vehicle.c

   1 #ifndef VEHICLE_C
   2 #define VEHICLE_C
   3
   4 #include "vehicle.h"
   5
   6 static int spawn_car( int argc, const char *argv[] ){
   7    v3f ra, rb, rx;
   8    v3_copy( skaterift.cam.pos, ra );
   9    v3_muladds( ra, skaterift.cam.transform[2], -10.0f, rb );
  10
  11    float t;
  12    if( spherecast_world( world_current_instance(), ra, rb,
  13                          gzoomer.obj.inf.sphere.radius, &t, rx, 0 ) != -1 )
  14    {
  15       v3_lerp( ra, rb, t, gzoomer.obj.rb.co );
  16       gzoomer.obj.rb.co[1] += 4.0f;
  17       q_axis_angle( gzoomer.obj.rb.q, (v3f){1.0f,0.0f,0.0f}, 0.001f );
  18       v3_zero( gzoomer.obj.rb.v );
  19       v3_zero( gzoomer.obj.rb.w );
  20
  21       rb_update_transform( &gzoomer.obj.rb );
  22       gzoomer.alive = 1;
  23
  24       vg_success( "Spawned car\n" );
  25    }
  26    else{
  27       vg_error( "Can't spawn here\n" );
  28    }
  29
  30    return 0;
  31 }
  32
  33 static void vehicle_init(void)
  34 {
  35    q_identity( gzoomer.obj.rb.q );
  36    v3_zero( gzoomer.obj.rb.w );
  37    v3_zero( gzoomer.obj.rb.v );
  38    v3_zero( gzoomer.obj.rb.co );
  39    rb_init_object( &gzoomer.obj );
  40
  41    VG_VAR_F32( k_car_spring,        flags=VG_VAR_PERSISTENT );
  42    VG_VAR_F32( k_car_spring_damp,   flags=VG_VAR_PERSISTENT );
  43    VG_VAR_F32( k_car_spring_length, flags=VG_VAR_PERSISTENT );
  44    VG_VAR_F32( k_car_wheel_radius,  flags=VG_VAR_PERSISTENT );
  45    VG_VAR_F32( k_car_friction_lat,  flags=VG_VAR_PERSISTENT );
  46    VG_VAR_F32( k_car_friction_roll, flags=VG_VAR_PERSISTENT );
  47    VG_VAR_F32( k_car_drive_force,   flags=VG_VAR_PERSISTENT );
  48    VG_VAR_F32( k_car_air_resistance,flags=VG_VAR_PERSISTENT );
  49    VG_VAR_F32( k_car_downforce,     flags=VG_VAR_PERSISTENT );
  50
  51    VG_VAR_I32( gzoomer.inside );
  52
  53    vg_console_reg_cmd( "spawn_car", spawn_car, NULL );
  54
  55    v3_copy((v3f){ -1.0f, -0.25f, -1.5f }, gzoomer.wheels_local[0] );
  56    v3_copy((v3f){  1.0f, -0.25f, -1.5f }, gzoomer.wheels_local[1] );
  57    v3_copy((v3f){ -1.0f, -0.25f,  1.5f }, gzoomer.wheels_local[2] );
  58    v3_copy((v3f){  1.0f, -0.25f,  1.5f }, gzoomer.wheels_local[3] );
  59 }
  60
  61 static void vehicle_wheel_force( int index )
  62 {
  63    v3f pa, pb, n;
  64    m4x3_mulv( gzoomer.obj.rb.to_world, gzoomer.wheels_local[index], pa );
  65    v3_muladds( pa, gzoomer.obj.rb.to_world[1], -k_car_spring_length, pb );
  66
  67
  68 #if 1
  69    float t;
  70    if( spherecast_world( world_current_instance(), pa, pb,
  71                          k_car_wheel_radius, &t, n, 0 ) == -1 )
  72    { t = 1.0f;
  73    }
  74
  75 #else
  76
  77    v3f dir;
  78    v3_muls( gzoomer.rb.up, -1.0f, dir );
  79
  80    ray_hit hit;
  81    hit.dist = k_car_spring_length;
  82    ray_world( pa, dir, &hit );
  83
  84    float t = hit.dist / k_car_spring_length;
  85
  86 #endif
  87
  88    v3f pc;
  89    v3_lerp( pa, pb, t, pc );
  90
  91    m4x3f mtx;
  92    m3x3_copy( gzoomer.obj.rb.to_world, mtx );
  93    v3_copy( pc, mtx[3] );
  94    vg_line_sphere( mtx, k_car_wheel_radius, VG__BLACK );
  95    vg_line( pa, pc, VG__WHITE );
