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