+VG_STATIC int rb_capsule_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ float h = rba->inf.capsule.height,
+ ra = rba->inf.capsule.radius,
+ rb = rbb->inf.sphere.radius;
+
+ v3f p0, p1;
+ v3_muladds( rba->co, rba->up, -h*0.5f+ra, p0 );
+ v3_muladds( rba->co, rba->up, h*0.5f-ra, p1 );
+
+ v3f c, delta;
+ closest_point_segment( p0, p1, rbb->co, c );
+ v3_sub( c, rbb->co, delta );
+
+ float d2 = v3_length2(delta),
+ r = ra + rb;
+
+ if( d2 < r*r )
+ {
+ float d = sqrtf(d2);
+
+ rb_ct *ct = buf;
+ v3_muls( delta, 1.0f/d, ct->n );
+ ct->p = r-d;
+
+ v3f p0, p1;
+ v3_muladds( c, ct->n, -ra, p0 );
+ v3_muladds( rbb->co, ct->n, rb, p1 );
+ v3_add( p0, p1, ct->co );
+ v3_muls( ct->co, 0.5f, ct->co );
+
+ ct->rba = rba;
+ ct->rbb = rbb;
+ ct->type = k_contact_type_default;
+
+ return 1;
+ }
+
+ return 0;
+}
+
+VG_STATIC int rb_capsule_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ if( !box_overlap( rba->bbx_world, rbb->bbx_world ) )
+ return 0;
+
+ float ha = rba->inf.capsule.height,
+ hb = rbb->inf.capsule.height,
+ ra = rba->inf.capsule.radius,
+ rb = rbb->inf.capsule.radius,
+ r = ra+rb;
+
+ v3f p0, p1, p2, p3;
+ v3_muladds( rba->co, rba->up, -ha*0.5f+ra, p0 );
+ v3_muladds( rba->co, rba->up, ha*0.5f-ra, p1 );
+ v3_muladds( rbb->co, rbb->up, -hb*0.5f+rb, p2 );
+ v3_muladds( rbb->co, rbb->up, hb*0.5f-rb, p3 );
+
+ capsule_manifold manifold;
+ rb_capsule_manifold_init( &manifold );
+
+ v3f pa, pb;
+ float ta, tb;
+ closest_segment_segment( p0, p1, p2, p3, &ta, &tb, pa, pb );
+ rb_capsule_manifold( pa, pb, ta, r, &manifold );
+
+ ta = closest_point_segment( p0, p1, p2, pa );
+ tb = closest_point_segment( p0, p1, p3, pb );
+ rb_capsule_manifold( pa, p2, ta, r, &manifold );
+ rb_capsule_manifold( pb, p3, tb, r, &manifold );
+
+ closest_point_segment( p2, p3, p0, pa );
+ closest_point_segment( p2, p3, p1, pb );
+ rb_capsule_manifold( p0, pa, 0.0f, r, &manifold );
+ rb_capsule_manifold( p1, pb, 1.0f, r, &manifold );
+
+ return rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+}
+
+/*
+ * Generates up to two contacts; optimised for the most stable manifold
+ */
+VG_STATIC int rb_capsule_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ float h = rba->inf.capsule.height,
+ r = rba->inf.capsule.radius;
+
+ /*
+ * Solving this in symetric local space of the cube saves us some time and a
+ * couple branches when it comes to the quad stage.
+ */
+ v3f centroid;
+ v3_add( rbb->bbx[0], rbb->bbx[1], centroid );
+ v3_muls( centroid, 0.5f, centroid );
+
+ boxf bbx;
+ v3_sub( rbb->bbx[0], centroid, bbx[0] );
+ v3_sub( rbb->bbx[1], centroid, bbx[1] );
+
+ v3f pc, p0w, p1w, p0, p1;
+ v3_muladds( rba->co, rba->up, -h*0.5f+r, p0w );
+ v3_muladds( rba->co, rba->up, h*0.5f-r, p1w );
+
+ m4x3_mulv( rbb->to_local, p0w, p0 );
+ m4x3_mulv( rbb->to_local, p1w, p1 );
+ v3_sub( p0, centroid, p0 );
+ v3_sub( p1, centroid, p1 );
+ v3_add( p0, p1, pc );
+ v3_muls( pc, 0.5f, pc );
+
+ /*
+ * Finding an appropriate quad to collide lines with
+ */
+ v3f region;
+ v3_div( pc, bbx[1], region );
+
+ v3f quad[4];
+ if( (fabsf(region[0]) > fabsf(region[1])) &&
+ (fabsf(region[0]) > fabsf(region[2])) )
+ {
+ float px = vg_signf(region[0]) * bbx[1][0];
+ v3_copy( (v3f){ px, bbx[0][1], bbx[0][2] }, quad[0] );
+ v3_copy( (v3f){ px, bbx[1][1], bbx[0][2] }, quad[1] );
+ v3_copy( (v3f){ px, bbx[1][1], bbx[1][2] }, quad[2] );
+ v3_copy( (v3f){ px, bbx[0][1], bbx[1][2] }, quad[3] );
+ }
+ else if( fabsf(region[1]) > fabsf(region[2]) )
+ {
+ float py = vg_signf(region[1]) * bbx[1][1];
+ v3_copy( (v3f){ bbx[0][0], py, bbx[0][2] }, quad[0] );
+ v3_copy( (v3f){ bbx[1][0], py, bbx[0][2] }, quad[1] );
+ v3_copy( (v3f){ bbx[1][0], py, bbx[1][2] }, quad[2] );
+ v3_copy( (v3f){ bbx[0][0], py, bbx[1][2] }, quad[3] );
+ }
+ else
+ {
+ float pz = vg_signf(region[2]) * bbx[1][2];
+ v3_copy( (v3f){ bbx[0][0], bbx[0][1], pz }, quad[0] );
+ v3_copy( (v3f){ bbx[1][0], bbx[0][1], pz }, quad[1] );
+ v3_copy( (v3f){ bbx[1][0], bbx[1][1], pz }, quad[2] );
+ v3_copy( (v3f){ bbx[0][0], bbx[1][1], pz }, quad[3] );
+ }
+
+ capsule_manifold manifold;
+ rb_capsule_manifold_init( &manifold );
+
+ v3f c0, c1;
+ closest_point_aabb( p0, bbx, c0 );
+ closest_point_aabb( p1, bbx, c1 );
+
+ v3f d0, d1, da;
+ v3_sub( c0, p0, d0 );
+ v3_sub( c1, p1, d1 );
+ v3_sub( p1, p0, da );
+
+ v3_normalize(d0);
+ v3_normalize(d1);
+ v3_normalize(da);
+
+ if( v3_dot( da, d0 ) <= 0.01f )
+ rb_capsule_manifold( p0, c0, 0.0f, r, &manifold );
+
+ if( v3_dot( da, d1 ) >= -0.01f )
+ rb_capsule_manifold( p1, c1, 1.0f, r, &manifold );
+
+ for( int i=0; i<4; i++ )
+ {
+ int i0 = i,
+ i1 = (i+1)%4;
+
+ v3f ca, cb;
+ float ta, tb;
+ closest_segment_segment( p0, p1, quad[i0], quad[i1], &ta, &tb, ca, cb );
+ rb_capsule_manifold( ca, cb, ta, r, &manifold );
+ }
+
+ /*
+ * Create final contacts based on line manifold
+ */
+ m3x3_mulv( rbb->to_world, manifold.d0, manifold.d0 );
+ m3x3_mulv( rbb->to_world, manifold.d1, manifold.d1 );
+
+ /*
+ * Debugging
+ */
+
+#if 0
+ for( int i=0; i<4; i++ )
+ {
+ v3f q0, q1;
+ int i0 = i,
+ i1 = (i+1)%4;
+
+ v3_add( quad[i0], centroid, q0 );
+ v3_add( quad[i1], centroid, q1 );
+
+ m4x3_mulv( rbb->to_world, q0, q0 );
+ m4x3_mulv( rbb->to_world, q1, q1 );
+
+ vg_line( q0, q1, 0xffffffff );
+ }
+#endif
+
+ return rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+}
+
+VG_STATIC int rb_sphere_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ v3f co, delta;
+
+ closest_point_obb( rba->co, rbb->bbx, rbb->to_world, rbb->to_local, co );
+ v3_sub( rba->co, co, delta );
+
+ float d2 = v3_length2(delta),
+ r = rba->inf.sphere.radius;
+
+ if( d2 <= r*r )
+ {
+ float d;
+
+ rb_ct *ct = buf;
+ if( d2 <= 0.0001f )
+ {
+ v3_sub( rba->co, rbb->co, delta );
+
+ /*
+ * some extra testing is required to find the best axis to push the
+ * object back outside the box. Since there isnt a clear seperating
+ * vector already, especially on really high aspect boxes.
