vehicle.h

   1 #ifndef VEHICLE_H
   2 #define VEHICLE_H
   3
   4 #define VG_GAME
   5 #include "vg/vg.h"
   6 #include "rigidbody.h"
   7 #include "world.h"
   8 #include "player.h"
   9
  10 VG_STATIC float k_car_spring = 1.0f,
  11                 k_car_spring_damp = 0.001f,
  12                 k_car_spring_length = 0.5f,
  13                 k_car_wheel_radius = 0.2f,
  14                 k_car_friction_lat = 0.6f,
  15                 k_car_friction_roll = 0.01f,
  16                 k_car_drive_force = 1.0f,
  17                 k_car_air_resistance = 0.1f,
  18                 k_car_downforce      = 0.5f;
  19
  20 typedef struct drivable_vehicle drivable_vehicle;
  21 VG_STATIC struct drivable_vehicle
  22 {
  23    int alive, inside;
  24    rb_object obj;
  25
  26    v3f wheels[4];
  27
  28    float tangent_mass[4][2],
  29          normal_forces[4],
  30          tangent_forces[4][2];
  31
  32    float steer, drive;
  33    v3f steerv;
  34
  35    v3f   tangent_vectors[4][2];
  36    v3f   wheels_local[4];
  37 }
  38 gzoomer =
  39 {
  40    .obj = { .type = k_rb_shape_sphere, .inf.sphere.radius = 1.0f }
  41 };
  42
  43 VG_STATIC int spawn_car( int argc, const char *argv[] )
  44 {
  45    v3f ra, rb, rx;
  46    v3_copy( main_camera.pos, ra );
  47    v3_muladds( ra, main_camera.transform[2], -10.0f, rb );
  48
  49    float t;
  50    if( spherecast_world( get_active_world(), ra, rb,
  51                          gzoomer.obj.inf.sphere.radius, &t, rx ) != -1 )
  52    {
  53       v3_lerp( ra, rb, t, gzoomer.obj.rb.co );
  54       gzoomer.obj.rb.co[1] += 4.0f;
  55       q_axis_angle( gzoomer.obj.rb.q, (v3f){1.0f,0.0f,0.0f}, 0.001f );
  56       v3_zero( gzoomer.obj.rb.v );
  57       v3_zero( gzoomer.obj.rb.w );
  58
  59       rb_update_transform( &gzoomer.obj.rb );
  60       gzoomer.alive = 1;
  61
  62       vg_success( "Spawned car\n" );
  63    }
  64    else{
  65       vg_error( "Can't spawn here\n" );
  66    }
  67
  68    return 0;
  69 }
  70
  71 VG_STATIC void vehicle_init(void)
  72 {
  73    q_identity( gzoomer.obj.rb.q );
  74    v3_zero( gzoomer.obj.rb.w );
  75    v3_zero( gzoomer.obj.rb.v );
  76    v3_zero( gzoomer.obj.rb.co );
  77    rb_init_object( &gzoomer.obj );
  78
  79    VG_VAR_F32_PERSISTENT( k_car_spring );
  80    VG_VAR_F32_PERSISTENT( k_car_spring_damp );
  81    VG_VAR_F32_PERSISTENT( k_car_spring_length );
  82    VG_VAR_F32_PERSISTENT( k_car_wheel_radius );
  83    VG_VAR_F32_PERSISTENT( k_car_friction_lat );
  84    VG_VAR_F32_PERSISTENT( k_car_friction_roll );
  85    VG_VAR_F32_PERSISTENT( k_car_drive_force );
  86    VG_VAR_F32_PERSISTENT( k_car_air_resistance );
  87    VG_VAR_F32_PERSISTENT( k_car_downforce );
  88
  89    VG_VAR_I32( gzoomer.inside );
  90
  91         vg_function_push( (struct vg_cmd){
  92                 .name = "spawn_car",
  93                 .function = spawn_car
  94         });
  95
  96    v3_copy((v3f){ -1.0f, -0.25f, -1.5f }, gzoomer.wheels_local[0] );
  97    v3_copy((v3f){  1.0f, -0.25f, -1.5f }, gzoomer.wheels_local[1] );
  98    v3_copy((v3f){ -1.0f, -0.25f,  1.5f }, gzoomer.wheels_local[2] );
  99    v3_copy((v3f){  1.0f, -0.25f,  1.5f }, gzoomer.wheels_local[3] );
 100 }
 101
 102 VG_STATIC void vehicle_wheel_force( int index )
 103 {
 104    v3f pa, pb, n;
 105    m4x3_mulv( gzoomer.obj.rb.to_world, gzoomer.wheels_local[index], pa );
 106    v3_muladds( pa, gzoomer.obj.rb.to_world[1], -k_car_spring_length, pb );
 107
 108
 109 #if 1
 110    float t;
 111    if( spherecast_world( get_active_world(), pa, pb,
