STATIC
void rb_capsule_manifold( v3f pa
, v3f pb
, float t
, float r
,
601 capsule_manifold
*manifold
){
603 v3_sub( pa
, pb
, delta
);
605 if( v3_length2(delta
) < r
*r
){
606 if( t
< manifold
->t0
){
607 v3_copy( delta
, manifold
->d0
);
612 if( t
> manifold
->t1
){
613 v3_copy( delta
, manifold
->d1
);
620 VG_STATIC
void rb_capsule_manifold_init( capsule_manifold
*manifold
){
621 manifold
->t0
= INFINITY
;
622 manifold
->t1
= -INFINITY
;
625 VG_STATIC
int rb_capsule__manifold_done( m4x3f mtx
, rb_capsule
*c
,
626 capsule_manifold
*manifold
,
629 v3_muladds( mtx
[3], mtx
[1], -c
->height
*0.5f
+c
->radius
, p0
);
630 v3_muladds( mtx
[3], mtx
[1], c
->height
*0.5f
-c
->radius
, p1
);
633 if( manifold
->t0
<= 1.0f
){
637 v3_muls( p0
, 1.0f
-manifold
->t0
, pa
);
638 v3_muladds( pa
, p1
, manifold
->t0
, pa
);
640 float d
= v3_length( manifold
->d0
);
641 v3_muls( manifold
->d0
, 1.0f
/d
, ct
->n
);
642 v3_muladds( pa
, ct
->n
, -c
->radius
, ct
->co
);
644 ct
->p
= manifold
->r0
- d
;
645 ct
->type
= k_contact_type_default
;
649 if( (manifold
->t1
>= 0.0f
) && (manifold
->t0
!= manifold
->t1
) ){
650 rb_ct
*ct
= buf
+count
;
653 v3_muls( p0
, 1.0f
-manifold
->t1
, pa
);
654 v3_muladds( pa
, p1
, manifold
->t1
, pa
);
656 float d
= v3_length( manifold
->d1
);
657 v3_muls( manifold
->d1
, 1.0f
/d
, ct
->n
);
658 v3_muladds( pa
, ct
->n
, -c
->radius
, ct
->co
);
660 ct
->p
= manifold
->r1
- d
;
661 ct
->type
= k_contact_type_default
;
671 vg_line( buf
[0].co
, buf
[1].co
, 0xff0000ff );
676 VG_STATIC
int rb_capsule_sphere( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
){
677 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
678 float h
= obja
->inf
.capsule
.height
,
679 ra
= obja
->inf
.capsule
.radius
,
680 rb
= objb
->inf
.sphere
.radius
;
683 v3_muladds( rba
->co
, rba
->to_world
[1], -h
*0.5f
+ra
, p0
);
684 v3_muladds( rba
->co
, rba
->to_world
[1], h
*0.5f
-ra
, p1
);
687 closest_point_segment( p0
, p1
, rbb
->co
, c
);
688 v3_sub( c
, rbb
->co
, delta
);
690 float d2
= v3_length2(delta
),
697 v3_muls( delta
, 1.0f
/d
, ct
->n
);
701 v3_muladds( c
, ct
->n
, -ra
, p0
);
702 v3_muladds( rbb
->co
, ct
->n
, rb
, p1
);
703 v3_add( p0
, p1
, ct
->co
);
704 v3_muls( ct
->co
, 0.5f
, ct
->co
);
708 ct
->type
= k_contact_type_default
;
716 VG_STATIC
int rb_capsule__capsule( m4x3f mtxA
, rb_capsule
*ca
,
717 m4x3f mtxB
, rb_capsule
*cb
, rb_ct
*buf
){
718 float ha
= ca
->height
,
725 v3_muladds( mtxA
[3], mtxA
[1], -ha
*0.5f
+ra
, p0
);
726 v3_muladds( mtxA
[3], mtxA
[1], ha
*0.5f
-ra
, p1
);
727 v3_muladds( mtxB
[3], mtxB
[1], -hb
*0.5f
+rb
, p2
);
728 v3_muladds( mtxB
[3], mtxB
[1], hb
*0.5f
-rb
, p3
);
730 capsule_manifold manifold
;
731 rb_capsule_manifold_init( &manifold
);
735 closest_segment_segment( p0
, p1
, p2
, p3
, &ta
, &tb
, pa
, pb
);
736 rb_capsule_manifold( pa
, pb
, ta
, r
, &manifold
);
738 ta
= closest_point_segment( p0
, p1
, p2
, pa
);
739 tb
= closest_point_segment( p0
, p1
, p3
, pb
);
740 rb_capsule_manifold( pa
, p2
, ta
, r
, &manifold
);
741 rb_capsule_manifold( pb
, p3
, tb
, r
, &manifold
);
743 closest_point_segment( p2
, p3
, p0
, pa
);
744 closest_point_segment( p2
, p3
, p1
, pb
);
745 rb_capsule_manifold( p0
, pa
, 0.0f
, r
, &manifold
);
746 rb_capsule_manifold( p1
, pb
, 1.0f
, r
, &manifold
);
748 return rb_capsule__manifold_done( mtxA
, ca
, &manifold
, buf
);
751 VG_STATIC
int rb_sphere_box( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
){
753 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
755 closest_point_obb( rba
->co
, rbb
->bbx
, rbb
->to_world
, rbb
->to_local
, co
);
756 v3_sub( rba
->co
, co
, delta
);
758 float d2
= v3_length2(delta
),
759 r
= obja
->inf
.sphere
.radius
;
766 v3_sub( rba
->co
, rbb
->co
, delta
);
769 * some extra testing is required to find the best axis to push the
770 * object back outside the box. Since there isnt a clear seperating
771 * vector already, especially on really high aspect boxes.
