#include <math.h>
-static bh_system bh_system_rigidbodies;
-
#ifndef RIGIDBODY_H
#define RIGIDBODY_H
k_penetration_slop = 0.01f,
k_inertia_scale = 4.0f,
k_phys_baumgarte = 0.2f,
- k_gravity = 9.6f;
+ k_gravity = 9.6f,
+ k_rb_density = 8.0f;
static float
k_limit_bias = 0.02f,
VG_VAR_F32( k_joint_impulse, flags=VG_VAR_CHEAT );
}
+enum rb_shape {
+ k_rb_shape_none = 0,
+ k_rb_shape_box = 1,
+ k_rb_shape_sphere = 2,
+ k_rb_shape_capsule = 3,
+};
+
/*
* -----------------------------------------------------------------------------
* structure definitions
*/
typedef struct rigidbody rigidbody;
-typedef struct rb_object rb_object;
typedef struct contact rb_ct;
-typedef struct rb_sphere rb_sphere;
typedef struct rb_capsule rb_capsule;
-typedef struct rb_scene rb_scene;
-
-struct rb_sphere{
- float radius;
-};
struct rb_capsule{
- float height, radius;
-};
-
-struct rb_scene{
- bh_tree *bh_scene;
+ f32 h, r;
};
struct rigidbody{
v3f co, v, w;
v4f q;
- boxf bbx, bbx_world;
- float inv_mass;
+ f32 inv_mass;
- /* inertia model and inverse world tensor */
- m3x3f iI, iIw;
+ m3x3f iI, iIw; /* inertia model and inverse world tensor */
m4x3f to_world, to_local;
};
-/* simple objects */
-struct rb_object{
- rigidbody rb;
- enum rb_shape{
- k_rb_shape_box = 0,
- k_rb_shape_sphere = 1,
- k_rb_shape_capsule = 2,
- k_rb_shape_scene = 3
- }
- type;
-
- union{
- struct rb_sphere sphere;
- struct rb_capsule capsule;
- struct rb_scene scene;
- }
- inf;
-};
-
static struct contact{
rigidbody *rba, *rbb;
v3f co, n;
}
}
-
-static void rb_object_debug( rb_object *obj, u32 colour ){
- if( obj->type == k_rb_shape_box ){
- v3f *box = obj->rb.bbx;
- vg_line_boxf_transformed( obj->rb.to_world, obj->rb.bbx, colour );
- }
- else if( obj->type == k_rb_shape_sphere ){
- vg_line_sphere( obj->rb.to_world, obj->inf.sphere.radius, colour );
- }
- else if( obj->type == k_rb_shape_capsule ){
- m4x3f m0, m1;
- float h = obj->inf.capsule.height,
- r = obj->inf.capsule.radius;
-
- vg_line_capsule( obj->rb.to_world, r, h, colour );
- }
- else if( obj->type == k_rb_shape_scene ){
- vg_line_boxf( obj->rb.bbx, colour );
- }
-}
-
/*
* -----------------------------------------------------------------------------
* Integration
*/
/*
- * Update world space bounding box based on local one
- */
-static void rb_update_bounds( rigidbody *rb ){
- box_init_inf( rb->bbx_world );
- m4x3_expand_aabb_aabb( rb->to_world, rb->bbx_world, rb->bbx );
-}
-
-/*
- * Commit transform to rigidbody. Updates matrices
+ * Update ALL matrices and tensors on rigidbody
*/
-static void rb_update_transform( rigidbody *rb )
-{
- q_normalize( rb->q );
+static void rb_update_matrices( rigidbody *rb ){
+ //q_normalize( rb->q );
q_m3x3( rb->q, rb->to_world );
v3_copy( rb->co, rb->to_world[3] );
-
m4x3_invert_affine( rb->to_world, rb->to_local );
/* I = R I_0 R^T */
m3x3_mul( rb->to_world, rb->iI, rb->iIw );
m3x3_mul( rb->iIw, rb->to_local, rb->iIw );
-
- rb_update_bounds( rb );
}
/*
* Extrapolate rigidbody into a transform based on vg accumulator.