+ */
+ float lx = v3_dot( rbb->right, delta ),
+ ly = v3_dot( rbb->up, delta ),
+ lz = v3_dot( rbb->forward, delta ),
+ px = rbb->bbx[1][0] - fabsf(lx),
+ py = rbb->bbx[1][1] - fabsf(ly),
+ pz = rbb->bbx[1][2] - fabsf(lz);
+
+ if( px < py && px < pz )
+ v3_muls( rbb->right, vg_signf(lx), ct->n );
+ else if( py < pz )
+ v3_muls( rbb->up, vg_signf(ly), ct->n );
+ else
+ v3_muls( rbb->forward, vg_signf(lz), ct->n );
+
+ v3_muladds( rba->co, ct->n, -r, ct->co );
+ ct->p = r;
+ }
+ else
+ {
+ d = sqrtf(d2);
+ v3_muls( delta, 1.0f/d, ct->n );
+ ct->p = r-d;
+ v3_copy( co, ct->co );
+ }
+
+ ct->rba = rba;
+ ct->rbb = rbb;
+ ct->type = k_contact_type_default;
+ return 1;
+ }
+
+ return 0;
+}
+
+VG_STATIC int rb_sphere_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ v3f delta;
+ v3_sub( rba->co, rbb->co, delta );
+
+ float d2 = v3_length2(delta),
+ r = rba->inf.sphere.radius + rbb->inf.sphere.radius;
+
+ if( d2 < r*r )
+ {
+ float d = sqrtf(d2);
+
+ rb_ct *ct = buf;
+ v3_muls( delta, 1.0f/d, ct->n );
+
+ v3f p0, p1;
+ v3_muladds( rba->co, ct->n,-rba->inf.sphere.radius, p0 );
+ v3_muladds( rbb->co, ct->n, rbb->inf.sphere.radius, p1 );
+ v3_add( p0, p1, ct->co );
+ v3_muls( ct->co, 0.5f, ct->co );
+ ct->type = k_contact_type_default;
+ ct->p = r-d;
+ ct->rba = rba;
+ ct->rbb = rbb;
+ return 1;
+ }
+
+ return 0;
+}
+
+//#define RIGIDBODY_DYNAMIC_MESH_EDGES
+
+VG_STATIC int rb_sphere_triangle( rigidbody *rba, rigidbody *rbb,
+ v3f tri[3], rb_ct *buf )
+{
+ v3f delta, co;
+
+#ifdef RIGIDBODY_DYNAMIC_MESH_EDGES
+ closest_on_triangle_1( rba->co, tri, co );
+#else
+ enum contact_type type = closest_on_triangle_1( rba->co, tri, co );
+#endif
+
+ v3_sub( rba->co, co, delta );
+
+ float d2 = v3_length2( delta ),
+ r = rba->inf.sphere.radius;
+
+ if( d2 < r*r )
+ {
+ rb_ct *ct = buf;
+
+ v3f ab, ac, tn;
+ v3_sub( tri[2], tri[0], ab );
+ v3_sub( tri[1], tri[0], ac );
+ v3_cross( ac, ab, tn );
+ v3_copy( tn, ct->n );
+
+ if( v3_length2( ct->n ) <= 0.00001f )
+ {
+ vg_error( "Zero area triangle!\n" );
+ return 0;
+ }
+
+ v3_normalize( ct->n );
+
+ float d = sqrtf(d2);
+
+ v3_copy( co, ct->co );
+ ct->type = type;
+ ct->p = r-d;
+ ct->rba = rba;
+ ct->rbb = rbb;
+ return 1;
+ }
+
+ return 0;
+}
+
+
+VG_STATIC void rb_debug_sharp_scene_edges( rigidbody *rbb, float sharp_ang,
+ boxf box, u32 colour )
+{
+ sharp_ang = cosf( sharp_ang );
+
+ scene *sc = rbb->inf.scene.bh_scene->user;
+ vg_line_boxf( box, 0xff00ff00 );
+
+ bh_iter it;
+ bh_iter_init( 0, &it );
+ int idx;
+
+ while( bh_next( rbb->inf.scene.bh_scene, &it, box, &idx ) )
+ {
+ u32 *ptri = &sc->arrindices[ idx*3 ];
+ v3f tri[3];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ for( int j=0; j<3; j++ )
+ {
+#if 0
+ v3f edir;
+ v3_sub( tri[(j+1)%3], tri[j], edir );
+
+ if( v3_dot( edir, (v3f){ 0.5184758473652127f,
+ 0.2073903389460850f,
+ -0.8295613557843402f } ) < 0.0f )
+ continue;
+#endif
+
+ bh_iter jt;
+ bh_iter_init( 0, &jt );
+
+ boxf region;
+ float const k_r = 0.02f;
+ v3_add( (v3f){ k_r, k_r, k_r }, tri[j], region[1] );
+ v3_add( (v3f){ -k_r, -k_r, -k_r }, tri[j], region[0] );
+
+ int jdx;
+ while( bh_next( rbb->inf.scene.bh_scene, &jt, region, &jdx ) )
+ {
+ if( idx <= jdx )
+ continue;
+
+ u32 *ptrj = &sc->arrindices[ jdx*3 ];
+ v3f trj[3];
+
+ for( int k=0; k<3; k++ )
+ v3_copy( sc->arrvertices[ptrj[k]].co, trj[k] );
+
+ for( int k=0; k<3; k++ )
+ {
+ if( v3_dist2( tri[j], trj[k] ) <= k_r*k_r )
+ {
+ int jp1 = (j+1)%3,
+ jp2 = (j+2)%3,
+ km1 = (k+3-1)%3,
+ km2 = (k+3-2)%3;
+
+ if( v3_dist2( tri[jp1], trj[km1] ) <= k_r*k_r )
+ {
+ v3f b0, b1, b2;
+ v3_sub( tri[jp1], tri[j], b0 );
+ v3_sub( tri[jp2], tri[j], b1 );
+ v3_sub( trj[km2], tri[j], b2 );
+
+ v3f cx0, cx1;
+ v3_cross( b0, b1, cx0 );
+ v3_cross( b2, b0, cx1 );
+
+ float polarity = v3_dot( cx0, b2 );
+
+ if( polarity < 0.0f )
+ {
+#if 0
+ vg_line( tri[j], tri[jp1], 0xff00ff00 );
+ float ang = v3_dot(cx0,cx1) /
+ (v3_length(cx0)*v3_length(cx1));
+ if( ang < sharp_ang )
+ {
+ vg_line( tri[j], tri[jp1], 0xff00ff00 );
+ }
+#endif
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+VG_STATIC int rb_sphere_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ scene *sc = rbb->inf.scene.bh_scene->user;
+
+ bh_iter it;
+ bh_iter_init( 0, &it );
+ int idx;
+
+ int count = 0;
+
+ while( bh_next( rbb->inf.scene.bh_scene, &it, rba->bbx_world, &idx ) )
+ {
+ u32 *ptri = &sc->arrindices[ idx*3 ];
+ v3f tri[3];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ buf[ count ].element_id = ptri[0];
+
+ vg_line( tri[0],tri[1],0x70ff6000 );
+ vg_line( tri[1],tri[2],0x70ff6000 );
+ vg_line( tri[2],tri[0],0x70ff6000 );
+
