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    void *heap;
  64    char  world_name[ 64 ];
  65    enum world_status{
  66       k_world_status_unloaded = 0,
  67       k_world_status_loading = 1,
  68       k_world_status_loaded = 2
  69    }
  70    status;
  71
  72    struct{
  73       boxf depthbounds;
  74       int depth_computed;
  75
  76       float height;
  77       int enabled;
  78       v4f plane;
  79    }
  80    water;
  81
  82    /* STD140 */
  83    struct ub_world_lighting{
  84       v4f g_cube_min,
  85           g_cube_inv_range;
  86
  87       v4f g_water_plane,
  88           g_depth_bounds;
  89
  90       v4f g_daysky_colour;
  91       v4f g_nightsky_colour;
  92       v4f g_sunset_colour;
  93       v4f g_ambient_colour;
  94       v4f g_sunset_ambient;
  95       v4f g_sun_colour;
  96       v4f g_sun_dir;
  97       v4f g_board_0;
  98       v4f g_board_1;
  99
 100       float g_water_fog;
 101       float g_time;
 102       float g_realtime;
 103       float g_shadow_length;
 104       float g_shadow_spread;
 105
 106       float g_time_of_day;
 107       float g_day_phase;
 108       float g_sunset_phase;
 109
 110       int g_light_preview;
 111       int g_shadow_samples;
 112
 113       int g_debug_indices;
 114       int g_debug_complexity;
 115    }
 116    ub_lighting;
 117    GLuint ubo_lighting;
 118    int    ubo_bind_point;
 119
 120    GLuint tbo_light_entities,
 121           tex_light_entities,
 122           tex_light_cubes;
 123
 124    float probabilities[3];
 125
 126    v3i light_cubes;
 127
 128    struct framebuffer heightmap;
 129
 130    /*
 131     * Dynamically allocated when world_load is called.
 132     *
 133     *                  the following arrays index somewhere into this linear
 134     *                  allocator
 135     *
 136     * (world_gen.h)
 137     * --------------------------------------------------------------------------
 138     */
 139
 140    /*
 141     * Main world .mdl
 142     */
 143    mdl_context meta;
 144
 145    GLuint *textures;
 146    u32 texture_count;
 147
 148    struct world_surface{
 149       mdl_material info;
 150       mdl_submesh sm_geo,
 151                   sm_no_collide;
 152    }
 153    * surfaces;
 154    u32 surface_count;
 155
 156    mdl_array_ptr ent_spawn,
 157                  ent_gate,
 158                  ent_light,
 159                  ent_route_node,
 160                  ent_path_index,
 161                  ent_checkpoint,
 162                  ent_route,
 163                  ent_water,
 164
 165                  ent_audio_clip,
 166                  ent_audio,
 167                  ent_volume,
 168                  ent_traffic,
 169                  ent_skateshop,
 170                  ent_marker,
 171                  ent_camera,
 172                  ent_swspreview;
 173
 174    ent_gate *rendering_gate;
 175
 176    /* logic
 177     * ----------------------------------------------------
 178     */
 179
 180    /* world geometry */
 181    scene_context scene_geo,
 182                  scene_no_collide,
 183                  scene_lines;
 184
 185    /* spacial mappings */
 186    bh_tree *audio_bh,
 187            *volume_bh,
 188            *geo_bh;
 189
 190    /* graphics */
 191    glmesh mesh_route_lines;
 192    glmesh mesh_geo,
 193           mesh_no_collide,
 194           mesh_water;
 195
 196    rb_object rb_geo;
 197 };
 198
 199 struct world_global{
 200    /*
 201     * Allocated as system memory
 202     * --------------------------------------------------------------------------
 203     */
 204    void *heap;
 205
 206    /* rendering */
 207    glmesh skydome;
 208    glmesh mesh_gate;
 209    mdl_submesh sm_gate_surface,
 210                sm_gate_marker[4];
 211
