player_replay.c

   1 #ifndef PLAYER_REPLAY_C
   2 #define PLAYER_REPLAY_C
   3
   4 #include "player_replay.h"
   5 #include "input.h"
   6 #include "gui.h"
   7 #include "freecam.h"
   8
   9 static void replay_clear( replay_buffer *replay ){
  10    replay->head = NULL;
  11    replay->tail = NULL;
  12    replay->cursor_frame = NULL;
  13    replay->statehead = NULL;
  14    replay->cursor = -99999.9;
  15 }
  16
  17 static
  18 void * replay_frame_data( replay_frame *frame, enum replay_framedata type ){
  19    if( frame->data_table[type][1] == 0 )
  20       return NULL;
  21
  22    void *baseptr = frame;
  23    return baseptr + frame->data_table[type][0];
  24 }
  25
  26 static u16 replay_frame_calculate_data_offsets(
  27       u16 data_table[k_replay_framedata_rows][2] ){
  28
  29    u32 total = vg_align8( sizeof(replay_frame) );
  30    for( u32 i=0; i<k_replay_framedata_rows; i++ ){
  31       data_table[i][0] = total;
  32       total += vg_align8(data_table[i][1]);
  33
  34       if( total > 0xffff )
  35          vg_fatal_error( "Exceeded frame storage capacity\n" );
  36    }
  37    return total;
  38 }
  39
  40 static void replay_tailpop( replay_buffer *replay ){
  41    if( replay->cursor_frame == replay->tail )
  42       replay->cursor_frame = NULL;
  43    if( replay->statehead == replay->tail )
  44       replay->statehead = NULL;
  45
  46    replay->tail = replay->tail->r;
  47
  48    if( replay->tail )
  49       replay->tail->l = NULL;
  50    else
  51       replay->head = NULL;
  52 }
  53
  54 static replay_frame *replay_newframe( replay_buffer *replay,
  55                                          u16 animator_size,
  56                                          u16 gamestate_size,
  57                                          u16 sfx_count,
  58                                          bool save_glider ){
  59    u16 data_table[ k_replay_framedata_rows ][2];
  60    data_table[ k_replay_framedata_animator ][1]  = animator_size;
  61    data_table[ k_replay_framedata_gamestate ][1] = gamestate_size;
  62    data_table[ k_replay_framedata_sfx ][1] = sfx_count*sizeof(struct net_sfx);
  63    data_table[ k_replay_framedata_internal_gamestate ][1] = 0;
  64    if( gamestate_size ){
  65       data_table[ k_replay_framedata_internal_gamestate ][1] =
  66          sizeof( replay_gamestate );
  67    }
  68
  69    data_table[ k_replay_framedata_glider ][1] = 0;
  70    if( save_glider ){
  71       data_table[ k_replay_framedata_glider ][1] =
  72          sizeof(struct replay_glider_data);
  73    }
  74
  75    u32 nextsize = replay_frame_calculate_data_offsets( data_table );
  76
  77    replay_frame *frame = NULL;
  78    if( replay->head ){
  79       u32 headsize = replay->head->total_size,
  80           nextpos  = ((void *)replay->head - replay->data) + headsize;
  81
  82       if( nextpos + nextsize > replay->size ){
  83          nextpos = 0;
  84
  85          /* maintain contiguity */
  86          while( replay->tail ){
  87             if( (void *)replay->tail - replay->data )
  88                replay_tailpop( replay );
  89             else break;
  90          }
  91       }
  92
  93 check_again:;
  94       u32 tailpos = (void *)replay->tail - replay->data;
  95
  96       if( tailpos >= nextpos ){
  97          if( nextpos + nextsize > tailpos ){
  98             replay_tailpop( replay );
  99
 100             if( replay->tail )
 101                goto check_again;
 102          }
 103       }
 104
 105       frame = replay->data + nextpos;
 106
 107       if( replay->head )
 108          replay->head->r = frame;
 109    }
 110    else