+ int contact = rb_sphere_triangle( rba, rbb, tri, buf+count );
+ count += contact;
+
+ if( count == 16 )
+ {
+ vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" );
+ return count;
+ }
+ }
+
+ return count;
+}
+
+VG_STATIC int rb_box_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ scene *sc = rbb->inf.scene.bh_scene->user;
+
+ v3f tri[3];
+
+ bh_iter it;
+ bh_iter_init( 0, &it );
+ int idx;
+
+ int count = 0;
+
+ while( bh_next( rbb->inf.scene.bh_scene, &it, rba->bbx_world, &idx ) )
+ {
+ u32 *ptri = &sc->arrindices[ idx*3 ];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ if( rb_box_triangle_sat( rba, tri ) )
+ {
+ vg_line(tri[0],tri[1],0xff50ff00 );
+ vg_line(tri[1],tri[2],0xff50ff00 );
+ vg_line(tri[2],tri[0],0xff50ff00 );
+ }
+ else
+ {
+ vg_line(tri[0],tri[1],0xff0000ff );
+ vg_line(tri[1],tri[2],0xff0000ff );
+ vg_line(tri[2],tri[0],0xff0000ff );
+
+ continue;
+ }
+
+ v3f v0,v1,n;
+ v3_sub( tri[1], tri[0], v0 );
+ v3_sub( tri[2], tri[0], v1 );
+ v3_cross( v0, v1, n );
+ v3_normalize( n );
+
+ /* find best feature */
+ float best = v3_dot( rba->right, n );
+ int axis = 0;
+
+ float cy = v3_dot( rba->up, n );
+ if( fabsf(cy) > fabsf(best) )
+ {
+ best = cy;
+ axis = 1;
+ }
+
+ float cz = -v3_dot( rba->forward, n );
+ if( fabsf(cz) > fabsf(best) )
+ {
+ best = cz;
+ axis = 2;
+ }
+
+ v3f manifold[4];
+
+ if( axis == 0 )
+ {
+ float px = best > 0.0f? rba->bbx[0][0]: rba->bbx[1][0];
+ manifold[0][0] = px;
+ manifold[0][1] = rba->bbx[0][1];
+ manifold[0][2] = rba->bbx[0][2];
+ manifold[1][0] = px;
+ manifold[1][1] = rba->bbx[1][1];
+ manifold[1][2] = rba->bbx[0][2];
+ manifold[2][0] = px;
+ manifold[2][1] = rba->bbx[1][1];
+ manifold[2][2] = rba->bbx[1][2];
+ manifold[3][0] = px;
+ manifold[3][1] = rba->bbx[0][1];
+ manifold[3][2] = rba->bbx[1][2];
+ }
+ else if( axis == 1 )
+ {
+ float py = best > 0.0f? rba->bbx[0][1]: rba->bbx[1][1];
+ manifold[0][0] = rba->bbx[0][0];
+ manifold[0][1] = py;
+ manifold[0][2] = rba->bbx[0][2];
+ manifold[1][0] = rba->bbx[1][0];
+ manifold[1][1] = py;
+ manifold[1][2] = rba->bbx[0][2];
+ manifold[2][0] = rba->bbx[1][0];
+ manifold[2][1] = py;
+ manifold[2][2] = rba->bbx[1][2];
+ manifold[3][0] = rba->bbx[0][0];
+ manifold[3][1] = py;
+ manifold[3][2] = rba->bbx[1][2];
+ }
+ else
+ {
+ float pz = best > 0.0f? rba->bbx[0][2]: rba->bbx[1][2];
+ manifold[0][0] = rba->bbx[0][0];
+ manifold[0][1] = rba->bbx[0][1];
+ manifold[0][2] = pz;
+ manifold[1][0] = rba->bbx[1][0];
+ manifold[1][1] = rba->bbx[0][1];
+ manifold[1][2] = pz;
+ manifold[2][0] = rba->bbx[1][0];
+ manifold[2][1] = rba->bbx[1][1];
+ manifold[2][2] = pz;
+ manifold[3][0] = rba->bbx[0][0];
+ manifold[3][1] = rba->bbx[1][1];
+ manifold[3][2] = pz;
+ }
+
+ for( int j=0; j<4; j++ )
+ m4x3_mulv( rba->to_world, manifold[j], manifold[j] );
+
+ vg_line( manifold[0], manifold[1], 0xffffffff );
+ vg_line( manifold[1], manifold[2], 0xffffffff );
+ vg_line( manifold[2], manifold[3], 0xffffffff );
+ vg_line( manifold[3], manifold[0], 0xffffffff );
+
+ for( int j=0; j<4; j++ )
+ {
+ rb_ct *ct = buf+count;
+
+ v3_copy( manifold[j], ct->co );
+ v3_copy( n, ct->n );
+
+ float l0 = v3_dot( tri[0], n ),
+ l1 = v3_dot( manifold[j], n );
+
+ ct->p = (l0-l1)*0.5f;
+ if( ct->p < 0.0f )
+ continue;
+
+ ct->type = k_contact_type_default;
+ ct->rba = rba;
+ ct->rbb = rbb;
+ count ++;
+
+ if( count >= 12 )
+ return count;
+ }
+ }
+ return count;
+}
+
+VG_STATIC int rb_capsule__triangle( m4x3f mtxA, rb_capsule *c,
+ v3f tri[3], rb_ct *buf )
+{
+ v3f pc, p0w, p1w;
+ v3_muladds( mtxA[3], mtxA[1], -c->height*0.5f+c->radius, p0w );
+ v3_muladds( mtxA[3], mtxA[1], c->height*0.5f-c->radius, p1w );
+
+ capsule_manifold manifold;
+ rb_capsule_manifold_init( &manifold );
+
+ v3f c0, c1;
+ closest_on_triangle_1( p0w, tri, c0 );
+ closest_on_triangle_1( p1w, tri, c1 );
+
+ v3f d0, d1, da;
+ v3_sub( c0, p0w, d0 );
+ v3_sub( c1, p1w, d1 );
+ v3_sub( p1w, p0w, da );
+
+ v3_normalize(d0);
+ v3_normalize(d1);
+ v3_normalize(da);
+
+ if( v3_dot( da, d0 ) <= 0.01f )
+ rb_capsule_manifold( p0w, c0, 0.0f, c->radius, &manifold );
+
+ if( v3_dot( da, d1 ) >= -0.01f )
+ rb_capsule_manifold( p1w, c1, 1.0f, c->radius, &manifold );
+
+ for( int i=0; i<3; i++ )
+ {
+ int i0 = i,
+ i1 = (i+1)%3;
+
+ v3f ca, cb;
+ float ta, tb;
+ closest_segment_segment( p0w, p1w, tri[i0], tri[i1], &ta, &tb, ca, cb );
+ rb_capsule_manifold( ca, cb, ta, c->radius, &manifold );
+ }
+
+ v3f v0, v1, n;
+ v3_sub( tri[1], tri[0], v0 );
+ v3_sub( tri[2], tri[0], v1 );
+ v3_cross( v0, v1, n );
+ v3_normalize( n );
+
+ int count = rb_capsule__manifold_done( mtxA, c, &manifold, buf );
+ for( int i=0; i<count; i++ )
+ v3_copy( n, buf[i].n );
