player_replay.c

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