 111       frame = replay->data;
 112
 113    for( u32 i=0; i<k_replay_framedata_rows; i++ ){
 114       frame->data_table[i][0] = data_table[i][0];
 115       frame->data_table[i][1] = data_table[i][1];
 116    }
 117
 118    frame->total_size = nextsize;
 119    frame->l = replay->head;
 120    frame->r = NULL;
 121    replay->head = frame;
 122    if( !replay->tail ) replay->tail = frame;
 123    if( gamestate_size ) replay->statehead = frame;
 124
 125    return frame;
 126 }
 127
 128 static void replay_emit_frame_sounds( replay_frame *frame ){
 129    void *baseptr = frame;
 130    u16 *inf = frame->data_table[k_replay_framedata_sfx];
 131    struct net_sfx *buffer = baseptr + inf[0];
 132    u32 count = inf[1] / sizeof(struct net_sfx);
 133
 134    for( u32 i=0; i<count; i ++ ){
 135       net_sfx_play( buffer + i );
 136    }
 137 }
 138
 139 static int replay_seek( replay_buffer *replay, f64 t ){
 140    if( !replay->head ) return 0;
 141
 142    if( t < replay->tail->time ) t = replay->tail->time;
 143    if( t > replay->head->time ) t = replay->head->time;
 144
 145    if( !replay->cursor_frame ) {
 146       replay->cursor = replay->head->time;
 147       replay->cursor_frame = replay->head;
 148
 149       if( fabs(replay->head->time-t) > fabs(replay->tail->time-t) ){
 150          replay->cursor = replay->tail->time;
 151          replay->cursor_frame = replay->tail;
 152       }
 153    }
 154
 155    f64 dir = t - replay->cursor;
 156    if( dir == 0.0 ) return 0;
 157    dir = vg_signf( dir );
 158
 159
 160    u32 i=4096;
 161    while( i --> 0 ){
 162       if( dir < 0.0 ){
 163          if( t > replay->cursor_frame->time ) {
 164             replay->cursor = t;
 165             return 1;
 166          }
 167       }
 168
 169       replay_frame *next;
 170       if( dir > 0.0 ) next = replay->cursor_frame->r;
 171       else            next = replay->cursor_frame->l;
 172
 173       if( !next ) break;
 174
 175       if( dir > 0.0 ){
 176          if( t < next->time ){
 177             replay->cursor = t;
 178             return 1;
 179          }
 180       }
 181
 182       replay_emit_frame_sounds( next );
 183
 184       replay->cursor_frame = next;
 185       replay->cursor = next->time;
 186
 187       if( !i ) return 1;
 188    }
 189
 190    replay->cursor = t;
 191    return 0;
 192 }
 193
 194 static replay_frame *replay_find_recent_stateframe( replay_buffer *replay ){
 195    replay_frame *frame = replay->cursor_frame;
 196    u32 i=4096;
 197    while( i --> 0 ){
 198       if( !frame ) return frame;
 199       if( frame->data_table[ k_replay_framedata_gamestate ][1] ) return frame;
 200       frame = frame->l;
 201    }
 202
 203    return NULL;
 204 }
 205
 206 static f32 replay_subframe_time( replay_buffer *replay ){
 207    replay_frame *frame = replay->cursor_frame;
 208    if( !frame ) return 0.0f;
 209    replay_frame *next = frame->r;
 210    if( next ){
 211       f64 l = next->time - frame->time,
 212           t = (l <= (1.0/128.0))? 0.0: (replay->cursor - frame->time) / l;
 213       return vg_clampf( t, 0.0f, 1.0f );
 214    }
 215    else
 216       return 0.0f;
 217 }
 218
 219 static void replay_get_frame_camera( replay_frame *frame, camera *cam ){
 220    cam->fov = frame->cam_fov;
 221    v3_copy( frame->cam_pos, cam->pos );
 222    v3_copy( frame->cam_angles, cam->angles );
 223 }
 224
 225 static void replay_get_camera( replay_buffer *replay, camera *cam ){
 226    cam->nearz = 0.1f;
 227    cam->farz = 100.0f;
 228    if( replay->cursor_frame ){
 229       replay_frame *next = replay->cursor_frame->r;
 230
 231       if( next ){