+
+ return count;
+}
+
+/*
+ * Generates up to two contacts; optimised for the most stable manifold
+ */
+__attribute__ ((deprecated))
+VG_STATIC int rb_capsule_triangle( rigidbody *rba, rigidbody *rbb,
+ v3f tri[3], rb_ct *buf )
+{
+ float h = rba->inf.capsule.height,
+ r = rba->inf.capsule.radius;
+
+ v3f pc, p0w, p1w;
+ v3_muladds( rba->co, rba->up, -h*0.5f+r, p0w );
+ v3_muladds( rba->co, rba->up, h*0.5f-r, p1w );
+
+ capsule_manifold manifold;
+ rb_capsule_manifold_init( &manifold );
+
+ v3f c0, c1;
+ closest_on_triangle_1( p0w, tri, c0 );
+ closest_on_triangle_1( p1w, tri, c1 );
+
+ v3f d0, d1, da;
+ v3_sub( c0, p0w, d0 );
+ v3_sub( c1, p1w, d1 );
+ v3_sub( p1w, p0w, da );
+
+ v3_normalize(d0);
+ v3_normalize(d1);
+ v3_normalize(da);
+
+ if( v3_dot( da, d0 ) <= 0.01f )
+ rb_capsule_manifold( p0w, c0, 0.0f, r, &manifold );
+
+ if( v3_dot( da, d1 ) >= -0.01f )
+ rb_capsule_manifold( p1w, c1, 1.0f, r, &manifold );
+
+ for( int i=0; i<3; i++ )
+ {
+ int i0 = i,
+ i1 = (i+1)%3;
+
+ v3f ca, cb;
+ float ta, tb;
+ closest_segment_segment( p0w, p1w, tri[i0], tri[i1], &ta, &tb, ca, cb );
+ rb_capsule_manifold( ca, cb, ta, r, &manifold );
+ }
+
+ v3f v0, v1, n;
+ v3_sub( tri[1], tri[0], v0 );
+ v3_sub( tri[2], tri[0], v1 );
+ v3_cross( v0, v1, n );
+ v3_normalize( n );
+
+ int count = rb_capsule_manifold_done( rba, rbb, &manifold, buf );
+ for( int i=0; i<count; i++ )
+ v3_copy( n, buf[i].n );
+
+ return count;
+}
+
+/* mtxB is defined only for tradition; it is not used currently */
+VG_STATIC int rb_capsule__scene( m4x3f mtxA, rb_capsule *c,
+ m4x3f mtxB, rb_scene *s,
+ rb_ct *buf )
+{
+ bh_iter it;
+ bh_iter_init( 0, &it );
+ int idx;
+ int count = 0;
+
+ boxf bbx;
+ v3_sub( mtxA[3], (v3f){ c->height, c->height, c->height }, bbx[0] );
+ v3_add( mtxA[3], (v3f){ c->height, c->height, c->height }, bbx[1] );
+
+ scene *sc = s->bh_scene->user;
+
+ while( bh_next( s->bh_scene, &it, bbx, &idx ) )
+ {
+ u32 *ptri = &sc->arrindices[ idx*3 ];
+ v3f tri[3];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ buf[ count ].element_id = ptri[0];
+
+ int contact = rb_capsule__triangle( mtxA, c, tri, &buf[count] );
+ count += contact;
+
+ if( count == 16 )
+ {
+ vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
+ return count;
+ }
+ }
+
+ return count;
+}
+
+__attribute__ ((deprecated))
+VG_STATIC int rb_capsule_scene( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ scene *sc = rbb->inf.scene.bh_scene->user;
+
+ bh_iter it;
+ bh_iter_init( 0, &it );
+ int idx;
+
+ int count = 0;
+
+ while( bh_next( rbb->inf.scene.bh_scene, &it, rba->bbx_world, &idx ) )
+ {
+ u32 *ptri = &sc->arrindices[ idx*3 ];
+ v3f tri[3];
+
+ for( int j=0; j<3; j++ )
+ v3_copy( sc->arrvertices[ptri[j]].co, tri[j] );
+
+ buf[ count ].element_id = ptri[0];
+
+#if 0
+ vg_line( tri[0],tri[1],0x70ff6000 );
+ vg_line( tri[1],tri[2],0x70ff6000 );
+ vg_line( tri[2],tri[0],0x70ff6000 );
+#endif
+
+ int contact = rb_capsule_triangle( rba, rbb, tri, buf+count );
+ count += contact;
+
+ if( count == 16 )
+ {
+ vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n");
+ return count;
+ }
+ }
+
+ return count;
+}
+
+VG_STATIC int rb_scene_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_scene( rbb, rba, buf );
+}
+
+VG_STATIC int RB_MATRIX_ERROR( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+#if 0
+ vg_error( "Collision type is unimplemented between types %d and %d\n",
+ rba->type, rbb->type );
+#endif
+
+ return 0;
+}
+
+VG_STATIC int rb_sphere_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_sphere( rbb, rba, buf );
+}
+
+VG_STATIC int rb_box_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_box( rbb, rba, buf );
+}
+
+VG_STATIC int rb_box_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_sphere_box( rbb, rba, buf );
+}
+
+VG_STATIC int rb_scene_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_box_scene( rbb, rba, buf );
+}
+
+VG_STATIC int (*rb_jump_table[4][4])( rigidbody *a, rigidbody *b, rb_ct *buf ) =
+{
+ /* box */ /* Sphere */ /* Capsule */ /* Mesh */
+ { RB_MATRIX_ERROR, rb_box_sphere, rb_box_capsule, rb_box_scene },
+ { rb_sphere_box, rb_sphere_sphere, rb_sphere_capsule, rb_sphere_scene },
+ { rb_capsule_box, rb_capsule_sphere, rb_capsule_capsule, rb_capsule_scene },
+ { rb_scene_box, RB_MATRIX_ERROR, rb_scene_capsule, RB_MATRIX_ERROR }
+};
+
+VG_STATIC int rb_collide( rigidbody *rba, rigidbody *rbb )
+{
+ int (*collider_jump)(rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+ = rb_jump_table[rba->type][rbb->type];
+
+ /*
+ * 12 is the maximum manifold size we can generate, so we are forced to abort
+ * potentially checking any more.
