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       gs->current_run_version = world_static.current_run_version;
 311
 312       /* permanent block */
 313       memcpy( &gs->rb, &localplayer.rb, sizeof(rigidbody) );
 314       memcpy( &gs->glider_rb, &player_glide.rb, sizeof(rigidbody) );
 315       memcpy( &gs->cam_control, &localplayer.cam_control,
 316                sizeof(struct player_cam_controller) );
 317       v3_copy( localplayer.angles, gs->angles );
 318
 319       void *dst = replay_frame_data( frame, k_replay_framedata_gamestate );
 320
 321       /* subsytem/dynamic block */
 322       if( localplayer.subsystem == k_player_subsystem_walk )
 323          memcpy( dst, &player_walk.state, gamestate_size );
 324       else if( localplayer.subsystem == k_player_subsystem_skate )
 325          memcpy( dst, &player_skate.state, gamestate_size );
 326       else if( localplayer.subsystem == k_player_subsystem_dead ){
 327          struct replay_rb *arr = dst;
 328          for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 329             rigidbody *rb = &localplayer.ragdoll.parts[i].rb;
 330             v3_copy( rb->co, arr[i].co );
 331             v3_copy( rb->w, arr[i].w );
 332             v3_copy( rb->v, arr[i].v );
 333             v4_copy( rb->q, arr[i].q );
 334          }
 335       }
 336       else if( localplayer.subsystem == k_player_subsystem_glide ){
 337          struct replay_rb *arr = dst;
 338          rigidbody *rb = &player_glide.rb;
 339          v3_copy( rb->co, arr[0].co );
 340          v3_copy( rb->w, arr[0].w );
 341          v3_copy( rb->v, arr[0].v );
 342          v4_copy( rb->q, arr[0].q );
 343       }
 344    }
 345
 346    if( save_glider ){
 347       struct replay_glider_data *inf =
 348          replay_frame_data( frame, k_replay_framedata_glider );
 349
 350       inf->have_glider   = localplayer.have_glider;
 351       inf->glider_orphan = localplayer.glider_orphan;
 352       inf->t             = player_glide.t;
 353       v3_copy( player_glide.rb.co, inf->co );
 354       v4_copy( player_glide.rb.q,  inf->q );
 355    }
 356
 357    replay->cursor = vg.time;
 358    replay->cursor_frame = frame;
 359    frame->time = vg.time;
 360
 361    /* camera */
 362    v3_copy( localplayer.cam.pos, frame->cam_pos );
 363    if( localplayer.gate_waiting ){
 364       m4x3_mulv( localplayer.gate_waiting->transport,
 365                   frame->cam_pos, frame->cam_pos );
 366
 367       v3f v0;
 368       v3_angles_vector( localplayer.cam.angles, v0 );
 369       m3x3_mulv( localplayer.gate_waiting->transport, v0, v0 );
 370       v3_angles( v0, frame->cam_angles );
 371    }
 372    else
 373       v3_copy( localplayer.cam.angles, frame->cam_angles );
 374
 375    frame->cam_fov = localplayer.cam.fov;
 376
 377    /* animator */
 378    void *dst = replay_frame_data( frame, k_replay_framedata_animator ),
 379         *src = player_subsystems[localplayer.subsystem]->animator_data;
 380    memcpy( dst, src, animator_size );
 381
 382    /* sound effects */
 383    memcpy( replay_frame_data( frame, k_replay_framedata_sfx ),
 384            localplayer.local_sfx_buffer,
 385            sizeof(struct net_sfx)*localplayer.local_sfx_buffer_count );
 386
 387    localplayer.local_sfx_buffer_count = 0;
 388 }
 389
 390 static
 391 void skaterift_restore_frame( replay_frame *frame ){
 392    replay_gamestate *gs =
 393       replay_frame_data( frame, k_replay_framedata_internal_gamestate );
 394    void *src = replay_frame_data( frame, k_replay_framedata_gamestate );
 395    u16 src_size = frame->data_table[ k_replay_framedata_gamestate ][1];
 396    assert( src_size );
 397    world_static.current_run_version = gs->current_run_version;
 398
 399    if(frame->system == k_player_subsystem_walk ){
 400       memcpy( &player_walk.state, src, src_size );
 401    }
