+ /* orientation */
+ m3x3f mtx;
+ skate_grind_orient( inf, mtx );
+ v3f target_fwd, fwd, up, target_up;
+ m3x3_mulv( mtx, s->grind_vec, target_fwd );
+ v3_copy( raw_nplane, fwd );
+ v3_copy( player->rb.to_world[1], up );
+ v3_copy( inf->n, target_up );
+
+ v3_muladds( target_fwd, inf->n, -v3_dot(inf->n,target_fwd), target_fwd );
+ v3_muladds( fwd, inf->n, -v3_dot(inf->n,fwd), fwd );
+
+ v3_normalize( target_fwd );
+ v3_normalize( fwd );
+
+
+ float way = player->input_js1v->axis.value *
+ vg_signf( v3_dot( raw_nplane, player->rb.v ) );
+
+ v4f q;
+ q_axis_angle( q, axis, VG_PIf*0.125f * way );
+ q_mulv( q, target_up, target_up );
+ q_mulv( q, target_fwd, target_fwd );
+
+ rb_effect_spring_target_vector( &player->rb, up, target_up,
+ k_grind_spring,
+ k_grind_dampener,
+ k_rb_delta );
+
+ rb_effect_spring_target_vector( &player->rb, fwd, target_fwd,
+ k_grind_spring*strength,
+ k_grind_dampener*strength,
+ k_rb_delta );
+
+ vg_line_arrow( player->rb.co, target_up, 1.0f, VG__GREEN );
+ vg_line_arrow( player->rb.co, fwd, 0.8f, VG__RED );
+ vg_line_arrow( player->rb.co, target_fwd, 1.0f, VG__YELOW );
+
+ s->grind_strength = strength;
+
+ /* Fake contact */
+ struct grind_limit *limit = &s->limits[ s->limit_count ++ ];
+ m4x3_mulv( player->rb.to_local, wsp, limit->ra );
+ m3x3_mulv( player->rb.to_local, inf->n, limit->n );
+ limit->p = 0.0f;
+
+ v3_copy( inf->dir, s->grind_dir );
+}
+
+VG_STATIC void skate_5050_apply( player_instance *player,
+ struct grind_info *inf_front,
+ struct grind_info *inf_back )
+{
+ struct player_skate *s = &player->_skate;
+ struct grind_info inf_avg;
+
+ v3_sub( inf_front->co, inf_back->co, inf_avg.dir );
+ v3_muladds( inf_back->co, inf_avg.dir, 0.5f, inf_avg.co );
+ v3_normalize( inf_avg.dir );
+
+ v3f axis_front, axis_back, axis;
+ v3_cross( inf_front->dir, inf_front->n, axis_front );
+ v3_cross( inf_back->dir, inf_back->n, axis_back );
+ v3_add( axis_front, axis_back, axis );
+ v3_normalize( axis );