 232          camera temp;
 233
 234          replay_get_frame_camera( replay->cursor_frame, cam );
 235          replay_get_frame_camera( next, &temp );
 236          camera_lerp( cam, &temp, replay_subframe_time( replay ), cam );
 237       }
 238       else {
 239          replay_get_frame_camera( replay->cursor_frame, cam );
 240       }
 241    }
 242    else {
 243       v3_zero( cam->pos );
 244       v3_zero( cam->angles );
 245       cam->fov = 90.0f;
 246    }
 247 }
 248
 249 struct replay_rb{
 250    v3f co, v, w;
 251    v4f q;
 252 };
 253
 254 static void skaterift_record_frame( replay_buffer *replay,
 255                                     int force_gamestate ){
 256    f64 delta      = 9999999.9,
 257        statedelta = 9999999.9;
 258
 259    if( replay->head )
 260       delta = vg.time - replay->head->time;
 261
 262    if( replay->statehead )
 263       statedelta = vg.time - replay->statehead->time;
 264
 265    const f64 k_replay_rate = 1.0/30.0,
 266              k_gamestate_rate = 0.5;
 267
 268    int save_frame = 0,
 269        save_state = 0,
 270        save_glider = 0;
 271
 272    if( force_gamestate ) save_state = 1;
 273    if( statedelta > k_gamestate_rate ) save_state = 1;
 274    if( delta > k_replay_rate ) save_frame = 1;
 275    if( save_state ) save_frame = 1;
 276
 277    if( localplayer.have_glider || localplayer.glider_orphan ||
 278        localplayer.subsystem == k_player_subsystem_glide ){
 279       save_glider = 1;
 280    }
 281
 282    if( !save_frame ) return;
 283
 284    u16 gamestate_size = 0;
 285    if( save_state ){
 286       /* TODO: have as part of system struct */
 287       gamestate_size = (u32 []){
 288          [k_player_subsystem_walk ] = sizeof(struct player_walk_state),
 289          [k_player_subsystem_drive] = 0,
 290          [k_player_subsystem_skate] = sizeof(struct player_skate_state),
 291          [k_player_subsystem_dead ] = localplayer.ragdoll.part_count *
 292                                        sizeof(struct replay_rb),
 293          [k_player_subsystem_glide] = sizeof(struct replay_rb),
 294       }[ localplayer.subsystem ];
 295    }
 296
 297    u16 animator_size = player_subsystems[localplayer.subsystem]->animator_size;
 298
 299    replay_frame *frame = replay_newframe( replay,
 300                                           animator_size, gamestate_size,
 301                                           localplayer.local_sfx_buffer_count,
 302                                           save_glider );
 303    frame->system = localplayer.subsystem;
 304
 305    if( save_state ){
 306       replay_gamestate *gs =
 307          replay_frame_data( frame, k_replay_framedata_internal_gamestate );
 308
 309       gs->current_run_version = world_static.current_run_version;
 310
 311       /* permanent block */
 312       memcpy( &gs->rb, &localplayer.rb, sizeof(rigidbody) );
 313       memcpy( &gs->glider_rb, &player_glide.rb, sizeof(rigidbody) );
 314       memcpy( &gs->cam_control, &localplayer.cam_control,
 315                sizeof(struct player_cam_controller) );
 316       v3_copy( localplayer.angles, gs->angles );
 317
 318       void *dst = replay_frame_data( frame, k_replay_framedata_gamestate );
 319
 320       /* subsytem/dynamic block */
 321       if( localplayer.subsystem == k_player_subsystem_walk )
 322          memcpy( dst, &player_walk.state, gamestate_size );
 323       else if( localplayer.subsystem == k_player_subsystem_skate )
 324          memcpy( dst, &player_skate.state, gamestate_size );
 325       else if( localplayer.subsystem == k_player_subsystem_dead ){
 326          struct replay_rb *arr = dst;
