X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=rigidbody.h;h=7d878e9a4976146a08cf09cb9cc2a5519e978408;hb=137d40d96fe923600d8378b8e138e3c276f27ff4;hp=e374f3fbd6e773cdbc5f33349a5202f576125903;hpb=1656d58a7bd17df4a1edcc9677ade4dbafc82229;p=carveJwlIkooP6JGAAIwe30JlM.git diff --git a/rigidbody.h b/rigidbody.h index e374f3f..7d878e9 100644 --- a/rigidbody.h +++ b/rigidbody.h @@ -1,41 +1,204 @@ +/* + * Copyright (C) 2021-2023 Mt.ZERO Software, Harry Godden - All Rights Reserved + */ + /* * Resources: Box2D - Erin Catto * qu3e - Randy Gaul */ -#include "common.h" -static void rb_tangent_basis( v3f n, v3f tx, v3f ty ); +#include "vg/vg_console.h" +#include "bvh.h" +#include "scene.h" + +#include + +static bh_system bh_system_rigidbodies; #ifndef RIGIDBODY_H #define RIGIDBODY_H -#include "bvh.h" +/* + * ----------------------------------------------------------------------------- + * (K)onstants + * ----------------------------------------------------------------------------- + */ -#define RB_DEPR +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 = 8.0f, + k_phys_baumgarte = 0.2f, + k_gravity = 9.6f; + +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 ); +} -#define k_rb_delta (1.0f/60.0f) +/* + * ----------------------------------------------------------------------------- + * structure definitions + * ----------------------------------------------------------------------------- + */ typedef struct rigidbody rigidbody; -struct rigidbody -{ - v3f co, v, I; +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; +}; + +struct rigidbody{ + v3f co, v, w; v4f q; + boxf bbx, bbx_world; float inv_mass; - struct contact - { - v3f co, n, delta; - v3f t[2]; - float bias, norm_impulse, tangent_impulse[2]; + /* inertia model and inverse world tensor */ + v3f I; + m3x3f iI, iIw; + 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; } - manifold[12]; - int manifold_count; + inf; +}; - v3f delta; /* where is the origin of this in relation to a parent body */ - m4x3f to_world, to_local; +static struct contact{ + 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; + +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; +}; + +/* + * ----------------------------------------------------------------------------- + * Debugging + * ----------------------------------------------------------------------------- + */ + +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_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 + */ static void rb_update_transform( rigidbody *rb ) { q_normalize( rb->q ); @@ -43,240 +206,506 @@ static void rb_update_transform( rigidbody *rb ) v3_copy( rb->co, rb->to_world[3] ); m4x3_invert_affine( rb->to_world, rb->to_local ); + m3x3_mul( rb->iI, rb->to_local, rb->iIw ); + m3x3_mul( rb->to_world, rb->iIw, rb->iIw ); - box_copy( rb->bbx, rb->bbx_world ); - m4x3_transform_aabb( rb->to_world, rb->bbx_world ); + rb_update_bounds( rb ); } -static void rb_init( rigidbody *rb ) +/* + * Extrapolate rigidbody into a transform based on vg accumulator. + * Useful for rendering + */ +static void rb_extrapolate( rigidbody *rb, v3f co, v4f q ) { - q_identity( rb->q ); - v3_zero( rb->v ); - v3_zero( rb->I ); + float substep = vg.time_fixed_extrapolate; + v3_muladds( rb->co, rb->v, k_rb_delta*substep, co ); - v3f dims; - v3_sub( rb->bbx[1], rb->bbx[0], dims ); + 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 ); + } +} + +/* + * Initialize rigidbody and calculate masses, inertia + */ +static void rb_init_object( rb_object *obj ){ + 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 ); + } - rb->inv_mass = 1.0f/(8.0f*dims[0]*dims[1]*dims[2]); + if( inert ){ + obj->rb.inv_mass = 0.0f; + v3_zero( obj->rb.I ); + m3x3_zero( obj->rb.iI ); + } + else{ + float mass = 2.0f*volume; + obj->rb.inv_mass = 1.0f/mass; + + v3f extent; + v3_sub( obj->rb.bbx[1], obj->rb.bbx[0], extent ); + v3_muls( extent, 0.5f, extent ); + + /* local intertia tensor */ + float scale = k_inertia_scale; + float ex2 = scale*extent[0]*extent[0], + ey2 = scale*extent[1]*extent[1], + ez2 = scale*extent[2]*extent[2]; + + obj->rb.I[0] = ((1.0f/12.0f) * mass * (ey2+ez2)); + obj->rb.I[1] = ((1.0f/12.0f) * mass * (ex2+ez2)); + obj->rb.I[2] = ((1.0f/12.0f) * mass * (ex2+ey2)); + + m3x3_identity( obj->rb.iI ); + obj->rb.iI[0][0] = obj->rb.I[0]; + obj->rb.iI[1][1] = obj->rb.I[1]; + obj->rb.iI[2][2] = obj->rb.I[2]; + m3x3_inv( obj->rb.iI, obj->rb.iI ); + } - rb_update_transform( rb ); + rb_update_transform( &obj->rb ); } -static void rb_iter( rigidbody *rb ) -{ - v3f gravity = { 0.0f, -9.6f, 0.0f }; +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->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 ); q_axis_angle( rotation, axis, mag*k_rb_delta ); q_mul( rotation, rb->q, rb->q ); } + + /* 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 ); } -static void rb_torque( rigidbody *rb, v3f axis, float mag ) -{ - v3_muladds( rb->I, axis, mag*k_rb_delta, rb->I ); + +/* + * ----------------------------------------------------------------------------- + * 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; } -static void rb_tangent_basis( v3f n, v3f tx, v3f ty ) -{ - /* Compute tangent basis (box2d) */ - if( fabsf( n[0] ) >= 0.57735027f ) - { - tx[0] = n[1]; - tx[1] = -n[0]; - tx[2] = 0.0f; - } - else - { - tx[0] = 0.0f; - tx[1] = n[2]; - tx[2] = -n[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] ); } - v3_normalize( tx ); - v3_cross( n, tx, ty ); -} + 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; -#include "world.h" + /* 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; -static void rb_manifold_reset( rigidbody *rb ) -{ - rb->manifold_count = 0; + /* normal */ + v3_cross( f0, f1, n ); + if(!rb_box_triangle_interval( extent, n, tri )) return 0; + + return 1; } -static void rb_build_manifold_terrain( rigidbody *rb ) -{ - v3f *box = rb->bbx; - v3f pts[8]; - float *p000 = pts[0], *p001 = pts[1], *p010 = pts[2], *p011 = pts[3], - *p100 = pts[4], *p101 = pts[5], *p110 = pts[6], *p111 = pts[7]; - - 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]; - - 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]; - - 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 ); +/* + * ----------------------------------------------------------------------------- + * Manifold + * ----------------------------------------------------------------------------- + */ - int count = 0; +static int rb_manifold_apply_filtered( rb_ct *man, int len ){ + int k = 0; - for( int i=0; i<8; i++ ) - { - float *point = pts[i]; - struct contact *ct = &rb->manifold[rb->manifold_count]; - - v3f surface; - v3_copy( point, surface ); - surface[1] += 4.0f; + for( int i=0; itype == k_contact_type_disabled ) continue; - v3_copy( hit.normal, ct->n ); - v3_copy( hit.pos, surface ); + man[k ++] = man[i]; + } - float p = vg_minf( surface[1] - point[1], 1.0f ); + return k; +} - if( p > 0.0f ) - { - v3_add( point, surface, ct->co ); - v3_muls( ct->co, 0.5f, ct->co ); +/* + * 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; - //vg_line_pt3( ct->co, 0.0125f, 0xff0000ff ); + v3_add( ci->co, cj->co, ci->co ); + v3_muls( ci->co, 0.5f, ci->co ); - 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] ); + v3f delta; + v3_sub( ci->rba->co, ci->co, delta ); - ct->norm_impulse = 0.0f; - ct->tangent_impulse[0] = 0.0f; - ct->tangent_impulse[1] = 0.0f; + float c0 = v3_dot( ci->n, delta ), + c1 = v3_dot( cj->n, delta ); - rb->manifold_count ++; - count ++; - if( count == 4 ) - break; + 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_constraint_manifold( rigidbody *rb ) -{ - float k_friction = 0.1f; +/* + * + */ +static void rb_manifold_filter_joint_edges( rb_ct *man, int len, float r ){ + for( int i=0; itype != k_contact_type_edge ) + continue; - /* Friction Impulse */ - for( int i=0; imanifold_count; i++ ) - { - struct contact *ct = &rb->manifold[i]; + 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 ); + } + } +} - v3f dv; - v3_cross( rb->I, ct->delta, dv ); - v3_add( rb->v, dv, dv ); +/* + * 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 ); - for( int j=0; j<2; j++ ) - { - float vt = vg_clampf( -v3_dot( dv, ct->t[j] ), - -k_friction, k_friction ); + if( v3_dot( delta, ct->n ) > -0.001f ) + ct->type = k_contact_type_disabled; + } +} - vt = -v3_dot( dv, ct->t[j] ); +/* + * 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 temp = ct->tangent_impulse[j]; - ct->tangent_impulse[j] = vg_clampf( temp+vt, -k_friction, k_friction ); - vt = ct->tangent_impulse[j] - temp; + float d2 = v3_dot( cj->co, ci->n ), + d = d2-d1; - v3f impulse; + if( fabsf( d ) <= w ){ + cj->type = k_contact_type_disabled; + } + } + } +} + +/* + * ----------------------------------------------------------------------------- + * Collision matrix + * ----------------------------------------------------------------------------- + */ + +/* + * 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 + */ - 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 ); +/* + * 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{ + float t0, t1; + float 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, float t, float 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; } } +} - /* Normal Impulse */ - for( int i=0; imanifold_count; i++ ) - { - struct contact *ct = &rb->manifold[i]; +static void rb_capsule_manifold_init( capsule_manifold *manifold ){ + manifold->t0 = INFINITY; + manifold->t1 = -INFINITY; +} - v3f dv; - v3_cross( rb->I, ct->delta, dv ); - v3_add( rb->v, dv, dv ); +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->height*0.5f+c->radius, p0 ); + v3_muladds( mtx[3], mtx[1], c->height*0.5f-c->radius, p1 ); - float vn = -v3_dot( dv, ct->n ); - vn += ct->bias; + int count = 0; + if( manifold->t0 <= 1.0f ){ + rb_ct *ct = buf; - float temp = ct->norm_impulse; - ct->norm_impulse = vg_maxf( temp + vn, 0.0f ); - vn = ct->norm_impulse - temp; + v3f pa; + v3_muls( p0, 1.0f-manifold->t0, pa ); + v3_muladds( pa, p1, manifold->t0, pa ); - v3f impulse; + 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_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 ); + 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 ); + + float d = v3_length( manifold->d1 ); + v3_muls( manifold->d1, 1.0f/d, ct->n ); + v3_muladds( pa, ct->n, -c->radius, 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; } -struct rb_angle_limit -{ - rigidbody *rba, *rbb; - v3f axis; - float impulse, bias; -}; +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; -static int rb_angle_limit_force( rigidbody *rba, v3f va, - rigidbody *rbb, v3f vb, - float max ) -{ - v3f wva, wvb; - m3x3_mulv( rba->to_world, va, wva ); - m3x3_mulv( rbb->to_world, vb, wvb ); - - float dt = v3_dot(wva,wvb)*0.999f, - ang = fabsf(dt); - ang = acosf( dt ); - if( ang > max ) - { - float correction = max-ang; + 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 axis; - v3_cross( wva, wvb, axis ); - - v4f rotation; - q_axis_angle( rotation, axis, -correction*0.25f ); - q_mul( rotation, rba->q, rba->q ); + v3f c, delta; + closest_point_segment( p0, p1, rbb->co, c ); + v3_sub( c, rbb->co, delta ); - q_axis_angle( rotation, axis, correction*0.25f ); - q_mul( rotation, rbb->q, rbb->q ); + 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; } @@ -284,308 +713,1124 @@ static int rb_angle_limit_force( rigidbody *rba, v3f va, return 0; } -static void rb_constraint_angle_limit( struct rb_angle_limit *limit ) -{ +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; + + 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; + 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( mtxA, ca, &manifold, buf ); +} +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 ); + + float d2 = v3_length2(delta), + r = obja->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->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; } +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 ); + + float d2 = v3_length2(delta), + r = obja->inf.sphere.radius + objb->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,-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; + } -RB_DEPR -static void rb_constraint_angle( rigidbody *rba, v3f va, - rigidbody *rbb, v3f vb, - float max, float spring ) -{ - v3f wva, wvb; - m3x3_mulv( rba->to_world, va, wva ); - m3x3_mulv( rbb->to_world, vb, wvb ); + return 0; +} - float dt = v3_dot(wva,wvb)*0.999f, - ang = fabsf(dt); +static int rb_sphere__triangle( m4x3f mtxA, rb_sphere *b, + v3f tri[3], rb_ct *buf ){ + v3f delta, co; + enum contact_type type = closest_on_triangle_1( mtxA[3], tri, co ); - 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_sub( mtxA[3], co, delta ); + + float d2 = v3_length2( delta ), + r = b->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 ){ +#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING + vg_error( "Zero area triangle!\n" ); +#endif + return 0; + } + + v3_normalize( ct->n ); + + float d = sqrtf(d2); + + v3_copy( co, ct->co ); + ct->type = type; + ct->p = r-d; + return 1; + } + + 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; + + int count = 0; - return; + 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] ); + + bh_iter it; + i32 idx; + bh_iter_init_box( 0, &it, box ); - /* TODO: convert max into the dot product value so we dont have to always - * evaluate acosf, only if its greater than the angle specified */ - ang = acosf( dt ); - if( ang > max ) - { - float correction = max-ang; + while( bh_next( s->bh_scene, &it, &idx ) ){ + u32 *ptri = &sc->arrindices[ idx*3 ]; + v3f tri[3]; + + if( sc->arrvertices[ptri[0]].flags & ignore ) continue; + + for( int j=0; j<3; j++ ) + v3_copy( sc->arrvertices[ptri[j]].co, tri[j] ); - v4f rotation; - q_axis_angle( rotation, axis, -correction*0.125f ); - q_mul( rotation, rba->q, rba->q ); + 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( mtxA, b, tri, &buf[count] ); + count += contact; - q_axis_angle( rotation, axis, correction*0.125f ); - q_mul( rotation, rbb->q, rbb->q ); + if( count == 16 ){ + vg_warn( "Exceeding sphere_vs_scene capacity. Geometry too dense!\n" ); + return count; + } } + + return count; } -static void rb_relative_velocity( rigidbody *ra, v3f lca, - rigidbody *rb, v3f lcb, v3f rcv ) -{ - v3f wca, wcb; - m3x3_mulv( ra->to_world, lca, wca ); - m3x3_mulv( rb->to_world, lcb, wcb ); +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; + v3f tri[3]; + + v3f extent, center; + v3_sub( bbx[1], bbx[0], extent ); + v3_muls( extent, 0.5f, extent ); + v3_add( bbx[0], extent, center ); + + float r = v3_length(extent); + boxf world_bbx; + v3_fill( world_bbx[0], -r ); + v3_fill( world_bbx[1], r ); + for( int i=0; i<2; i++ ){ + v3_add( center, world_bbx[i], world_bbx[i] ); + v3_add( mtxA[3], world_bbx[i], world_bbx[i] ); + } - v3_sub( ra->v, rb->v, rcv ); + m4x3f to_local; + m4x3_invert_affine( mtxA, to_local ); - v3f rcv_Ra, rcv_Rb; - v3_cross( ra->I, wca, rcv_Ra ); - v3_cross( rb->I, wcb, rcv_Rb ); - v3_add( rcv_Ra, rcv, rcv ); - v3_sub( rcv, rcv_Rb, rcv ); -} + bh_iter it; + bh_iter_init_box( 0, &it, world_bbx ); + int idx; + int count = 0; -static void rb_constraint_position( rigidbody *ra, v3f lca, - rigidbody *rb, v3f lcb ) -{ - /* C = (COa + Ra*LCa) - (COb + Rb*LCb) = 0 */ - v3f wca, wcb; - m3x3_mulv( ra->to_world, lca, wca ); - m3x3_mulv( rb->to_world, lcb, wcb ); + vg_line_boxf( world_bbx, VG__RED ); + + while( bh_next( s->bh_scene, &it, &idx ) ){ + u32 *ptri = &sc->arrindices[ idx*3 ]; + if( sc->arrvertices[ptri[0]].flags & ignore ) continue; - v3f delta; - v3_add( wcb, rb->co, delta ); - v3_sub( delta, wca, delta ); - v3_sub( delta, ra->co, delta ); + for( int j=0; j<3; j++ ) + v3_copy( sc->arrvertices[ptri[j]].co, tri[j] ); - v3_muladds( ra->co, delta, 0.5f, ra->co ); - v3_muladds( rb->co, delta, -0.5f, rb->co ); + if( rb_box_triangle_sat( extent, center, to_local, 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 rcv; - v3_sub( ra->v, rb->v, rcv ); + v3f v0,v1,n; + v3_sub( tri[1], tri[0], v0 ); + v3_sub( tri[2], tri[0], v1 ); + v3_cross( v0, v1, n ); - v3f rcv_Ra, rcv_Rb; - v3_cross( ra->I, wca, rcv_Ra ); - v3_cross( rb->I, wcb, rcv_Rb ); - v3_add( rcv_Ra, rcv, rcv ); - v3_sub( rcv, rcv_Rb, rcv ); + if( v3_length2( n ) <= 0.00001f ){ +#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING + vg_error( "Zero area triangle!\n" ); +#endif + return 0; + } - float nm = 0.5f/(rb->inv_mass + ra->inv_mass); + v3_normalize( n ); - float mass_a = 1.0f/ra->inv_mass, - mass_b = 1.0f/rb->inv_mass, - total_mass = mass_a+mass_b; + /* find best feature */ + float best = v3_dot( mtxA[0], n ); + int axis = 0; + + for( int i=1; i<3; i++ ){ + float c = v3_dot( mtxA[i], n ); + + if( fabsf(c) > fabsf(best) ){ + best = c; + axis = i; + } + } + + v3f manifold[4]; + + if( axis == 0 ){ + float px = best > 0.0f? bbx[0][0]: bbx[1][0]; + manifold[0][0] = px; + manifold[0][1] = bbx[0][1]; + manifold[0][2] = bbx[0][2]; + manifold[1][0] = px; + manifold[1][1] = bbx[1][1]; + manifold[1][2] = bbx[0][2]; + manifold[2][0] = px; + manifold[2][1] = bbx[1][1]; + manifold[2][2] = bbx[1][2]; + manifold[3][0] = px; + manifold[3][1] = bbx[0][1]; + manifold[3][2] = bbx[1][2]; + } + else if( axis == 1 ){ + float py = best > 0.0f? bbx[0][1]: bbx[1][1]; + manifold[0][0] = bbx[0][0]; + manifold[0][1] = py; + manifold[0][2] = bbx[0][2]; + manifold[1][0] = bbx[1][0]; + manifold[1][1] = py; + manifold[1][2] = bbx[0][2]; + manifold[2][0] = bbx[1][0]; + manifold[2][1] = py; + manifold[2][2] = bbx[1][2]; + manifold[3][0] = bbx[0][0]; + manifold[3][1] = py; + manifold[3][2] = bbx[1][2]; + } + else{ + float pz = best > 0.0f? bbx[0][2]: bbx[1][2]; + manifold[0][0] = bbx[0][0]; + manifold[0][1] = bbx[0][1]; + manifold[0][2] = pz; + manifold[1][0] = bbx[1][0]; + manifold[1][1] = bbx[0][1]; + manifold[1][2] = pz; + manifold[2][0] = bbx[1][0]; + manifold[2][1] = bbx[1][1]; + manifold[2][2] = pz; + manifold[3][0] = bbx[0][0]; + manifold[3][1] = bbx[1][1]; + manifold[3][2] = pz; + } - v3f impulse; - 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 ); + for( int j=0; j<4; j++ ) + m4x3_mulv( mtxA, manifold[j], manifold[j] ); - 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 ); + 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 ); -#if 0 - v3f impulse; - v3_muls( delta, 0.5f*spring, impulse ); + for( int j=0; j<4; j++ ){ + rb_ct *ct = buf+count; + + v3_copy( manifold[j], ct->co ); + v3_copy( n, ct->n ); - v3_add( impulse, ra->v, ra->v ); - v3_cross( wca, impulse, impulse ); - v3_add( impulse, ra->I, ra->I ); + float l0 = v3_dot( tri[0], n ), + l1 = v3_dot( manifold[j], n ); - v3_muls( delta, -0.5f*spring, impulse ); + ct->p = (l0-l1)*0.5f; + if( ct->p < 0.0f ) + continue; + + ct->type = k_contact_type_default; + count ++; - v3_add( impulse, rb->v, rb->v ); - v3_cross( wcb, impulse, impulse ); - v3_add( impulse, rb->I, rb->I ); + if( count >= 12 ) + return count; + } + } + return count; +} + +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 ); + + if( v3_length2( n ) <= 0.00001f ){ +#ifdef RIGIDBODY_CRY_ABOUT_EVERYTHING + vg_error( "Zero area triangle!\n" ); #endif + return 0; + } + + v3_normalize( n ); + + int count = rb_capsule__manifold_done( mtxA, c, &manifold, buf ); + for( int i=0; ibbx; - v3f p000, p001, p010, p011, p100, p101, p110, p111; - - 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]; - - 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]; - - 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 ); +/* 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 ){ + 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] ); - vg_line( p000, p001, colour ); - vg_line( p001, p011, colour ); - vg_line( p011, p010, colour ); - vg_line( p010, p000, colour ); + scene_context *sc = s->bh_scene->user; + + bh_iter it; + bh_iter_init_box( 0, &it, bbx ); + i32 idx; + while( bh_next( s->bh_scene, &it, &idx ) ){ + u32 *ptri = &sc->arrindices[ idx*3 ]; + if( sc->arrvertices[ptri[0]].flags & ignore ) continue; + + 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( p100, p101, colour ); - vg_line( p101, p111, colour ); - vg_line( p111, p110, colour ); - vg_line( p110, p100, colour ); + int contact = rb_capsule__triangle( mtxA, c, tri, &buf[count] ); + count += contact; - vg_line( p100, p000, colour ); - vg_line( p101, p001, colour ); - vg_line( p110, p010, colour ); - vg_line( p111, p011, colour ); + if( count >= 16 ){ + vg_warn("Exceeding capsule_vs_scene capacity. Geometry too dense!\n"); + return count; + } + } - vg_line( p000, p110, colour ); - vg_line( p100, p010, colour ); + return count; +} + +static int rb_global_has_space( void ){ + if( rb_contact_count + 16 > vg_list_size(rb_contact_buffer) ) + return 0; + + return 1; +} + +static rb_ct *rb_global_buffer( void ){ + return &rb_contact_buffer[ rb_contact_count ]; } /* - * out penetration distance, normal + * ----------------------------------------------------------------------------- + * Dynamics + * ----------------------------------------------------------------------------- */ -static int rb_point_in_body( rigidbody *rb, v3f pos, float *pen, v3f normal ) -{ - v3f local; - m4x3_mulv( rb->to_local, pos, local ); - 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 ); +static void rb_solver_reset(void){ + rb_contact_count = 0; +} - v3_sub( rb->bbx[1], rb->bbx[0], area ); - v3_sub( local, com, comrel ); - v3_div( comrel, area, comrel ); +static rb_ct *rb_global_ct(void){ + return rb_contact_buffer + rb_contact_count; +} - int axis = 0; - float max_mag = fabsf(comrel[0]); - - if( fabsf(comrel[1]) > max_mag ) +static void rb_prepare_contact( rb_ct *ct, float timestep ){ + ct->bias = -0.2f * (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. 