  96    v3_copy( pc, gzoomer.wheels[index] );
  97
  98    if( t < 1.0f ){
  99       /* spring force */
 100       float Fv = (1.0f-t) * k_car_spring*k_rb_delta;
 101
 102       v3f delta;
 103       v3_sub( pa, gzoomer.obj.rb.co, delta );
 104
 105       v3f rv;
 106       v3_cross( gzoomer.obj.rb.w, delta, rv );
 107       v3_add( gzoomer.obj.rb.v, rv, rv );
 108
 109       Fv += v3_dot( rv, gzoomer.obj.rb.to_world[1] )
 110                * -k_car_spring_damp*k_rb_delta;
 111
 112       /* scale by normal incident */
 113       Fv *= v3_dot( n, gzoomer.obj.rb.to_world[1] );
 114
 115       v3f F;
 116       v3_muls( gzoomer.obj.rb.to_world[1], Fv, F );
 117
 118       rb_linear_impulse( &gzoomer.obj.rb, delta, F );
 119
 120       /* friction vectors
 121        * -------------------------------------------------------------*/
 122       v3f tx, ty;
 123
 124       if( index <= 1 )
 125          v3_cross( gzoomer.steerv, n, tx );
 126       else
 127          v3_cross( n, gzoomer.obj.rb.to_world[2], tx );
 128       v3_cross( tx, n, ty );
 129
 130       v3_copy( tx, gzoomer.tangent_vectors[ index ][0] );
 131       v3_copy( ty, gzoomer.tangent_vectors[ index ][1] );
 132
 133       gzoomer.normal_forces[ index ] = Fv;
 134       gzoomer.tangent_forces[ index ][0] = 0.0f;
 135       gzoomer.tangent_forces[ index ][1] = 0.0f;
 136
 137       /* orient inverse inertia tensors */
 138       v3f raW;
 139       m3x3_mulv( gzoomer.obj.rb.to_world, gzoomer.wheels_local[index], raW );
 140
 141       v3f raCtx, raCtxI, raCty, raCtyI;
 142       v3_cross( tx, raW, raCtx );
 143       v3_cross( ty, raW, raCty );
 144       m3x3_mulv( gzoomer.obj.rb.iIw, raCtx, raCtxI );
 145       m3x3_mulv( gzoomer.obj.rb.iIw, raCty, raCtyI );
 146
 147       gzoomer.tangent_mass[index][0] = gzoomer.obj.rb.inv_mass;
 148       gzoomer.tangent_mass[index][0] += v3_dot( raCtx, raCtxI );
 149       gzoomer.tangent_mass[index][0] = 1.0f/gzoomer.tangent_mass[index][0];
 150
 151       gzoomer.tangent_mass[index][1] = gzoomer.obj.rb.inv_mass;
 152       gzoomer.tangent_mass[index][1] += v3_dot( raCty, raCtyI );
 153       gzoomer.tangent_mass[index][1] = 1.0f/gzoomer.tangent_mass[index][1];
 154
 155       /* apply drive force */
 156       if( index >= 2 ){
 157          v3_muls( ty, -gzoomer.drive * k_car_drive_force * k_rb_delta, F );
 158          rb_linear_impulse( &gzoomer.obj.rb, raW, F );
 159       }
 160    }
 161    else{
 162       gzoomer.normal_forces[ index ] = 0.0f;
 163       gzoomer.tangent_forces[ index ][0] = 0.0f;
 164       gzoomer.tangent_forces[ index ][1] = 0.0f;
 165    }
 166 }
 167
 168 static void vehicle_solve_friction(void)
 169 {
 170    rigidbody *rb = &gzoomer.obj.rb;
 171    for( int i=0; i<4; i++ ){
 172       v3f raW;
 173       m3x3_mulv( rb->to_world, gzoomer.wheels_local[i], raW );
 174
 175       v3f rv;
 176       v3_cross( rb->w, raW, rv );
 177       v3_add( rb->v, rv, rv );
 178
 179       float     fx = k_car_friction_lat * gzoomer.normal_forces[i],
 180                 fy = k_car_friction_roll * gzoomer.normal_forces[i],
 181                vtx = v3_dot( rv, gzoomer.tangent_vectors[i][0] ),
 182                vty = v3_dot( rv, gzoomer.tangent_vectors[i][1] ),
