player_replay.c

   1 #include "skaterift.h"
   2 #include "player.h"
   3 #include "player_replay.h"
   4 #include "input.h"
   5 #include "gui.h"
   6 #include "freecam.h"
   7
   8 #include "player_walk.h"
   9 #include "player_skate.h"
  10 #include "player_dead.h"
  11 #include "player_glide.h"
  12
  13 struct replay_globals player_replay;
  14
  15 void replay_clear( replay_buffer *replay )
  16 {
  17    replay->head = NULL;
  18    replay->tail = NULL;
  19    replay->cursor_frame = NULL;
  20    replay->statehead = NULL;
  21    replay->cursor = -99999.9;
  22 }
  23
  24 void *replay_frame_data( replay_frame *frame, enum replay_framedata type )
  25 {
  26    if( frame->data_table[type][1] == 0 )
  27       return NULL;
  28
  29    void *baseptr = frame;
  30    return baseptr + frame->data_table[type][0];
  31 }
  32
  33 static u16 replay_frame_calculate_data_offsets(
  34       u16 data_table[k_replay_framedata_rows][2] ){
  35
  36    u32 total = vg_align8( sizeof(replay_frame) );
  37    for( u32 i=0; i<k_replay_framedata_rows; i++ ){
  38       data_table[i][0] = total;
  39       total += vg_align8(data_table[i][1]);
  40
  41       if( total > 0xffff )
  42          vg_fatal_error( "Exceeded frame storage capacity\n" );
  43    }
  44    return total;
  45 }
  46
  47 static void replay_tailpop( replay_buffer *replay ){
  48    if( replay->cursor_frame == replay->tail )
  49       replay->cursor_frame = NULL;
  50    if( replay->statehead == replay->tail )
  51       replay->statehead = NULL;
  52
  53    replay->tail = replay->tail->r;
  54
  55    if( replay->tail )
  56       replay->tail->l = NULL;
  57    else
  58       replay->head = NULL;
  59 }
  60
  61 static replay_frame *replay_newframe( replay_buffer *replay,
  62                                          u16 animator_size,
  63                                          u16 gamestate_size,
  64                                          u16 sfx_count,
  65                                          bool save_glider ){
  66    u16 data_table[ k_replay_framedata_rows ][2];
  67    data_table[ k_replay_framedata_animator ][1]  = animator_size;
  68    data_table[ k_replay_framedata_gamestate ][1] = gamestate_size;
  69    data_table[ k_replay_framedata_sfx ][1] = sfx_count*sizeof(struct net_sfx);
  70    data_table[ k_replay_framedata_internal_gamestate ][1] = 0;
  71    if( gamestate_size ){
  72       data_table[ k_replay_framedata_internal_gamestate ][1] =
  73          sizeof( replay_gamestate );
  74    }
  75
  76    data_table[ k_replay_framedata_glider ][1] = 0;
  77    if( save_glider ){
  78       data_table[ k_replay_framedata_glider ][1] =
  79          sizeof(struct replay_glider_data);
  80    }
  81
  82    u32 nextsize = replay_frame_calculate_data_offsets( data_table );
  83
  84    replay_frame *frame = NULL;
  85    if( replay->head ){
  86       u32 headsize = replay->head->total_size,
  87           nextpos  = ((void *)replay->head - replay->data) + headsize;
  88
  89       if( nextpos + nextsize > replay->size ){
  90          nextpos = 0;
  91
  92          /* maintain contiguity */
  93          while( replay->tail ){
  94             if( (void *)replay->tail - replay->data )
  95                replay_tailpop( replay );
  96             else break;
  97          }
  98       }
  99
 100 check_again:;
 101       u32 tailpos = (void *)replay->tail - replay->data;
 102
 103       if( tailpos >= nextpos ){
 104          if( nextpos + nextsize > tailpos ){
 105             replay_tailpop( replay );
 106
 107             if( replay->tail )
 108                goto check_again;
 109          }
 110       }
 111
 112       frame = replay->data + nextpos;
