From f18bfa7b6ef6458cb8a23c83707808f0816cbc6a Mon Sep 17 00:00:00 2001 From: hgn Date: Wed, 24 Jan 2024 09:26:56 +0000 Subject: [PATCH] move rigidbody to vg --- vg_m.h | 135 ++++++- vg_rigidbody.h | 240 +++++++++++ vg_rigidbody_collision.h | 803 +++++++++++++++++++++++++++++++++++++ vg_rigidbody_constraints.h | 522 ++++++++++++++++++++++++ 4 files changed, 1696 insertions(+), 4 deletions(-) create mode 100644 vg_rigidbody.h create mode 100644 vg_rigidbody_collision.h create mode 100644 vg_rigidbody_constraints.h diff --git a/vg_m.h b/vg_m.h index f5ed405..6cbac62 100644 --- a/vg_m.h +++ b/vg_m.h @@ -19,9 +19,10 @@ * 5.d Raycast & Spherecasts * 5.e Curves * 5.f Volumes + * 5.g Inertia tensors * 6. Statistics * 6.a Random numbers - **/ + */ #ifndef VG_M_H #define VG_M_H @@ -2270,9 +2271,135 @@ static void eval_bezier3( v3f p0, v3f p1, v3f p2, f32 t, v3f p ) * ----------------------------------------------------------------------------- */ -static float vg_sphere_volume( float radius ){ - float r3 = radius*radius*radius; - return (4.0f/3.0f) * VG_PIf * r3; +static f32 vg_sphere_volume( f32 r ){ + return (4.0f/3.0f) * VG_PIf * r*r*r; +} + +static f32 vg_box_volume( boxf box ){ + v3f e; + v3_sub( box[1], box[0], e ); + return e[0]*e[1]*e[2]; +} + +static f32 vg_cylinder_volume( f32 r, f32 h ){ + return VG_PIf * r*r * h; +} + +static f32 vg_capsule_volume( f32 r, f32 h ){ + return vg_sphere_volume( r ) + vg_cylinder_volume( r, h-r*2.0f ); +} + +static void vg_sphere_bound( f32 r, boxf out_box ){ + v3_fill( out_box[0], -r ); + v3_fill( out_box[1], r ); +} + +static void vg_capsule_bound( f32 r, f32 h, boxf out_box ){ + v3_copy( (v3f){-r,-h*0.5f,r}, out_box[0] ); + v3_copy( (v3f){-r, h*0.5f,r}, out_box[1] ); +} + + +/* + * ----------------------------------------------------------------------------- + * Section 5.g Inertia Tensors + * ----------------------------------------------------------------------------- + */ + +/* + * Translate existing inertia tensor + */ +static void vg_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 vg_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 vg_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 } ); + vg_translate_inertia( out_inertia, mass, com ); +} + +/* + * Create inertia tensor for sphere + */ +static void vg_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 } ); +} + +/* + * Create inertia tensor for capsule + */ +static void vg_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), + + aux0= (hm*2.0f*r*r)/5.0f; + + iy += aux0 * 2.0f; + + f32 aux1= ch*0.5f, + aux2= aux0 + hm*(aux1*aux1 + 3.0f*(1.0f/8.0f)*ch*r); + + ixz += aux2*2.0f; + + m3x3_identity( out_inertia ); + m3x3_setdiagonalv3( out_inertia, (v3f){ ixz, iy, ixz } ); } /* diff --git a/vg_rigidbody.h b/vg_rigidbody.h new file mode 100644 index 0000000..c44aa5d --- /dev/null +++ b/vg_rigidbody.h @@ -0,0 +1,240 @@ +#pragma once + +/* + * Copyright (C) 2021-2024 Mt.ZERO Software - All Rights Reserved + * + * Rigidbody main file, related: + * vg_rigidbody_collision.h + * vg_rigidbody_constraints.h + */ + +#include "vg_console.h" +#include + +/* + * ----------------------------------------------------------------------------- + * (K)onstants + * ----------------------------------------------------------------------------- + */ + +static const float + k_rb_rate = (1.0/VG_TIMESTEP_FIXED), + k_rb_delta = (1.0/k_rb_rate), + k_friction = 0.4f, + k_damp_linear = 0.1f, /* scale velocity 1/(1+x) */ + k_damp_angular = 0.1f, /* scale angular 1/(1+x) */ + k_penetration_slop = 0.01f, + k_inertia_scale = 4.0f, + k_phys_baumgarte = 0.2f, + k_gravity = 9.6f, + k_rb_density = 8.0f; + +static float + k_limit_bias = 0.02f, + k_joint_correction = 0.01f, + k_joint_impulse = 1.0f, + k_joint_bias = 0.08f; /* positional joints */ + +static void rb_register_cvar(void){ + VG_VAR_F32( k_limit_bias, flags=VG_VAR_CHEAT ); + VG_VAR_F32( k_joint_bias, flags=VG_VAR_CHEAT ); + VG_VAR_F32( k_joint_correction, flags=VG_VAR_CHEAT ); + 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_capsule rb_capsule; + +struct rb_capsule{ + f32 h, r; +}; + +struct rigidbody{ + v3f co, v, w; + v4f q; + + f32 inv_mass; + + m3x3f iI, iIw; /* inertia model and inverse world tensor */ + m4x3f to_world, to_local; +}; + +/* + * Initialize rigidbody inverse mass and inertia tensor with some common shapes + */ +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; + + rb->inv_mass = 1.0f/mass; + + m3x3f I; + vg_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; + vg_box_inertia( box, mass * inertia_scale, I ); + m3x3_inv( I, rb->iI ); +} + +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; + vg_sphere_inertia( r, mass * inertia_scale, I ); + m3x3_inv( I, rb->iI ); +} + +/* + * Update ALL matrices and tensors on rigidbody + */ +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 ); +} + +/* + * Extrapolate rigidbody into a transform based on vg accumulator. + * Useful for rendering + */ +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 ); + + if( v3_length2( rb->w ) > 0.0f ){ + v4f rotation; + v3f axis; + v3_copy( rb->w, axis ); + + float mag = v3_length( axis ); + v3_divs( axis, mag, axis ); + q_axis_angle( rotation, axis, mag*k_rb_delta*substep ); + q_mul( rotation, rb->q, q ); + q_normalize( q ); + } + else{ + v4_copy( rb->q, q ); + } +} + +static void rb_iter( rigidbody *rb ){ + if( !vg_validf( rb->v[0] ) || + !vg_validf( rb->v[1] ) || + !vg_validf( rb->v[2] ) ) + { + vg_fatal_error( "NaN velocity" ); + } + + v3f gravity = { 0.0f, -9.8f, 0.0f }; + v3_muladds( rb->v, gravity, k_rb_delta, rb->v ); + + /* intergrate velocity */ + v3_muladds( rb->co, rb->v, k_rb_delta, rb->co ); + v3_lerp( rb->w, (v3f){0.0f,0.0f,0.0f}, 0.0025f, rb->w ); + + /* inegrate inertia */ + if( v3_length2( rb->w ) > 0.0f ){ + v4f rotation; + v3f axis; + v3_copy( rb->w, axis ); + + float mag = v3_length( 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 ); + } +} + +/* + * Creates relative contact velocity vector + */ +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 + */ +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 ); +} + +/* + * Effectors + */ + +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 ); +} + +/* apply a spring&dampener force to match ra(worldspace) on rigidbody, to + * rt(worldspace) + */ +static void rb_effect_spring_target_vector( rigidbody *rba, v3f ra, v3f rt, + float spring, float dampening, + float timestep ){ + float d = v3_dot( rt, ra ); + float a = acosf( vg_clampf( d, -1.0f, 1.0f ) ); + + v3f axis; + v3_cross( rt, ra, axis ); + + float Fs = -a * spring, + Fd = -v3_dot( rba->w, axis ) * dampening; + + v3_muladds( rba->w, axis, (Fs+Fd) * timestep, rba->w ); +} diff --git a/vg_rigidbody_collision.h b/vg_rigidbody_collision.h new file mode 100644 index 0000000..31bd1bb --- /dev/null +++ b/vg_rigidbody_collision.h @@ -0,0 +1,803 @@ +#pragma once +#include "vg_rigidbody.h" + +typedef struct rb_ct rb_ct; +static struct rb_ct{ + rigidbody *rba, *rbb; + v3f co, n; + v3f t[2]; + float p, bias, norm_impulse, tangent_impulse[2], + normal_mass, tangent_mass[2]; + + u32 