773 float lx
= v3_dot( rbb
->to_world
[0], delta
),
774 ly
= v3_dot( rbb
->to_world
[1], delta
),
775 lz
= v3_dot( rbb
->to_world
[2], delta
),
776 px
= rbb
->bbx
[1][0] - fabsf(lx
),
777 py
= rbb
->bbx
[1][1] - fabsf(ly
),
778 pz
= rbb
->bbx
[1][2] - fabsf(lz
);
780 if( px
< py
&& px
< pz
)
781 v3_muls( rbb
->to_world
[0], vg_signf(lx
), ct
->n
);
783 v3_muls( rbb
->to_world
[1], vg_signf(ly
), ct
->n
);
785 v3_muls( rbb
->to_world
[2], vg_signf(lz
), ct
->n
);
787 v3_muladds( rba
->co
, ct
->n
, -r
, ct
->co
);
792 v3_muls( delta
, 1.0f
/d
, ct
->n
);
794 v3_copy( co
, ct
->co
);
799 ct
->type
= k_contact_type_default
;
806 VG_STATIC
int rb_sphere_sphere( rb_object
*obja
, rb_object
*objb
, rb_ct
*buf
){
807 rigidbody
*rba
= &obja
->rb
, *rbb
= &objb
->rb
;
809 v3_sub( rba
->co
, rbb
->co
, delta
);
811 float d2
= v3_length2(delta
),
812 r
= obja
->inf
.sphere
.radius
+ objb
->inf
.sphere
.radius
;
818 v3_muls( delta
, 1.0f
/d
, ct
->n
);
821 v3_muladds( rba
->co
, ct
->n
,-obja
->inf
.sphere
.radius
, p0
);
822 v3_muladds( rbb
->co
, ct
->n
, objb
->inf
.sphere
.radius
, p1
);
823 v3_add( p0
, p1
, ct
->co
);
824 v3_muls( ct
->co
, 0.5f
, ct
->co
);
825 ct
->type
= k_contact_type_default
;
835 VG_STATIC
int rb_sphere__triangle( m4x3f mtxA
, rb_sphere
*b
,
836 v3f tri
[3], rb_ct
*buf
){
838 enum contact_type type
= closest_on_triangle_1( mtxA
[3], tri
, co
);
840 v3_sub( mtxA
[3], co
, delta
);
842 float d2
= v3_length2( delta
),
849 v3_sub( tri
[2], tri
[0], ab
);
850 v3_sub( tri
[1], tri
[0], ac
);
851 v3_cross( ac
, ab
, tn
);
852 v3_copy( tn
, ct
->n
);
854 if( v3_length2( ct
->n
) <= 0.00001f
){
855 #ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
856 vg_error( "Zero area triangle!\n" );
861 v3_normalize( ct
->n
);
865 v3_copy( co
, ct
->co
);
874 VG_STATIC
int rb_sphere__scene( m4x3f mtxA
, rb_sphere
*b
,
875 m4x3f mtxB
, rb_scene
*s
, rb_ct
*buf
,
877 scene_context
*sc
= s
->bh_scene
->user
;
881 float r
= b
->radius
+ 0.1f
;
883 v3_sub( mtxA
[3], (v3f
){ r
,r
,r
}, box
[0] );
884 v3_add( mtxA
[3], (v3f
){ r
,r
,r
}, box
[1] );
888 bh_iter_init_box( 0, &it
, box
);
890 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
891 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
894 if( sc
->arrvertices
[ptri
[0]].flags
& ignore
) continue;
896 for( int j
=0; j
<3; j
++ )
897 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
899 buf
[ count
].element_id
= ptri
[0];
901 vg_line( tri
[0],tri
[1],0x70ff6000 );
902 vg_line( tri
[1],tri
[2],0x70ff6000 );
903 vg_line( tri
[2],tri
[0],0x70ff6000 );
905 int contact
= rb_sphere__triangle( mtxA
, b
, tri
, &buf
[count
] );
909 vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" );
917 VG_STATIC
int rb_box__scene( m4x3f mtxA
, boxf bbx
,
918 m4x3f mtxB
, rb_scene
*s
, rb_ct
*buf
, u16 ignore
){
919 scene_context
*sc
= s
->bh_scene
->user
;
923 v3_sub( bbx
[1], bbx
[0], extent
);
924 v3_muls( extent
, 0.5f
, extent
);
925 v3_add( bbx
[0], extent
, center
);
927 float r
= v3_length(extent
);
929 v3_fill( world_bbx
[0], -r
);
930 v3_fill( world_bbx
[1], r
);
931 for( int i
=0; i
<2; i
++ ){
932 v3_add( center
, world_bbx
[i
], world_bbx
[i
] );
933 v3_add( mtxA
[3], world_bbx
[i
], world_bbx
[i
] );
937 m4x3_invert_affine( mtxA
, to_local
);
940 bh_iter_init_box( 0, &it
, world_bbx
);
944 vg_line_boxf( world_bbx
, VG__RED
);
946 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
947 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
948 if( sc
->arrvertices
[ptri
[0]].flags
& ignore
) continue;
950 for( int j
=0; j
<3; j
++ )
951 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
953 if( rb_box_triangle_sat( extent
, center
, to_local
, tri
) ){
954 vg_line(tri
[0],tri
[1],0xff50ff00 );
955 vg_line(tri
[1],tri
[2],0xff50ff00 );