 327          for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 328             rigidbody *rb = &localplayer.ragdoll.parts[i].rb;
 329             v3_copy( rb->co, arr[i].co );
 330             v3_copy( rb->w, arr[i].w );
 331             v3_copy( rb->v, arr[i].v );
 332             v4_copy( rb->q, arr[i].q );
 333          }
 334       }
 335       else if( localplayer.subsystem == k_player_subsystem_glide ){
 336          struct replay_rb *arr = dst;
 337          rigidbody *rb = &player_glide.rb;
 338          v3_copy( rb->co, arr[0].co );
 339          v3_copy( rb->w, arr[0].w );
 340          v3_copy( rb->v, arr[0].v );
 341          v4_copy( rb->q, arr[0].q );
 342       }
 343    }
 344
 345    if( save_glider ){
 346       struct replay_glider_data *inf =
 347          replay_frame_data( frame, k_replay_framedata_glider );
 348
 349       inf->have_glider   = localplayer.have_glider;
 350       inf->glider_orphan = localplayer.glider_orphan;
 351       inf->t             = player_glide.t;
 352       v3_copy( player_glide.rb.co, inf->co );
 353       v4_copy( player_glide.rb.q,  inf->q );
 354    }
 355
 356    replay->cursor = vg.time;
 357    replay->cursor_frame = frame;
 358    frame->time = vg.time;
 359
 360    /* camera */
 361    v3_copy( localplayer.cam.pos, frame->cam_pos );
 362    if( localplayer.gate_waiting ){
 363       m4x3_mulv( localplayer.gate_waiting->transport,
 364                   frame->cam_pos, frame->cam_pos );
 365
 366       v3f v0;
 367       v3_angles_vector( localplayer.cam.angles, v0 );
 368       m3x3_mulv( localplayer.gate_waiting->transport, v0, v0 );
 369       v3_angles( v0, frame->cam_angles );
 370    }
 371    else
 372       v3_copy( localplayer.cam.angles, frame->cam_angles );
 373
 374    frame->cam_fov = localplayer.cam.fov;
 375
 376    /* animator */
 377    void *dst = replay_frame_data( frame, k_replay_framedata_animator ),
 378         *src = player_subsystems[localplayer.subsystem]->animator_data;
 379    memcpy( dst, src, animator_size );
 380
 381    /* sound effects */
 382    memcpy( replay_frame_data( frame, k_replay_framedata_sfx ),
 383            localplayer.local_sfx_buffer,
 384            sizeof(struct net_sfx)*localplayer.local_sfx_buffer_count );
 385
 386    localplayer.local_sfx_buffer_count = 0;
 387 }
 388
 389 static
 390 void skaterift_restore_frame( replay_frame *frame ){
 391    replay_gamestate *gs =
 392       replay_frame_data( frame, k_replay_framedata_internal_gamestate );
 393    void *src = replay_frame_data( frame, k_replay_framedata_gamestate );
 394    u16 src_size = frame->data_table[ k_replay_framedata_gamestate ][1];
 395    world_static.current_run_version = gs->current_run_version;
 396
 397    if(frame->system == k_player_subsystem_walk ){
 398       memcpy( &player_walk.state, src, src_size );
 399    }
 400    else if( frame->system == k_player_subsystem_skate ){
 401       memcpy( &player_skate.state, src, src_size );
 402    }
 403    else if( frame->system == k_player_subsystem_dead ){
 404       player__dead_transition(0);
 405       struct replay_rb *arr = src;
 406
 407       for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 408          struct ragdoll_part *part = &localplayer.ragdoll.parts[i];
 409          rigidbody *rb = &part->rb;
 410
 411          v3_copy( arr[i].co, rb->co );
 412          v3_copy( arr[i].w, rb->w );
 413          v3_copy( arr[i].v, rb->v );
 414          v4_copy( arr[i].q, rb->q );
 415
 416          v3_copy( arr[i].co, part->prev_co );
 417          v4_copy( arr[i].q, part->prev_q );
 418          rb_update_matrices( rb );