+ */
+ if( rb_contact_count + 12 > vg_list_size(rb_contact_buffer) )
+ {
+ vg_warn( "Too many contacts made in global collider buffer (%d of %d\n)",
+ rb_contact_count, vg_list_size(rb_contact_buffer) );
+ return 0;
+ }
+
+ /*
+ * FUTURE: Replace this with a more dedicated broad phase pass
+ */
+ if( box_overlap( rba->bbx_world, rbb->bbx_world ) )
+ {
+ int count = collider_jump( rba, rbb, rb_contact_buffer+rb_contact_count);
+ rb_contact_count += count;
+ return count;
+ }
+ else
+ return 0;
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Dynamics
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_solver_reset(void)
+{
+ rb_contact_count = 0;
+}
+
+VG_STATIC rb_ct *rb_global_ct(void)
+{
+ return rb_contact_buffer + rb_contact_count;
+}
+
+VG_STATIC void rb_prepare_contact( rb_ct *ct )
+{
+ ct->bias = -0.2f * k_rb_rate * vg_minf( 0.0f, -ct->p+k_penetration_slop );
+ rb_tangent_basis( ct->n, ct->t[0], ct->t[1] );
+
+#if 0
+ ct->type = k_contact_type_default;
+#endif
+ ct->norm_impulse = 0.0f;
+ ct->tangent_impulse[0] = 0.0f;
+ ct->tangent_impulse[1] = 0.0f;
+}
+
+/*
+ * Initializing things like tangent vectors
+ */
+VG_STATIC void rb_presolve_contacts( rb_ct *buffer, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_ct *ct = &buffer[i];
+ rb_prepare_contact( ct );
+
+ v3f ra, rb, raCn, rbCn, raCt, rbCt;
+ v3_sub( ct->co, ct->rba->co, ra );
+ v3_sub( ct->co, ct->rbb->co, rb );
+ v3_cross( ra, ct->n, raCn );
+ v3_cross( rb, ct->n, rbCn );
+
+ /* orient inverse inertia tensors */
+ v3f raCnI, rbCnI;
+ m3x3_mulv( ct->rba->iIw, raCn, raCnI );
+ m3x3_mulv( ct->rbb->iIw, rbCn, rbCnI );
+
+ ct->normal_mass = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->normal_mass += v3_dot( raCn, raCnI );
+ ct->normal_mass += v3_dot( rbCn, rbCnI );
+ ct->normal_mass = 1.0f/ct->normal_mass;
+
+ for( int j=0; j<2; j++ )
+ {
+ v3f raCtI, rbCtI;
+ v3_cross( ct->t[j], ra, raCt );
+ v3_cross( ct->t[j], rb, rbCt );
+ m3x3_mulv( ct->rba->iIw, raCt, raCtI );
+ m3x3_mulv( ct->rbb->iIw, rbCt, rbCtI );
+
+ ct->tangent_mass[j] = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->tangent_mass[j] += v3_dot( raCt, raCtI );
+ ct->tangent_mass[j] += v3_dot( rbCt, rbCtI );
+ ct->tangent_mass[j] = 1.0f/ct->tangent_mass[j];
+ }
+
+ rb_debug_contact( ct );
+ }
+}
+
+/*
+ * Creates relative contact velocity vector
+ */
+VG_STATIC void rb_rcv( rigidbody *rba, rigidbody *rbb, v3f ra, v3f rb, v3f rv )
+{
+ v3f rva, rvb;
+ v3_cross( rba->w, ra, rva );
+ v3_add( rba->v, rva, rva );
+ v3_cross( rbb->w, rb, rvb );
+ v3_add( rbb->v, rvb, rvb );
+
+ v3_sub( rva, rvb, rv );
+}
+
+/*
+ * Apply impulse to object
+ */
+VG_STATIC void rb_linear_impulse( rigidbody *rb, v3f delta, v3f impulse )
+{
+ /* linear */
+ v3_muladds( rb->v, impulse, rb->inv_mass, rb->v );
+
+ /* Angular velocity */
+ v3f wa;
+ v3_cross( delta, impulse, wa );
+
+ m3x3_mulv( rb->iIw, wa, wa );
+ v3_add( rb->w, wa, rb->w );
+}
+
+/*
+ * One iteration to solve the contact constraint
+ */
+VG_STATIC void rb_solve_contacts( rb_ct *buf, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ struct contact *ct = &buf[i];
+
+ v3f rv, ra, rb;
+ v3_sub( ct->co, ct->rba->co, ra );
+ v3_sub( ct->co, ct->rbb->co, rb );
+ rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
+
+ /* Friction */
+ for( int j=0; j<2; j++ )
+ {
+ float f = k_friction * ct->norm_impulse,
+ vt = v3_dot( rv, ct->t[j] ),
+ lambda = ct->tangent_mass[j] * -vt;
+
+ float temp = ct->tangent_impulse[j];
+ ct->tangent_impulse[j] = vg_clampf( temp + lambda, -f, f );
+ lambda = ct->tangent_impulse[j] - temp;
+
+ v3f impulse;
+ v3_muls( ct->t[j], lambda, impulse );
+ rb_linear_impulse( ct->rba, ra, impulse );
+
+ v3_muls( ct->t[j], -lambda, impulse );
+ rb_linear_impulse( ct->rbb, rb, impulse );
+ }
+
+ /* Normal */
+ rb_rcv( ct->rba, ct->rbb, ra, rb, rv );
+ float vn = v3_dot( rv, ct->n ),
+ lambda = ct->normal_mass * (-vn + ct->bias);
+
+ float temp = ct->norm_impulse;
+ ct->norm_impulse = vg_maxf( temp + lambda, 0.0f );
+ lambda = ct->norm_impulse - temp;
+
+ v3f impulse;
+ v3_muls( ct->n, lambda, impulse );
+ rb_linear_impulse( ct->rba, ra, impulse );
+
+ v3_muls( ct->n, -lambda, impulse );
+ rb_linear_impulse( ct->rbb, rb, impulse );
+ }
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Constraints
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_debug_position_constraints( rb_constr_pos *buffer, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_pos *constr = &buffer[i];