956 vg_line(tri
[2],tri
[0],0xff50ff00 );
959 vg_line(tri
[0],tri
[1],0xff0000ff );
960 vg_line(tri
[1],tri
[2],0xff0000ff );
961 vg_line(tri
[2],tri
[0],0xff0000ff );
966 v3_sub( tri
[1], tri
[0], v0
);
967 v3_sub( tri
[2], tri
[0], v1
);
968 v3_cross( v0
, v1
, n
);
970 if( v3_length2( n
) <= 0.00001f
){
971 #ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
972 vg_error( "Zero area triangle!\n" );
979 /* find best feature */
980 float best
= v3_dot( mtxA
[0], n
);
983 for( int i
=1; i
<3; i
++ ){
984 float c
= v3_dot( mtxA
[i
], n
);
986 if( fabsf(c
) > fabsf(best
) ){
995 float px
= best
> 0.0f
? bbx
[0][0]: bbx
[1][0];
997 manifold
[0][1] = bbx
[0][1];
998 manifold
[0][2] = bbx
[0][2];
1000 manifold
[1][1] = bbx
[1][1];
1001 manifold
[1][2] = bbx
[0][2];
1002 manifold
[2][0] = px
;
1003 manifold
[2][1] = bbx
[1][1];
1004 manifold
[2][2] = bbx
[1][2];
1005 manifold
[3][0] = px
;
1006 manifold
[3][1] = bbx
[0][1];
1007 manifold
[3][2] = bbx
[1][2];
1009 else if( axis
== 1 ){
1010 float py
= best
> 0.0f
? bbx
[0][1]: bbx
[1][1];
1011 manifold
[0][0] = bbx
[0][0];
1012 manifold
[0][1] = py
;
1013 manifold
[0][2] = bbx
[0][2];
1014 manifold
[1][0] = bbx
[1][0];
1015 manifold
[1][1] = py
;
1016 manifold
[1][2] = bbx
[0][2];
1017 manifold
[2][0] = bbx
[1][0];
1018 manifold
[2][1] = py
;
1019 manifold
[2][2] = bbx
[1][2];
1020 manifold
[3][0] = bbx
[0][0];
1021 manifold
[3][1] = py
;
1022 manifold
[3][2] = bbx
[1][2];
1025 float pz
= best
> 0.0f
? bbx
[0][2]: bbx
[1][2];
1026 manifold
[0][0] = bbx
[0][0];
1027 manifold
[0][1] = bbx
[0][1];
1028 manifold
[0][2] = pz
;
1029 manifold
[1][0] = bbx
[1][0];
1030 manifold
[1][1] = bbx
[0][1];
1031 manifold
[1][2] = pz
;
1032 manifold
[2][0] = bbx
[1][0];
1033 manifold
[2][1] = bbx
[1][1];
1034 manifold
[2][2] = pz
;
1035 manifold
[3][0] = bbx
[0][0];
1036 manifold
[3][1] = bbx
[1][1];
1037 manifold
[3][2] = pz
;
1040 for( int j
=0; j
<4; j
++ )
1041 m4x3_mulv( mtxA
, manifold
[j
], manifold
[j
] );
1043 vg_line( manifold
[0], manifold
[1], 0xffffffff );
1044 vg_line( manifold
[1], manifold
[2], 0xffffffff );
1045 vg_line( manifold
[2], manifold
[3], 0xffffffff );
1046 vg_line( manifold
[3], manifold
[0], 0xffffffff );
1048 for( int j
=0; j
<4; j
++ ){
1049 rb_ct
*ct
= buf
+count
;
1051 v3_copy( manifold
[j
], ct
->co
);
1052 v3_copy( n
, ct
->n
);
1054 float l0
= v3_dot( tri
[0], n
),
1055 l1
= v3_dot( manifold
[j
], n
);
1057 ct
->p
= (l0
-l1
)*0.5f
;
1061 ct
->type
= k_contact_type_default
;
1071 VG_STATIC
int rb_capsule__triangle( m4x3f mtxA
, rb_capsule
*c
,
1072 v3f tri
[3], rb_ct
*buf
){
1074 v3_muladds( mtxA
[3], mtxA
[1], -c
->height
*0.5f
+c
->radius
, p0w
);
1075 v3_muladds( mtxA
[3], mtxA
[1], c
->height
*0.5f
-c
->radius
, p1w
);
1077 capsule_manifold manifold
;
1078 rb_capsule_manifold_init( &manifold
);
1081 closest_on_triangle_1( p0w
, tri
, c0
);
1082 closest_on_triangle_1( p1w
, tri
, c1
);
1085 v3_sub( c0
, p0w
, d0
);
1086 v3_sub( c1
, p1w
, d1
);
1087 v3_sub( p1w
, p0w
, da
);
1093 if( v3_dot( da
, d0
) <= 0.01f
)
1094 rb_capsule_manifold( p0w
, c0
, 0.0f
, c
->radius
, &manifold
);
1096 if( v3_dot( da
, d1
) >= -0.01f
)
1097 rb_capsule_manifold( p1w
, c1
, 1.0f
, c
->radius
, &manifold
);
1099 for( int i
=0; i
<3; i
++ ){
1105 closest_segment_segment( p0w
, p1w
, tri
[i0
], tri
[i1
], &ta
, &tb
, ca
, cb
);
1106 rb_capsule_manifold( ca
, cb
, ta
, c
->radius
, &manifold
);
1110 v3_sub( tri
[1], tri
[0], v0
);
1111 v3_sub( tri
[2], tri
[0], v1
);
1112 v3_cross( v0
, v1
, n
);
1114 if( v3_length2( n
) <= 0.00001f
){
1115 #ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING
1116 vg_error( "Zero area triangle!\n" );
1123 int count
= rb_capsule__manifold_done( mtxA
, c
, &manifold
, buf
);
1124 for( int i
=0; i
<count
; i
++ )
1125 v3_copy( n