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 ); } - if( fabsf(comrel[2]) > max_mag ) - { - axis = 2; - max_mag = fabsf(comrel[2]); + } +} + +/* + * 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 ); + } +} + +/* + * 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 ); +} + +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; + } +} + +/* + * 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 ); +} + +/* + * 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 ); - v3_zero( normal ); - normal[axis] = vg_signf(comrel[axis]); + /* 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 ); + } - if( normal[axis] < 0.0f ) - *pen = local[axis] - rb->bbx[0][axis]; - else - *pen = rb->bbx[1][axis] - local[axis]; + /* Normal */ + rb_rcv( ct->rba, ct->rbb, ra, rb, rv ); + float vn = v3_dot( rv, ct->n ), + lambda = ct->normal_mass * (-vn + ct->bias); - m3x3_mulv( rb->to_world, normal, normal ); - return 1; + 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 ); } +} - return 0; +/* + * ----------------------------------------------------------------------------- + * 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_build_manifold_rb_static( rigidbody *ra, rigidbody *rb_static ) -{ - v3f verts[8]; +static void rb_presolve_swingtwist_constraints( rb_constr_swingtwist *buf, + int len ){ + float size = 0.12f; - v3f a, b; - v3_copy( ra->bbx[0], a ); - v3_copy( ra->bbx[1], b ); - - 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] ); + 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 ); + } - int count = 0; + v3f refaxis; + v3_cross( vy, va, refaxis ); /* our default rotation */ + v3_normalize( refaxis ); - for( int i=0; i<8; i++ ) - { - if( ra->manifold_count == vg_list_size(ra->manifold) ) - return; + 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); - struct contact *ct = &ra->manifold[ ra->manifold_count ]; + 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; in ); - v3_muladds( verts[i], ct->n, p*0.5f, ct->co ); - v3_sub( ct->co, ra->co, ct->delta ); + 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 ); - 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] ); + float rx = st->conevx[3], /* elipse radii */ + ry = st->conevy[3]; - ct->norm_impulse = 0.0f; - ct->tangent_impulse[0] = 0.0f; - ct->tangent_impulse[1] = 0.0f; + v3f p0, p1; + v3_muladds( center, va, size, p1 ); + vg_line( center, p1, 0xffffffff ); + vg_line_point( p1, 0.00025f, 0xffffffff ); - ra->manifold_count ++; - count ++; - if( count == 4 ) - return; + 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 ); } } /* - * BVH implementation, this is ONLY for static rigidbodies, its to slow for - * realtime use. + * 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; -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 ); + 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 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_solve_swingtwist_constraints( rb_constr_swingtwist *buf, + int len ){ + float size = 0.12f; + + 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 ); + } } -static void rb_bh_swap( void *user, u32 ia, u32 ib ) -{ - rigidbody temp, *rba, *rbb; - rba = &((rigidbody *)user)[ ia ]; - rbb = &((rigidbody *)user)[ ib ]; +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 ); - temp = *rba; - *rba = *rbb; - *rbb = temp; + 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 ); } -static void rb_bh_debug( void *user, u32 item_index ) -{ - rigidbody *rb = &((rigidbody *)user)[ item_index ]; - rb_debug( rb, 0xff00ffff ); +/* + * 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 ); + + v3_muladds( rbb->co, d, -1.0f * amt, rbb->co ); + rb_update_transform( rbb ); + } } -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, +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 ); + + 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; iaxis_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 ); + } + } +} + +static void rb_correct_contact_constraints( rb_ct *buf, int len, float amt ){ + for( int i=0; irba, + *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 + */ + +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 ); +} #endif /* RIGIDBODY_H */