+ rigidbody *rba = constr->rba, *rbb = constr->rbb;
+
+ v3f wca, wcb;
+ m3x3_mulv( rba->to_world, constr->lca, wca );
+ m3x3_mulv( rbb->to_world, constr->lcb, wcb );
+
+ v3f p0, p1;
+ v3_add( wca, rba->co, p0 );
+ v3_add( wcb, rbb->co, p1 );
+ vg_line_pt3( p0, 0.0025f, 0xff000000 );
+ vg_line_pt3( p1, 0.0025f, 0xffffffff );
+ vg_line2( p0, p1, 0xff000000, 0xffffffff );
+ }
+}
+
+VG_STATIC void rb_presolve_swingtwist_constraints( rb_constr_swingtwist *buf,
+ int len )
+{
+ float size = 0.12f;
+
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[ i ];
+
+ v3f vx, vy, va, vxb, axis, center;
+
+ m3x3_mulv( st->rba->to_world, st->conevx, vx );
+ m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
+ m3x3_mulv( st->rba->to_world, st->conevy, vy );
+ m3x3_mulv( st->rbb->to_world, st->coneva, va );
+ m4x3_mulv( st->rba->to_world, st->view_offset, center );
+ v3_cross( vy, vx, axis );
+
+ /* Constraint violated ? */
+ float fx = v3_dot( vx, va ), /* projection world */
+ fy = v3_dot( vy, va ),
+ fn = v3_dot( va, axis ),
+
+ rx = st->conevx[3], /* elipse radii */
+ ry = st->conevy[3],
+
+ lx = fx/rx, /* projection local (fn==lz) */
+ ly = fy/ry;
+
+ st->tangent_violation = ((lx*lx + ly*ly) > fn*fn) || (fn <= 0.0f);
+ if( st->tangent_violation )
+ {
+ /* Calculate a good position and the axis to solve on */
+ v2f closest, tangent,
+ p = { fx/fabsf(fn), fy/fabsf(fn) };
+
+ closest_point_elipse( p, (v2f){rx,ry}, closest );
+ tangent[0] = -closest[1] / (ry*ry);
+ tangent[1] = closest[0] / (rx*rx);
+ v2_normalize( tangent );
+
+ v3f v0, v1;
+ v3_muladds( axis, vx, closest[0], v0 );
+ v3_muladds( v0, vy, closest[1], v0 );
+ v3_normalize( v0 );
+
+ v3_muls( vx, tangent[0], v1 );
+ v3_muladds( v1, vy, tangent[1], v1 );
+
+ v3_copy( v0, st->tangent_target );
+ v3_copy( v1, st->tangent_axis );
+
+ /* calculate mass */
+ v3f aIw, bIw;
+ m3x3_mulv( st->rba->iIw, st->tangent_axis, aIw );
+ m3x3_mulv( st->rbb->iIw, st->tangent_axis, bIw );
+ st->tangent_mass = 1.0f / (v3_dot( st->tangent_axis, aIw ) +
+ v3_dot( st->tangent_axis, bIw ));
+
+ float angle = v3_dot( va, st->tangent_target );
+ }
+
+ v3f refaxis;
+ v3_cross( vy, va, refaxis ); /* our default rotation */
+ v3_normalize( refaxis );
+
+ float angle = v3_dot( refaxis, vxb );
+ st->axis_violation = fabsf(angle) < st->conet;
+
+ if( st->axis_violation )
+ {
+ v3f dir_test;
+ v3_cross( refaxis, vxb, dir_test );
+
+ if( v3_dot(dir_test, va) < 0.0f )
+ st->axis_violation = -st->axis_violation;
+
+ float newang = (float)st->axis_violation * acosf(st->conet-0.0001f);
+
+ v3f refaxis_up;
+ v3_cross( va, refaxis, refaxis_up );
+ v3_muls( refaxis_up, sinf(newang), st->axis_target );
+ v3_muladds( st->axis_target, refaxis, -cosf(newang), st->axis_target );
+
+ /* calculate mass */
+ v3_copy( va, st->axis );
+ v3f aIw, bIw;
+ m3x3_mulv( st->rba->iIw, st->axis, aIw );
+ m3x3_mulv( st->rbb->iIw, st->axis, bIw );
+ st->axis_mass = 1.0f / (v3_dot( st->axis, aIw ) +
+ v3_dot( st->axis, bIw ));
+ }
+ }
+}
+
+VG_STATIC void rb_debug_swingtwist_constraints( rb_constr_swingtwist *buf,
+ int len )
+{
+ float size = 0.12f;
+
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[ i ];
+
+ v3f vx, vxb, vy, va, axis, center;
+
+ m3x3_mulv( st->rba->to_world, st->conevx, vx );
+ m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
+ m3x3_mulv( st->rba->to_world, st->conevy, vy );
+ m3x3_mulv( st->rbb->to_world, st->coneva, va );
+ m4x3_mulv( st->rba->to_world, st->view_offset, center );
+ v3_cross( vy, vx, axis );
+
+ float rx = st->conevx[3], /* elipse radii */
+ ry = st->conevy[3];
+
+ v3f p0, p1;
+ v3_muladds( center, va, size, p1 );
+ vg_line( center, p1, 0xffffffff );
+ vg_line_pt3( p1, 0.00025f, 0xffffffff );
+
+ if( st->tangent_violation )
+ {
+ v3_muladds( center, st->tangent_target, size, p0 );
+
+ vg_line( center, p0, 0xff00ff00 );
+ vg_line_pt3( p0, 0.00025f, 0xff00ff00 );
+ vg_line( p1, p0, 0xff000000 );
+ }
+
+ for( int x=0; x<32; x++ )
+ {
+ float t0 = ((float)x * (1.0f/32.0f)) * VG_TAUf,
+ t1 = (((float)x+1.0f) * (1.0f/32.0f)) * VG_TAUf,
+ c0 = cosf( t0 ),
+ s0 = sinf( t0 ),
+ c1 = cosf( t1 ),
+ s1 = sinf( t1 );
+
+ v3f v0, v1;
+ v3_muladds( axis, vx, c0*rx, v0 );
+ v3_muladds( v0, vy, s0*ry, v0 );
+ v3_muladds( axis, vx, c1*rx, v1 );
+ v3_muladds( v1, vy, s1*ry, v1 );
+
+ v3_normalize( v0 );
+ v3_normalize( v1 );
+
+ v3_muladds( center, v0, size, p0 );