, buf
[i
].n
);
1130 /* mtxB is defined only for tradition; it is not used currently */
1131 VG_STATIC
int rb_capsule__scene( m4x3f mtxA
, rb_capsule
*c
,
1132 m4x3f mtxB
, rb_scene
*s
,
1133 rb_ct
*buf
, u16 ignore
){
1137 v3_sub( mtxA
[3], (v3f
){ c
->height
, c
->height
, c
->height
}, bbx
[0] );
1138 v3_add( mtxA
[3], (v3f
){ c
->height
, c
->height
, c
->height
}, bbx
[1] );
1140 scene_context
*sc
= s
->bh_scene
->user
;
1143 bh_iter_init_box( 0, &it
, bbx
);
1145 while( bh_next( s
->bh_scene
, &it
, &idx
) ){
1146 u32
*ptri
= &sc
->arrindices
[ idx
*3 ];
1147 if( sc
->arrvertices
[ptri
[0]].flags
& ignore
) continue;
1150 for( int j
=0; j
<3; j
++ )
1151 v3_copy( sc
->arrvertices
[ptri
[j
]].co
, tri
[j
] );
1153 buf
[ count
].element_id
= ptri
[0];
1155 int contact
= rb_capsule__triangle( mtxA
, c
, tri
, &buf
[count
] );
1159 vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
1167 VG_STATIC
int rb_global_has_space( void ){
1168 if( rb_contact_count
+ 16 > vg_list_size(rb_contact_buffer
) )
1174 VG_STATIC rb_ct
*rb_global_buffer( void ){
1175 return &rb_contact_buffer
[ rb_contact_count
];
1179 * -----------------------------------------------------------------------------
1181 * -----------------------------------------------------------------------------
1184 VG_STATIC
void rb_solver_reset(void){
1185 rb_contact_count
= 0;
1188 VG_STATIC rb_ct
*rb_global_ct(void){
1189 return rb_contact_buffer
+ rb_contact_count
;
1192 VG_STATIC
void rb_prepare_contact( rb_ct
*ct
, float timestep
){
1193 ct
->bias
= -0.2f
* (timestep
*3600.0f
)
1194 * vg_minf( 0.0f
, -ct
->p
+k_penetration_slop
);
1196 v3_tangent_basis( ct
->n
, ct
->t
[0], ct
->t
[1] );
1197 ct
->norm_impulse
= 0.0f
;
1198 ct
->tangent_impulse
[0] = 0.0f
;
1199 ct
->tangent_impulse
[1] = 0.0f
;
1202 /* calculate total move. manifold should belong to ONE object only */
1203 VG_STATIC
void rb_depenetrate( rb_ct
*manifold
, int len
, v3f dt
){
1206 for( int j
=0; j
<7; j
++ )
1208 for( int i
=0; i
<len
; i
++ )
1210 struct contact
*ct
= &manifold
[i
];
1212 float resolved_amt
= v3_dot( ct
->n
, dt
),
1213 remaining
= (ct
->p
-k_penetration_slop
) - resolved_amt
,
1214 apply
= vg_maxf( remaining
, 0.0f
) * 0.4f
;
1216 v3_muladds( dt
, ct
->n
, apply
, dt
);
1222 * Initializing things like tangent vectors
1224 VG_STATIC
void rb_presolve_contacts( rb_ct
*buffer
, int len
){
1225 for( int i
=0; i
<len
; i
++ ){
1226 rb_ct
*ct
= &buffer
[i
];
1227 rb_prepare_contact( ct
, k_rb_delta
);
1229 v3f ra
, rb
, raCn
, rbCn
, raCt
, rbCt
;
1230 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1231 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1232 v3_cross( ra
, ct
->n
, raCn
);
1233 v3_cross( rb
, ct
->n
, rbCn
);
1235 /* orient inverse inertia tensors */
1237 m3x3_mulv( ct
->rba
->iIw
, raCn
, raCnI
);
1238 m3x3_mulv( ct
->rbb
->iIw
, rbCn
, rbCnI
);
1240 ct
->normal_mass
= ct
->rba
->inv_mass
+ ct
->rbb
->inv_mass
;
1241 ct
->normal_mass
+= v3_dot( raCn
, raCnI
);
1242 ct
->normal_mass
+= v3_dot( rbCn
, rbCnI
);
1243 ct
->normal_mass
= 1.0f
/ct
->normal_mass
;
1245 for( int j
=0; j
<2; j
++ ){
1247 v3_cross( ct
->t
[j
], ra
, raCt
);
1248 v3_cross( ct
->t
[j
], rb
, rbCt
);
1249 m3x3_mulv( ct
->rba
->iIw
, raCt
, raCtI
);
1250 m3x3_mulv( ct
->rbb
->iIw
, rbCt
, rbCtI
);
1252 ct
->tangent_mass
[j
] = ct
->rba
->inv_mass
+ ct
->rbb
->inv_mass
;
1253 ct
->tangent_mass
[j
] += v3_dot( raCt
, raCtI
);
1254 ct
->tangent_mass
[j
] += v3_dot( rbCt
, rbCtI
);
1255 ct
->tangent_mass
[j
] = 1.0f
/ct
->tangent_mass
[j
];
1258 rb_debug_contact( ct
);
1263 * Creates relative contact velocity vector
1265 VG_STATIC
void rb_rcv( rigidbody
*rba
, rigidbody
*rbb
, v3f ra
, v3f rb
, v3f rv
){
1267 v3_cross( rba
->w
, ra
, rva
);
1268 v3_add( rba
->v
, rva
