world.h

   1 /*
   2  * Copyright (C) 2021-2022 Mt.ZERO Software, Harry Godden - All Rights Reserved
   3  */
   4
   5 #include "common.h"
   6
   7 #ifndef WORLD_H
   8 #define WORLD_H
   9
  10 typedef struct world_instance world_instance;
  11
  12 #include "vg/vg_loader.h"
  13
  14 #include "network.h"
  15 #include "network_msg.h"
  16 #include "scene.h"
  17 #include "render.h"
  18 #include "rigidbody.h"
  19 #include "bvh.h"
  20 #include "model.h"
  21 #include "entity.h"
  22 #include "font.h"
  23
  24 #include "shaders/scene_standard.h"
  25 #include "shaders/scene_standard_alphatest.h"
  26 #include "shaders/scene_vertex_blend.h"
  27 #include "shaders/scene_terrain.h"
  28 #include "shaders/scene_depth.h"
  29 #include "shaders/scene_position.h"
  30
  31 #include "shaders/model_sky.h"
  32
  33 enum { k_max_ui_segments = 8 };
  34
  35 enum { k_max_ui_elements = k_max_ui_segments };
  36 enum { k_max_element_verts = 10 };
  37 enum { k_max_element_indices = 20 };
  38
  39 enum { k_route_ui_max_verts = k_max_ui_elements*k_max_element_verts };
  40 enum { k_route_ui_max_indices = k_max_ui_elements*k_max_element_indices };
  41
  42 enum logic_type
  43 {
  44    k_logic_type_relay         = 1,
  45    k_logic_type_chance        = 2,
  46    k_logic_type_achievement   = 3
  47 };
  48
  49 enum geo_type
  50 {
  51    k_geo_type_solid = 0,
  52    k_geo_type_nonsolid = 1,
  53    k_geo_type_water = 2
  54 };
  55
  56 static const float k_light_cube_size = 8.0f;
  57
  58 struct world_instance {
  59    /* Fixed items
  60     * -------------------------------------------------------
  61     */
  62
  63    char  world_name[ 64 ];
  64
  65    struct{
  66       boxf depthbounds;
  67       int depth_computed;
  68
  69       float height;
  70       int enabled;
  71       v4f plane;
  72    }
  73    water;
  74
  75    /* STD140 */
  76    struct ub_world_lighting{
  77       v4f g_cube_min,
  78           g_cube_inv_range;
  79
  80       v4f g_water_plane,
  81           g_depth_bounds;
  82
  83       v4f g_daysky_colour;
  84       v4f g_nightsky_colour;
  85       v4f g_sunset_colour;
  86       v4f g_ambient_colour;
  87       v4f g_sunset_ambient;
  88       v4f g_sun_colour;
  89       v4f g_sun_dir;
  90
  91       float g_water_fog;
  92       float g_time;
  93       float g_realtime;
  94       float g_shadow_length;
  95       float g_shadow_spread;
  96
  97       float g_time_of_day;
  98       float g_day_phase;
  99       float g_sunset_phase;
 100
 101       int g_light_preview;
 102       int g_shadow_samples;
 103
 104       int g_debug_indices;
 105       int g_debug_complexity;
 106    }
 107    ub_lighting;
 108    GLuint ubo_lighting;
 109    int    ubo_bind_point;
 110
 111    GLuint tbo_light_entities,
 112           tex_light_entities,
 113           tex_light_cubes;
 114
 115    float probabilities[3];
 116
 117    v3i light_cubes;
 118
 119    struct framebuffer heightmap;
 120
 121    /*
 122     * Dynamically allocated when world_load is called.