 212    double sky_time, sky_rate, sky_target_rate;
 213
 214    u32 current_run_version;
 215    double time, rewind_from, rewind_to, last_use;
 216
 217    /* water rendering */
 218    struct{
 219       struct framebuffer fbreflect, fbdepth;
 220    }
 221    water;
 222
 223    /* split flap display */
 224    struct{
 225       glmesh mesh_base, mesh_display;
 226       mdl_submesh sm_base;
 227       u32 active_route_board;
 228       scene_context scene;
 229
 230       u32 w, h;
 231       float *buffer;
 232    }
 233    sfd;
 234
 235    v3f render_gate_pos;
 236    int in_volume;
 237
 238    int switching_to_new_world;
 239
 240    world_instance worlds[4];
 241    u32            world_count;
 242    u32            active_world;
 243
 244    /* text particles */
 245    font3d font;
 246
 247    struct timer_text{
 248       char text[8];
 249       m4x3f transform;
 250       ent_gate *gate;
 251       ent_route *route;
 252    }
 253    timer_texts[4];
 254    u32 timer_text_count;
 255
 256    struct text_particle{
 257       rb_object obj;
 258       m4x3f mlocal;
 259       ent_glyph *glyph;
 260       v4f colour;
 261
 262       m4x3f mdl;
 263    }
 264    text_particles[6*4];
 265    u32 text_particle_count;
 266 }
 267 static world_global;
 268 VG_STATIC void entity_call( world_instance *world, ent_call *call );
 269
 270 VG_STATIC world_instance *get_active_world( void )
 271 {
 272    return &world_global.worlds[ world_global.active_world ];
 273 }
 274
 275 /*
 276  * API
 277  */
 278
 279 VG_STATIC
 280 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 281
 282 VG_STATIC
 283 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 284
 285 VG_STATIC
 286 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 287
 288 VG_STATIC
 289 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 290
 291 VG_STATIC
 292 ent_spawn *world_find_closest_spawn( world_instance *world, v3f position )
 293 {
 294    ent_spawn *rp = NULL, *r;
 295    float min_dist = INFINITY;
 296
 297    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 298       r = mdl_arritm( &world->ent_spawn, i );
 299       float d = v3_dist2( r->transform.co, position );
 300
 301       if( d < min_dist ){
 302          min_dist = d;
 303          rp = r;
 304       }
 305    }
 306
 307    if( !rp ){
 308       if( mdl_arrcount(&world->ent_spawn) ){
 309          vg_warn( "Invalid distances to spawns.. defaulting to first one.\n" );
 310          return mdl_arritm( &world->ent_spawn, 0 );
 311       }
 312       else{
 313          vg_error( "There are no spawns in the level!\n" );
 314       }
 315    }
 316
 317    return rp;
 318 }
 319
 320 VG_STATIC
 321 ent_spawn *world_find_spawn_by_name( world_instance *world, const char *name )
 322 {
 323    ent_spawn *rp = NULL, *r;
 324    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 325       r = mdl_arritm( &world->ent_spawn, i );
 326       if( !strcmp( mdl_pstr(&world->meta, r->pstr_name), name ) ){
 327          rp = r;
 328          break;
 329       }
 330    }
 331
 332    if( !rp )
 333       vg_warn( "No spawn named '%s'\n", name );
 334
 335    return rp;
 336 }
 337
 338 /*
 339  * Submodules
 340  */
 341
 342 VG_STATIC float
 343    k_day_length            = 30.0f; /* minutes */
 344
 345 VG_STATIC int   k_debug_light_indices = 0,
 346                 k_debug_light_complexity = 0,
 347                 k_light_preview = 0;
 348
 349 #include "world_routes.h"
 350 #include "world_sfd.h"
 351 #include "world_render.h"
 352 #include "world_water.h"
 353 #include "world_volumes.h"
 354 #include "world_gen.h"
 355 #include "world_gate.h"
 356
 357 /*
 358  * -----------------------------------------------------------------------------
 359  *                                    Events