 402    else if( frame->system == k_player_subsystem_skate ){
 403       memcpy( &player_skate.state, src, src_size );
 404    }
 405    else if( frame->system == k_player_subsystem_dead ){
 406       player__dead_transition(0);
 407       struct replay_rb *arr = src;
 408
 409       for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 410          struct ragdoll_part *part = &localplayer.ragdoll.parts[i];
 411          rigidbody *rb = &part->rb;
 412
 413          v3_copy( arr[i].co, rb->co );
 414          v3_copy( arr[i].w, rb->w );
 415          v3_copy( arr[i].v, rb->v );
 416          v4_copy( arr[i].q, rb->q );
 417
 418          v3_copy( arr[i].co, part->prev_co );
 419          v4_copy( arr[i].q, part->prev_q );
 420          rb_update_matrices( rb );
 421       }
 422    }
 423    else if( frame->system == k_player_subsystem_glide ){
 424       struct replay_rb *arr = src;
 425       rigidbody *rb = &player_glide.rb;
 426       v3_copy( arr[0].co, rb->co );
 427       v3_copy( arr[0].w, rb->w );
 428       v3_copy( arr[0].v, rb->v );
 429       v4_copy( arr[0].q, rb->q );
 430       rb_update_matrices( rb );
 431    }
 432
 433    localplayer.subsystem = frame->system;
 434
 435    /* restore the seperated glider data if we have it */
 436    if( frame->data_table[ k_replay_framedata_glider ][1] ){
 437       struct replay_glider_data *inf =
 438          replay_frame_data( frame, k_replay_framedata_glider );
 439
 440       localplayer.have_glider   = inf->have_glider;
 441       localplayer.glider_orphan = inf->glider_orphan;
 442       player_glide.t            = inf->t;
 443    }
 444    else {
 445       localplayer.have_glider = 0;
 446       localplayer.glider_orphan = 0;
 447       player_glide.t = 0.0f;
 448    }
 449
 450    memcpy( &localplayer.rb, &gs->rb, sizeof(rigidbody) );
 451    memcpy( &player_glide.rb, &gs->glider_rb, sizeof(rigidbody) );
 452    v3_copy( gs->angles, localplayer.angles );
 453
 454    v3_copy( frame->cam_pos, localplayer.cam.pos );
 455    v3_copy( frame->cam_angles, localplayer.cam.angles );
 456    localplayer.cam.fov = frame->cam_fov;
 457
 458    memcpy( &localplayer.cam_control, &gs->cam_control,
 459             sizeof(struct player_cam_controller) );
 460
 461    /* chop end off replay */
 462    frame->r = NULL;
 463    skaterift.replay.statehead = frame;
 464    skaterift.replay.head = frame;
 465    skaterift.replay.cursor_frame = frame;
 466    skaterift.replay.cursor = frame->time;
 467    skaterift.replay_control = k_replay_control_scrub;
 468    skaterift.activity = k_skaterift_default;
 469    vg.time = frame->time;
 470 }
 471
 472 static void skaterift_replay_resume(void){
 473    replay_frame *prev = replay_find_recent_stateframe(&skaterift.replay);
 474
 475    if( prev ){
 476       skaterift.replay_control = k_replay_control_resume;
 477       skaterift.resume_target = prev;
 478       skaterift.resume_begin = skaterift.replay.cursor;
 479       skaterift.resume_transition = 0.0f;
 480    }
 481
 482    gui_helper_clear();
 483 }
 484
 485 static void skaterift_replay_update_helpers(void);
 486
 487 static void skaterift_replay_pre_update(void){
 488    if( skaterift.activity != k_skaterift_replay ) return;
 489
 490    if( skaterift.replay_control == k_replay_control_resume ){
 491       if( skaterift.replay.cursor_frame == skaterift.resume_target ||
 492           skaterift.replay.cursor_frame == NULL ){
 493          skaterift_restore_frame( skaterift.resume_target );
 494       }
 495       else {
 496          vg_slewf( &skaterift.resume_transition, 1.0f,
 497                    vg.time_frame_delta * (1.0f/1.0f) );
 498
 499          if( skaterift.resume_transition >= 1.0f )
 500             skaterift_restore_frame( skaterift.resume_target );
 501          else {
 502             f64 target = vg_lerp( skaterift.resume_begin,
 503                               skaterift.resume_target->time,