element_id; + + enum contact_type type; +} +rb_contact_buffer[256]; +static int rb_contact_count = 0; + +/* + * 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 + */ + +/* + * By collecting the minimum(time) and maximum(time) pairs of points, we + * build a reduced and stable exact manifold. + * + * tx: time at point + * rx: minimum distance of these points + * dx: the delta between the two points + * + * pairs will only ammend these if they are creating a collision + */ +typedef struct capsule_manifold capsule_manifold; +struct capsule_manifold{ + f32 t0, t1; + f32 r0, r1; + v3f d0, d1; +}; + +/* + * Expand a line manifold with a new pair. t value is the time along segment + * on the oriented object which created this pair. + */ +static void rb_capsule_manifold( v3f pa, v3f pb, f32 t, f32 r, + capsule_manifold *manifold ){ + v3f delta; + v3_sub( pa, pb, delta ); + + if( v3_length2(delta) < r*r ){ + if( t < manifold->t0 ){ + v3_copy( delta, manifold->d0 ); + manifold->t0 = t; + manifold->r0 = r; + } + + if( t > manifold->t1 ){ + v3_copy( delta, manifold->d1 ); + manifold->t1 = t; + manifold->r1 = r; + } + } +} + +static void rb_capsule_manifold_init( capsule_manifold *manifold ){ + manifold->t0 = INFINITY; + manifold->t1 = -INFINITY; +} + +static int rb_capsule__manifold_done( m4x3f mtx, rb_capsule *c, + capsule_manifold *manifold, + rb_ct *buf ){ + v3f p0, 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 ){ + rb_ct *ct = buf; + + v3f pa; + v3_muls( p0, 1.0f-manifold->t0, pa ); + v3_muladds( pa, p1, manifold->t0, pa ); + + f32 d = v3_length( manifold->d0 ); + v3_muls( manifold->d0, 1.0f/d, ct->n ); + v3_muladds( pa, ct->n, -c->r, ct->co ); + + ct->p = manifold->r0 - d; + ct->type = k_contact_type_default; + count ++; + } + + if( (manifold->t1 >= 0.0f) && (manifold->t0 != manifold->t1) ){ + rb_ct *ct = buf+count; + + v3f pa; + v3_muls( p0, 1.0f-manifold->t1, pa ); + v3_muladds( pa, p1, manifold->t1, pa ); + + f32 d = v3_length( manifold->d1 ); + v3_muls( manifold->d1, 1.0f/d, ct->n ); + v3_muladds( pa, ct->n, -c->r, ct->co ); + + ct->p = manifold->r1 - d; + ct->type = k_contact_type_default; + + count ++; + } + + /* + * Debugging + */ + + if( count == 2 ) + vg_line( buf[0].co, buf[1].co, 0xff0000ff ); + + 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; + f32 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 ); + v3_muladds( rba->co, rba->to_world[1], h*0.5f-ra, p1 ); + + v3f c, delta; + closest_point_segment( p0, p1, rbb->co, c ); + v3_sub( c, rbb->co, delta ); + + f32 d2 = v3_length2(delta), + r = ra + rb; + + if( d2 < r*r ){ + f32 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; +} +#endif + +static int rb_capsule__capsule( m4x3f mtxA, rb_capsule *ca, + 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 ); + v3_muladds( mtxA[3], mtxA[1], ha*0.5f-ra, p1 ); + v3_muladds( mtxB[3], mtxB[1], -hb*0.5f+rb, p2 ); + v3_muladds( mtxB[3], mtxB[1], hb*0.5f-rb, p3 ); + + capsule_manifold manifold; + rb_capsule_manifold_init( &manifold ); + + v3f pa, pb; + f32 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( 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; + + closest_point_obb( rba->co, rbb->bbx, rbb->to_world, rbb->to_local, co ); + v3_sub( rba->co, co, delta ); + + f32 d2 = v3_length2(delta), + r = obja->inf.sphere.radius; + + if( d2 <= r*r ){ + f32 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. + */ + f32 lx = v3_dot( rbb->to_world[0], delta ), + ly = v3_dot( rbb->to_world[1], delta ), + lz = v3_dot( rbb->to_world[2], 