* Useful for rendering
*/
-static void rb_extrapolate( rigidbody *rb, v3f co, v4f q )
-{
+static void rb_extrapolate( rigidbody *rb, v3f co, v4f q ){
float substep = vg.time_fixed_extrapolate;
v3_muladds( rb->co, rb->v, k_rb_delta*substep, co );
}
/*
- * Initialize rigidbody and calculate masses, inertia
+ * Inertia
+ * -----------------------------------------------------------------------------
*/
-static void rb_init_object( rb_object *obj, f32 inertia_scale ){
- float volume = 1.0f;
- int inert = 0;
-
- if( obj->type == k_rb_shape_box ){
- v3f dims;
- v3_sub( obj->rb.bbx[1], obj->rb.bbx[0], dims );
- volume = dims[0]*dims[1]*dims[2];
- }
- else if( obj->type == k_rb_shape_sphere ){
- volume = vg_sphere_volume( obj->inf.sphere.radius );
- v3_fill( obj->rb.bbx[0], -obj->inf.sphere.radius );
- v3_fill( obj->rb.bbx[1], obj->inf.sphere.radius );
- }
- else if( obj->type == k_rb_shape_capsule ){
- float r = obj->inf.capsule.radius,
- h = obj->inf.capsule.height;
- volume = vg_sphere_volume( r ) + VG_PIf * r*r * (h - r*2.0f);
-
- v3_fill( obj->rb.bbx[0], -r );
- v3_fill( obj->rb.bbx[1], r );
- obj->rb.bbx[0][1] = -h;
- obj->rb.bbx[1][1] = h;
- }
- else if( obj->type == k_rb_shape_scene ){
- inert = 1;
- box_copy( obj->inf.scene.bh_scene->nodes[0].bbx, obj->rb.bbx );
- }
- if( inert ){
- obj->rb.inv_mass = 0.0f;
- m3x3_zero( obj->rb.iI );
- }
- else{
- f32 mass = 8.0f*volume;
- obj->rb.inv_mass = 1.0f/mass;
+/*
+ * Translate existing inertia tensor
+ */
+static void rb_translate_inertia( m3x3f inout_inertia, f32 mass, v3f d ){
+ /*
+ * I = I_0 + m*[(d.d)E_3 - d(X)d]
+ *
+ * I: updated tensor
+ * I_0: original tensor
+ * m: scalar mass
+ * d: translation vector
+ * (X): outer product
+ * E_3: identity matrix
+ */
+ m3x3f t, outer, scale;
+ m3x3_diagonal( t, v3_dot(d,d) );
+ m3x3_outer_product( outer, d, d );
+ m3x3_sub( t, outer, t );
+ m3x3_diagonal( scale, mass );
+ m3x3_mul( scale, t, t );
+ m3x3_add( inout_inertia, t, inout_inertia );
+}
+
+/*
+ * Rotate existing inertia tensor
+ */
+static void rb_rotate_inertia( m3x3f inout_inertia, m3x3f rotation ){
+ /*
+ * I = R I_0 R^T
+ *
+ * I: updated tensor
+ * I_0: original tensor
+ * R: rotation matrix
+ * R^T: tranposed rotation matrix
+ */
+
+ m3x3f Rt;
+ m3x3_transpose( rotation, Rt );
+ m3x3_mul( rotation, inout_inertia, inout_inertia );
+ m3x3_mul( inout_inertia, Rt, inout_inertia );
+}
+/*
+ * Create inertia tensor for box
+ */
+static void rb_box_inertia( boxf box, f32 mass, m3x3f out_inertia ){
+ v3f e, com;
+ v3_sub( box[1], box[0], e );
+ v3_muladds( box[0], e, 0.5f, com );
+
+ f32 ex2 = e[0]*e[0],
+ ey2 = e[1]*e[1],
+ ez2 = e[2]*e[2],
+ ix = (ey2+ez2) * mass * (1.0f/12.0f),
+ iy = (ex2+ez2) * mass * (1.0f/12.0f),