 504                               vg_smoothstepf( skaterift.resume_transition ) );
 505             if( replay_seek( &skaterift.replay, target ) )
 506                skaterift.track_velocity = 1.0f;
 507             else
 508                skaterift.track_velocity = 0.0f;
 509          }
 510       }
 511    }
 512    else {
 513       if( button_down( k_srbind_replay_play ) )
 514          skaterift.replay_control = k_replay_control_play;
 515       if( button_down( k_srbind_replay_freecam ) ){
 516          skaterift.freecam = skaterift.freecam ^ 0x1;
 517
 518          if( skaterift.freecam )
 519             replay_get_camera( &skaterift.replay, &skaterift.replay_freecam );
 520
 521          skaterift_replay_update_helpers();
 522       }
 523
 524       f32 target_speed = axis_state( k_sraxis_replay_h ) * 5.0;
 525       if( button_press( k_srbind_reset ) )
 526          target_speed += -2.0;
 527
 528       if( fabsf(target_speed) > 0.01f )
 529          skaterift.replay_control = k_replay_control_scrub;
 530
 531       if( skaterift.replay_control == k_replay_control_play )
 532          target_speed = 1.0;
 533
 534       vg_slewf( &skaterift.track_velocity, target_speed,
 535                 18.0f*vg.time_frame_delta );
 536
 537       if( fabsf( skaterift.track_velocity ) > 0.0001f ){
 538          f64 target = skaterift.replay.cursor;
 539          target += skaterift.track_velocity * vg.time_frame_delta;
 540
 541          if( !replay_seek( &skaterift.replay, target ) )
 542             skaterift.track_velocity = 0.0f;
 543       }
 544
 545       if( button_down( k_srbind_mback ) ){
 546          if( skaterift.replay.statehead )
 547             skaterift_restore_frame( skaterift.replay.statehead );
 548          else
 549             skaterift.activity = k_skaterift_default;
 550          srinput.state = k_input_state_resume;
 551          gui_helper_clear();
 552       }
 553
 554       if( skaterift.freecam ){
 555          //freecam_preupdate();
 556       }
 557       else {
 558          if( button_down( k_srbind_replay_resume ) ){
 559             skaterift_replay_resume();
 560          }
 561       }
 562    }
 563 }
 564
 565 static void skaterift_replay_update_helpers(void){
 566    skaterift.helper_resume->greyed = skaterift.freecam;
 567
 568    vg_str freecam_text;
 569    vg_strnull( &freecam_text, skaterift.helper_freecam->text,
 570                GUI_HELPER_TEXT_LENGTH );
 571    vg_strcat( &freecam_text, skaterift.freecam? "exit freecam": "freecam" );
 572 }
 573
 574 static void skaterift_replay_post_render(void){
 575 #ifndef SR_ALLOW_REWIND_HUB
 576    if( world_static.active_instance != k_world_purpose_client )
 577       return;
 578 #endif
 579
 580    /* capture the current resume frame at the very last point */
 581    if( button_down( k_srbind_reset ) ){
 582       if( skaterift.activity == k_skaterift_default ){
 583          localplayer.rewinded_since_last_gate = 1;
 584          skaterift.activity = k_skaterift_replay;
 585          skaterift_record_frame( &skaterift.replay, 1 );
 586          if( skaterift.replay.head ){
 587             skaterift.replay.cursor = skaterift.replay.head->time;
 588             skaterift.replay.cursor_frame = skaterift.replay.head;
 589          }
 590          skaterift.replay_control = k_replay_control_scrub;
 591
 592          gui_helper_clear();
 593          vg_str text;
 594
 595          if( gui_new_helper( input_axis_list[k_sraxis_replay_h], &text ) )
 596             vg_strcat( &text, "scrub" );
 597
 598          if( (skaterift.helper_resume = gui_new_helper(
 599                      input_button_list[k_srbind_replay_resume], &text )) )
 600             vg_strcat( &text, "resume" );
 601
 602          if( gui_new_helper( input_button_list[k_srbind_replay_play], &text ))
 603             vg_strcat( &text, "playback" );
 604