 113
 114       if( replay->head )
 115          replay->head->r = frame;
 116    }
 117    else
 118       frame = replay->data;
 119
 120    for( u32 i=0; i<k_replay_framedata_rows; i++ ){
 121       frame->data_table[i][0] = data_table[i][0];
 122       frame->data_table[i][1] = data_table[i][1];
 123    }
 124
 125    frame->total_size = nextsize;
 126    frame->l = replay->head;
 127    frame->r = NULL;
 128    replay->head = frame;
 129    if( !replay->tail ) replay->tail = frame;
 130    if( gamestate_size ) replay->statehead = frame;
 131
 132    return frame;
 133 }
 134
 135 static void replay_emit_frame_sounds( replay_frame *frame ){
 136    void *baseptr = frame;
 137    u16 *inf = frame->data_table[k_replay_framedata_sfx];
 138    struct net_sfx *buffer = baseptr + inf[0];
 139    u32 count = inf[1] / sizeof(struct net_sfx);
 140
 141    for( u32 i=0; i<count; i ++ ){
 142       net_sfx_play( buffer + i );
 143    }
 144 }
 145
 146 int replay_seek( replay_buffer *replay, f64 t )
 147 {
 148    if( !replay->head ) return 0;
 149
 150    if( t < replay->tail->time ) t = replay->tail->time;
 151    if( t > replay->head->time ) t = replay->head->time;
 152
 153    if( !replay->cursor_frame ) {
 154       replay->cursor = replay->head->time;
 155       replay->cursor_frame = replay->head;
 156
 157       if( fabs(replay->head->time-t) > fabs(replay->tail->time-t) ){
 158          replay->cursor = replay->tail->time;
 159          replay->cursor_frame = replay->tail;
 160       }
 161    }
 162
 163    f64 dir = t - replay->cursor;
 164    if( dir == 0.0 ) return 0;
 165    dir = vg_signf( dir );
 166
 167
 168    u32 i=4096;
 169    while( i --> 0 ){
 170       if( dir < 0.0 ){
 171          if( t > replay->cursor_frame->time ) {
 172             replay->cursor = t;
 173             return 1;
 174          }
 175       }
 176
 177       replay_frame *next;
 178       if( dir > 0.0 ) next = replay->cursor_frame->r;
 179       else            next = replay->cursor_frame->l;
 180
 181       if( !next ) break;
 182
 183       if( dir > 0.0 ){
 184          if( t < next->time ){
 185             replay->cursor = t;
 186             return 1;
 187          }
 188       }
 189
 190       replay_emit_frame_sounds( next );
 191
 192       replay->cursor_frame = next;
 193       replay->cursor = next->time;
 194
 195       if( !i ) return 1;
 196    }
 197
 198    replay->cursor = t;
 199    return 0;
 200 }
 201
 202 replay_frame *replay_find_recent_stateframe( replay_buffer *replay )
 203 {
 204    replay_frame *frame = replay->cursor_frame;
 205    u32 i=4096;
 206    while( i --> 0 ){
 207       if( !frame ) return frame;
 208       if( frame->data_table[ k_replay_framedata_gamestate ][1] ) return frame;
 209       frame = frame->l;
 210    }
 211
 212    return NULL;
 213 }
 214
 215 f32 replay_subframe_time( replay_buffer *replay )
 216 {
 217    replay_frame *frame = replay->cursor_frame;
 218    if( !frame ) return 0.0f;
 219    replay_frame *next = frame->r;
 220    if( next ){
 221       f64 l = next->time - frame->time,
 222           t = (l <= (1.0/128.0))? 0.0: (replay->cursor - frame->time) / l;
 223       return vg_clampf( t, 0.0f, 1.0f );
 224    }
 225    else
 226       return 0.0f;
 227 }
 228
 229 void replay_get_frame_camera( replay_frame *frame, vg_camera *cam )
 230 {
 231    cam->fov = frame->cam_fov;
 232    v3_copy( frame->cam_pos, cam->pos );
 233    v3_copy( frame->cam_angles, cam->angles );
 234 }
 235
 236 void replay_get_camera( replay_buffer *replay, vg_camera *cam )
 237 {
 238    cam->nearz = 0.1f;
 239    cam->farz = 100.0f;
 240    if( replay->cursor_frame ){
 241       replay_frame *next = replay->cursor_frame->r;