, rva
);
1269 v3_cross( rbb
->w
, rb
, rvb
);
1270 v3_add( rbb
->v
, rvb
, rvb
);
1272 v3_sub( rva
, rvb
, rv
);
1275 VG_STATIC
void rb_contact_restitution( rb_ct
*ct
, float cr
){
1277 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1278 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1279 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1281 float v
= v3_dot( rv
, ct
->n
);
1284 ct
->bias
+= -cr
* v
;
1289 * Apply impulse to object
1291 VG_STATIC
void rb_linear_impulse( rigidbody
*rb
, v3f delta
, v3f impulse
){
1293 v3_muladds( rb
->v
, impulse
, rb
->inv_mass
, rb
->v
);
1295 /* Angular velocity */
1297 v3_cross( delta
, impulse
, wa
);
1299 m3x3_mulv( rb
->iIw
, wa
, wa
);
1300 v3_add( rb
->w
, wa
, rb
->w
);
1304 * One iteration to solve the contact constraint
1306 VG_STATIC
void rb_solve_contacts( rb_ct
*buf
, int len
){
1307 for( int i
=0; i
<len
; i
++ ){
1308 struct contact
*ct
= &buf
[i
];
1311 v3_sub( ct
->co
, ct
->rba
->co
, ra
);
1312 v3_sub( ct
->co
, ct
->rbb
->co
, rb
);
1313 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1316 for( int j
=0; j
<2; j
++ ){
1317 float f
= k_friction
* ct
->norm_impulse
,
1318 vt
= v3_dot( rv
, ct
->t
[j
] ),
1319 lambda
= ct
->tangent_mass
[j
] * -vt
;
1321 float temp
= ct
->tangent_impulse
[j
];
1322 ct
->tangent_impulse
[j
] = vg_clampf( temp
+ lambda
, -f
, f
);
1323 lambda
= ct
->tangent_impulse
[j
] - temp
;
1326 v3_muls( ct
->t
[j
], lambda
, impulse
);
1327 rb_linear_impulse( ct
->rba
, ra
, impulse
);
1329 v3_muls( ct
->t
[j
], -lambda
, impulse
);
1330 rb_linear_impulse( ct
->rbb
, rb
, impulse
);
1334 rb_rcv( ct
->rba
, ct
->rbb
, ra
, rb
, rv
);
1335 float vn
= v3_dot( rv
, ct
->n
),
1336 lambda
= ct
->normal_mass
* (-vn
+ ct
->bias
);
1338 float temp
= ct
->norm_impulse
;
1339 ct
->norm_impulse
= vg_maxf( temp
+ lambda
, 0.0f
);
1340 lambda
= ct
->norm_impulse
- temp
;
1343 v3_muls( ct
->n
, lambda
, impulse
);
1344 rb_linear_impulse( ct
->rba
, ra
, impulse
);
1346 v3_muls( ct
->n
, -lambda
, impulse
);
1347 rb_linear_impulse( ct
->rbb
, rb
, impulse
);
1352 * -----------------------------------------------------------------------------
1354 * -----------------------------------------------------------------------------
1357 VG_STATIC
void rb_debug_position_constraints( rb_constr_pos
*buffer
, int len
){
1358 for( int i
=0; i
<len
; i
++ ){
1359 rb_constr_pos
*constr
= &buffer
[i
];
1360 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
1363 m3x3_mulv( rba
->to_world
, constr
->lca
, wca
);
1364 m3x3_mulv( rbb
->to_world
, constr
->lcb
, wcb
);
1367 v3_add( wca
, rba
->co
, p0
);
1368 v3_add( wcb
, rbb
->co
, p1
);
1369 vg_line_point( p0
, 0.0025f
, 0xff000000 );
1370 vg_line_point( p1
, 0.0025f
, 0xffffffff );
1371 vg_line2( p0
, p1
, 0xff000000, 0xffffffff );
1375 VG_STATIC
void rb_presolve_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1379 for( int i
=0; i
<len
; i
++ ){
1380 rb_constr_swingtwist
*st
= &buf
[ i
];
1382 v3f vx
, vy
, va
, vxb
, axis
, center
;
1384 m3x3_mulv( st
->rba
->to_world
, st
->conevx
, vx
);
1385 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
1386 m3x3_mulv( st
->rba
->to_world
, st
->conevy
, vy
);
1387 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
1388 m4x3_mulv( st
->rba
->to_world
, st
->view_offset
, center
);
1389 v3_cross( vy
, vx
, axis
);
1391 /* Constraint violated ? */
1392 float fx
= v3_dot( vx
, va
), /* projection world */
1393 fy
= v3_dot( vy
, va
),
1394 fn
= v3_dot( va
, axis
),
1396 rx
= st
->conevx
[3], /* elipse radii */
1399 lx
= fx
/rx
, /* projection local (fn==lz) */
1402 st
->tangent_violation
= ((lx
*lx
+ ly
*ly
) > fn
*fn
) || (fn
<= 0.0f
);
1403 if( st
->tangent_violation
){
1404 /* Calculate a good position and the axis to solve on */