 183            lambdax = gzoomer.tangent_mass[i][0] * -vtx,
 184            lambday = gzoomer.tangent_mass[i][1] * -vty;
 185
 186       float tempx = gzoomer.tangent_forces[i][0],
 187             tempy = gzoomer.tangent_forces[i][1];
 188       gzoomer.tangent_forces[i][0] = vg_clampf( tempx + lambdax, -fx, fx );
 189       gzoomer.tangent_forces[i][1] = vg_clampf( tempy + lambday, -fy, fy );
 190       lambdax = gzoomer.tangent_forces[i][0] - tempx;
 191       lambday = gzoomer.tangent_forces[i][1] - tempy;
 192
 193       v3f impulsex, impulsey;
 194       v3_muls( gzoomer.tangent_vectors[i][0], lambdax, impulsex );
 195       v3_muls( gzoomer.tangent_vectors[i][1], lambday, impulsey );
 196       rb_linear_impulse( rb, raW, impulsex );
 197       rb_linear_impulse( rb, raW, impulsey );
 198    }
 199 }
 200
 201 static void vehicle_update_fixed(void)
 202 {
 203    if( !gzoomer.alive )
 204       return;
 205
 206    rigidbody *rb = &gzoomer.obj.rb;
 207
 208    v3_muls( rb->to_world[2], -cosf(gzoomer.steer), gzoomer.steerv );
 209    v3_muladds( gzoomer.steerv, rb->to_world[0],
 210                sinf(gzoomer.steer), gzoomer.steerv );
 211
 212    /* apply air resistance */
 213    v3f Fair, Fdown;
 214
 215    v3_muls( rb->v, -k_car_air_resistance, Fair );
 216    v3_muls( rb->to_world[1], -fabsf(v3_dot( rb->v, rb->to_world[2] )) *
 217                                  k_car_downforce, Fdown );
 218
 219    v3_muladds( rb->v, Fair,  k_rb_delta, rb->v );
 220    v3_muladds( rb->v, Fdown, k_rb_delta, rb->v );
 221
 222    for( int i=0; i<4; i++ )
 223       vehicle_wheel_force( i );
 224
 225    rb_ct manifold[64];
 226    int len = rb_sphere__scene( rb->to_world, &gzoomer.obj.inf.sphere, NULL,
 227                                &world_current_instance()->rb_geo.inf.scene,
 228                                manifold, 0 );
 229    for( int j=0; j<len; j++ ){
 230       manifold[j].rba = rb;
 231       manifold[j].rbb = &world_current_instance()->rb_geo.rb;
 232    }
 233    rb_manifold_filter_coplanar( manifold, len, 0.05f );
 234
 235    if( len > 1 ){
 236       rb_manifold_filter_backface( manifold, len );
 237       rb_manifold_filter_joint_edges( manifold, len, 0.05f );
 238       rb_manifold_filter_pairs( manifold, len, 0.05f );
 239    }
 240    len = rb_manifold_apply_filtered( manifold, len );
 241
 242    rb_presolve_contacts( manifold, len );
 243    for( int i=0; i<8; i++ ){
 244       rb_solve_contacts( manifold, len );
 245       vehicle_solve_friction();
 246    }
 247
 248    rb_iter( rb );
 249    rb_update_transform( rb );
 250 }
 251
 252 static void vehicle_update_post(void)
 253 {
 254    if( !gzoomer.alive )
 255       return;
 256
 257    rb_object_debug( &gzoomer.obj, VG__WHITE );
 258
 259    /* draw friction vectors */
 260    v3f p0, px, py;
 261
 262    for( int i=0; i<4; i++ ){
 263       v3_copy( gzoomer.wheels[i], p0 );
 264       v3_muladds( p0, gzoomer.tangent_vectors[i][0], 0.5f, px );
 265       v3_muladds( p0, gzoomer.tangent_vectors[i][1], 0.5f, py );
 266
 267       vg_line( p0, px, VG__RED );
 268       vg_line( p0, py, VG__GREEN );
 269    }
 270 }
 271
 272 #endif /* VEHICLE_H */