 242
 243       if( next ){
 244          vg_camera temp;
 245
 246          replay_get_frame_camera( replay->cursor_frame, cam );
 247          replay_get_frame_camera( next, &temp );
 248          vg_camera_lerp( cam, &temp, replay_subframe_time( replay ), cam );
 249       }
 250       else {
 251          replay_get_frame_camera( replay->cursor_frame, cam );
 252       }
 253    }
 254    else {
 255       v3_zero( cam->pos );
 256       v3_zero( cam->angles );
 257       cam->fov = 90.0f;
 258    }
 259 }
 260
 261 struct replay_rb{
 262    v3f co, v, w;
 263    v4f q;
 264 };
 265
 266 void skaterift_record_frame( replay_buffer *replay, int force_gamestate )
 267 {
 268    f64 delta      = 9999999.9,
 269        statedelta = 9999999.9;
 270
 271    if( replay->head )
 272       delta = vg.time - replay->head->time;
 273
 274    if( replay->statehead )
 275       statedelta = vg.time - replay->statehead->time;
 276
 277    const f64 k_replay_rate = 1.0/30.0,
 278              k_gamestate_rate = 0.5;
 279
 280    int save_frame = 0,
 281        save_state = 0,
 282        save_glider = 0;
 283
 284    if( force_gamestate ) save_state = 1;
 285    if( statedelta > k_gamestate_rate ) save_state = 1;
 286    if( delta > k_replay_rate ) save_frame = 1;
 287    if( save_state ) save_frame = 1;
 288
 289    if( localplayer.have_glider || localplayer.glider_orphan ||
 290        localplayer.subsystem == k_player_subsystem_glide ){
 291       save_glider = 1;
 292    }
 293
 294    if( !save_frame ) return;
 295
 296    u16 gamestate_size = 0;
 297    if( save_state ){
 298       /* TODO: have as part of system struct */
 299       gamestate_size = (u32 []){
 300          [k_player_subsystem_walk ] = sizeof(struct player_walk_state),
 301          [k_player_subsystem_drive] = 0,
 302          [k_player_subsystem_skate] = sizeof(struct player_skate_state),
 303          [k_player_subsystem_dead ] = localplayer.ragdoll.part_count *
 304                                        sizeof(struct replay_rb),
 305          [k_player_subsystem_glide] = sizeof(struct replay_rb),
 306       }[ localplayer.subsystem ];
 307    }
 308
 309    u16 animator_size = player_subsystems[localplayer.subsystem]->animator_size;
 310
 311    replay_frame *frame = replay_newframe( replay,
 312                                           animator_size, gamestate_size,
 313                                           localplayer.local_sfx_buffer_count,
 314                                           save_glider );
 315    frame->system = localplayer.subsystem;
 316
 317    if( save_state ){
 318       replay_gamestate *gs =
 319          replay_frame_data( frame, k_replay_framedata_internal_gamestate );
 320
 321       gs->current_run_version = world_static.current_run_version;
 322
 323       /* permanent block */
 324       memcpy( &gs->rb, &localplayer.rb, sizeof(rigidbody) );
 325       memcpy( &gs->glider_rb, &player_glide.rb, sizeof(rigidbody) );
 326       memcpy( &gs->cam_control, &localplayer.cam_control,
 327                sizeof(struct player_cam_controller) );
 328       v3_copy( localplayer.angles, gs->angles );
 329
 330       void *dst = replay_frame_data( frame, k_replay_framedata_gamestate );
 331
 332       /* subsytem/dynamic block */
 333       if( localplayer.subsystem == k_player_subsystem_walk )
 334          memcpy( dst, &player_walk.state, gamestate_size );
 335       else if( localplayer.subsystem == k_player_subsystem_skate )
 336          memcpy( dst, &player_skate.state, gamestate_size );
 337       else if( localplayer.subsystem == k_player_subsystem_dead ){
 338          struct replay_rb *arr = dst;