 123     *
 124     *                  the following arrays index somewhere into this linear
 125     *                  allocator
 126     *
 127     * (world_gen.h)
 128     * --------------------------------------------------------------------------
 129     */
 130
 131    /*
 132     * Main world .mdl
 133     */
 134    mdl_context meta;
 135
 136    GLuint *textures;
 137    u32 texture_count;
 138
 139    struct world_surface{
 140       mdl_material info;
 141       mdl_submesh sm_geo,
 142                   sm_no_collide;
 143    }
 144    * surfaces;
 145    u32 surface_count;
 146
 147    mdl_array_ptr ent_spawn,
 148                  ent_gate,
 149                  ent_light,
 150                  ent_route_node,
 151                  ent_path_index,
 152                  ent_checkpoint,
 153                  ent_route,
 154                  ent_water,
 155
 156                  ent_audio_clip,
 157                  ent_audio,
 158                  ent_volume;
 159
 160    ent_gate *rendering_gate;
 161
 162    /* logic
 163     * ----------------------------------------------------
 164     */
 165
 166    /* world geometry */
 167    scene *scene_geo,
 168          *scene_no_collide,
 169          *scene_lines;
 170
 171    /* spacial mappings */
 172    bh_tree *audio_bh,
 173            *volume_bh,
 174            *geo_bh;
 175
 176    /* graphics */
 177    glmesh mesh_route_lines;
 178    glmesh mesh_geo,
 179           mesh_no_collide,
 180           mesh_water;
 181
 182    rb_object rb_geo;
 183 };
 184
 185 VG_STATIC struct world_global{
 186    /*
 187     * Allocated as system memory
 188     * --------------------------------------------------------------------------
 189     */
 190    void *generic_heap;
 191
 192    /* rendering */
 193    glmesh skydome;
 194    glmesh mesh_gate;
 195    mdl_submesh sm_gate_surface,
 196                sm_gate_marker[4];
 197
 198    double sky_time, sky_rate, sky_target_rate;
 199
 200    u32 current_run_version;
 201    double time, rewind_from, rewind_to, last_use;
 202
 203    /* water rendering */
 204    struct{
 205       struct framebuffer fbreflect, fbdepth;
 206    }
 207    water;
 208
 209    /* split flap display */
 210    struct{
 211       glmesh mesh_base, mesh_display;
 212       mdl_submesh sm_base;
 213       u32 active_route_board;
 214
 215       u32 w, h;
 216       float *buffer;
 217    }
 218    sfd;
 219
 220    v3f render_gate_pos;
 221    int in_volume;
 222
 223    int switching_to_new_world;
 224
 225    world_instance worlds[4];
 226    u32            world_count;
 227    u32            active_world;
 228
 229    /* text particles */
 230    font3d font;
 231
 232    struct timer_text{
 233       char text[8];
 234       m4x3f transform;
 235       ent_gate *gate;
 236       ent_route *route;
 237    }
 238    timer_texts[4];
 239    u32 timer_text_count;
 240
 241    struct text_particle{
 242       rb_object obj;
 243       m4x3f mlocal;
 244       ent_glyph *glyph;
 245       v4f colour;
 246
 247       m4x3f mdl;
 248    }
 249    text_particles[6*4];
 250    u32 text_particle_count;
 251
 252 }
 253 world_global;
 254
 255 VG_STATIC world_instance *get_active_world( void )
 256 {
 257    return &world_global.worlds[ world_global.active_world ];
 258 }
 259
 260 /*
 261  * API
 262  */
 263
 264 VG_STATIC
 265 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 266
 267 VG_STATIC
 268 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 269
 270 VG_STATIC
 271 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 272
 273 VG_STATIC
 274 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 275
 276 /*
 277  * Submodules
 278  */
 279
 280 #include "world_routes.h"
 281 #include "world_sfd.h"
 282 #include "world_render.h"
 283 #include "world_water.h"
 284 #include "world_volumes.h"
 285 #include "world_gen.h"
 286 #include "world_gate.h"
 287
 288 /*
 289  * -----------------------------------------------------------------------------
 290  *                                    Events
 291  * -----------------------------------------------------------------------------
 292  */
