X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=rigidbody.h;h=c00b0f04f75817ad21072755ed983ce098094bfb;hb=84a7ae83a25966e0004a1a4b409dbb3d49fae286;hp=01734e8f2d74760ab32659165a1a51c633a4785c;hpb=7758c7efec3956c68294bc914e7524045a2b1bd7;p=carveJwlIkooP6JGAAIwe30JlM.git diff --git a/rigidbody.h b/rigidbody.h index 01734e8..c00b0f0 100644 --- a/rigidbody.h +++ b/rigidbody.h @@ -3,39 +3,84 @@ * qu3e - Randy Gaul */ -#include "vg/vg.h" +#include "common.h" +#include "bvh.h" + static void rb_tangent_basis( v3f n, v3f tx, v3f ty ); +static bh_system bh_system_rigidbodies; #ifndef RIGIDBODY_H #define RIGIDBODY_H #define RB_DEPR - -#include "world.h" - -#define k_rb_delta (1.0f/60.0f) +#define k_rb_rate 60.0f +#define k_rb_delta (1.0f/k_rb_rate) typedef struct rigidbody rigidbody; +typedef struct contact rb_ct; + struct rigidbody { - v3f co, v, I; + v3f co, v, w; v4f q; - boxf bbx; - float inv_mass; - struct contact + enum rb_shape { - v3f co, n, delta; - v3f t[2]; - float bias, norm_impulse, tangent_impulse[2]; + k_rb_shape_box, + k_rb_shape_sphere, + k_rb_shape_capsule + } + type; + + union + { + struct rb_sphere + { + float radius; + } + sphere; + + struct rb_capsule + { + float height, radius; + } + capsule; } - manifold[4]; - int manifold_count; + inf; + + v3f right, up, forward; + + int is_world; + + boxf bbx, bbx_world; + float inv_mass; v3f delta; /* where is the origin of this in relation to a parent body */ m4x3f to_world, to_local; }; +static rigidbody rb_static_null = +{ + .co={0.0f,0.0f,0.0f}, + .q={0.0f,0.0f,0.0f,1.0f}, + .v={0.0f,0.0f,0.0f}, + .w={0.0f,0.0f,0.0f}, + .is_world = 1, + .inv_mass = 0.0f +}; + +static void rb_debug( rigidbody *rb, u32 colour ); + +static struct contact +{ + rigidbody *rba, *rbb; + v3f co, n; + v3f t[2]; + float mass_total, p, bias, norm_impulse, tangent_impulse[2]; +} +rb_contact_buffer[256]; +static int rb_contact_count = 0; + static void rb_update_transform( rigidbody *rb ) { q_normalize( rb->q ); @@ -43,18 +88,60 @@ static void rb_update_transform( rigidbody *rb ) v3_copy( rb->co, rb->to_world[3] ); m4x3_invert_affine( rb->to_world, rb->to_local ); + + box_copy( rb->bbx, rb->bbx_world ); + m4x3_transform_aabb( rb->to_world, rb->bbx_world ); + + m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f, 0.0f}, rb->right ); + m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f, 0.0f}, rb->up ); + m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,-1.0f}, rb->forward ); +} + +static float sphere_volume( float radius ) +{ + float r3 = radius*radius*radius; + return (4.0f/3.0f) * VG_PIf * r3; } static void rb_init( rigidbody *rb ) { - q_identity( rb->q ); - v3_zero( rb->v ); - v3_zero( rb->I ); + float volume = 1.0f; + + if( rb->type == k_rb_shape_box ) + { + v3f dims; + v3_sub( rb->bbx[1], rb->bbx[0], dims ); + volume = dims[0]*dims[1]*dims[2]; + } + else if( rb->type == k_rb_shape_sphere ) + { + volume = sphere_volume( rb->inf.sphere.radius ); + v3_fill( rb->bbx[0], -rb->inf.sphere.radius ); + v3_fill( rb->bbx[1], rb->inf.sphere.radius ); + } + else if( rb->type == k_rb_shape_capsule ) + { + float r = rb->inf.capsule.radius, + h = rb->inf.capsule.height; + volume = sphere_volume( r ) + VG_PIf * r*r * (h - r*2.0f); + + v3_fill( rb->bbx[0], -rb->inf.sphere.radius ); + v3_fill( rb->bbx[1], rb->inf.sphere.radius ); + rb->bbx[0][1] = -h; + rb->bbx[1][1] = h; + } - v3f dims; - v3_sub( rb->bbx[1], rb->bbx[0], dims ); + if( rb->is_world ) + { + rb->inv_mass = 0.0f; + } + else + { + rb->inv_mass = 1.0f/(8.0f*volume); + } - rb->inv_mass = 1.0f/(8.0f*dims[0]*dims[1]*dims[2]); + v3_zero( rb->v ); + v3_zero( rb->w ); rb_update_transform( rb ); } @@ -66,15 +153,14 @@ static void rb_iter( rigidbody *rb ) /* intergrate velocity */ v3_muladds( rb->co, rb->v, k_rb_delta, rb->co ); - - v3_lerp( rb->I, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->I ); + v3_lerp( rb->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w ); /* inegrate inertia */ - if( v3_length2( rb->I ) > 0.0f ) + if( v3_length2( rb->w ) > 0.0f ) { v4f rotation; v3f axis; - v3_copy( rb->I, axis ); + v3_copy( rb->w, axis ); float mag = v3_length( axis ); v3_divs( axis, mag, axis ); @@ -85,7 +171,7 @@ static void rb_iter( rigidbody *rb ) static void rb_torque( rigidbody *rb, v3f axis, float mag ) { - v3_muladds( rb->I, axis, mag*k_rb_delta, rb->I ); + v3_muladds( rb->w, axis, mag*k_rb_delta, rb->w ); } static void rb_tangent_basis( v3f n, v3f tx, v3f ty ) @@ -108,7 +194,455 @@ static void rb_tangent_basis( v3f n, v3f tx, v3f ty ) v3_cross( n, tx, ty ); } -static void rb_build_manifold( rigidbody *rb ) +static void rb_solver_reset(void); +static void rb_build_manifold_terrain( rigidbody *rb ); +static void rb_build_manifold_terrain_sphere( rigidbody *rb ); +static void rb_solve_contacts(void); + +/* + * These closest point tests were learned from Real-Time Collision Detection by + * Christer Ericson + */ +static float closest_segment_segment( v3f p1, v3f q1, v3f p2, v3f q2, + float *s, float *t, v3f c1, v3f c2) +{ + v3f d1,d2,r; + v3_sub( q1, p1, d1 ); + v3_sub( q2, p2, d2 ); + v3_sub( p1, p2, r ); + + float a = v3_length2( d1 ), + e = v3_length2( d2 ), + f = v3_dot( d2, r ); + + const float kEpsilon = 0.0001f; + + if( a <= kEpsilon && e <= kEpsilon ) + { + *s = 0.0f; + *t = 0.0f; + v3_copy( p1, c1 ); + v3_copy( p2, c2 ); + + v3f v0; + v3_sub( c1, c2, v0 ); + + return v3_length2( v0 ); + } + + if( a<= kEpsilon ) + { + *s = 0.0f; + *t = vg_clampf( f / e, 0.0f, 1.0f ); + } + else + { + float c = v3_dot( d1, r ); + if( e <= kEpsilon ) + { + *t = 0.0f; + *s = vg_clampf( -c / a, 0.0f, 1.0f ); + } + else + { + float b = v3_dot(d1,d2), + d = a*e-b*b; + + if( d != 0.0f ) + { + *s = vg_clampf((b*f - c*e)/d, 0.0f, 1.0f); + } + else + { + *s = 0.0f; + } + + *t = (b*(*s)+f) / e; + + if( *t < 0.0f ) + { + *t = 0.0f; + *s = vg_clampf( -c / a, 0.0f, 1.0f ); + } + else if( *t > 1.0f ) + { + *t = 1.0f; + *s = vg_clampf((b-c)/a,0.0f,1.0f); + } + } + } + + v3_muladds( p1, d1, *s, c1 ); + v3_muladds( p2, d2, *t, c2 ); + + v3f v0; + v3_sub( c1, c2, v0 ); + return v3_length2( v0 ); +} + +static void closest_point_aabb( v3f p, boxf box, v3f dest ) +{ + v3_maxv( p, box[0], dest ); + v3_minv( dest, box[1], dest ); +} + +static void closest_point_obb( v3f p, rigidbody *rb, v3f dest ) +{ + v3f local; + m4x3_mulv( rb->to_local, p, local ); + closest_point_aabb( local, rb->bbx, local ); + m4x3_mulv( rb->to_world, local, dest ); +} + +static void closest_point_segment( v3f a, v3f b, v3f point, v3f dest ) +{ + v3f v0, v1; + v3_sub( b, a, v0 ); + v3_sub( point, a, v1 ); + + float t = v3_dot( v1, v0 ) / v3_length2(v0); + v3_muladds( a, v0, vg_clampf(t,0.0f,1.0f), dest ); +} + +static void closest_on_triangle( v3f p, v3f tri[3], v3f dest ) +{ + v3f ab, ac, ap; + float d1, d2; + + /* Region outside A */ + v3_sub( tri[1], tri[0], ab ); + v3_sub( tri[2], tri[0], ac ); + v3_sub( p, tri[0], ap ); + + d1 = v3_dot(ab,ap); + d2 = v3_dot(ac,ap); + if( d1 <= 0.0f && d2 <= 0.0f ) + { + v3_copy( tri[0], dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* Region outside B */ + v3f bp; + float d3, d4; + + v3_sub( p, tri[1], bp ); + d3 = v3_dot( ab, bp ); + d4 = v3_dot( ac, bp ); + + if( d3 >= 0.0f && d4 <= d3 ) + { + v3_copy( tri[1], dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* Edge region of AB */ + float vc = d1*d4 - d3*d2; + if( vc <= 0.0f && d1 >= 0.0f && d3 <= 0.0f ) + { + float v = d1 / (d1-d3); + v3_muladds( tri[0], ab, v, dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* Region outside C */ + v3f cp; + float d5, d6; + v3_sub( p, tri[2], cp ); + d5 = v3_dot(ab, cp); + d6 = v3_dot(ac, cp); + + if( d6 >= 0.0f && d5 <= d6 ) + { + v3_copy( tri[2], dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* Region of AC */ + float vb = d5*d2 - d1*d6; + if( vb <= 0.0f && d2 >= 0.0f && d6 <= 0.0f ) + { + float w = d2 / (d2-d6); + v3_muladds( tri[0], ac, w, dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* Region of BC */ + float va = d3*d6 - d5*d4; + if( va <= 0.0f && (d4-d3) >= 0.0f && (d5-d6) >= 0.0f ) + { + float w = (d4-d3) / ((d4-d3) + (d5-d6)); + v3f bc; + v3_sub( tri[2], tri[1], bc ); + v3_muladds( tri[1], bc, w, dest ); + v3_copy( (v3f){INFINITY,INFINITY,INFINITY}, dest ); + return; + } + + /* P inside region, Q via barycentric coordinates uvw */ + float d = 1.0f/(va+vb+vc), + v = vb*d, + w = vc*d; + + v3_muladds( tri[0], ab, v, dest ); + v3_muladds( dest, ac, w, dest ); +} + +/* + * Contact generators + * + * These do not automatically allocate contacts, an appropriately sized + * buffer must be supplied. The function returns the size of the manifold + * which was generated. + * + * The values set on the contacts are: n, co, p, rba, rbb + */ + +static void rb_debug_contact( rb_ct *ct ) +{ + v3f p1; + v3_muladds( ct->co, ct->n, 0.2f, p1 ); + vg_line_pt3( ct->co, 0.1f, 0xff0000ff ); + vg_line( ct->co, p1, 0xffffffff ); +} + +static int rb_sphere_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf ) +{ + v3f co, delta; + + closest_point_obb( rba->co, rbb, co ); + v3_sub( rba->co, co, delta ); + + float d2 = v3_length2(delta), + r = rba->inf.sphere.radius; + + if( d2 <= r*r ) + { + float d; + if( d2 <= 0.0001f ) + { + v3_sub( rbb->co, rba->co, delta ); + d2 = v3_length2(delta); + } + + d = sqrtf(d2); + + rb_ct *ct = buf; + v3_muls( delta, 1.0f/d, ct->n ); + v3_copy( co, ct->co ); + ct->p = r-d; + ct->rba = rba; + ct->rbb = rbb; + return 1; + } + + return 0; +} + +static int rb_sphere_vs_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->p = r-d; + ct->rba = rba; + ct->rbb = rbb; + return 1; + } + + return 0; +} + +static int rb_box_vs_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf ) +{ + return rb_sphere_vs_box( rbb, rba, buf ); +} + +static int rb_box_vs_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf ) +{ + /* TODO: Generating a stable quad manifold, lots of clipping */ + return 0; +} + +/* + * This function does not accept triangle as a dynamic object, it is assumed + * to always be static. + * + * The triangle is also assumed to be one sided for better detection + */ +static int rb_sphere_vs_triangle( rigidbody *rba, v3f tri[3], rb_ct *buf ) +{ + v3f delta, co; + + closest_on_triangle( rba->co, tri, co ); + v3_sub( rba->co, co, delta ); + + float d2 = v3_length2( delta ), + r = rba->inf.sphere.radius; + + if( d2 < r*r ) + { + v3f ab, ac, tn; + v3_sub( tri[1], tri[0], ab ); + v3_sub( tri[2], tri[0], ac ); + v3_cross( ac, ab, tn ); + + if( v3_dot( delta, tn ) > 0.0f ) + v3_muls( delta, -1.0f, delta ); + + float d = sqrtf(d2); + + rb_ct *ct = buf; + v3_muls( delta, 1.0f/d, ct->n ); + v3_copy( co, ct->co ); + ct->p = r-d; + ct->rba = rba; + ct->rbb = &rb_static_null; + return 1; + } + + return 0; +} + + +/* + * Generic functions + */ + +RB_DEPR +static int sphere_vs_triangle( v3f c, float r, v3f tri[3], + v3f co, v3f norm, float *p ) +{ + v3f delta; + closest_on_triangle( c, tri, co ); + + v3_sub( c, co, delta ); + + + float d = v3_length2( delta ); + if( d < r*r ) + { + v3f ab, ac, tn; + v3_sub( tri[1], tri[0], ab ); + v3_sub( tri[2], tri[0], ac ); + v3_cross( ac, ab, tn ); + + if( v3_dot( delta, tn ) > 0.0f ) + v3_muls( delta, -1.0f, delta ); + + vg_line_pt3( co, 0.05f, 0xff00ff00 ); + + d = sqrtf(d); + v3_muls( delta, 1.0f/d, norm ); + + *p = r-d; + return 1; + } + + return 0; +} + +#include "world.h" + +static void rb_solver_reset(void) +{ + rb_contact_count = 0; +} + +static rb_ct *rb_global_ct(void) +{ + return rb_contact_buffer + rb_contact_count; +} + +static struct contact *rb_start_contact(void) +{ + if( rb_contact_count == vg_list_size(rb_contact_buffer) ) + { + vg_error( "rigidbody: too many contacts generated (%u)\n", + rb_contact_count ); + return NULL; + } + + return &rb_contact_buffer[ rb_contact_count ]; +} + +static void rb_commit_contact( struct contact *ct, float p ) +{ + ct->bias = -0.2f*k_rb_rate*vg_minf(0.0f,-p+0.04f); + rb_tangent_basis( ct->n, ct->t[0], ct->t[1] ); + + ct->norm_impulse = 0.0f; + ct->tangent_impulse[0] = 0.0f; + ct->tangent_impulse[1] = 0.0f; + + rb_contact_count ++; +} + +static void rb_build_manifold_terrain_sphere( rigidbody *rb ) +{ + u32 geo[256]; + v3f tri[3]; + int len = bh_select( &world.geo.bhtris, rb->bbx_world, geo, 256 ); + + for( int i=0; ico, rb->inf.sphere.radius, tri,co,norm,&p)) + { + struct contact *ct = rb_start_contact(); + + if( !ct ) + return; + + v3f p1; + v3_muladds( rb->co, norm, p, p1 ); + vg_line( rb->co, p1, 0xffffffff ); + + ct->rba = rb; + v3_copy( co, ct->co ); + v3_copy( norm, ct->n ); + rb_commit_contact( ct, p ); + } + } + } + +} + +RB_DEPR +static void rb_build_manifold_terrain( rigidbody *rb ) { v3f *box = rb->bbx; v3f pts[8]; @@ -134,12 +668,17 @@ static void rb_build_manifold( rigidbody *rb ) m4x3_mulv( rb->to_world, p110, p110 ); m4x3_mulv( rb->to_world, p111, p111 ); - rb->manifold_count = 0; + int count = 0; for( int i=0; i<8; i++ ) { float *point = pts[i]; - struct contact *ct = &rb->manifold[rb->manifold_count]; + struct contact *ct = rb_start_contact(); + + if( !ct ) + return; + + ct->rba = rb; v3f surface; v3_copy( point, surface ); @@ -150,76 +689,123 @@ static void rb_build_manifold( rigidbody *rb ) if( !ray_world( surface, (v3f){0.0f,-1.0f,0.0f}, &hit )) continue; - v3_copy( hit.normal, ct->n ); v3_copy( hit.pos, surface ); float p = vg_minf( surface[1] - point[1], 1.0f ); if( p > 0.0f ) { + v3_copy( hit.normal, ct->n ); v3_add( point, surface, ct->co ); v3_muls( ct->co, 0.5f, ct->co ); - //vg_line_pt3( ct->co, 0.0125f, 0xff0000ff ); + rb_commit_contact( ct, p ); + count ++; + if( count == 4 ) + break; + } + } +} - v3_sub( ct->co, rb->co, ct->delta ); - ct->bias = -0.2f * (1.0f/k_rb_delta) * vg_minf( 0.0f, -p+0.04f ); - rb_tangent_basis( ct->n, ct->t[0], ct->t[1] ); +/* + * Initializing things like tangent vectors + */ +static void rb_presolve_contacts(void) +{ + for( int i=0; inorm_impulse = 0.0f; - ct->tangent_impulse[0] = 0.0f; - ct->tangent_impulse[1] = 0.0f; + ct->bias = -0.2f * k_rb_rate * vg_minf(0.0f,-ct->p+0.04f); + rb_tangent_basis( ct->n, ct->t[0], ct->t[1] ); - rb->manifold_count ++; - if( rb->manifold_count == 4 ) - break; - } + ct->norm_impulse = 0.0f; + ct->tangent_impulse[0] = 0.0f; + ct->tangent_impulse[1] = 0.0f; + ct->mass_total = 1.0f/(ct->rba->inv_mass + ct->rbb->inv_mass); + + rb_debug_contact( ct ); } } -static void rb_constraint_manifold( rigidbody *rb ) +/* + * Creates relative contact velocity vector, and offsets between each body */ +static void rb_rcv( rb_ct *ct, v3f rv, v3f da, v3f db ) +{ + rigidbody *rba = ct->rba, + *rbb = ct->rbb; + + v3_sub( rba->co, ct->co, da ); + v3_sub( rbb->co, ct->co, db ); + + v3f rva, rvb; + v3_cross( rba->w, da, rva ); + v3_add( rba->v, rva, rva ); + + v3_cross( rbb->w, db, rvb ); + v3_add( rbb->v, rvb, rvb ); + v3_add( rva, rvb, rv ); +} + +static void rb_standard_impulse( rb_ct *ct, v3f da, v3f db, v3f impulse ) +{ + rigidbody *rba = ct->rba, + *rbb = ct->rbb; + + /* response */ + v3_muladds( rba->v, impulse, ct->mass_total * rba->inv_mass, rba->v ); + v3_muladds( rbb->v, impulse, ct->mass_total * rbb->inv_mass, rbb->v ); + + /* Angular velocity */ + v3f wa, wb; + v3_cross( da, impulse, wa ); + v3_cross( db, impulse, wb ); + v3_muladds( rba->w, wa, ct->mass_total * rba->inv_mass, rba->w ); + v3_muladds( rbb->w, wb, ct->mass_total * rbb->inv_mass, rbb->w ); +} + +static void rb_solve_contacts(void) { float k_friction = 0.1f; + /* TODO: second object + * Static objects route to static element */ + /* Friction Impulse */ - for( int i=0; imanifold_count; i++ ) + for( int i=0; imanifold[i]; + struct contact *ct = &rb_contact_buffer[i]; + rigidbody *rb = ct->rba; - v3f dv; - v3_cross( rb->I, ct->delta, dv ); - v3_add( rb->v, dv, dv ); + v3f rv, da, db; + rb_rcv( ct, rv, da, db ); for( int j=0; j<2; j++ ) { - float vt = vg_clampf( -v3_dot( dv, ct->t[j] ), - -k_friction, k_friction ); - - vt = -v3_dot( dv, ct->t[j] ); + float f = k_friction * ct->norm_impulse, + vt = -v3_dot( rv, ct->t[j] ); float temp = ct->tangent_impulse[j]; - ct->tangent_impulse[j] = vg_clampf( temp+vt, -k_friction, k_friction ); + ct->tangent_impulse[j] = vg_clampf( temp+vt, -f, f ); vt = ct->tangent_impulse[j] - temp; v3f impulse; - v3_muls( ct->t[j], vt, impulse ); - v3_add( impulse, rb->v, rb->v ); - v3_cross( ct->delta, impulse, impulse ); - v3_add( impulse, rb->I, rb->I ); + rb_standard_impulse( ct, da, db, impulse ); } } /* Normal Impulse */ - for( int i=0; imanifold_count; i++ ) + for( int i=0; imanifold[i]; + struct contact *ct = &rb_contact_buffer[i]; + rigidbody *rba = ct->rba, + *rbb = ct->rbb; - v3f dv; - v3_cross( rb->I, ct->delta, dv ); - v3_add( rb->v, dv, dv ); + v3f rv, da, db; + rb_rcv( ct, rv, da, db ); - float vn = -v3_dot( dv, ct->n ); + float vn = -v3_dot( rv, ct->n ); vn += ct->bias; float temp = ct->norm_impulse; @@ -227,11 +813,8 @@ static void rb_constraint_manifold( rigidbody *rb ) vn = ct->norm_impulse - temp; v3f impulse; - v3_muls( ct->n, vn, impulse ); - v3_add( impulse, rb->v, rb->v ); - v3_cross( ct->delta, impulse, impulse ); - v3_add( impulse, rb->I, rb->I ); + rb_standard_impulse( ct, da, db, impulse ); } } @@ -242,8 +825,7 @@ struct rb_angle_limit float impulse, bias; }; -static int rb_angle_limit_force( - rigidbody *rba, v3f va, +static int rb_angle_limit_force( rigidbody *rba, v3f va, rigidbody *rbb, v3f vb, float max ) { @@ -279,7 +861,6 @@ static void rb_constraint_angle_limit( struct rb_angle_limit *limit ) } - RB_DEPR static void rb_constraint_angle( rigidbody *rba, v3f va, rigidbody *rbb, v3f vb, @@ -294,8 +875,8 @@ static void rb_constraint_angle( rigidbody *rba, v3f va, v3f axis; v3_cross( wva, wvb, axis ); - v3_muladds( rba->I, axis, ang*spring*0.5f, rba->I ); - v3_muladds( rbb->I, axis, -ang*spring*0.5f, rbb->I ); + v3_muladds( rba->w, axis, ang*spring*0.5f, rba->w ); + v3_muladds( rbb->w, axis, -ang*spring*0.5f, rbb->w ); return; @@ -325,8 +906,8 @@ static void rb_relative_velocity( rigidbody *ra, v3f lca, v3_sub( ra->v, rb->v, rcv ); v3f rcv_Ra, rcv_Rb; - v3_cross( ra->I, wca, rcv_Ra ); - v3_cross( rb->I, wcb, rcv_Rb ); + v3_cross( ra->w, wca, rcv_Ra ); + v3_cross( rb->w, wcb, rcv_Rb ); v3_add( rcv_Ra, rcv, rcv ); v3_sub( rcv, rcv_Rb, rcv ); } @@ -351,8 +932,8 @@ static void rb_constraint_position( rigidbody *ra, v3f lca, v3_sub( ra->v, rb->v, rcv ); v3f rcv_Ra, rcv_Rb; - v3_cross( ra->I, wca, rcv_Ra ); - v3_cross( rb->I, wcb, rcv_Rb ); + v3_cross( ra->w, wca, rcv_Ra ); + v3_cross( rb->w, wcb, rcv_Rb ); v3_add( rcv_Ra, rcv, rcv ); v3_sub( rcv, rcv_Rb, rcv ); @@ -366,70 +947,278 @@ static void rb_constraint_position( rigidbody *ra, v3f lca, v3_muls( rcv, 1.0f, impulse ); v3_muladds( rb->v, impulse, mass_b/total_mass, rb->v ); v3_cross( wcb, impulse, impulse ); - v3_add( impulse, rb->I, rb->I ); + v3_add( impulse, rb->w, rb->w ); v3_muls( rcv, -1.0f, impulse ); v3_muladds( ra->v, impulse, mass_a/total_mass, ra->v ); v3_cross( wca, impulse, impulse ); - v3_add( impulse, ra->I, ra->I ); + v3_add( impulse, ra->w, ra->w ); #if 0 + /* + * this could be used for spring joints + * its not good for position constraint + */ v3f impulse; v3_muls( delta, 0.5f*spring, impulse ); v3_add( impulse, ra->v, ra->v ); v3_cross( wca, impulse, impulse ); - v3_add( impulse, ra->I, ra->I ); + v3_add( impulse, ra->w, ra->w ); v3_muls( delta, -0.5f*spring, impulse ); v3_add( impulse, rb->v, rb->v ); v3_cross( wcb, impulse, impulse ); - v3_add( impulse, rb->I, rb->I ); + v3_add( impulse, rb->w, rb->w ); #endif } +static void debug_sphere( m4x3f m, float radius, u32 colour ) +{ + v3f ly = { 0.0f, 0.0f, radius }, + lx = { 0.0f, radius, 0.0f }, + lz = { 0.0f, 0.0f, radius }; + + for( int i=0; i<16; i++ ) + { + float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f, + s = sinf(t), + c = cosf(t); + + v3f py = { s*radius, 0.0f, c*radius }, + px = { s*radius, c*radius, 0.0f }, + pz = { 0.0f, s*radius, c*radius }; + + v3f p0, p1, p2, p3, p4, p5; + m4x3_mulv( m, py, p0 ); + m4x3_mulv( m, ly, p1 ); + m4x3_mulv( m, px, p2 ); + m4x3_mulv( m, lx, p3 ); + m4x3_mulv( m, pz, p4 ); + m4x3_mulv( m, lz, p5 ); + + vg_line( p0, p1, colour == 0x00? 