 339          for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 340             rigidbody *rb = &localplayer.ragdoll.parts[i].rb;
 341             v3_copy( rb->co, arr[i].co );
 342             v3_copy( rb->w, arr[i].w );
 343             v3_copy( rb->v, arr[i].v );
 344             v4_copy( rb->q, arr[i].q );
 345          }
 346       }
 347       else if( localplayer.subsystem == k_player_subsystem_glide ){
 348          struct replay_rb *arr = dst;
 349          rigidbody *rb = &player_glide.rb;
 350          v3_copy( rb->co, arr[0].co );
 351          v3_copy( rb->w, arr[0].w );
 352          v3_copy( rb->v, arr[0].v );
 353          v4_copy( rb->q, arr[0].q );
 354       }
 355    }
 356
 357    if( save_glider ){
 358       struct replay_glider_data *inf =
 359          replay_frame_data( frame, k_replay_framedata_glider );
 360
 361       inf->have_glider   = localplayer.have_glider;
 362       inf->glider_orphan = localplayer.glider_orphan;
 363       inf->t             = player_glide.t;
 364       v3_copy( player_glide.rb.co, inf->co );
 365       v4_copy( player_glide.rb.q,  inf->q );
 366    }
 367
 368    replay->cursor = vg.time;
 369    replay->cursor_frame = frame;
 370    frame->time = vg.time;
 371
 372    /* camera */
 373    v3_copy( localplayer.cam.pos, frame->cam_pos );
 374    if( localplayer.gate_waiting ){
 375       m4x3_mulv( localplayer.gate_waiting->transport,
 376                   frame->cam_pos, frame->cam_pos );
 377
 378       v3f v0;
 379       v3_angles_vector( localplayer.cam.angles, v0 );
 380       m3x3_mulv( localplayer.gate_waiting->transport, v0, v0 );
 381       v3_angles( v0, frame->cam_angles );
 382    }
 383    else
 384       v3_copy( localplayer.cam.angles, frame->cam_angles );
 385
 386    frame->cam_fov = localplayer.cam.fov;
 387
 388    /* animator */
 389    void *dst = replay_frame_data( frame, k_replay_framedata_animator ),
 390         *src = player_subsystems[localplayer.subsystem]->animator_data;
 391    memcpy( dst, src, animator_size );
 392
 393    /* sound effects */
 394    memcpy( replay_frame_data( frame, k_replay_framedata_sfx ),
 395            localplayer.local_sfx_buffer,
 396            sizeof(struct net_sfx)*localplayer.local_sfx_buffer_count );
 397
 398    localplayer.local_sfx_buffer_count = 0;
 399 }
 400
 401 static
 402 void skaterift_restore_frame( replay_frame *frame ){
 403    replay_gamestate *gs =
 404       replay_frame_data( frame, k_replay_framedata_internal_gamestate );
 405    void *src = replay_frame_data( frame, k_replay_framedata_gamestate );
 406    u16 src_size = frame->data_table[ k_replay_framedata_gamestate ][1];
 407    world_static.current_run_version = gs->current_run_version;
 408
 409    if(frame->system == k_player_subsystem_walk ){
 410       memcpy( &player_walk.state, src, src_size );
 411    }
 412    else if( frame->system == k_player_subsystem_skate ){
 413       memcpy( &player_skate.state, src, src_size );
 414    }
 415    else if( frame->system == k_player_subsystem_dead ){
 416       player__dead_transition(0);
 417       struct replay_rb *arr = src;
 418
 419       for( u32 i=0; i<localplayer.ragdoll.part_count; i ++ ){
 420          struct ragdoll_part *part = &localplayer.ragdoll.parts[i];
 421          rigidbody *rb = &part->rb;
 422
 423          v3_copy( arr[i].co, rb->co );
 424          v3_copy( arr[i].w, rb->w );
 425          v3_copy( arr[i].v, rb->v );
 426          v4_copy( arr[i].q, rb->q );
 427
 428          v3_copy( arr[i].co, part->prev_co );
 429          v4_copy( arr[i].q, part->prev_q );
 430          rb_update_matrices( rb );
 431       }
 432    }
 433    else if( frame->system == k_player_subsystem_glide ){
 434       struct replay_rb *arr = src;