 293
 294 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 295 {
 296    world_instance *world = get_active_world();
 297    return 0;
 298 }
 299
 300 VG_STATIC void world_init(void)
 301 {
 302    world_global.sky_rate = 1.0;
 303    world_global.sky_target_rate = 1.0;
 304
 305    shader_scene_standard_register();
 306    shader_scene_standard_alphatest_register();
 307    shader_scene_vertex_blend_register();
 308    shader_scene_terrain_register();
 309    shader_scene_depth_register();
 310    shader_scene_position_register();
 311
 312    shader_model_sky_register();
 313
 314    vg_info( "Loading world resources\n" );
 315
 316    vg_linear_clear( vg_mem.scratch );
 317
 318    mdl_context msky;
 319    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 320    mdl_load_metadata_block( &msky, vg_mem.scratch );
 321    mdl_load_mesh_block( &msky, vg_mem.scratch );
 322    mdl_close( &msky );
 323
 324    vg_acquire_thread_sync();
 325    {
 326       mdl_unpack_glmesh( &msky, &world_global.skydome );
 327    }
 328    vg_release_thread_sync();
 329
 330    /* Other systems */
 331    vg_info( "Loading other world systems\n" );
 332
 333    vg_loader_step( world_render_init, NULL );
 334    vg_loader_step( world_sfd_init, NULL );
 335    vg_loader_step( world_water_init, NULL );
 336    vg_loader_step( world_gates_init, NULL );
 337    vg_loader_step( world_routes_init, NULL );
 338
 339    /* Allocate dynamic world memory arena */
 340    u32 max_size = 76*1024*1024;
 341    world_global.generic_heap = vg_create_linear_allocator( vg_mem.rtmemory,
 342                                                            max_size,
 343                                                            VG_MEMORY_SYSTEM );
 344 }
 345
 346 typedef struct ent_call ent_call;
 347 struct ent_call{
 348    ent_index ent;
 349    u32 function;
 350    void *data;
 351 };
 352
 353 VG_STATIC void entity_call( world_instance *world, ent_call *call );
 354
 355 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 356 {
 357    ent_volume *volume = mdl_arritm( &world->ent_volume, call->ent.index );
 358    if( !volume->target.type ) return;
 359
 360    if( call->function == k_ent_function_trigger ){
 361       call->ent = volume->target;
 362
 363       if( volume->type == k_volume_subtype_particle ){
 364          float *co = alloca( sizeof(float)*3 );
 365          co[0] = vg_randf()*2.0f-1.0f;
 366          co[1] = vg_randf()*2.0f-1.0f;
 367          co[2] = vg_randf()*2.0f-1.0f;
 368          m4x3_mulv( volume->to_world, co, co );
 369
 370          call->function = k_ent_function_particle_spawn;
 371          call->data = co;
 372          entity_call( world, call );
 373       }
 374       else
 375          entity_call( world, call );
 376    }
 377 }
 378
 379 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 380 {
 381    ent_audio *audio = mdl_arritm( &world->ent_audio, call->ent.index );
 382
 383    v3f sound_co;
 384
 385    if( call->function == k_ent_function_particle_spawn ){
 386       v3_copy( call->data, sound_co );
 387    }
 388    else if( call->function == k_ent_function_trigger ){
 389       v3_copy( audio->transform.co, sound_co );
 390    }
 391    else
 392       vg_fatal_exit_loop( "ent_audio_call (invalid function id)" );
 393
 394    float chance = vg_randf()*100.0f,
 395          bar = 0.0f;
 396
 397    for( u32 i=0; i<audio->clip_count; i++ ){
 398       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 399                                           audio->clip_start+i );
 400
 401       float mod = world->probabilities[ audio->probability_curve ],
 402             p   = clip->probability * mod;
 403
 404       bar += p;
 405
 406       if( chance < bar ){
 407
 408          audio_lock();
 409
 410          if( audio->behaviour == k_channel_behaviour_unlimited ){
 411             audio_oneshot_3d( &clip->clip, sound_co,
 412                               audio->transform.s[0],
 413                               audio->volume );
 414          }
 415          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 416             audio_channel *ch =