0xff00ff00: colour ); + vg_line( p2, p3, colour == 0x00? 0xff0000ff: colour ); + vg_line( p4, p5, colour == 0x00? 0xffff0000: colour ); + + v3_copy( py, ly ); + v3_copy( px, lx ); + v3_copy( pz, lz ); + } +} + static void rb_debug( rigidbody *rb, u32 colour ) { - v3f *box = rb->bbx; - v3f p000, p001, p010, p011, p100, p101, p110, p111; + if( rb->type == k_rb_shape_box ) + { + v3f *box = rb->bbx; + vg_line_boxf_transformed( rb->to_world, rb->bbx, colour ); + } + else if( rb->type == k_rb_shape_sphere ) + { + debug_sphere( rb->to_world, rb->inf.sphere.radius, colour ); + } +} - p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2]; - p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2]; - p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2]; - p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2]; +/* + * out penetration distance, normal + */ +static int rb_point_in_body( rigidbody *rb, v3f pos, float *pen, v3f normal ) +{ + v3f local; + m4x3_mulv( rb->to_local, pos, local ); - p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2]; - p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2]; - p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2]; - p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2]; + if( local[0] > rb->bbx[0][0] && local[0] < rb->bbx[1][0] && + local[1] > rb->bbx[0][1] && local[1] < rb->bbx[1][1] && + local[2] > rb->bbx[0][2] && local[2] < rb->bbx[1][2] ) + { + v3f area, com, comrel; + v3_add( rb->bbx[0], rb->bbx[1], com ); + v3_muls( com, 0.5f, com ); - m4x3_mulv( rb->to_world, p000, p000 ); - m4x3_mulv( rb->to_world, p001, p001 ); - m4x3_mulv( rb->to_world, p010, p010 ); - m4x3_mulv( rb->to_world, p011, p011 ); - m4x3_mulv( rb->to_world, p100, p100 ); - m4x3_mulv( rb->to_world, p101, p101 ); - m4x3_mulv( rb->to_world, p110, p110 ); - m4x3_mulv( rb->to_world, p111, p111 ); + v3_sub( rb->bbx[1], rb->bbx[0], area ); + v3_sub( local, com, comrel ); + v3_div( comrel, area, comrel ); + + int axis = 0; + float max_mag = fabsf(comrel[0]); + + if( fabsf(comrel[1]) > max_mag ) + { + axis = 1; + max_mag = fabsf(comrel[1]); + } + if( fabsf(comrel[2]) > max_mag ) + { + axis = 2; + max_mag = fabsf(comrel[2]); + } + + v3_zero( normal ); + normal[axis] = vg_signf(comrel[axis]); + + if( normal[axis] < 0.0f ) + *pen = local[axis] - rb->bbx[0][axis]; + else + *pen = rb->bbx[1][axis] - local[axis]; + + m3x3_mulv( rb->to_world, normal, normal ); + return 1; + } + + return 0; +} + +#if 0 +static void rb_build_manifold_rb_static( rigidbody *ra, rigidbody *rb_static ) +{ + v3f verts[8]; + + v3f a, b; + v3_copy( ra->bbx[0], a ); + v3_copy( ra->bbx[1], b ); - vg_line( p000, p001, colour ); - vg_line( p001, p011, colour ); - vg_line( p011, p010, colour ); - vg_line( p010, p000, colour ); + m4x3_mulv( ra->to_world, (v3f){ a[0], a[1], a[2] }, verts[0] ); + m4x3_mulv( ra->to_world, (v3f){ a[0], b[1], a[2] }, verts[1] ); + m4x3_mulv( ra->to_world, (v3f){ b[0], b[1], a[2] }, verts[2] ); + m4x3_mulv( ra->to_world, (v3f){ b[0], a[1], a[2] }, verts[3] ); + m4x3_mulv( ra->to_world, (v3f){ a[0], a[1], b[2] }, verts[4] ); + m4x3_mulv( ra->to_world, (v3f){ a[0], b[1], b[2] }, verts[5] ); + m4x3_mulv( ra->to_world, (v3f){ b[0], b[1], b[2] }, verts[6] ); + m4x3_mulv( ra->to_world, (v3f){ b[0], a[1], b[2] }, verts[7] ); + + vg_line_boxf_transformed( rb_static->to_world, rb_static->bbx, 0xff0000ff ); - vg_line( p100, p101, colour ); - vg_line( p101, p111, colour ); - vg_line( p111, p110, colour ); - vg_line( p110, p100, colour ); + int count = 0; - vg_line( p100, p000, colour ); - vg_line( p101, p001, colour ); - vg_line( p110, p010, colour ); - vg_line( p111, p011, colour ); + for( int i=0; i<8; i++ ) + { + if( ra->manifold_count == vg_list_size(ra->manifold) ) + return; + + struct contact *ct = &ra->manifold[ ra->manifold_count ]; + + float p; + v3f normal; + + if( rb_point_in_body( rb_static, verts[i], &p, normal )) + { + v3_copy( normal, ct->n ); + v3_muladds( verts[i], ct->n, p*0.5f, ct->co ); + v3_sub( ct->co, ra->co, ct->delta ); - vg_line( p000, p110, colour ); - vg_line( p100, p010, colour ); + vg_line_pt3( ct->co, 0.0125f, 0xffff00ff ); + + ct->bias = -0.2f * (1.0f/k_rb_delta) * vg_minf( 0.0f, -p+0.04f ); + rb_tangent_basis( ct->n, ct->t[0], ct->t[1] ); + + ct->norm_impulse = 0.0f; + ct->tangent_impulse[0] = 0.0f; + ct->tangent_impulse[1] = 0.0f; + + ra->manifold_count ++; + count ++; + if( count == 4 ) + return; + } + } } +#endif + +/* + * Capsule phyics + */ + +static void debug_capsule( m4x3f m, float height, float radius, u32 colour ) +{ + v3f last = { 0.0f, 0.0f, radius }; + m4x3f lower, upper; + m3x3_copy( m, lower ); + m3x3_copy( m, upper ); + m4x3_mulv( m, (v3f){0.0f,-height*0.5f+radius,0.0f}, lower[3] ); + m4x3_mulv( m, (v3f){0.0f, height*0.5f-radius,0.0f}, upper[3] ); + + for( int i=0; i<16; i++ ) + { + float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f, + s = sinf(t), + c = cosf(t); + + v3f p = { s*radius, 0.0f, c*radius }; + + v3f p0, p1; + m4x3_mulv( lower, p, p0 ); + m4x3_mulv( lower, last, p1 ); + vg_line( p0, p1, colour ); + + m4x3_mulv( upper, p, p0 ); + m4x3_mulv( upper, last, p1 ); + vg_line( p0, p1, colour ); + + v3_copy( p, last ); + } + + for( int i=0; i<4; i++ ) + { + float t = ((float)(i) * (1.0f/4.0f)) * VG_PIf * 2.0f, + s = sinf(t), + c = cosf(t); + + v3f p = { s*radius, 0.0f, c*radius }; + + v3f p0, p1; + m4x3_mulv( lower, p, p0 ); + m4x3_mulv( upper, p, p1 ); + vg_line( p0, p1, colour ); + + m4x3_mulv( lower, (v3f){0.0f,-radius,0.0f}, p0 ); + m4x3_mulv( upper, (v3f){0.0f, radius,0.0f}, p1 ); + vg_line( p0, p1, colour ); + } +} + +/* + * BVH implementation, this is ONLY for static rigidbodies, its to slow for + * realtime use. + */ + +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 ); +} + +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; +} + +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; +} + +static void rb_bh_debug( void *user, u32 item_index ) +{ + rigidbody *rb = &((rigidbody *)user)[ item_index ]; + rb_debug( rb, 0xff00ffff ); +} + +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 +}; #endif /* RIGIDBODY_H */