+ return count;
+}
+
+static int RB_MATRIX_ERROR( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ vg_error( "Collision type is unimplemented between types %d and %d\n",
+ rba->type, rbb->type );
+
+ return 0;
+}
+
+static int rb_sphere_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_sphere( rbb, rba, buf );
+}
+
+static int rb_box_capsule( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_capsule_box( rbb, rba, buf );
+}
+
+static int rb_box_sphere( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_sphere_box( rbb, rba, buf );
+}
+
+static int rb_scene_box( rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+{
+ return rb_box_scene( rbb, rba, buf );
+}
+
+static int (*rb_jump_table[4][4])( rigidbody *a, rigidbody *b, rb_ct *buf ) =
+{
+ /* box */ /* Sphere */ /* Capsule */ /* Mesh */
+ { RB_MATRIX_ERROR, rb_box_sphere, rb_box_capsule, rb_box_scene },
+ { rb_sphere_box, rb_sphere_sphere, rb_sphere_capsule, rb_sphere_scene },
+ { rb_capsule_box, rb_capsule_sphere, rb_capsule_capsule, RB_MATRIX_ERROR },
+ { rb_scene_box, RB_MATRIX_ERROR, RB_MATRIX_ERROR, RB_MATRIX_ERROR }
+};
+
+static int rb_collide( rigidbody *rba, rigidbody *rbb )
+{
+ int (*collider_jump)(rigidbody *rba, rigidbody *rbb, rb_ct *buf )
+ = rb_jump_table[rba->type][rbb->type];
+
+ /*
+ * 12 is the maximum manifold size we can generate, so we are forced to abort
+ * potentially checking any more.
+ */
+ if( rb_contact_count + 12 > vg_list_size(rb_contact_buffer) )
+ {
+ vg_warn( "Too many contacts made in global collider buffer (%d of %d\n)",
+ rb_contact_count, vg_list_size(rb_contact_buffer) );
+ return 0;
+ }
+
+ /*
+ * TODO: Replace this with a more dedicated broad phase pass
+ */
+ if( box_overlap( rba->bbx_world, rbb->bbx_world ) )
+ {
+ int count = collider_jump( rba, rbb, rb_contact_buffer+rb_contact_count);
+ rb_contact_count += count;
+ return count;
+ }
+ else
+ return 0;
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Dynamics
+ * -----------------------------------------------------------------------------
+ */
+
+static void rb_solver_reset(void)
+{
+ rb_contact_count = 0;
+}
+
+static rb_ct *rb_global_ct(void)
+{
+ return rb_contact_buffer + rb_contact_count;
+}
+
+/*
+ * Initializing things like tangent vectors
+ */
+static void rb_presolve_contacts( rb_ct *buffer, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ rb_ct *ct = &buffer[i];
+ ct->bias = -0.2f * k_rb_rate * vg_minf( 0.0f, -ct->p+k_penetration_slop );
+ rb_tangent_basis( ct->n, ct->t[0], ct->t[1] );
+
+ ct->norm_impulse = 0.0f;
+ ct->tangent_impulse[0] = 0.0f;
+ ct->tangent_impulse[1] = 0.0f;
+
+ v3f ra, rb, raCn, rbCn, raCt, rbCt;
+ v3_sub( ct->co, ct->rba->co, ra );
+ v3_sub( ct->co, ct->rbb->co, rb );
+ v3_cross( ra, ct->n, raCn );
+ v3_cross( rb, ct->n, rbCn );
+
+ /* orient inverse inertia tensors */
+ v3f raCnI, rbCnI;
+ m3x3_mulv( ct->rba->iIw, raCn, raCnI );
+ m3x3_mulv( ct->rbb->iIw, rbCn, rbCnI );
+
+ ct->normal_mass = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->normal_mass += v3_dot( raCn, raCnI );
+ ct->normal_mass += v3_dot( rbCn, rbCnI );
+ ct->normal_mass = 1.0f/ct->normal_mass;
+
+ for( int j=0; j<2; j++ )
+ {
+ v3f raCtI, rbCtI;
+ v3_cross( ct->t[j], ra, raCt );
+ v3_cross( ct->t[j], rb, rbCt );
+ m3x3_mulv( ct->rba->iIw, raCt, raCtI );
+ m3x3_mulv( ct->rbb->iIw, rbCt, rbCtI );
+
+ ct->tangent_mass[j] = ct->rba->inv_mass + ct->rbb->inv_mass;
+ ct->tangent_mass[j] += v3_dot( raCt, raCtI );