+ iz = (ex2+ey2) * mass * (1.0f/12.0f);
+
+ m3x3_identity( out_inertia );
+ m3x3_setdiagonalv3( out_inertia, (v3f){ ix, iy, iz } );
+ rb_translate_inertia( out_inertia, mass, com );
+}
+
+/*
+ * Create inertia tensor for sphere
+ */
+static void rb_sphere_inertia( f32 r, f32 mass, m3x3f out_inertia ){
+ f32 ixyz = r*r * mass * (2.0f/5.0f);
+
+ m3x3_identity( out_inertia );
+ m3x3_setdiagonalv3( out_inertia, (v3f){ ixyz, ixyz, ixyz } );
+}
- v3f extent, com;
- v3_sub( obj->rb.bbx[1], obj->rb.bbx[0], extent );
- v3_muladds( obj->rb.bbx[0], extent, 0.5f, com );
+/*
+ * Create inertia tensor for capsule
+ *
+ * TODO: UNTESTED
+ */
+static void rb_capsule_inertia( f32 r, f32 h, f32 mass, m3x3f out_inertia ){
+ f32 density = mass / vg_capsule_volume( r, h ),
+ ch = h-r*2.0f, /* cylinder height */
+ cm = VG_PIf * ch*r*r * density, /* cylinder mass */
+ hm = VG_TAUf * (1.0f/3.0f) * r*r*r * density, /* hemisphere mass */
+
+ iy = r*r*cm * 0.5f,
+ ixz = iy * 0.5f + cm*ch*ch*(1.0f/12.0f),
- /* local intertia tensor */
- f32 ex2 = extent[0]*extent[0],
- ey2 = extent[1]*extent[1],
- ez2 = extent[2]*extent[2];
+ aux0= (hm*2.0f*r*r)/5.0f;
- /* compute inertia tensor */
- v3f I;
+ iy += aux0 * 2.0f;
- if( obj->type == k_rb_shape_box ){
- I[0] = inertia_scale * (ey2+ez2) * mass * (1.0f/12.0f);
- I[1] = inertia_scale * (ex2+ez2) * mass * (1.0f/12.0f);
- I[2] = inertia_scale * (ex2+ey2) * mass * (1.0f/12.0f);
- }
- else if( obj->type == k_rb_shape_sphere ){
- f32 r = obj->inf.sphere.radius;
- v3_fill( I, inertia_scale * r*r * mass * (2.0f/5.0f) );
- }
- else if( obj->type == k_rb_shape_capsule ){
- f32 r = obj->inf.capsule.radius;
- I[1] = inertia_scale * r*r * mass * (2.0f/5.0f);
- I[0] = inertia_scale * (ey2+ez2) * mass * (1.0f/12.0f);
- I[2] = inertia_scale * (ey2+ex2) * mass * (1.0f/12.0f);
- }
- else {
- vg_fatal_error( "" );
- }
+ f32 aux1= ch*0.5f,
+ aux2= aux0 + hm*(aux1*aux1 + 3.0f*(1.0f/8.0f)*ch*r);
- m3x3f i;
- m3x3_identity( i );
- m3x3_setdiagonalv3( i, I );
+ ixz += aux2*2.0f;
- /* compute translation */
- m3x3f i_t, i_t_outer, i_t_scale;
- m3x3_diagonal( i_t, v3_dot(com,com) );
- m3x3_outer_product( i_t_outer, com, com );
- m3x3_sub( i_t, i_t_outer, i_t );
- m3x3_diagonal( i_t_scale, mass );
- m3x3_mul( i_t_scale, i_t, i_t );
+ m3x3_identity( out_inertia );
+ m3x3_setdiagonalv3( out_inertia, (v3f){ ixz, iy, ixz } );
+}
- /* TODO: compute rotation */
+static void rb_setbody_capsule( rigidbody *rb, f32 r, f32 h,
+ f32 density, f32 inertia_scale ){
+ f32 vol = vg_capsule_volume( r, h ),
+ mass = vol*density;
- /* add Ic and Ict */
- m3x3_add( i, i_t, i );
+ rb->inv_mass = 1.0f/mass;
- /* store as inverted */
- m3x3_inv( i, obj->rb.iI );
- }
+ m3x3f I;
+ rb_capsule_inertia( r, h, mass * inertia_scale, I );