 112                          k_car_wheel_radius, &t, n ) == -1 )
 113    { t = 1.0f;
 114    }
 115
 116 #else
 117
 118    v3f dir;
 119    v3_muls( gzoomer.rb.up, -1.0f, dir );
 120
 121    ray_hit hit;
 122    hit.dist = k_car_spring_length;
 123    ray_world( pa, dir, &hit );
 124
 125    float t = hit.dist / k_car_spring_length;
 126
 127 #endif
 128
 129    v3f pc;
 130    v3_lerp( pa, pb, t, pc );
 131
 132    m4x3f mtx;
 133    m3x3_copy( gzoomer.obj.rb.to_world, mtx );
 134    v3_copy( pc, mtx[3] );
 135    debug_sphere( mtx, k_car_wheel_radius, VG__BLACK );
 136    vg_line( pa, pc, VG__WHITE );
 137    v3_copy( pc, gzoomer.wheels[index] );
 138
 139    if( t < 1.0f ){
 140       /* spring force */
 141       float Fv = (1.0f-t) * k_car_spring*k_rb_delta;
 142
 143       v3f delta;
 144       v3_sub( pa, gzoomer.obj.rb.co, delta );
 145
 146       v3f rv;
 147       v3_cross( gzoomer.obj.rb.w, delta, rv );
 148       v3_add( gzoomer.obj.rb.v, rv, rv );
 149
 150       Fv += v3_dot( rv, gzoomer.obj.rb.to_world[1] )
 151                * -k_car_spring_damp*k_rb_delta;
 152
 153       /* scale by normal incident */
 154       Fv *= v3_dot( n, gzoomer.obj.rb.to_world[1] );
 155
 156       v3f F;
 157       v3_muls( gzoomer.obj.rb.to_world[1], Fv, F );
 158
 159       rb_linear_impulse( &gzoomer.obj.rb, delta, F );
 160
 161       /* friction vectors
 162        * -------------------------------------------------------------*/
 163       v3f tx, ty;
 164
 165       if( index <= 1 )
 166          v3_cross( gzoomer.steerv, n, tx );
 167       else
 168          v3_cross( n, gzoomer.obj.rb.to_world[2], tx );
 169       v3_cross( tx, n, ty );
 170
 171       v3_copy( tx, gzoomer.tangent_vectors[ index ][0] );
 172       v3_copy( ty, gzoomer.tangent_vectors[ index ][1] );
 173
 174       gzoomer.normal_forces[ index ] = Fv;
 175       gzoomer.tangent_forces[ index ][0] = 0.0f;
 176       gzoomer.tangent_forces[ index ][1] = 0.0f;
 177
 178       /* orient inverse inertia tensors */
 179       v3f raW;
 180       m3x3_mulv( gzoomer.obj.rb.to_world, gzoomer.wheels_local[index], raW );
 181
 182       v3f raCtx, raCtxI, raCty, raCtyI;
 183       v3_cross( tx, raW, raCtx );
 184       v3_cross( ty, raW, raCty );
 185       m3x3_mulv( gzoomer.obj.rb.iIw, raCtx, raCtxI );
 186       m3x3_mulv( gzoomer.obj.rb.iIw, raCty, raCtyI );
 187
 188       gzoomer.tangent_mass[index][0] = gzoomer.obj.rb.inv_mass;
 189       gzoomer.tangent_mass[index][0] += v3_dot( raCtx, raCtxI );
 190       gzoomer.tangent_mass[index][0] = 1.0f/gzoomer.tangent_mass[index][0];
 191
 192       gzoomer.tangent_mass[index][1] = gzoomer.obj.rb.inv_mass;
 193       gzoomer.tangent_mass[index][1] += v3_dot( raCty, raCtyI );
 194       gzoomer.tangent_mass[index][1] = 1.0f/gzoomer.tangent_mass[index][1];
 195
 196       /* apply drive force */
 197       if( index >= 2 ){
 198          v3_muls( ty, -gzoomer.drive * k_car_drive_force * k_rb_delta, F );
 199          rb_linear_impulse( &gzoomer.obj.rb, raW, F );
 200       }
 201    }
 202    else{
 203       gzoomer.normal_forces[ index ] = 0.0f;
 204       gzoomer.tangent_forces[ index ][0] = 0.0f;
 205       gzoomer.tangent_forces[ index ][1] = 0.0f;
 206    }
 207 }
 208
 209 VG_STATIC void vehicle_solve_friction(void)
 210 {
 211    rigidbody *rb = &gzoomer.obj.rb;
 212    for( int i=0; i<4; i++ ){
 213       v3f raW;
 214       m3x3_mulv( rb->to_world, gzoomer.wheels_local[i], raW );
 215
 216       v3f rv;
 217       v3_cross( rb->w, raW, rv );