+ ct->tangent_mass[j] += v3_dot( rbCt, rbCtI );
+ ct->tangent_mass[j] = 1.0f/ct->tangent_mass[j];
+ }
+
+ rb_debug_contact( ct );
+ }
+}
+
+/*
+ * Creates relative contact velocity vector, and offsets between each body
+ */
+static void rb_rcv( rb_ct *ct, v3f rv, v3f da, v3f db )
+{
+ rigidbody *rba = ct->rba,
+ *rbb = ct->rbb;
+
+ v3_sub( ct->co, rba->co, da );
+ v3_sub( ct->co, rbb->co, db );
+
+ v3f rva, rvb;
+ v3_cross( rba->w, da, rva );
+ v3_add( rba->v, rva, rva );
+ v3_cross( rbb->w, db, rvb );
+ v3_add( rbb->v, rvb, rvb );
+
+ v3_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 );
+}
+
+/*
+ * One iteration to solve the contact constraint
+ */
+static void rb_solve_contacts( rb_ct *buf, int len )
+{
+ for( int i=0; i<len; i++ )
+ {
+ struct contact *ct = &buf[i];
+ rigidbody *rb = ct->rba;
+
+ v3f rv, da, db;
+ rb_rcv( ct, rv, da, db );
+
+ /* 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, da, impulse );
+
+ v3_muls( ct->t[j], -lambda, impulse );
+ rb_linear_impulse( ct->rbb, db, impulse );
+ }
+
+ /* Normal */
+ rb_rcv( ct, rv, da, db );
+ 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, da, impulse );
+
+ v3_muls( ct->n, -lambda, impulse );
+ rb_linear_impulse( ct->rbb, db, impulse );
+ }
+}
+
+/*
+ * -----------------------------------------------------------------------------
+ * Constraints
+ * -----------------------------------------------------------------------------
+ */
+
+static void draw_angle_limit( v3f c, v3f major, v3f minor,
+ float amin, float amax, float measured,
+ u32 colour )
+{
+ float f = 0.05f;
+ v3f ay, ax;
+ v3_muls( major, f, ay );
+ v3_muls( minor, f, ax );
+
+ for( int x=0; x<16; x++ )
+ {
+ float t0 = (float)x / 16.0f,
+ t1 = (float)(x+1) / 16.0f,
+ a0 = vg_lerpf( amin, amax, t0 ),
+ a1 = vg_lerpf( amin, amax, t1 );
+
+ v3f p0, p1;
+ v3_muladds( c, ay, cosf(a0), p0 );
+ v3_muladds( p0, ax, sinf(a0), p0 );
+ v3_muladds( c, ay, cosf(a1), p1 );
+ v3_muladds( p1, ax, sinf(a1), p1 );
+
+ vg_line( p0, p1, colour );
+
+ if( x == 0 )
+ vg_line( c, p0, colour );
+ if( x == 15 )
+ vg_line( c, p1, colour );
+ }
+
+ v3f p2;
+ v3_muladds( c, ay, cosf(measured)*1.2f, p2 );
+ v3_muladds( p2, ax, sinf(measured)*1.2f, p2 );
+ vg_line( c, p2, colour );
+}
+
+static void rb_debug_constraint_limits( rigidbody *ra, rigidbody *rb, v3f lca,
+ v3f limits[2] )
+{
+ v3f ax, ay, az, bx, by, bz;
+ m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
+ m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+
+ v2f px, py, pz;
+ px[0] = v3_dot( ay, by );
+ px[1] = v3_dot( az, by );
+
+ py[0] = v3_dot( az, bz );
+ py[1] = v3_dot( ax, bz );
+
+ pz[0] = v3_dot( ax, bx );
+ pz[1] = v3_dot( ay, bx );
+
+ float r0 = atan2f( px[1], px[0] ),
+ r1 = atan2f( py[1], py[0] ),
+ r2 = atan2f( pz[1], pz[0] );
+
+ v3f c;
+ m4x3_mulv( ra->to_world, lca, c );
+ draw_angle_limit( c, ay, az, limits[0][0], limits[1][0], r0, 0xff0000ff );
+ draw_angle_limit( c, az, ax, limits[0][1], limits[1][1], r1, 0xff00ff00 );
+ draw_angle_limit( c, ax, ay, limits[0][2], limits[1][2], r2, 0xffff0000 );
+}
+
+static void rb_limit_cure( rigidbody *ra, rigidbody *rb, v3f axis, float d )
+{
+ if( d != 0.0f )
+ {
+ float avx = v3_dot( ra->w, axis ) - v3_dot( rb->w, axis );
+ float joint_mass = rb->inv_mass + ra->inv_mass;
+ joint_mass = 1.0f/joint_mass;
+
+ float bias = (k_limit_bias * k_rb_rate) * d,
+ lambda = -(avx + bias) * joint_mass;
+
+ /* Angular velocity */
+ v3f wa, wb;