 419       }
 420    }
 421    else if( frame->system == k_player_subsystem_glide ){
 422       struct replay_rb *arr = src;
 423       rigidbody *rb = &player_glide.rb;
 424       v3_copy( arr[0].co, rb->co );
 425       v3_copy( arr[0].w, rb->w );
 426       v3_copy( arr[0].v, rb->v );
 427       v4_copy( arr[0].q, rb->q );
 428       rb_update_matrices( rb );
 429    }
 430
 431    localplayer.subsystem = frame->system;
 432
 433    /* restore the seperated glider data if we have it */
 434    if( frame->data_table[ k_replay_framedata_glider ][1] ){
 435       struct replay_glider_data *inf =
 436          replay_frame_data( frame, k_replay_framedata_glider );
 437
 438       localplayer.have_glider   = inf->have_glider;
 439       localplayer.glider_orphan = inf->glider_orphan;
 440       player_glide.t            = inf->t;
 441    }
 442    else {
 443       localplayer.have_glider = 0;
 444       localplayer.glider_orphan = 0;
 445       player_glide.t = 0.0f;
 446    }
 447
 448    memcpy( &localplayer.rb, &gs->rb, sizeof(rigidbody) );
 449    memcpy( &player_glide.rb, &gs->glider_rb, sizeof(rigidbody) );
 450    v3_copy( gs->angles, localplayer.angles );
 451
 452    v3_copy( frame->cam_pos, localplayer.cam.pos );
 453    v3_copy( frame->cam_angles, localplayer.cam.angles );
 454    localplayer.cam.fov = frame->cam_fov;
 455
 456    memcpy( &localplayer.cam_control, &gs->cam_control,
 457             sizeof(struct player_cam_controller) );
 458
 459    /* chop end off replay */
 460    frame->r = NULL;
 461    skaterift.replay.statehead = frame;
 462    skaterift.replay.head = frame;
 463    skaterift.replay.cursor_frame = frame;
 464    skaterift.replay.cursor = frame->time;
 465    skaterift.replay_control = k_replay_control_scrub;
 466    skaterift.activity = k_skaterift_default;
 467    vg.time = frame->time;
 468 }
 469
 470 static void skaterift_replay_resume(void){
 471    replay_frame *prev = replay_find_recent_stateframe(&skaterift.replay);
 472
 473    if( prev ){
 474       skaterift.replay_control = k_replay_control_resume;
 475       skaterift.resume_target = prev;
 476       skaterift.resume_begin = skaterift.replay.cursor;
 477       skaterift.resume_transition = 0.0f;
 478    }
 479
 480    gui_helper_clear();
 481 }
 482
 483 static void skaterift_replay_update_helpers(void);
 484
 485 static void skaterift_replay_pre_update(void){
 486    if( skaterift.activity != k_skaterift_replay ) return;
 487
 488    if( skaterift.replay_control == k_replay_control_resume ){
 489       if( skaterift.replay.cursor_frame == skaterift.resume_target ||
 490           skaterift.replay.cursor_frame == NULL ){
 491          skaterift_restore_frame( skaterift.resume_target );
 492       }
 493       else {
 494          vg_slewf( &skaterift.resume_transition, 1.0f,
 495                    vg.time_frame_delta * (1.0f/1.0f) );
 496
 497          if( skaterift.resume_transition >= 1.0f )
 498             skaterift_restore_frame( skaterift.resume_target );
 499          else {
 500             f64 target = vg_lerp( skaterift.resume_begin,
 501                               skaterift.resume_target->time,
 502                               vg_smoothstepf( skaterift.resume_transition ) );
 503             if( replay_seek( &skaterift.replay, target ) )
 504                skaterift.track_velocity = 1.0f;
 505             else
 506                skaterift.track_velocity = 0.0f;
 507          }
 508       }
 509    }
 510    else {
 511       if( button_down( k_srbind_replay_play ) )
 512          skaterift.replay_control = k_replay_control_play;
 513       if( button_down( k_srbind_replay_freecam ) ){