 435       rigidbody *rb = &player_glide.rb;
 436       v3_copy( arr[0].co, rb->co );
 437       v3_copy( arr[0].w, rb->w );
 438       v3_copy( arr[0].v, rb->v );
 439       v4_copy( arr[0].q, rb->q );
 440       rb_update_matrices( rb );
 441    }
 442
 443    localplayer.subsystem = frame->system;
 444
 445    /* restore the seperated glider data if we have it */
 446    if( frame->data_table[ k_replay_framedata_glider ][1] ){
 447       struct replay_glider_data *inf =
 448          replay_frame_data( frame, k_replay_framedata_glider );
 449
 450       localplayer.have_glider   = inf->have_glider;
 451       localplayer.glider_orphan = inf->glider_orphan;
 452       player_glide.t            = inf->t;
 453    }
 454    else {
 455       localplayer.have_glider = 0;
 456       localplayer.glider_orphan = 0;
 457       player_glide.t = 0.0f;
 458    }
 459
 460    memcpy( &localplayer.rb, &gs->rb, sizeof(rigidbody) );
 461    memcpy( &player_glide.rb, &gs->glider_rb, sizeof(rigidbody) );
 462    v3_copy( gs->angles, localplayer.angles );
 463
 464    v3_copy( frame->cam_pos, localplayer.cam.pos );
 465    v3_copy( frame->cam_angles, localplayer.cam.angles );
 466    localplayer.cam.fov = frame->cam_fov;
 467
 468    memcpy( &localplayer.cam_control, &gs->cam_control,
 469             sizeof(struct player_cam_controller) );
 470
 471    /* chop end off replay */
 472    frame->r = NULL;
 473    player_replay.local.statehead = frame;
 474    player_replay.local.head = frame;
 475    player_replay.local.cursor_frame = frame;
 476    player_replay.local.cursor = frame->time;
 477    player_replay.replay_control = k_replay_control_scrub;
 478    skaterift.activity = k_skaterift_default;
 479    vg.time = frame->time;
 480 }
 481
 482 static void skaterift_replay_resume(void){
 483    replay_frame *prev = replay_find_recent_stateframe(&player_replay.local);
 484
 485    if( prev ){
 486       player_replay.replay_control = k_replay_control_resume;
 487       player_replay.resume_target = prev;
 488       player_replay.resume_begin = player_replay.local.cursor;
 489       player_replay.resume_transition = 0.0f;
 490    }
 491
 492    gui_helper_clear();
 493 }
 494
 495 static void skaterift_replay_update_helpers(void);
 496
 497 void skaterift_replay_pre_update(void)
 498 {
 499    if( skaterift.activity != k_skaterift_replay ) return;
 500
 501    if( player_replay.replay_control == k_replay_control_resume )
 502    {
 503       if( player_replay.local.cursor_frame == player_replay.resume_target ||
 504           player_replay.local.cursor_frame == NULL )
 505       {
 506          skaterift_restore_frame( player_replay.resume_target );
 507       }
 508       else
 509       {
 510          vg_slewf( &player_replay.resume_transition, 1.0f,
 511                    vg.time_frame_delta * (1.0f/1.0f) );
 512
 513          if( player_replay.resume_transition >= 1.0f )
 514             skaterift_restore_frame( player_replay.resume_target );
 515          else {
 516             f64 target = vg_lerp( player_replay.resume_begin,
 517                            player_replay.resume_target->time,
 518                            vg_smoothstepf( player_replay.resume_transition ) );
 519             if( replay_seek( &player_replay.local, target ) )
 520                player_replay.track_velocity = 1.0f;
 521             else
 522                player_replay.track_velocity = 0.0f;
 523          }
 524       }
 525    }
 526    else {
 527       if( button_down( k_srbind_replay_play ) )
 528          player_replay.replay_control = k_replay_control_play;
 529       if( button_down( k_srbind_replay_freecam ) ){