+ v3_muls( axis, lambda * ra->inv_mass, wa );
+ v3_muls( axis, -lambda * rb->inv_mass, wb );
+
+ v3_add( ra->w, wa, ra->w );
+ v3_add( rb->w, wb, rb->w );
+ }
+}
+
+static void rb_constraint_limits( rigidbody *ra, v3f lca,
+ rigidbody *rb, v3f lcb, v3f limits[2] )
+{
+ /* TODO: Code dupe remover */
+ v3f ax, ay, az, bx, by, bz;
+ m3x3_mulv( ra->to_world, (v3f){1.0f,0.0f,0.0f}, ax );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,1.0f,0.0f}, ay );
+ m3x3_mulv( ra->to_world, (v3f){0.0f,0.0f,1.0f}, az );
+ m3x3_mulv( rb->to_world, (v3f){1.0f,0.0f,0.0f}, bx );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,1.0f,0.0f}, by );
+ m3x3_mulv( rb->to_world, (v3f){0.0f,0.0f,1.0f}, bz );
+
+ v2f px, py, pz;
+ px[0] = v3_dot( ay, by );
+ px[1] = v3_dot( az, by );
+
+ py[0] = v3_dot( az, bz );
+ py[1] = v3_dot( ax, bz );
+
+ pz[0] = v3_dot( ax, bx );
+ pz[1] = v3_dot( ay, bx );
+
+ float r0 = atan2f( px[1], px[0] ),
+ r1 = atan2f( py[1], py[0] ),
+ r2 = atan2f( pz[1], pz[0] );
+
+ /* calculate angle deltas */
+ float dx = 0.0f, dy = 0.0f, dz = 0.0f;
+
+ if( r0 < limits[0][0] ) dx = limits[0][0] - r0;
+ if( r0 > limits[1][0] ) dx = limits[1][0] - r0;
+ if( r1 < limits[0][1] ) dy = limits[0][1] - r1;
+ if( r1 > limits[1][1] ) dy = limits[1][1] - r1;
+ if( r2 < limits[0][2] ) dz = limits[0][2] - r2;
+ if( r2 > limits[1][2] ) dz = limits[1][2] - r2;
+
+ v3f wca, wcb;
+ m3x3_mulv( ra->to_world, lca, wca );
+ m3x3_mulv( rb->to_world, lcb, wcb );
+
+ rb_limit_cure( ra, rb, ax, dx );
+ rb_limit_cure( ra, rb, ay, dy );
+ rb_limit_cure( ra, rb, az, dz );
+}
+
+static void rb_debug_constraint_position( rigidbody *ra, v3f lca,
+ rigidbody *rb, v3f lcb )
+{
+ v3f wca, wcb;
+ m3x3_mulv( ra->to_world, lca, wca );
+ m3x3_mulv( rb->to_world, lcb, wcb );
+
+ v3f p0, p1;
+ v3_add( wca, ra->co, p0 );
+ v3_add( wcb, rb->co, p1 );
+ vg_line_pt3( p0, 0.005f, 0xffffff00 );
+ vg_line_pt3( p1, 0.005f, 0xffffff00 );
+ vg_line( p0, p1, 0xffffff00 );
+}
+
+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 );
+
+ v3f rcv;
+ v3_sub( ra->v, rb->v, rcv );
+
+ v3f rcv_Ra, rcv_Rb;
+ v3_cross( ra->w, wca, rcv_Ra );
+ v3_cross( rb->w, wcb, rcv_Rb );
+ v3_add( rcv_Ra, rcv, rcv );
+ v3_sub( rcv, rcv_Rb, rcv );
+
+ v3f delta;
+ v3f p0, p1;
+ v3_add( wca, ra->co, p0 );
+ v3_add( wcb, rb->co, p1 );
+ v3_sub( p1, p0, delta );
+
+ float dist2 = v3_length2( delta );
+
+ if( dist2 > 0.00001f )
+ {
+ float dist = sqrtf(dist2);
+ v3_muls( delta, 1.0f/dist, delta );
+
+ float joint_mass = rb->inv_mass + ra->inv_mass;
+
+ v3f raCn, rbCn, raCt, rbCt;
+ v3_cross( wca, delta, raCn );
+ v3_cross( wcb, delta, rbCn );
+
+ /* orient inverse inertia tensors */
+ v3f raCnI, rbCnI;
+ m3x3_mulv( ra->iIw, raCn, raCnI );
+ m3x3_mulv( rb->iIw, rbCn, rbCnI );
+ joint_mass += v3_dot( raCn, raCnI );
+ joint_mass += v3_dot( rbCn, rbCnI );
+ joint_mass = 1.0f/joint_mass;
+
+ float vd = v3_dot( rcv, delta ),
+ bias = -(k_joint_bias * k_rb_rate) * dist,
+ lambda = -(vd + bias) * joint_mass;
+
+ v3f impulse;
+ v3_muls( delta, lambda, impulse );
+ rb_linear_impulse( ra, wca, impulse );
+ v3_muls( delta, -lambda, impulse );
+ rb_linear_impulse( rb, wcb, impulse );
+
+ /* 'fake' snap */
+ v3_muladds( ra->co, delta, dist * k_joint_correction, ra->co );
+ v3_muladds( rb->co, delta, -dist * k_joint_correction, rb->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 * ktimestep, ra->v );
+
+ if( depth < 0.0f )
+ v3_muls( ra->v, 1.0f-(drag*ktimestep), ra->v );