1405 v2f closest
, tangent
,
1406 p
= { fx
/fabsf(fn
), fy
/fabsf(fn
) };
1408 closest_point_elipse( p
, (v2f
){rx
,ry
}, closest
);
1409 tangent
[0] = -closest
[1] / (ry
*ry
);
1410 tangent
[1] = closest
[0] / (rx
*rx
);
1411 v2_normalize( tangent
);
1414 v3_muladds( axis
, vx
, closest
[0], v0
);
1415 v3_muladds( v0
, vy
, closest
[1], v0
);
1418 v3_muls( vx
, tangent
[0], v1
);
1419 v3_muladds( v1
, vy
, tangent
[1], v1
);
1421 v3_copy( v0
, st
->tangent_target
);
1422 v3_copy( v1
, st
->tangent_axis
);
1424 /* calculate mass */
1426 m3x3_mulv( st
->rba
->iIw
, st
->tangent_axis
, aIw
);
1427 m3x3_mulv( st
->rbb
->iIw
, st
->tangent_axis
, bIw
);
1428 st
->tangent_mass
= 1.0f
/ (v3_dot( st
->tangent_axis
, aIw
) +
1429 v3_dot( st
->tangent_axis
, bIw
));
1431 float angle
= v3_dot( va
, st
->tangent_target
);
1435 v3_cross( vy
, va
, refaxis
); /* our default rotation */
1436 v3_normalize( refaxis
);
1438 float angle
= v3_dot( refaxis
, vxb
);
1439 st
->axis_violation
= fabsf(angle
) < st
->conet
;
1441 if( st
->axis_violation
){
1443 v3_cross( refaxis
, vxb
, dir_test
);
1445 if( v3_dot(dir_test
, va
) < 0.0f
)
1446 st
->axis_violation
= -st
->axis_violation
;
1448 float newang
= (float)st
->axis_violation
* acosf(st
->conet
-0.0001f
);
1451 v3_cross( va
, refaxis
, refaxis_up
);
1452 v3_muls( refaxis_up
, sinf(newang
), st
->axis_target
);
1453 v3_muladds( st
->axis_target
, refaxis
, -cosf(newang
), st
->axis_target
);
1455 /* calculate mass */
1456 v3_copy( va
, st
->axis
);
1458 m3x3_mulv( st
->rba
->iIw
, st
->axis
, aIw
);
1459 m3x3_mulv( st
->rbb
->iIw
, st
->axis
, bIw
);
1460 st
->axis_mass
= 1.0f
/ (v3_dot( st
->axis
, aIw
) +
1461 v3_dot( st
->axis
, bIw
));
1466 VG_STATIC
void rb_debug_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1470 for( int i
=0; i
<len
; i
++ ){
1471 rb_constr_swingtwist
*st
= &buf
[ i
];
1473 v3f vx
, vxb
, vy
, va
, axis
, center
;
1475 m3x3_mulv( st
->rba
->to_world
, st
->conevx
, vx
);
1476 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
1477 m3x3_mulv( st
->rba
->to_world
, st
->conevy
, vy
);
1478 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
1479 m4x3_mulv( st
->rba
->to_world
, st
->view_offset
, center
);
1480 v3_cross( vy
, vx
, axis
);
1482 float rx
= st
->conevx
[3], /* elipse radii */
1486 v3_muladds( center
, va
, size
, p1
);
1487 vg_line( center
, p1
, 0xffffffff );
1488 vg_line_point( p1
, 0.00025f
, 0xffffffff );
1490 if( st
->tangent_violation
){
1491 v3_muladds( center
, st
->tangent_target
, size
, p0
);
1493 vg_line( center
, p0
, 0xff00ff00 );
1494 vg_line_point( p0
, 0.00025f
, 0xff00ff00 );
1495 vg_line( p1
, p0
, 0xff000000 );
1498 for( int x
=0; x
<32; x
++ ){
1499 float t0
= ((float)x
* (1.0f
/32.0f
)) * VG_TAUf
,
1500 t1
= (((float)x
+1.0f
) * (1.0f
/32.0f
)) * VG_TAUf
,
1507 v3_muladds( axis
, vx
, c0
*rx
, v0
);
1508 v3_muladds( v0
, vy
, s0
*ry
, v0
);
1509 v3_muladds( axis
, vx
, c1
*rx
, v1
);
1510 v3_muladds( v1
, vy
, s1
*ry
, v1
);
1515 v3_muladds( center
, v0
, size
, p0
);
1516 v3_muladds( center
, v1
, size
, p1
);
1518 u32 col0r
= fabsf(c0
) * 255.0f
,
1519 col0g
= fabsf(s0
) * 255.0f
,
1520 col1r
= fabsf(c1
) * 255.0f
,
1521 col1g
= fabsf(s1
) * 255.0f
,
1522 col
= st
->tangent_violation
? 0xff0000ff: 0xff000000,
1523 col0
= col
| (col0r
<<16) | (col0g
<< 8),
1524 col1
= col
| (col1r
<<16) | (col1g
<< 8);
1526 vg_line2( center
, p0
, VG__NONE
, col0
);
1527 vg_line2( p0
, p1
, col0
, col1
);
1531 v3_muladds( center
, va
, size
, p0
);
1532 v3_muladds( p0
, vxb
, size
, p1
);
1534 vg_line( p0
, p1
, 0xff0000ff );
1536 if( st
->axis_violation
){
1537 v3_muladds( p0
, st
->axis_target
, size
*1.25f
, p1
);
1538 vg_line( p0
, p1
, 0xffffff00 );
1539 vg_line_point( p1
, 0.0025f
, 0xffffff80 );
1543 v3_cross( vy