 417                audio_get_group_idle_channel( audio->group,
 418                                              audio->max_channels );
 419
 420             if( ch ){
 421                audio_channel_init( ch, &clip->clip, audio->flags );
 422                audio_channel_group( ch, audio->group );
 423                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 424                audio_channel_edit_volume( ch, audio->volume, 1 );
 425                ch = audio_relinquish_channel( ch );
 426             }
 427          }
 428          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 429             audio_channel *ch =
 430                audio_get_group_idle_channel( audio->group,
 431                                              audio->max_channels );
 432
 433             /* group is full */
 434             if( !ch ){
 435                audio_channel *existing =
 436                   audio_get_group_first_active_channel( audio->group );
 437
 438                if( existing ){
 439                   if( existing->source == &clip->clip ){
 440                      audio_unlock();
 441                      return;
 442                   }
 443
 444                   existing->group = 0;
 445                   existing = audio_channel_fadeout(existing, audio->crossfade);
 446                }
 447
 448                ch = audio_get_first_idle_channel();
 449             }
 450
 451             if( ch ){
 452                audio_channel_init( ch, &clip->clip, audio->flags );
 453                audio_channel_group( ch, audio->group );
 454                audio_channel_fadein( ch, audio->crossfade );
 455                ch = audio_relinquish_channel( ch );
 456             }
 457          }
 458
 459          audio_unlock();
 460          return;
 461       }
 462    }
 463 }
 464
 465 VG_STATIC void entity_call( world_instance *world, ent_call *call )
 466 {
 467    if( call->ent.type == k_ent_volume ){
 468       ent_volume_call( world, call );
 469    } else if( call->ent.type == k_ent_audio ){
 470       ent_audio_call( world, call );
 471    }
 472 }
 473
 474 VG_STATIC void world_update( world_instance *world, v3f pos )
 475 {
 476    /* TEMP!!!!!! */
 477    static double g_time = 0.0;
 478    g_time += vg.time_delta * (1.0/(k_day_length*60.0));
 479
 480
 481    struct ub_world_lighting *state = &world->ub_lighting;
 482
 483    state->g_time = g_time;
 484    state->g_realtime = vg.time;
 485    state->g_debug_indices = k_debug_light_indices;
 486    state->g_light_preview = k_light_preview;
 487    state->g_debug_complexity = k_debug_light_complexity;
 488
 489    state->g_time_of_day = vg_fractf( g_time );
 490    state->g_day_phase   = cosf( state->g_time_of_day * VG_PIf * 2.0f );
 491    state->g_sunset_phase= cosf( state->g_time_of_day * VG_PIf * 4.0f + VG_PIf );
 492
 493    state->g_day_phase    =       state->g_day_phase    * 0.5f + 0.5f;
 494    state->g_sunset_phase = powf( state->g_sunset_phase * 0.5f + 0.5f, 6.0f );
 495
 496    float a = state->g_time_of_day * VG_PIf * 2.0f;
 497    state->g_sun_dir[0] = sinf( a );
 498    state->g_sun_dir[1] = cosf( a );
 499    state->g_sun_dir[2] = 0.2f;
 500    v3_normalize( state->g_sun_dir );
 501
 502
 503    world->probabilities[ k_probability_curve_constant ] = 1.0f;
 504
 505    float dp = state->g_day_phase;
 506
 507    world->probabilities[ k_probability_curve_wildlife_day ] =
 508       (dp*dp*0.8f+state->g_sunset_phase)*0.8f;
 509    world->probabilities[ k_probability_curve_wildlife_night ] =
 510       1.0f-powf(fabsf((state->g_time_of_day-0.5f)*5.0f),5.0f);
 511
 512
 513    glBindBuffer( GL_UNIFORM_BUFFER, world->ubo_lighting );
 514    glBufferSubData( GL_UNIFORM_BUFFER, 0,
 515                     sizeof(struct ub_world_lighting), &world->ub_lighting );
 516    /* TEMP!!!!!! */
 517
 518    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 519    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 520                                     world_global.sky_target_rate,
 521                                     vg.time_delta * 5.0 );
 522
 523    world_routes_update_timer_texts( world );