 514          skaterift.freecam = skaterift.freecam ^ 0x1;
 515
 516          if( skaterift.freecam )
 517             replay_get_camera( &skaterift.replay, &skaterift.replay_freecam );
 518
 519          skaterift_replay_update_helpers();
 520       }
 521
 522       f32 target_speed = axis_state( k_sraxis_replay_h ) * 5.0;
 523       if( button_press( k_srbind_reset ) )
 524          target_speed += -2.0;
 525
 526       if( fabsf(target_speed) > 0.01f )
 527          skaterift.replay_control = k_replay_control_scrub;
 528
 529       if( skaterift.replay_control == k_replay_control_play )
 530          target_speed = 1.0;
 531
 532       vg_slewf( &skaterift.track_velocity, target_speed,
 533                 18.0f*vg.time_frame_delta );
 534
 535       if( fabsf( skaterift.track_velocity ) > 0.0001f ){
 536          f64 target = skaterift.replay.cursor;
 537          target += skaterift.track_velocity * vg.time_frame_delta;
 538
 539          if( !replay_seek( &skaterift.replay, target ) )
 540             skaterift.track_velocity = 0.0f;
 541       }
 542
 543       if( button_down( k_srbind_mback ) ){
 544          if( skaterift.replay.statehead )
 545             skaterift_restore_frame( skaterift.replay.statehead );
 546          else
 547             skaterift.activity = k_skaterift_default;
 548          srinput.state = k_input_state_resume;
 549          gui_helper_clear();
 550       }
 551
 552       if( skaterift.freecam ){
 553          //freecam_preupdate();
 554       }
 555       else {
 556          if( button_down( k_srbind_replay_resume ) ){
 557             skaterift_replay_resume();
 558          }
 559       }
 560    }
 561 }
 562
 563 static void skaterift_replay_update_helpers(void){
 564    skaterift.helper_resume->greyed = skaterift.freecam;
 565
 566    vg_str freecam_text;
 567    vg_strnull( &freecam_text, skaterift.helper_freecam->text,
 568                GUI_HELPER_TEXT_LENGTH );
 569    vg_strcat( &freecam_text, skaterift.freecam? "exit freecam": "freecam" );
 570 }
 571
 572 static void skaterift_replay_post_render(void){
 573 #ifndef SR_ALLOW_REWIND_HUB
 574    if( world_static.active_instance != k_world_purpose_client )
 575       return;
 576 #endif
 577
 578    /* capture the current resume frame at the very last point */
 579    if( button_down( k_srbind_reset ) ){
 580       if( skaterift.activity == k_skaterift_default ){
 581          localplayer.rewinded_since_last_gate = 1;
 582          skaterift.activity = k_skaterift_replay;
 583          skaterift_record_frame( &skaterift.replay, 1 );
 584          if( skaterift.replay.head ){
 585             skaterift.replay.cursor = skaterift.replay.head->time;
 586             skaterift.replay.cursor_frame = skaterift.replay.head;
 587          }
 588          skaterift.replay_control = k_replay_control_scrub;
 589
 590          gui_helper_clear();
 591          vg_str text;
 592
 593          if( gui_new_helper( input_axis_list[k_sraxis_replay_h], &text ) )
 594             vg_strcat( &text, "scrub" );
 595
 596          if( (skaterift.helper_resume = gui_new_helper(
 597                      input_button_list[k_srbind_replay_resume], &text )) )
 598             vg_strcat( &text, "resume" );
 599
 600          if( gui_new_helper( input_button_list[k_srbind_replay_play], &text ))
 601             vg_strcat( &text, "playback" );
 602
 603          skaterift.helper_freecam = gui_new_helper(
 604                input_button_list[k_srbind_replay_freecam], &text );
 605
 606          skaterift_replay_update_helpers();
 607       }
 608    }
 609 }
 610
 611 static void skaterift_replay_debug_info(void){