, va
, refaxis
); /* our default rotation */
1544 v3_normalize( refaxis
);
1546 v3_cross( va
, refaxis
, refaxis_up
);
1547 float newang
= acosf(st
->conet
-0.0001f
);
1549 v3_muladds( p0
, refaxis_up
, sinf(newang
)*size
, p1
);
1550 v3_muladds( p1
, refaxis
, -cosf(newang
)*size
, p1
);
1551 vg_line( p0
, p1
, 0xff000000 );
1553 v3_muladds( p0
, refaxis_up
, sinf(-newang
)*size
, p1
);
1554 v3_muladds( p1
, refaxis
, -cosf(-newang
)*size
, p1
);
1555 vg_line( p0
, p1
, 0xff404040 );
1560 * Solve a list of positional constraints
1562 VG_STATIC
void rb_solve_position_constraints( rb_constr_pos
*buf
, int len
){
1563 for( int i
=0; i
<len
; i
++ ){
1564 rb_constr_pos
*constr
= &buf
[i
];
1565 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
1568 m3x3_mulv( rba
->to_world
, constr
->lca
, wa
);
1569 m3x3_mulv( rbb
->to_world
, constr
->lcb
, wb
);
1571 m3x3f ssra
, ssrat
, ssrb
, ssrbt
;
1573 m3x3_skew_symetric( ssrat
, wa
);
1574 m3x3_skew_symetric( ssrbt
, wb
);
1575 m3x3_transpose( ssrat
, ssra
);
1576 m3x3_transpose( ssrbt
, ssrb
);
1578 v3f b
, b_wa
, b_wb
, b_a
, b_b
;
1579 m3x3_mulv( ssra
, rba
->w
, b_wa
);
1580 m3x3_mulv( ssrb
, rbb
->w
, b_wb
);
1581 v3_add( rba
->v
, b_wa
, b
);
1582 v3_sub( b
, rbb
->v
, b
);
1583 v3_sub( b
, b_wb
, b
);
1584 v3_muls( b
, -1.0f
, b
);
1587 m3x3_diagonal( invMa
, rba
->inv_mass
);
1588 m3x3_diagonal( invMb
, rbb
->inv_mass
);
1591 m3x3_mul( ssra
, rba
->iIw
, ia
);
1592 m3x3_mul( ia
, ssrat
, ia
);
1593 m3x3_mul( ssrb
, rbb
->iIw
, ib
);
1594 m3x3_mul( ib
, ssrbt
, ib
);
1597 m3x3_add( invMa
, ia
, cma
);
1598 m3x3_add( invMb
, ib
, cmb
);
1601 m3x3_add( cma
, cmb
, A
);
1603 /* Solve Ax = b ( A^-1*b = x ) */
1606 m3x3_inv( A
, invA
);
1607 m3x3_mulv( invA
, b
, impulse
);
1609 v3f delta_va
, delta_wa
, delta_vb
, delta_wb
;
1611 m3x3_mul( rba
->iIw
, ssrat
, iwa
);
1612 m3x3_mul( rbb
->iIw
, ssrbt
, iwb
);
1614 m3x3_mulv( invMa
, impulse
, delta_va
);
1615 m3x3_mulv( invMb
, impulse
, delta_vb
);
1616 m3x3_mulv( iwa
, impulse
, delta_wa
);
1617 m3x3_mulv( iwb
, impulse
, delta_wb
);
1619 v3_add( rba
->v
, delta_va
, rba
->v
);
1620 v3_add( rba
->w
, delta_wa
, rba
->w
);
1621 v3_sub( rbb
->v
, delta_vb
, rbb
->v
);
1622 v3_sub( rbb
->w
, delta_wb
, rbb
->w
);
1626 VG_STATIC
void rb_solve_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1630 for( int i
=0; i
<len
; i
++ ){
1631 rb_constr_swingtwist
*st
= &buf
[ i
];
1633 if( !st
->axis_violation
)
1636 float rv
= v3_dot( st
->axis
, st
->rbb
->w
) -
1637 v3_dot( st
->axis
, st
->rba
->w
);
1639 if( rv
* (float)st
->axis_violation
> 0.0f
)
1642 v3f impulse
, wa
, wb
;
1643 v3_muls( st
->axis
, rv
*st
->axis_mass
, impulse
);
1644 m3x3_mulv( st
->rba
->iIw
, impulse
, wa
);
1645 v3_add( st
->rba
->w
, wa
, st
->rba
->w
);
1647 v3_muls( impulse
, -1.0f
, impulse
);
1648 m3x3_mulv( st
->rbb
->iIw
, impulse
, wb
);
1649 v3_add( st
->rbb
->w
, wb
, st
->rbb
->w
);
1651 float rv2
= v3_dot( st
->axis
, st
->rbb
->w
) -
1652 v3_dot( st
->axis
, st
->rba
->w
);
1655 for( int i
=0; i
<len
; i
++ ){
1656 rb_constr_swingtwist
*st
= &buf
[ i
];
1658 if( !st
->tangent_violation
)
1661 float rv
= v3_dot( st
->tangent_axis
, st
->rbb
->w
) -
1662 v3_dot( st
->tangent_axis
, st
->rba
->w
);
1667 v3f impulse
, wa
, wb
;
1668 v3_muls( st
->tangent_axis
, rv
*st
->tangent_mass
, impulse
);
1669 m3x3_mulv( st
->rba
->iIw
, impulse
, wa
);
1670 v3_add( st
->rba
->w
, wa
, st
->rba
->w
);
1672 v3_muls( impulse
, -1.0f
, impulse
);
1673 m3x3_mulv( st
->rbb
->iIw
, impulse
, wb
);
1674 v3_add( st
->rbb
->w
, wb
, st
->rbb
->w
);
1676 float rv2
= v3_dot( st
->tangent_axis
, st
->rbb
->w
) -
1677 v3_dot( st
->tangent_axis
, st
->rba
->w
);
1681 VG_STATIC
void rb_solve_constr_angle( rigidbody
*rba
, rigidbody
*rbb
,