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->to_world[0], vg_signf(lx), ct->n ); + else if( py < pz ) + v3_muls( rbb->to_world[1], vg_signf(ly), ct->n ); + else + v3_muls( rbb->to_world[2], 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; +} +#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; + v3_sub( rba->co, rbb->co, delta ); + + f32 d2 = v3_length2(delta), + r = obja->inf.sphere.radius + objb->inf.sphere.radius; + + if( d2 < r*r ){ + f32 d = sqrtf(d2); + + rb_ct *ct = buf; + v3_muls( delta, 1.0f/d, ct->n ); + + v3f p0, p1; + v3_muladds( rba->co, ct->n,-obja->inf.sphere.radius, p0 ); + v3_muladds( rbb->co, ct->n, objb->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; +} +#endif + +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 ); + f32 d2 = v3_length2( delta ); + + 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 ){ +#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING + vg_error( "Zero area triangle!\n" ); +#endif + return 0; + } + + v3_normalize( ct->n ); + + f32 d = sqrtf(d2); + + v3_copy( co, ct->co ); + ct->type = type; + ct->p = r-d; + return 1; + } + + return 0; +} + +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->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 ); + + v3f v0, v1, n; + v3_sub( tri[1], tri[0], v0 ); + v3_sub( tri[2], tri[0], v1 ); + v3_cross( v0, v1, n ); + + if( v3_length2( n ) <= 0.00001f ){ +#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING + vg_error( "Zero area triangle!\n" ); +#endif + return 0; + } + + v3_normalize( n ); + +#if 1 + /* deep penetration recovery. for when we clip through the triangles. so its + * not very 'correct' */ + f32 dist; + if( ray_tri( tri, p0w, mtxA[1], &dist, 1 ) ){ + f32 l = c->h - c->r*2.0f; + if( (dist >= 0.0f) && (dist < l) ){ + v3f co; + v3_muladds( p0w, mtxA[1], dist, co ); + vg_line_point( co, 0.02f, 0xffffff00 ); + + v3f d0, d1; + v3_sub( p0w, co, d0 ); + v3_sub( p1w, co, d1 ); + + f32 p = vg_minf( v3_dot( n, d0 ), v3_dot( n, d1 ) ) - c->r; + + rb_ct *ct = buf; + ct->p = -p; + ct->type = k_contact_type_default; + v3_copy( n, ct->n ); + v3_muladds( co, n, p, ct->co ); + + return 1; + } + } +#endif + + 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); + + /* the two balls at the ends */ + if( v3_dot( da, d0 ) <= 0.01f ) + 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->r, &manifold ); + + /* the edges to edges */ + for( int i=0; i<3; i++ ){ + int i0 = i, + i1 = (i+1)%3; + + v3f ca, cb; + f32 ta, tb; + closest_segment_segment( p0w, p1w, tri[i0], tri[i1], &ta, &tb, ca, cb ); + rb_capsule_manifold( ca, cb, ta, c->r, &manifold ); + } + + int count = rb_capsule__manifold_done( mtxA, c, &manifold, buf ); + for( int i=0; i vg_list_size(rb_contact_buffer) ) + return 0; + + return 1; +} + +static rb_ct *rb_global_buffer( void ){ + return &rb_contact_buffer[ rb_contact_count ]; +} + +/* + * ----------------------------------------------------------------------------- + * Boolean shape overlap functions + * ----------------------------------------------------------------------------- + */ + +/* + * Project AABB, and triangle interval onto axis to check if they overlap + */ +static int rb_box_triangle_interval( v3f extent, v3f axis, v3f tri[3] ){ + float + + r = extent[0] * fabsf(axis[0]) + + extent[1] * fabsf(axis[1]) + + extent[2] * fabsf(axis[2]), + + p0 = v3_dot( axis, tri[0] ), + p1 = v3_dot( axis, tri[1] ), + p2 = v3_dot( axis, tri[2] ), + + e = vg_maxf(-vg_maxf(p0,vg_maxf(p1,p2)), vg_minf(p0,vg_minf(p1,p2))); + + if( e > r ) return 0; + else return 1; +} + +/* + * Seperating axis test box vs triangle + */ +static int rb_box_triangle_sat( v3f extent, v3f center, + m4x3f to_local, v3f tri_src[3] ){ + v3f tri[3]; + + for( int i=0; i<3; i++ ){ + m4x3_mulv( to_local, tri_src[i], tri[i] ); + v3_sub( tri[i], center, tri[i] ); + } + + v3f f0,f1,f2,n; + v3_sub( tri[1], tri[0], f0 ); + v3_sub( tri[2], tri[1], f1 ); + v3_sub( tri[0], tri[2], f2 ); + + + v3f axis[9]; + v3_cross( (v3f){1.0f,0.0f,0.0f}, f0, axis[0] ); + v3_cross( (v3f){1.0f,0.0f,0.0f}, f1, axis[1] ); + v3_cross( (v3f){1.0f,0.0f,0.0f}, f2, axis[2] ); + v3_cross( (v3f){0.0f,1.0f,0.0f}, f0, axis[3] ); + v3_cross( (v3f){0.0f,1.0f,0.0f}, f1, axis[4] ); + v3_cross( (v3f){0.0f,1.0f,0.0f}, f2, axis[5] ); + v3_cross( (v3f){0.0f,0.0f,1.0f}, f0, axis[6] ); + v3_cross( (v3f){0.0f,0.0f,1.0f}, f1, axis[7] ); + v3_cross( (v3f){0.0f,0.0f,1.0f}, f2, axis[8] ); + + for( int i=0; i<9; i++ ) + if(!rb_box_triangle_interval( extent, axis[i], tri )) return 0; + + /* u0, u1, u2 */ + if(!rb_box_triangle_interval( extent, (v3f){1.0f,0.0f,0.0f}, tri )) return 0; + if(!rb_box_triangle_interval( extent, (v3f){0.0f,1.0f,0.0f}, tri )) return 0; + if(!rb_box_triangle_interval( extent, (v3f){0.0f,0.0f,1.0f}, tri )) return 0; + + /* normal */ + v3_cross( f0, f1, n ); + if(!rb_box_triangle_interval( extent, n, tri )) return 0; + + return 1; +} + +/* + * ----------------------------------------------------------------------------- + * Manifold + * ----------------------------------------------------------------------------- + */ + +static int rb_manifold_apply_filtered( rb_ct *man, int len ){ + int k = 0; + + for( int i=0; itype == k_contact_type_disabled ) + continue; + + man[k ++] = man[i]; + } + + return k; +} + +/* + * Merge two contacts if they are within radius(r) of eachother + */ +static void rb_manifold_contact_weld( rb_ct *ci, rb_ct *cj, float r ){ + if( v3_dist2( ci->co, cj->co ) < r*r ){ + cj->type = k_contact_type_disabled; + ci->p = (ci->p + cj->p) * 0.5f; + + v3_add( ci->co, cj->co, ci->co ); + v3_muls( ci->co, 0.5f, ci->co ); + + v3f delta; + v3_sub( ci->rba->co, ci->co, delta ); + + float c0 = v3_dot( ci->n, delta ), + c1 = v3_dot( cj->n, delta ); + + if( c0 < 0.0f || c1 < 0.0f ){ + /* error */ + ci->type = k_contact_type_disabled; + } + else{ + v3f n; + v3_muls( ci->n, c0, n ); + v3_muladds( n, cj->n, c1, n ); + v3_normalize( n ); + v3_copy( n, ci->n ); + } + } +} + +/* + * + */ +static void rb_manifold_filter_joint_edges( rb_ct *man, int len, float r ){ + for( int i=0; itype != k_contact_type_edge ) + continue; + + for( int j=i+1; jtype != k_contact_type_edge ) + continue; + + rb_manifold_contact_weld( ci, cj, r ); + } + } +} + +/* + * Resolve overlapping pairs + */ +static void rb_manifold_filter_pairs( rb_ct *man, int len, float r ){ + for( int i=0; itype == k_contact_type_disabled ) continue; + + for( int j=i+1; jtype == k_contact_type_disabled ) continue; + + if( v3_dist2( ci->co, cj->co ) < r*r ){ + cj->type = k_contact_type_disabled; + v3_add( cj->n, ci->n, ci->n ); + ci->p += cj->p; + similar ++; + } + } + + if( similar ){ + float n = 1.0f/((float)similar+1.0f); + v3_muls( ci->n, n, ci->n ); + ci->p *= n; + + if( v3_length2(ci->n) < 0.1f*0.1f ) + ci->type = k_contact_type_disabled; + else + v3_normalize( ci->n ); + } + } +} + +/* + * Remove contacts that are facing away from A + */ +static void rb_manifold_filter_backface( rb_ct *man, int len ){ + for( int i=0; itype == k_contact_type_disabled ) + continue; + + v3f delta; + v3_sub( ct->co, ct->rba->co, delta ); + + if( v3_dot( delta, ct->n ) > -0.001f ) + ct->type = k_contact_type_disabled; + } +} + +/* + * Filter out duplicate coplanar results. Good for spheres. + */ +static void rb_manifold_filter_coplanar( rb_ct *man, int len, float w ){ + for( int i=0; itype == k_contact_type_disabled || + ci->type == k_contact_type_edge ) + continue; + + float d1 = v3_dot( ci->co, ci->n ); + + for( int j=0; jtype == k_contact_type_disabled ) + continue; + + float d2 = v3_dot( cj->co, ci->n ), + d = d2-d1; + + if( fabsf( d ) <= w ){ + cj->type = k_contact_type_disabled; + } + } + } +} + +static void rb_debug_contact( rb_ct *ct ){ + v3f p1; + v3_muladds( ct->co, ct->n, 0.05f, p1 ); + + if( ct->type == k_contact_type_default ){ + vg_line_point( ct->co, 0.0125f, 0xff0000ff ); + vg_line( ct->co, p1, 0xffffffff ); + } + else if( ct->type == k_contact_type_edge ){ + vg_line_point( ct->co, 0.0125f, 0xff00ffc0 ); + vg_line( ct->co, p1, 0xffffffff ); + } +} + +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 void rb_prepare_contact( rb_ct *ct, float timestep ){ + ct->bias = -k_phys_baumgarte * (timestep*3600.0f) + * vg_minf( 0.0f, -ct->p+k_penetration_slop ); + + v3_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; +} + +/* + * calculate total move to depenetrate object from contacts. + * manifold should belong to ONE object only + */ +static void rb_depenetrate( rb_ct *manifold, int len, v3f dt ){ + v3_zero( dt ); + + for( int j=0; j<7; j++ ){ + for( int i=0; in, dt ), + remaining = (ct->p-k_penetration_slop) - resolved_amt, + apply = vg_maxf( remaining, 0.0f ) * 0.4f; + + v3_muladds( dt, ct->n, apply, dt ); + } + } +} + +/* + * Initializing things like tangent vectors + */ +static void rb_presolve_contacts( rb_ct *buffer, int len ){ + for( int i=0; ico, 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 ); + } +} + +static void rb_contact_restitution( rb_ct *ct, float cr ){ + 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 ); + + float v = v3_dot( rv, ct->n ); + + if( v < -1.0f ){ + ct->bias += -cr * v; + } +} + +/* + * One iteration to solve the contact constraint + */ +static void rb_solve_contacts( rb_ct *buf, int len ){ + for( int i=0; ico, 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 ); + } +} + diff --git a/vg_rigidbody_constraints.h b/vg_rigidbody_constraints.h new file mode 100644 index 0000000..410b14f --- /dev/null +++ b/vg_rigidbody_constraints.h @@ -0,0 +1,522 @@ +#pragma once +#include "vg_rigidbody.h" + +typedef struct rb_constr_pos rb_constr_pos; +typedef struct rb_constr_swingtwist rb_constr_swingtwist; + +struct rb_constr_pos{ + rigidbody *rba, *rbb; + v3f lca, lcb; +}; + +struct rb_constr_swingtwist{ + rigidbody *rba, *rbb; + + v4f conevx, conevy; /* relative to rba */ + v3f view_offset, /* relative to rba */ + coneva, conevxb;/* relative to rbb */ + + int tangent_violation, axis_violation; + v3f axis, tangent_axis, tangent_target, axis_target; + + float conet; + float tangent_mass, axis_mass; + + f32 conv_tangent, conv_axis; +}; + +/* + * ----------------------------------------------------------------------------- + * Constraints + * ----------------------------------------------------------------------------- + */ + +static void rb_debug_position_constraints( rb_constr_pos *buffer, int len ){ + for( int i=0; irba, *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_point( p0, 0.0025f, 0xff000000 ); + vg_line_point( p1, 0.0025f, 0xffffffff ); + vg_line2( p0, p1, 0xff000000, 0xffffffff ); + } +} + +static void