 612    player__debugtext( 2, "replay info" );
 613
 614    replay_buffer *replay = &skaterift.replay;
 615
 616    u32 head = 0,
 617        tail = 0;
 618    if( replay->tail ) tail = (void *)replay->tail - replay->data;
 619    if( replay->head ) head = (void *)replay->head - replay->data;
 620
 621    player__debugtext( 1, "head @%u | tail @%u\n", head, tail );
 622
 623    if( replay->statehead ){
 624       for( u32 i=0; i<k_replay_framedata_rows; i++ ){
 625          player__debugtext( 1, "[%u]: [%hu, %hu]\n", i,
 626               replay->statehead->data_table[i][0],
 627               replay->statehead->data_table[i][1] );
 628       }
 629       u32 state = (void *)replay->statehead - replay->data;
 630       player__debugtext( 1, "gs @%u\n", state );
 631       player__debugtext( 1, "gamestate_size: %hu\n",
 632            replay->statehead->data_table[k_replay_framedata_gamestate][1] );
 633    }
 634    else
 635       player__debugtext( 1, "gs @NULL\n" );
 636
 637    f64 start = replay->cursor,
 638        end   = replay->cursor;
 639    if( replay->tail ) start = replay->tail->time;
 640    if( replay->head ) end = replay->head->time;
 641
 642    f64 cur = replay->cursor - start,
 643        len = end - start;
 644
 645    player__debugtext( 1, "cursor: %.2fs / %.2fs\n", cur, len );
 646 }
 647
 648 static void skaterift_replay_imgui(void){
 649    if( skaterift.activity != k_skaterift_replay ) return;
 650
 651    replay_buffer *replay = &skaterift.replay;
 652    f64 start = replay->cursor,
 653        end   = replay->cursor;
 654    if( replay->tail ) start = replay->tail->time;
 655    if( replay->head ) end = replay->head->time;
 656    f64 len = end - start,
 657        cur = (replay->cursor - start) / len;
 658
 659    char buffer[ 128 ];
 660
 661    /* mainbar */
 662    ui_px height = 32,
 663          cwidth = 2;
 664    ui_rect bar = { 0, 0, vg.window_x, height };
 665    ui_fill( bar, ui_colour( k_ui_bg ) );
 666
 667    /* cursor frame block */
 668    if( replay->cursor_frame ){
 669       if( replay->cursor_frame->r ){
 670          f64 l = (replay->cursor_frame->r->time-replay->cursor_frame->time)/len,
 671              s = (replay->cursor_frame->time - start) / len;
 672          ui_rect box = { s*(f64)vg.window_x, 0,
 673                          VG_MAX(4,(ui_px)(l*vg.window_x)), bar[3]+2 };
 674          ui_fill( box, ui_colour( k_ui_bg+4 ) );
 675       }
 676    }
 677
 678    /* cursor */
 679    ui_rect cusor = { cur * (f64)vg.window_x - (cwidth/2), 0,
 680                      cwidth, bar[3] };
 681    ui_fill( cusor, ui_colour( k_ui_bg+7 ) );
 682
 683    /* latest state marker */
 684    if( replay->statehead ){
 685       f64 t = (replay->statehead->time - start) / len;
 686       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 687       ui_fill( tag, ui_colour( k_ui_green+k_ui_brighter ) );
 688    }
 689
 690    /* previous state marker */
 691    replay_frame *prev = replay_find_recent_stateframe( replay );
 692    if( prev ){
 693       f64 t = (prev->time - start) / len;
 694       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 695       ui_fill( tag, ui_colour( k_ui_yellow+k_ui_brighter ) );
 696    }
 697
 698    cusor[1] -= height;
 699    cusor[2] = 200;
 700    snprintf( buffer, 128, "-%.2fs\n", (end-replay->cursor) );
 701    ui_text( cusor, buffer, 1, k_ui_align_middle_left, 0 );
 702
 703    snprintf( buffer, 128, "-%.2fs\n", len );
 704    ui_text( bar, buffer, 1, k_ui_align_middle_left, 0 );
 705    ui_text( bar, "0s", 1, k_ui_align_middle_right, 0 );
 706 }
 707
 708 #endif /* PLAYER_REPLAY_C */