 530          player_replay.freecam = player_replay.freecam ^ 0x1;
 531
 532          if( player_replay.freecam )
 533             replay_get_camera( &player_replay.local,
 534                                &player_replay.replay_freecam );
 535          skaterift_replay_update_helpers();
 536       }
 537
 538       f32 target_speed = axis_state( k_sraxis_replay_h ) * 5.0;
 539       if( button_press( k_srbind_reset ) )
 540          target_speed += -2.0;
 541
 542       if( fabsf(target_speed) > 0.01f )
 543          player_replay.replay_control = k_replay_control_scrub;
 544
 545       if( player_replay.replay_control == k_replay_control_play )
 546          target_speed = 1.0;
 547
 548       vg_slewf( &player_replay.track_velocity, target_speed,
 549                 18.0f*vg.time_frame_delta );
 550
 551       if( fabsf( player_replay.track_velocity ) > 0.0001f )
 552       {
 553          f64 target = player_replay.local.cursor;
 554          target += player_replay.track_velocity * vg.time_frame_delta;
 555
 556          if( !replay_seek( &player_replay.local, target ) )
 557             player_replay.track_velocity = 0.0f;
 558       }
 559
 560       if( button_down( k_srbind_mback ) )
 561       {
 562          if( player_replay.local.statehead )
 563             skaterift_restore_frame( player_replay.local.statehead );
 564          else
 565             skaterift.activity = k_skaterift_default;
 566          srinput.state = k_input_state_resume;
 567          gui_helper_clear();
 568       }
 569
 570       if( player_replay.freecam ){
 571          //freecam_preupdate();
 572       }
 573       else {
 574          if( button_down( k_srbind_replay_resume ) ){
 575             skaterift_replay_resume();
 576          }
 577       }
 578    }
 579 }
 580
 581 static void skaterift_replay_update_helpers(void){
 582    player_replay.helper_resume->greyed = player_replay.freecam;
 583
 584    vg_str freecam_text;
 585    vg_strnull( &freecam_text, player_replay.helper_freecam->text,
 586                GUI_HELPER_TEXT_LENGTH );
 587    vg_strcat( &freecam_text, player_replay.freecam? "exit freecam": "freecam" );
 588 }
 589
 590 void skaterift_replay_post_render(void)
 591 {
 592 #ifndef SR_ALLOW_REWIND_HUB
 593    if( world_static.active_instance != k_world_purpose_client )
 594       return;
 595 #endif
 596
 597    /* capture the current resume frame at the very last point */
 598    if( button_down( k_srbind_reset ) )
 599    {
 600       if( skaterift.activity == k_skaterift_default )
 601       {
 602          localplayer.rewinded_since_last_gate = 1;
 603          skaterift.activity = k_skaterift_replay;
 604          skaterift_record_frame( &player_replay.local, 1 );
 605          if( player_replay.local.head )
 606          {
 607             player_replay.local.cursor = player_replay.local.head->time;
 608             player_replay.local.cursor_frame = player_replay.local.head;
 609          }
 610          player_replay.replay_control = k_replay_control_scrub;
 611
 612          gui_helper_clear();
 613          vg_str text;
 614
 615          if( gui_new_helper( input_axis_list[k_sraxis_replay_h], &text ) )
 616             vg_strcat( &text, "scrub" );
 617
 618          if( (player_replay.helper_resume = gui_new_helper(
 619                      input_button_list[k_srbind_replay_resume], &text )) )
 620             vg_strcat( &text, "resume" );
 621
 622          if( gui_new_helper( input_button_list[k_srbind_replay_play], &text ))
 623             vg_strcat( &text, "playback" );
 624
 625          player_replay.helper_freecam = gui_new_helper(
 626                input_button_list[k_srbind_replay_freecam], &text );
 627