 218       v3_add( rb->v, rv, rv );
 219
 220       float     fx = k_car_friction_lat * gzoomer.normal_forces[i],
 221                 fy = k_car_friction_roll * gzoomer.normal_forces[i],
 222                vtx = v3_dot( rv, gzoomer.tangent_vectors[i][0] ),
 223                vty = v3_dot( rv, gzoomer.tangent_vectors[i][1] ),
 224            lambdax = gzoomer.tangent_mass[i][0] * -vtx,
 225            lambday = gzoomer.tangent_mass[i][1] * -vty;
 226
 227       float tempx = gzoomer.tangent_forces[i][0],
 228             tempy = gzoomer.tangent_forces[i][1];
 229       gzoomer.tangent_forces[i][0] = vg_clampf( tempx + lambdax, -fx, fx );
 230       gzoomer.tangent_forces[i][1] = vg_clampf( tempy + lambday, -fy, fy );
 231       lambdax = gzoomer.tangent_forces[i][0] - tempx;
 232       lambday = gzoomer.tangent_forces[i][1] - tempy;
 233
 234       v3f impulsex, impulsey;
 235       v3_muls( gzoomer.tangent_vectors[i][0], lambdax, impulsex );
 236       v3_muls( gzoomer.tangent_vectors[i][1], lambday, impulsey );
 237       rb_linear_impulse( rb, raW, impulsex );
 238       rb_linear_impulse( rb, raW, impulsey );
 239    }
 240 }
 241
 242 player_instance *tmp_localplayer(void);
 243 VG_STATIC void vehicle_update_fixed(void)
 244 {
 245    if( !gzoomer.alive )
 246       return;
 247
 248    rigidbody *rb = &gzoomer.obj.rb;
 249
 250    v3_muls( rb->to_world[2], -cosf(gzoomer.steer), gzoomer.steerv );
 251    v3_muladds( gzoomer.steerv, rb->to_world[0],
 252                sinf(gzoomer.steer), gzoomer.steerv );
 253
 254    /* apply air resistance */
 255    v3f Fair, Fdown;
 256
 257    v3_muls( rb->v, -k_car_air_resistance, Fair );
 258    v3_muls( rb->to_world[1], -fabsf(v3_dot( rb->v, rb->to_world[2] )) *
 259                                  k_car_downforce, Fdown );
 260
 261    v3_muladds( rb->v, Fair,  k_rb_delta, rb->v );
 262    v3_muladds( rb->v, Fdown, k_rb_delta, rb->v );
 263
 264    for( int i=0; i<4; i++ )
 265       vehicle_wheel_force( i );
 266
 267    rb_ct manifold[64];
 268    int len = rb_sphere__scene( rb->to_world, &gzoomer.obj.inf.sphere,
 269                                NULL, &get_active_world()->rb_geo.inf.scene,
 270                                manifold );
 271    for( int j=0; j<len; j++ ){
 272       manifold[j].rba = rb;
 273       manifold[j].rbb = &get_active_world()->rb_geo.rb;
 274    }
 275    rb_manifold_filter_coplanar( manifold, len, 0.05f );
 276
 277    if( len > 1 ){
 278       rb_manifold_filter_backface( manifold, len );
 279       rb_manifold_filter_joint_edges( manifold, len, 0.05f );
 280       rb_manifold_filter_pairs( manifold, len, 0.05f );
 281    }
 282    len = rb_manifold_apply_filtered( manifold, len );
 283
 284    rb_presolve_contacts( manifold, len );
 285    for( int i=0; i<8; i++ ){
 286       rb_solve_contacts( manifold, len );
 287       vehicle_solve_friction();
 288    }
 289
 290    rb_iter( rb );
 291    rb_update_transform( rb );
 292 }
 293
 294 VG_STATIC void vehicle_update_post(void)
 295 {
 296    if( !gzoomer.alive )
 297       return;
 298
 299    rb_object_debug( &gzoomer.obj, VG__WHITE );
 300
 301    /* draw friction vectors */
 302    v3f p0, px, py;
 303
 304    for( int i=0; i<4; i++ ){
 305       v3_copy( gzoomer.wheels[i], p0 );
 306       v3_muladds( p0, gzoomer.tangent_vectors[i][0], 0.5f, px );
 307       v3_muladds( p0, gzoomer.tangent_vectors[i][1], 0.5f, py );
 308
 309       vg_line( p0, px, VG__RED );
 310       vg_line( p0, py, VG__GREEN );
 311    }
 312 }
 313
 314 #endif /* VEHICLE_H */