+ m3x3_inv( I, rb->iI );
+}
+
+static void rb_setbody_box( rigidbody *rb, boxf box,
+ f32 density, f32 inertia_scale ){
+ f32 vol = vg_box_volume( box ),
+ mass = vol*density;
+
+ rb->inv_mass = 1.0f/mass;
+
+ m3x3f I;
+ rb_box_inertia( box, mass * inertia_scale, I );
+ m3x3_inv( I, rb->iI );
+}
- rb_update_transform( &obj->rb );
+static void rb_setbody_sphere( rigidbody *rb, f32 r,
+ f32 density, f32 inertia_scale ){
+ f32 vol = vg_sphere_volume( r ),
+ mass = vol*density;
+
+ rb->inv_mass = 1.0f/mass;
+ m3x3f I;
+ rb_sphere_inertia( r, mass * inertia_scale, I );
+ m3x3_inv( I, rb->iI );
}
static void rb_iter( rigidbody *rb ){
v3_lerp( rb->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w );
/* inegrate inertia */
- if( v3_length2( rb->w ) > 0.0f )
- {
+ if( v3_length2( rb->w ) > 0.0f ){
v4f rotation;
v3f axis;
v3_copy( rb->w, axis );
v3_divs( axis, mag, axis );
q_axis_angle( rotation, axis, mag*k_rb_delta );
q_mul( rotation, rb->q, rb->q );
+ q_normalize( rb->q );
}
-
-#if 0
- /* damping */
- v3_muls( rb->v, 1.0f/(1.0f+k_rb_delta*k_damp_linear), rb->v );
- v3_muls( rb->w, 1.0f/(1.0f+k_rb_delta*k_damp_angular), rb->w );
-#endif
}
-
/*
* -----------------------------------------------------------------------------
* Boolean shape overlap functions
}
static int rb_capsule__manifold_done( m4x3f mtx, rb_capsule *c,
- capsule_manifold *manifold,
- rb_ct *buf ){
+ capsule_manifold *manifold,
+ rb_ct *buf ){
v3f p0, p1;
- v3_muladds( mtx[3], mtx[1], -c->height*0.5f+c->radius, p0 );
- v3_muladds( mtx[3], mtx[1], c->height*0.5f-c->radius, p1 );
+ v3_muladds( mtx[3], mtx[1], -c->h*0.5f+c->r, p0 );
+ v3_muladds( mtx[3], mtx[1], c->h*0.5f-c->r, p1 );
int count = 0;
if( manifold->t0 <= 1.0f ){
float d = v3_length( manifold->d0 );
v3_muls( manifold->d0, 1.0f/d, ct->n );
- v3_muladds( pa, ct->n, -c->radius, ct->co );
+ v3_muladds( pa, ct->n, -c->r, ct->co );
ct->p = manifold->r0 - d;
ct->type = k_contact_type_default;
float d = v3_length( manifold->d1 );
v3_muls( manifold->d1, 1.0f/d, ct->n );
- v3_muladds( pa, ct->n, -c->radius, ct->co );
+ v3_muladds( pa, ct->n, -c->r, ct->co );
ct->p = manifold->r1 - d;
ct->type = k_contact_type_default;
return count;
}
+#if 0
static int rb_capsule_sphere( rb_object *obja, rb_object *objb, rb_ct *buf ){
rigidbody *rba = &obja->rb, *rbb = &objb->rb;
- float h = obja->inf.capsule.height,
- ra = obja->inf.capsule.radius,
- rb = objb->inf.sphere.radius;
+ float h = obja->inf.capsule.h,
+ ra = obja->inf.capsule.r,
+ rb = objb->inf.sphere.r;
v3f p0, p1;
v3_muladds( rba->co, rba->to_world[1], -h*0.5f+ra, p0 );
return 0;
}
+#endif
static int rb_capsule__capsule( m4x3f mtxA, rb_capsule *ca,
- m4x3f mtxB, rb_capsule *cb, rb_ct *buf ){
- float ha = ca->height,