 628          skaterift_replay_update_helpers();
 629       }
 630    }
 631 }
 632
 633 void skaterift_replay_debug_info(void)
 634 {
 635    player__debugtext( 2, "replay info" );
 636    replay_buffer *replay = &player_replay.local;
 637
 638    u32 head = 0,
 639        tail = 0;
 640    if( replay->tail ) tail = (void *)replay->tail - replay->data;
 641    if( replay->head ) head = (void *)replay->head - replay->data;
 642
 643    player__debugtext( 1, "head @%u | tail @%u\n", head, tail );
 644
 645    if( replay->statehead ){
 646       for( u32 i=0; i<k_replay_framedata_rows; i++ ){
 647          player__debugtext( 1, "[%u]: [%hu, %hu]\n", i,
 648               replay->statehead->data_table[i][0],
 649               replay->statehead->data_table[i][1] );
 650       }
 651       u32 state = (void *)replay->statehead - replay->data;
 652       player__debugtext( 1, "gs @%u\n", state );
 653       player__debugtext( 1, "gamestate_size: %hu\n",
 654            replay->statehead->data_table[k_replay_framedata_gamestate][1] );
 655    }
 656    else
 657       player__debugtext( 1, "gs @NULL\n" );
 658
 659    f64 start = replay->cursor,
 660        end   = replay->cursor;
 661    if( replay->tail ) start = replay->tail->time;
 662    if( replay->head ) end = replay->head->time;
 663
 664    f64 cur = replay->cursor - start,
 665        len = end - start;
 666
 667    player__debugtext( 1, "cursor: %.2fs / %.2fs\n", cur, len );
 668 }
 669
 670 void skaterift_replay_imgui(void)
 671 {
 672    if( skaterift.activity != k_skaterift_replay ) return;
 673
 674    replay_buffer *replay = &player_replay.local;
 675    f64 start = replay->cursor,
 676        end   = replay->cursor;
 677    if( replay->tail ) start = replay->tail->time;
 678    if( replay->head ) end = replay->head->time;
 679    f64 len = end - start,
 680        cur = (replay->cursor - start) / len;
 681
 682    char buffer[ 128 ];
 683
 684    /* mainbar */
 685    ui_px height = 32,
 686          cwidth = 2;
 687    ui_rect bar = { 0, 0, vg.window_x, height };
 688    ui_fill( bar, ui_colour( k_ui_bg ) );
 689
 690    /* cursor frame block */
 691    if( replay->cursor_frame ){
 692       if( replay->cursor_frame->r ){
 693          f64 l = (replay->cursor_frame->r->time-replay->cursor_frame->time)/len,
 694              s = (replay->cursor_frame->time - start) / len;
 695          ui_rect box = { s*(f64)vg.window_x, 0,
 696                          VG_MAX(4,(ui_px)(l*vg.window_x)), bar[3]+2 };
 697          ui_fill( box, ui_colour( k_ui_bg+4 ) );
 698       }
 699    }
 700
 701    /* cursor */
 702    ui_rect cusor = { cur * (f64)vg.window_x - (cwidth/2), 0,
 703                      cwidth, bar[3] };
 704    ui_fill( cusor, ui_colour( k_ui_bg+7 ) );
 705
 706    /* latest state marker */
 707    if( replay->statehead ){
 708       f64 t = (replay->statehead->time - start) / len;
 709       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 710       ui_fill( tag, ui_colour( k_ui_green+k_ui_brighter ) );
 711    }
 712
 713    /* previous state marker */
 714    replay_frame *prev = replay_find_recent_stateframe( replay );
 715    if( prev ){
 716       f64 t = (prev->time - start) / len;
 717       ui_rect tag = { t*(f64)vg.window_x, 0, 2, bar[3]+8 };
 718       ui_fill( tag, ui_colour( k_ui_yellow+k_ui_brighter ) );
 719    }
 720
 721    cusor[1] -= height;
 722    cusor[2] = 200;
 723    snprintf( buffer, 128, "-%.2fs\n", (end-replay->cursor) );
 724    ui_text( cusor, buffer, 1, k_ui_align_middle_left, 0 );
 725
 726    snprintf( buffer, 128, "-%.2fs\n", len );
 727    ui_text( bar, buffer, 1, k_ui_align_middle_left, 0 );
 728    ui_text( bar, "0s", 1, k_ui_align_middle_right, 0 );
 729 }