 524    world_routes_update( world );
 525    //world_routes_debug( world );
 526
 527    /* ---- SFD ------------ */
 528
 529    if( mdl_arrcount( &world->ent_route ) ){
 530       u32 closest = 0;
 531       float min_dist = INFINITY;
 532
 533       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 534          ent_route *route = mdl_arritm( &world->ent_route, i );
 535          float dist = v3_dist2( route->board_transform[3], pos );
 536
 537          if( dist < min_dist ){
 538             min_dist = dist;
 539             closest = i;
 540          }
 541       }
 542
 543       if( (world_global.sfd.active_route_board != closest)
 544           || network_scores_updated )
 545       {
 546          network_scores_updated = 0;
 547          world_global.sfd.active_route_board = closest;
 548
 549          ent_route *route = mdl_arritm( &world->ent_route, closest );
 550          u32 id = route->official_track_id;
 551
 552          if( id != 0xffffffff ){
 553             struct netmsg_board *local_board =
 554                &scoreboard_client_data.boards[id];
 555
 556             for( int i=0; i<13; i++ ){
 557                sfd_encode( i, &local_board->data[27*i] );
 558             }
 559          }else{
 560             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 561             sfd_encode( 1, "No data" );
 562          }
 563       }
 564    }
 565    sfd_update();
 566
 567
 568
 569    static float random_accum = 0.0f;
 570    random_accum += vg.time_delta;
 571
 572    u32 random_ticks = 0;
 573
 574    while( random_accum > 0.1f ){
 575       random_accum -= 0.1f;
 576       random_ticks ++;
 577    }
 578
 579    float radius = 25.0f;
 580    boxf volume_proximity;
 581    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 582    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 583
 584    bh_iter it;
 585    bh_iter_init( 0, &it );
 586    int idx;
 587
 588    int in_volume = 0;
 589
 590    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 591       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 592
 593       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 594
 595       if( volume->type == k_volume_subtype_trigger ){
 596          v3f local;
 597          m4x3_mulv( volume->to_local, pos, local );
 598
 599          if( (fabsf(local[0]) <= 1.0f) &&
 600              (fabsf(local[1]) <= 1.0f) &&
 601              (fabsf(local[2]) <= 1.0f) )
 602          {
 603             in_volume = 1;
 604             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 605
 606             if( !world_global.in_volume ){
 607                ent_call basecall;
 608                basecall.ent.index = idx;
 609                basecall.ent.type = k_ent_volume;
 610                basecall.function = k_ent_function_trigger;
 611                basecall.data = NULL;
 612
 613                entity_call( world, &basecall );
 614             }
 615          }
 616          else
 617             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 618       }
 619       else if( volume->type == k_volume_subtype_particle ){
 620          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 621
 622          for( int j=0; j<random_ticks; j++ ){
 623             ent_call basecall;
 624             basecall.ent.index = idx;
 625             basecall.ent.type = k_ent_volume;
 626             basecall.function = k_ent_function_trigger;
 627             basecall.data = NULL;
 628
 629             entity_call( world, &basecall );
 630          }
 631       }
 632    }
 633    world_global.in_volume = in_volume;
 634
 635 #if 0
 636    if( k_debug_light_indices )
 637    {
 638       for( int i=0; i<world->light_count; i++ ){
 639          struct world_light *light = &world->lights[i];
 640          struct classtype_world_light *inf = light->inf;
 641
 642          u32 colour = 0xff000000;
 643          u8 r = inf->colour[0] * 255.0f,
 644             g = inf->colour[1] * 255.0f,
 645             b = inf->colour[2] * 255.0f;
 646
 647          colour |= r;
 648          colour |= g << 8;
 649          colour |= b << 16;
 650