- hb = cb->height,
- ra = ca->radius,
- rb = cb->radius,
- r = ra+rb;
+ m4x3f mtxB, rb_capsule *cb, rb_ct *buf ){
+ f32 ha = ca->h,
+ hb = cb->h,
+ ra = ca->r,
+ rb = cb->r,
+ r = ra+rb;
v3f p0, p1, p2, p3;
v3_muladds( mtxA[3], mtxA[1], -ha*0.5f+ra, p0 );
rb_capsule_manifold_init( &manifold );
v3f pa, pb;
- float ta, tb;
+ f32 ta, tb;
closest_segment_segment( p0, p1, p2, p3, &ta, &tb, pa, pb );
rb_capsule_manifold( pa, pb, ta, r, &manifold );
return rb_capsule__manifold_done( mtxA, ca, &manifold, buf );
}
+#if 0
static int rb_sphere_box( rb_object *obja, rb_object *objb, rb_ct *buf ){
v3f co, delta;
rigidbody *rba = &obja->rb, *rbb = &objb->rb;
return 0;
}
+#endif
+#if 0
static int rb_sphere_sphere( rb_object *obja, rb_object *objb, rb_ct *buf ){
rigidbody *rba = &obja->rb, *rbb = &objb->rb;
v3f delta;
return 0;
}
+#endif
-static int rb_sphere__triangle( m4x3f mtxA, rb_sphere *b,
- v3f tri[3], rb_ct *buf ){
+static int rb_sphere__triangle( m4x3f mtxA, f32 r,
+ v3f tri[3], rb_ct *buf ){
v3f delta, co;
enum contact_type type = closest_on_triangle_1( mtxA[3], tri, co );
-
v3_sub( mtxA[3], co, delta );
-
- float d2 = v3_length2( delta ),
- r = b->radius;
+ f32 d2 = v3_length2( delta );
if( d2 <= r*r ){
rb_ct *ct = buf;
return 0;
}
-static int rb_sphere__scene( m4x3f mtxA, rb_sphere *b,
- m4x3f mtxB, rb_scene *s, rb_ct *buf,
- u16 ignore ){
- scene_context *sc = s->bh_scene->user;
+static int rb_sphere__scene( m4x3f mtxA, f32 r,
+ m4x3f mtxB, bh_tree *scene_bh, rb_ct *buf,
+ u16 ignore ){
+ scene_context *sc = scene_bh->user;
int count = 0;
- float r = b->radius + 0.1f;
boxf box;
v3_sub( mtxA[3], (v3f){ r,r,r }, box[0] );
v3_add( mtxA[3], (v3f){ r,r,r }, box[1] );
i32 idx;
bh_iter_init_box( 0, &it, box );
- while( bh_next( s->bh_scene, &it, &idx ) ){
+ while( bh_next( scene_bh, &it, &idx ) ){
u32 *ptri = &sc->arrindices[ idx*3 ];
v3f tri[3];
vg_line( tri[1],tri[2],0x70ff6000 );
vg_line( tri[2],tri[0],0x70ff6000 );
- int contact = rb_sphere__triangle( mtxA, b, tri, &buf[count] );
+ int contact = rb_sphere__triangle( mtxA, r, tri, &buf[count] );
count += contact;
if( count == 16 ){
}
static int rb_box__scene( m4x3f mtxA, boxf bbx,
- m4x3f mtxB, rb_scene *s, rb_ct *buf, u16 ignore ){
- scene_context *sc = s->bh_scene->user;
+ m4x3f mtxB, bh_tree *scene_bh,
+ rb_ct *buf, u16 ignore ){
+ scene_context *sc = scene_bh->user;
v3f tri[3];
v3f extent, center;
vg_line_boxf( world_bbx, VG__RED );
- while( bh_next( s->bh_scene, &it, &idx ) ){
+ while( bh_next( scene_bh, &it, &idx ) ){
u32 *ptri = &sc->arrindices[ idx*3 ];
if( sc->arrvertices[ptri[0]].flags & ignore ) continue;
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 );
+ v3_muladds( mtxA[3], mtxA[1], -c->h*0.5f+c->r, p0w );