rb_presolve_swingtwist_constraints( rb_constr_swingtwist *buf, + int len ){ + for( int i=0; irba->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 )); + } + } +} + +static void rb_debug_swingtwist_constraints( rb_constr_swingtwist *buf, + int len ){ + float size = 0.12f; + + for( int i=0; irba->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_point( p1, 0.00025f, 0xffffffff ); + + if( st->tangent_violation ){ + v3_muladds( center, st->tangent_target, size, p0 ); + + vg_line( center, p0, 0xff00ff00 ); + vg_line_point( 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_point( 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 + */ +static void rb_solve_position_constraints( rb_constr_pos *buf, int len ){ + for( int i=0; irba, *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 ); + } +} + +static void rb_solve_swingtwist_constraints( rb_constr_swingtwist *buf, + int len ){ + for( int i=0; iaxis_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; itangent_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 ); + } +} + +/* debugging */ +static void rb_postsolve_swingtwist_constraints( rb_constr_swingtwist *buf, + u32 len ){ + for( int i=0; iaxis_violation ){ + st->conv_axis = 0.0f; + continue; + } + + f32 rv = v3_dot( st->axis, st->rbb->w ) - + v3_dot( st->axis, st->rba->w ); + + if( rv * (f32)st->axis_violation > 0.0f ) + st->conv_axis = 0.0f; + else + st->conv_axis = rv; + } + + for( int i=0; itangent_violation ){ + st->conv_tangent = 0.0f; + continue; + } + + f32 rv = v3_dot( st->tangent_axis, st->rbb->w ) - + v3_dot( st->tangent_axis, st->rba->w ); + + if( rv > 0.0f ) + st->conv_tangent = 0.0f; + else + st->conv_tangent = rv; + } +} + +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 + */ +static void rb_correct_position_constraints( rb_constr_pos *buf, int len, + float amt ){ + for( int i=0; irba, *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 ); + +#if 1 + v3_muladds( rbb->co, d, -1.0f * amt, rbb->co ); + rb_update_matrices( rbb ); +#else + f32 mt = 1.0f/(rba->inv_mass+rbb->inv_mass), + a = mt * (k_phys_baumgarte/k_rb_delta); + + v3_muladds( rba->v, d, a* rba->inv_mass, rba->v ); + v3_muladds( rbb->v, d, a*-rbb->inv_mass, rbb->v ); +#endif + } +} + +static void rb_correct_swingtwist_constraints( rb_constr_swingtwist *buf, + int len, float amt ){ + for( int i=0; itangent_violation ) + continue; + + v3f va; + m3x3_mulv( st->rbb->to_world, st->coneva, va ); + + f32 angle = v3_dot( va, st->tangent_target ); + + if( fabsf(angle) < 0.9999f ){ + v3f axis; + v3_cross( va, st->tangent_target, axis ); +#if 1 + angle = acosf(angle) * amt; + v4f correction; + q_axis_angle( correction, axis, angle ); + q_mul( correction, st->rbb->q, st->rbb->q ); + 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); + //v3_muladds( st->rba->w, axis, wa*-st->rba->inv_mass, st->rba->w ); + v3_muladds( st->rbb->w, axis, wa* st->rbb->inv_mass, st->rbb->w ); +#endif + } + } + + for( int i=0; iaxis_violation ) + continue; + + v3f vxb; + m3x3_mulv( st->rbb->to_world, st->conevxb, vxb ); + + f32 angle = v3_dot( vxb, st->axis_target ); + + if( fabsf(angle) < 0.9999f ){ + v3f axis; + v3_cross( vxb, st->axis_target, axis ); + +#if 1 + angle = acosf(angle) * amt; + v4f correction; + q_axis_angle( correction, axis, angle ); + q_mul( correction, st->rbb->q, st->rbb->q ); + 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); + //v3_muladds( st->rba->w, axis, wa*-0.5f, st->rba->w ); + v3_muladds( st->rbb->w, axis, wa* st->rbb->inv_mass, st->rbb->w ); +#endif + } + } +} -- 2.25.1