 605          skaterift.helper_freecam = gui_new_helper(
 606                input_button_list[k_srbind_replay_freecam], &text );
 607
 608          skaterift_replay_update_helpers();
 609       }
 610    }
 611 }
 612
 613 static void skaterift_replay_debug_info(void){
 614    player__debugtext( 2, "replay info" );
 615
 616    replay_buffer *replay = &skaterift.replay;
 617
 618    u32 head = 0,
 619        tail = 0;
 620    if( replay->tail ) tail = (void *)replay->tail - replay->data;
 621    if( replay->head ) head = (void *)replay->head - replay->data;
 622
 623    player__debugtext( 1, "head @%u | tail @%u\n", head, tail );
 624
 625    if( replay->statehead ){
 626       for( u32 i=0; i<k_replay_framedata_rows; i++ ){
 627          player__debugtext( 1, "[%u]: [%hu, %hu]\n", i,
 628               replay->statehead->data_table[i][0],
 629               replay->statehead->data_table[i][1] );
 630       }
 631       u32 state = (void *)replay->statehead - replay->data;
 632       player__debugtext( 1, "gs @%u\n", state );
 633       player__debugtext( 1, "gamestate_size: %hu\n",
 634            replay->statehead->data_table[k_replay_framedata_gamestate][1] );
 635    }
 636    else
 637       player__debugtext( 1, "gs @NULL\n" );
 638
 639    f64 start = replay->cursor,
 640        end   = replay->cursor;
 641    if( replay->tail ) start = replay->tail->time;
 642    if( replay->head ) end = replay->head->time;
 643
 644    f64 cur = replay->cursor - start,
 645        len = end - start;
 646
 647    player__debugtext( 1, "cursor: %.2fs / %.2fs\n", cur, len );
 648 }
 649
 650 static void skaterift_replay_imgui(void){
 651    if( skaterift.activity != k_skaterift_replay ) return;
 652
 653    replay_buffer *replay = &skaterift.replay;
 654    f64 start = replay->cursor,
 655        end   = replay->cursor;
 656    if( replay->tail ) start = replay->tail->time;
 657    if( replay->head ) end = replay->head->time;
 658    f64 len = end - start,
 659        cur = (replay->cursor - start) / len;
 660
 661    char buffer[ 128 ];
 662
 663    /* mainbar */
 664    ui_px height = 32,
 665          cwidth = 2;
 666    ui_rect bar = { 0, 0, vg.window_x, height };
 667    ui_fill( bar, ui_colour( k_ui_bg ) );
 668
 669    /* cursor frame block */
 670    if( replay->cursor_frame ){
 671       if( replay->cursor_frame->r ){
 672          f64 l = (replay->cursor_frame->r->time-replay->cursor_frame->time)/len,
 673              s = (replay->cursor_frame->time - start) / len;
 674          ui_rect box = { s*(f64)vg.window_x, 0,
 675                          VG_MAX(4,(ui_px)(l*vg.window_x)), bar[3]+2 };
 676          ui_fill( box, ui_colour( k_ui_bg+4 ) );
 677       }
 678    }
 679
 680    /* cursor */
 681    ui_rect cusor = { cur * (f64)vg.window_x - (cwidth/2), 0,
 682                      cwidth, bar[3] };
 683    ui_fill( cusor, ui_colour( k_ui_bg+7 ) );
 684
 685    /* latest state marker */
 686    if( replay->statehead ){
 687       f64 t = (replay->statehead->time - start) / len;
 688       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 689       ui_fill( tag, ui_colour( k_ui_green+k_ui_brighter ) );
 690    }
 691
 692    /* previous state marker */
 693    replay_frame *prev = replay_find_recent_stateframe( replay );
 694    if( prev ){
 695       f64 t = (prev->time - start) / len;
 696       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 697       ui_fill( tag, ui_colour( k_ui_yellow+k_ui_brighter ) );
 698    }
 699
 700    cusor[1] -= height;
 701    cusor[2] = 200;
 702    snprintf( buffer, 128, "-%.2fs\n", (end-replay->cursor) );
 703    ui_text( cusor, buffer, 1, k_ui_align_middle_left, 0 );
 704
 705    snprintf( buffer, 128, "-%.2fs\n", len );
 706    ui_text( bar, buffer, 1, k_ui_align_middle_left, 0 );
 707    ui_text( bar, "0s", 1, k_ui_align_middle_right, 0 );
 708 }
 709
 710 #endif /* PLAYER_REPLAY_C */