+ v3_muladds( mtxA[3], mtxA[1], c->h*0.5f-c->r, p1w );
capsule_manifold manifold;
rb_capsule_manifold_init( &manifold );
* not very 'correct' */
f32 dist;
if( ray_tri( tri, p0w, mtxA[1], &dist, 1 ) ){
- f32 l = c->height - c->radius*2.0f;
+ f32 l = c->h - c->r*2.0f;
if( (dist >= 0.0f) && (dist < l) ){
v3f co;
v3_muladds( p0w, mtxA[1], dist, co );
v3_sub( p0w, co, d0 );
v3_sub( p1w, co, d1 );
- f32 p = vg_minf( v3_dot( n, d0 ), v3_dot( n, d1 ) ) - c->radius;
+ f32 p = vg_minf( v3_dot( n, d0 ), v3_dot( n, d1 ) ) - c->r;
rb_ct *ct = buf;
ct->p = -p;
/* the two balls at the ends */
if( v3_dot( da, d0 ) <= 0.01f )
- rb_capsule_manifold( p0w, c0, 0.0f, c->radius, &manifold );
+ rb_capsule_manifold( p0w, c0, 0.0f, c->r, &manifold );
if( v3_dot( da, d1 ) >= -0.01f )
- rb_capsule_manifold( p1w, c1, 1.0f, c->radius, &manifold );
+ rb_capsule_manifold( p1w, c1, 1.0f, c->r, &manifold );
/* the edges to edges */
for( int i=0; i<3; i++ ){
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 );
+ rb_capsule_manifold( ca, cb, ta, c->r, &manifold );
}
int count = rb_capsule__manifold_done( mtxA, c, &manifold, buf );
/* mtxB is defined only for tradition; it is not used currently */
static int rb_capsule__scene( m4x3f mtxA, rb_capsule *c,
- m4x3f mtxB, rb_scene *s,
- rb_ct *buf, u16 ignore ){
+ m4x3f mtxB, bh_tree *scene_bh,
+ rb_ct *buf, u16 ignore ){
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] );
+ v3_sub( mtxA[3], (v3f){ c->h, c->h, c->h }, bbx[0] );
+ v3_add( mtxA[3], (v3f){ c->h, c->h, c->h }, bbx[1] );
- scene_context *sc = s->bh_scene->user;
+ scene_context *sc = scene_bh->user;
bh_iter it;
bh_iter_init_box( 0, &it, bbx );
i32 idx;
- while( bh_next( s->bh_scene, &it, &idx ) ){
+ while( bh_next( scene_bh, &it, &idx ) ){
u32 *ptri = &sc->arrindices[ idx*3 ];
if( sc->arrvertices[ptri[0]].flags & ignore ) continue;
#if 1
v3_muladds( rbb->co, d, -1.0f * amt, rbb->co );
- rb_update_transform( rbb );
+ rb_update_matrices( rbb );
#else
f32 mt = 1.0f/(rba->inv_mass+rbb->inv_mass),
a = mt * (k_phys_baumgarte/k_rb_delta);
v4f correction;
q_axis_angle( correction, axis, angle );
q_mul( correction, st->rbb->q, st->rbb->q );
- rb_update_transform( st->rbb );
+ q_normalize( st->rbb->q );
+ rb_update_matrices( st->rbb );
#else
f32 mt = 1.0f/(st->rba->inv_mass+st->rbb->inv_mass),
wa = mt * acosf(angle) * (k_phys_baumgarte/k_rb_delta);
v4f correction;
q_axis_angle( correction, axis, angle );
q_mul( correction, st->rbb->q, st->rbb->q );
- rb_update_transform( st->rbb );
+ q_normalize( st->rbb->q );
+ rb_update_matrices( st->rbb );
#else
f32 mt = 1.0f/(st->rba->inv_mass+st->rbb->inv_mass),
wa = mt * acosf(angle) * (k_phys_baumgarte/k_rb_delta);
projects / carveJwlIkooP6JGAAIwe30JlM.git / blobdiff