+ v3_muladds( center, v1, size, p1 );
+
+ u32 col0r = fabsf(c0) * 255.0f,
+ col0g = fabsf(s0) * 255.0f,
+ col1r = fabsf(c1) * 255.0f,
+ col1g = fabsf(s1) * 255.0f,
+ col = st->tangent_violation? 0xff0000ff: 0xff000000,
+ col0 = col | (col0r<<16) | (col0g << 8),
+ col1 = col | (col1r<<16) | (col1g << 8);
+
+ vg_line2( center, p0, VG__NONE, col0 );
+ vg_line2( p0, p1, col0, col1 );
+ }
+
+ /* Draw twist */
+ v3_muladds( center, va, size, p0 );
+ v3_muladds( p0, vxb, size, p1 );
+
+ vg_line( p0, p1, 0xff0000ff );
+
+ if( st->axis_violation )
+ {
+ v3_muladds( p0, st->axis_target, size*1.25f, p1 );
+ vg_line( p0, p1, 0xffffff00 );
+ vg_line_pt3( p1, 0.0025f, 0xffffff80 );
+ }
+
+ v3f refaxis;
+ v3_cross( vy, va, refaxis ); /* our default rotation */
+ v3_normalize( refaxis );
+ v3f refaxis_up;
+ v3_cross( va, refaxis, refaxis_up );
+ float newang = acosf(st->conet-0.0001f);
+
+ v3_muladds( p0, refaxis_up, sinf(newang)*size, p1 );
+ v3_muladds( p1, refaxis, -cosf(newang)*size, p1 );
+ vg_line( p0, p1, 0xff000000 );
+
+ v3_muladds( p0, refaxis_up, sinf(-newang)*size, p1 );
+ v3_muladds( p1, refaxis, -cosf(-newang)*size, p1 );
+ vg_line( p0, p1, 0xff404040 );
+ }
+}
+
+/*
+ * Solve a list of positional constraints
+ */
+VG_STATIC void rb_solve_position_constraints( rb_constr_pos *buf, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_pos *constr = &buf[i];
+ rigidbody *rba = constr->rba, *rbb = constr->rbb;
+
+ v3f wa, wb;
+ m3x3_mulv( rba->to_world, constr->lca, wa );
+ m3x3_mulv( rbb->to_world, constr->lcb, wb );
+
+ m3x3f ssra, ssrat, ssrb, ssrbt;
+
+ m3x3_skew_symetric( ssrat, wa );
+ m3x3_skew_symetric( ssrbt, wb );
+ m3x3_transpose( ssrat, ssra );
+ m3x3_transpose( ssrbt, ssrb );
+
+ v3f b, b_wa, b_wb, b_a, b_b;
+ m3x3_mulv( ssra, rba->w, b_wa );
+ m3x3_mulv( ssrb, rbb->w, b_wb );
+ v3_add( rba->v, b_wa, b );
+ v3_sub( b, rbb->v, b );
+ v3_sub( b, b_wb, b );
+ v3_muls( b, -1.0f, b );
+
+ m3x3f invMa, invMb;
+ m3x3_diagonal( invMa, rba->inv_mass );
+ m3x3_diagonal( invMb, rbb->inv_mass );
+
+ m3x3f ia, ib;
+ m3x3_mul( ssra, rba->iIw, ia );
+ m3x3_mul( ia, ssrat, ia );
+ m3x3_mul( ssrb, rbb->iIw, ib );
+ m3x3_mul( ib, ssrbt, ib );
+
+ m3x3f cma, cmb;
+ m3x3_add( invMa, ia, cma );
+ m3x3_add( invMb, ib, cmb );
+
+ m3x3f A;
+ m3x3_add( cma, cmb, A );
+
+ /* Solve Ax = b ( A^-1*b = x ) */
+ v3f impulse;
+ m3x3f invA;
+ m3x3_inv( A, invA );
+ m3x3_mulv( invA, b, impulse );
+
+ v3f delta_va, delta_wa, delta_vb, delta_wb;
+ m3x3f iwa, iwb;
+ m3x3_mul( rba->iIw, ssrat, iwa );
+ m3x3_mul( rbb->iIw, ssrbt, iwb );
+
+ m3x3_mulv( invMa, impulse, delta_va );
+ m3x3_mulv( invMb, impulse, delta_vb );
+ m3x3_mulv( iwa, impulse, delta_wa );
+ m3x3_mulv( iwb, impulse, delta_wb );
+
+ v3_add( rba->v, delta_va, rba->v );
+ v3_add( rba->w, delta_wa, rba->w );
+ v3_sub( rbb->v, delta_vb, rbb->v );
+ v3_sub( rbb->w, delta_wb, rbb->w );
+ }
+}
+
+VG_STATIC void rb_solve_swingtwist_constraints( rb_constr_swingtwist *buf,
+ int len )
+{
+ float size = 0.12f;
+
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[ i ];
+
+ if( !st->axis_violation )
+ continue;
+
+ float rv = v3_dot( st->axis, st->rbb->w ) -
+ v3_dot( st->axis, st->rba->w );
+
+ if( rv * (float)st->axis_violation > 0.0f )
+ continue;
+
+ v3f impulse, wa, wb;
+ v3_muls( st->axis, rv*st->axis_mass, impulse );
+ m3x3_mulv( st->rba->iIw, impulse, wa );
+ v3_add( st->rba->w, wa, st->rba->w );
+
+ v3_muls( impulse, -1.0f, impulse );
+ m3x3_mulv( st->rbb->iIw, impulse, wb );
+ v3_add( st->rbb->w, wb, st->rbb->w );
+
+ float rv2 = v3_dot( st->axis, st->rbb->w ) -
+ v3_dot( st->axis, st->rba->w );
+ }
+
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[ i ];
+
+ if( !st->tangent_violation )
+ continue;
+
+ float rv = v3_dot( st->tangent_axis, st->rbb->w ) -
+ v3_dot( st->tangent_axis, st->rba->w );
+
+ if( rv > 0.0f )
+ continue;
+
+ v3f impulse, wa, wb;
+ v3_muls( st->tangent_axis, rv*st->tangent_mass, impulse );
+ m3x3_mulv( st->rba->iIw, impulse, wa );
+ v3_add( st->rba->w, wa, st->rba->w );
+
+ v3_muls( impulse, -1.0f, impulse );
+ m3x3_mulv( st->rbb->iIw, impulse, wb );
+ v3_add( st->rbb->w, wb, st->rbb->w );
+
+ float rv2 = v3_dot( st->tangent_axis, st->rbb->w ) -
+ v3_dot( st->tangent_axis, st->rba->w );
+ }
+}
+
+VG_STATIC void rb_solve_constr_angle( rigidbody *rba, rigidbody *rbb,
+ v3f ra, v3f rb )
+{
+ m3x3f ssra, ssrb, ssrat, ssrbt;
+ m3x3f cma, cmb;
+
+ m3x3_skew_symetric( ssrat, ra );