1683 m3x3f ssra
, ssrb
, ssrat
, ssrbt
;
1686 m3x3_skew_symetric( ssrat
, ra
);
1687 m3x3_skew_symetric( ssrbt
, rb
);
1688 m3x3_transpose( ssrat
, ssra
);
1689 m3x3_transpose( ssrbt
, ssrb
);
1691 m3x3_mul( ssra
, rba
->iIw
, cma
);
1692 m3x3_mul( cma
, ssrat
, cma
);
1693 m3x3_mul( ssrb
, rbb
->iIw
, cmb
);
1694 m3x3_mul( cmb
, ssrbt
, cmb
);
1697 m3x3_add( cma
, cmb
, A
);
1698 m3x3_inv( A
, invA
);
1701 m3x3_mulv( ssra
, rba
->w
, b_wa
);
1702 m3x3_mulv( ssrb
, rbb
->w
, b_wb
);
1703 v3_add( b_wa
, b_wb
, b
);
1707 m3x3_mulv( invA
, b
, impulse
);
1709 v3f delta_wa
, delta_wb
;
1711 m3x3_mul( rba
->iIw
, ssrat
, iwa
);
1712 m3x3_mul( rbb
->iIw
, ssrbt
, iwb
);
1713 m3x3_mulv( iwa
, impulse
, delta_wa
);
1714 m3x3_mulv( iwb
, impulse
, delta_wb
);
1715 v3_add( rba
->w
, delta_wa
, rba
->w
);
1716 v3_sub( rbb
->w
, delta_wb
, rbb
->w
);
1720 * Correct position constraint drift errors
1721 * [ 0.0 <= amt <= 1.0 ]: the correction amount
1723 VG_STATIC
void rb_correct_position_constraints( rb_constr_pos
*buf
, int len
,
1725 for( int i
=0; i
<len
; i
++ ){
1726 rb_constr_pos
*constr
= &buf
[i
];
1727 rigidbody
*rba
= constr
->rba
, *rbb
= constr
->rbb
;
1730 m3x3_mulv( rba
->to_world
, constr
->lca
, p0
);
1731 m3x3_mulv( rbb
->to_world
, constr
->lcb
, p1
);
1732 v3_add( rba
->co
, p0
, p0
);
1733 v3_add( rbb
->co
, p1
, p1
);
1734 v3_sub( p1
, p0
, d
);
1736 v3_muladds( rbb
->co
, d
, -1.0f
* amt
, rbb
->co
);
1737 rb_update_transform( rbb
);
1741 VG_STATIC
void rb_correct_swingtwist_constraints( rb_constr_swingtwist
*buf
,
1742 int len
, float amt
){
1743 for( int i
=0; i
<len
; i
++ ){
1744 rb_constr_swingtwist
*st
= &buf
[i
];
1746 if( !st
->tangent_violation
)
1750 m3x3_mulv( st
->rbb
->to_world
, st
->coneva
, va
);
1752 float angle
= v3_dot( va
, st
->tangent_target
);
1754 if( fabsf(angle
) < 0.9999f
){
1756 v3_cross( va
, st
->tangent_target
, axis
);
1759 q_axis_angle( correction
, axis
, acosf(angle
) * amt
);
1760 q_mul( correction
, st
->rbb
->q
, st
->rbb
->q
);
1761 rb_update_transform( st
->rbb
);
1765 for( int i
=0; i
<len
; i
++ ){
1766 rb_constr_swingtwist
*st
= &buf
[i
];
1768 if( !st
->axis_violation
)
1772 m3x3_mulv( st
->rbb
->to_world
, st
->conevxb
, vxb
);
1774 float angle
= v3_dot( vxb
, st
->axis_target
);
1776 if( fabsf(angle
) < 0.9999f
){
1778 v3_cross( vxb
, st
->axis_target
, axis
);
1781 q_axis_angle( correction
, axis
, acosf(angle
) * amt
);
1782 q_mul( correction
, st
->rbb
->q
, st
->rbb
->q
);
1783 rb_update_transform( st
->rbb
);
1788 VG_STATIC
void rb_correct_contact_constraints( rb_ct
*buf
, int len
, float amt
){
1789 for( int i
=0; i
<len
; i
++ ){
1790 rb_ct
*ct
= &buf
[i
];
1791 rigidbody
*rba
= ct
->rba
,
1794 float mass_total
= 1.0f
/ (rba
->inv_mass
+ rbb
->inv_mass
);
1796 v3_muladds( rba
->co
, ct
->n
, -mass_total
* rba
->inv_mass
, rba
->co
);
1797 v3_muladds( rbb
->co
, ct
->n
, mass_total
* rbb
->inv_mass
, rbb
->co
);
1806 VG_STATIC
void rb_effect_simple_bouyency( rigidbody
*ra
, v4f plane
,
1807 float amt
, float drag
){
1809 float depth
= v3_dot( plane
, ra
->co
) - plane
[3],
1810 lambda
= vg_clampf( -depth
, 0.0f
, 1.0f
) * amt
;
1812 v3_muladds( ra
->v
, plane
, lambda
* k_rb_delta
, ra
->v
);
1815 v3_muls( ra
->v
, 1.0f
-(drag
*k_rb_delta
), ra
->v
);
1818 /* apply a spring&dampener force to match ra(worldspace) on rigidbody, to
1821 VG_STATIC
void rb_effect_spring_target_vector( rigidbody
*rba
, v3f ra
, v3f rt
,
1822 float spring
, float dampening
,
1824 float d
= v3_dot( rt
, ra
);
1825 float a
= acosf( vg_clampf( d
, -1.0f
, 1.0f
) );
1828 v3_cross( rt
, ra
, axis
);
1830 float Fs
= -a
* spring
,
1831 Fd
= -v3_dot( rba
->w
, axis
) * dampening
;
1833 v3_muladds( rba
->w
, axis
, (Fs
+Fd
) * timestep
, rba
->w
);
1836 #endif /* RIGIDBODY_H */