 651          vg_line_pt3( light->node->co, 0.25f, colour );
 652       }
 653    }
 654
 655 #endif
 656
 657 #if 0
 658
 659    /* process soundscape transactions */
 660    audio_lock();
 661    for( int i=0; i<world->soundscape_count; i++ )
 662    {
 663       struct soundscape *s = &world->soundscapes[i];
 664       s->usage_count = 0;
 665
 666       for( int j=0; j<s->max_instances; j++ )
 667       {
 668          if( s->channels[j] )
 669          {
 670             if( audio_channel_finished(s->channels[j]) )
 671                s->channels[j] = audio_relinquish_channel( s->channels[j] );
 672             else
 673                s->usage_count ++;
 674          }
 675       }
 676    }
 677    audio_unlock();
 678 #endif
 679 }
 680
 681 /*
 682  * -----------------------------------------------------------------------------
 683  *                              API implementation
 684  * -----------------------------------------------------------------------------
 685  */
 686
 687 VG_STATIC void ray_world_get_tri( world_instance *world,
 688                                   ray_hit *hit, v3f tri[3] )
 689 {
 690    for( int i=0; i<3; i++ )
 691       v3_copy( world->scene_geo->arrvertices[ hit->tri[i] ].co, tri[i] );
 692 }
 693
 694 VG_STATIC int ray_world( world_instance *world,
 695                          v3f pos, v3f dir, ray_hit *hit )
 696 {
 697    return scene_raycast( world->scene_geo, world->geo_bh, pos, dir, hit );
 698 }
 699
 700 /*
 701  * Cast a sphere from a to b and see what time it hits
 702  */
 703 VG_STATIC int spherecast_world( world_instance *world,
 704                                 v3f pa, v3f pb, float r, float *t, v3f n )
 705 {
 706    bh_iter it;
 707    bh_iter_init( 0, &it );
 708
 709    boxf region;
 710    box_init_inf( region );
 711    box_addpt( region, pa );
 712    box_addpt( region, pb );
 713
 714    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 715    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 716
 717    v3f dir;
 718    v3_sub( pb, pa, dir );
 719
 720    v3f dir_inv;
 721    dir_inv[0] = 1.0f/dir[0];
 722    dir_inv[1] = 1.0f/dir[1];
 723    dir_inv[2] = 1.0f/dir[2];
 724
 725    int hit = -1;
 726    float min_t = 1.0f;
 727
 728    int idx;
 729    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 730       u32 *ptri = &world->scene_geo->arrindices[ idx*3 ];
 731       v3f tri[3];
 732
 733       boxf box;
 734       box_init_inf( box );
 735
 736       for( int j=0; j<3; j++ ){
 737          v3_copy( world->scene_geo->arrvertices[ptri[j]].co, tri[j] );
 738          box_addpt( box, tri[j] );
 739       }
 740
 741       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 742       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 743
 744       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 745          continue;
 746
 747       float t;
 748       v3f n1;
 749       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 750          if( t < min_t ){
 751             min_t = t;
 752             hit = idx;
 753             v3_copy( n1, n );
 754          }
 755       }
 756    }
 757
 758    *t = min_t;
 759    return hit;
 760 }
 761
 762 VG_STATIC
 763 struct world_surface *world_tri_index_surface( world_instance *world,
 764                                                  u32 index )
 765 {
 766    for( int i=1; i<world->surface_count; i++ ){
 767       struct world_surface *surf = &world->surfaces[i];
 768
 769       if( (index >= surf->sm_geo.vertex_start) &&
 770           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 771       {
 772          return surf;
 773       }
 774    }
 775
 776    return &world->surfaces[0];
 777 }
 778
 779 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 780                                                          rb_ct *ct )
 781 {
 782    return world_tri_index_surface( world, ct->element_id );
 783 }
 784
 785 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 786                                                  ray_hit *hit )
 787 {
 788    return world_tri_index_surface( world, hit->tri[0] );
 789 }
 790
 791 #endif /* WORLD_H */