+ m3x3_skew_symetric( ssrbt, rb );
+ m3x3_transpose( ssrat, ssra );
+ m3x3_transpose( ssrbt, ssrb );
+
+ m3x3_mul( ssra, rba->iIw, cma );
+ m3x3_mul( cma, ssrat, cma );
+ m3x3_mul( ssrb, rbb->iIw, cmb );
+ m3x3_mul( cmb, ssrbt, cmb );
+
+ m3x3f A, invA;
+ m3x3_add( cma, cmb, A );
+ m3x3_inv( A, invA );
+
+ v3f b_wa, b_wb, b;
+ m3x3_mulv( ssra, rba->w, b_wa );
+ m3x3_mulv( ssrb, rbb->w, b_wb );
+ v3_add( b_wa, b_wb, b );
+ v3_negate( b, b );
+
+ v3f impulse;
+ m3x3_mulv( invA, b, impulse );
+
+ v3f delta_wa, delta_wb;
+ m3x3f iwa, iwb;
+ m3x3_mul( rba->iIw, ssrat, iwa );
+ m3x3_mul( rbb->iIw, ssrbt, iwb );
+ m3x3_mulv( iwa, impulse, delta_wa );
+ m3x3_mulv( iwb, impulse, delta_wb );
+ v3_add( rba->w, delta_wa, rba->w );
+ v3_sub( rbb->w, delta_wb, rbb->w );
+}
+
+/*
+ * Correct position constraint drift errors
+ * [ 0.0 <= amt <= 1.0 ]: the correction amount
+ */
+VG_STATIC void rb_correct_position_constraints( rb_constr_pos *buf, int len,
+ float amt )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_pos *constr = &buf[i];
+ rigidbody *rba = constr->rba, *rbb = constr->rbb;
+
+ v3f p0, p1, d;
+ m3x3_mulv( rba->to_world, constr->lca, p0 );
+ m3x3_mulv( rbb->to_world, constr->lcb, p1 );
+ v3_add( rba->co, p0, p0 );
+ v3_add( rbb->co, p1, p1 );
+ v3_sub( p1, p0, d );
+
+ v3_muladds( rbb->co, d, -1.0f * amt, rbb->co );
+ rb_update_transform( rbb );
+ }
+}
+
+VG_STATIC void rb_correct_swingtwist_constraints( rb_constr_swingtwist *buf,
+ int len, float amt )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[i];
+
+ if( !st->tangent_violation )
+ continue;
+
+ v3f va;
+ m3x3_mulv( st->rbb->to_world, st->coneva, va );
+
+ float angle = v3_dot( va, st->tangent_target );
+
+ if( fabsf(angle) < 0.9999f )
+ {
+ v3f axis;
+ v3_cross( va, st->tangent_target, axis );
+
+ v4f correction;
+ q_axis_angle( correction, axis, acosf(angle) * amt );
+ q_mul( correction, st->rbb->q, st->rbb->q );
+ rb_update_transform( st->rbb );
+ }
+ }
+
+ for( int i=0; i<len; i++ )
+ {
+ rb_constr_swingtwist *st = &buf[i];
+
+ if( !st->axis_violation )
+ continue;
+
+ v3f vxb;
+ m3x3_mulv( st->rbb->to_world, st->conevxb, vxb );
+
+ float angle = v3_dot( vxb, st->axis_target );
+
+ if( fabsf(angle) < 0.9999f )
+ {
+ v3f axis;
+ v3_cross( vxb, st->axis_target, axis );
+
+ v4f correction;
+ q_axis_angle( correction, axis, acosf(angle) * amt );
+ q_mul( correction, st->rbb->q, st->rbb->q );
+ rb_update_transform( st->rbb );
+ }
+ }
+}
+
+VG_STATIC void rb_correct_contact_constraints( rb_ct *buf, int len, float amt )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_ct *ct = &buf[i];
+ rigidbody *rba = ct->rba,
+ *rbb = ct->rbb;
+
+ float mass_total = 1.0f / (rba->inv_mass + rbb->inv_mass);
+
+ v3_muladds( rba->co, ct->n, -mass_total * rba->inv_mass, rba->co );
+ v3_muladds( rbb->co, ct->n, mass_total * rbb->inv_mass, rbb->co );
+ }
+}
+
+
+/*
+ * Effectors
+ */
+
+VG_STATIC void rb_effect_simple_bouyency( rigidbody *ra, v4f plane,
+ float amt, float drag )
+{
+ /* float */
+ float depth = v3_dot( plane, ra->co ) - plane[3],
+ lambda = vg_clampf( -depth, 0.0f, 1.0f ) * amt;
+
+ v3_muladds( ra->v, plane, lambda * k_rb_delta, ra->v );
+
+ if( depth < 0.0f )
+ v3_muls( ra->v, 1.0f-(drag*k_rb_delta), ra->v );
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * BVH implementation, this is ONLY for VG_STATIC rigidbodies, its to slow for
+ * realtime use.
+ * -----------------------------------------------------------------------------
+ */
+
+VG_STATIC void rb_bh_expand_bound( void *user, boxf bound, u32 item_index )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ box_concat( bound, rb->bbx_world );
+}
+
+VG_STATIC float rb_bh_centroid( void *user, u32 item_index, int axis )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ return (rb->bbx_world[axis][0] + rb->bbx_world[1][axis]) * 0.5f;
+}
+
+VG_STATIC void rb_bh_swap( void *user, u32 ia, u32 ib )
+{
+ rigidbody temp, *rba, *rbb;
+ rba = &((rigidbody *)user)[ ia ];
+ rbb = &((rigidbody *)user)[ ib ];
+
+ temp = *rba;
+ *rba = *rbb;
+ *rbb = temp;
+}
+
+VG_STATIC void rb_bh_debug( void *user, u32 item_index )
+{
+ rigidbody *rb = &((rigidbody *)user)[ item_index ];
+ rb_debug( rb, 0xff00ffff );
+}
+
+VG_STATIC bh_system bh_system_rigidbodies =
+{
+ .expand_bound = rb_bh_expand_bound,
+ .item_centroid = rb_bh_centroid,
+ .item_swap = rb_bh_swap,
+ .item_debug = rb_bh_debug,
+ .cast_ray = NULL
+};
+