 360  * -----------------------------------------------------------------------------
 361  */
 362
 363 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 364 {
 365    world_instance *world = get_active_world();
 366    return 0;
 367 }
 368
 369 VG_STATIC void world_init(void)
 370 {
 371    VG_VAR_F32( k_day_length );
 372    VG_VAR_I32( k_debug_light_indices );
 373    VG_VAR_I32( k_debug_light_complexity );
 374    VG_VAR_I32( k_light_preview );
 375
 376    world_global.sky_rate = 1.0;
 377    world_global.sky_target_rate = 1.0;
 378
 379    shader_scene_standard_register();
 380    shader_scene_standard_alphatest_register();
 381    shader_scene_vertex_blend_register();
 382    shader_scene_terrain_register();
 383    shader_scene_depth_register();
 384    shader_scene_position_register();
 385
 386    shader_model_sky_register();
 387
 388    vg_info( "Loading world resources\n" );
 389
 390    vg_linear_clear( vg_mem.scratch );
 391
 392    mdl_context msky;
 393    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 394    mdl_load_metadata_block( &msky, vg_mem.scratch );
 395    mdl_async_load_glmesh( &msky, &world_global.skydome );
 396    mdl_close( &msky );
 397
 398    /* Other systems */
 399    vg_info( "Loading other world systems\n" );
 400
 401    vg_loader_step( world_render_init, NULL );
 402    vg_loader_step( world_sfd_init, NULL );
 403    vg_loader_step( world_water_init, NULL );
 404    vg_loader_step( world_gates_init, NULL );
 405    vg_loader_step( world_routes_init, NULL );
 406
 407    /* Allocate dynamic world memory arena */
 408    u32 max_size = 76*1024*1024;
 409    world_global.heap = vg_create_linear_allocator( vg_mem.rtmemory, max_size,
 410                                                    VG_MEMORY_SYSTEM );
 411 }
 412
 413 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 414 {
 415    u32 index = mdl_entity_id_id( call->id );
 416    ent_volume *volume = mdl_arritm( &world->ent_volume, index );
 417    if( !volume->target ) return;
 418
 419    if( call->function == k_ent_function_trigger ){
 420       call->id = volume->target;
 421
 422       if( volume->type == k_volume_subtype_particle ){
 423          float *co = alloca( sizeof(float)*3 );
 424          co[0] = vg_randf64()*2.0f-1.0f;
 425          co[1] = vg_randf64()*2.0f-1.0f;
 426          co[2] = vg_randf64()*2.0f-1.0f;
 427          m4x3_mulv( volume->to_world, co, co );
 428
 429          call->function = k_ent_function_particle_spawn;
 430          call->data = co;
 431          entity_call( world, call );
 432       }
 433       else{
 434          entity_call( world, call );
 435       }
 436    }
 437 }
 438
 439 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 440 {
 441    u32 index = mdl_entity_id_id( call->id );
 442    ent_audio *audio = mdl_arritm( &world->ent_audio, index );
 443
 444    v3f sound_co;
 445
 446    if( call->function == k_ent_function_particle_spawn ){
 447       v3_copy( call->data, sound_co );
 448    }
 449    else if( call->function == k_ent_function_trigger ){
 450       v3_copy( audio->transform.co, sound_co );
 451    }
 452    else
 453       vg_fatal_error( "ent_audio_call (invalid function id)" );
 454
 455    float chance = vg_randf64()*100.0f,
 456          bar = 0.0f;
 457
 458    for( u32 i=0; i<audio->clip_count; i++ ){
 459       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 460                                           audio->clip_start+i );
 461
 462       float mod = world->probabilities[ audio->probability_curve ],
 463             p   = clip->probability * mod;
 464
 465       bar += p;
 466
 467       if( chance < bar ){
 468
 469          audio_lock();
 470
 471          if( audio->behaviour == k_channel_behaviour_unlimited ){
 472             audio_oneshot_3d( &clip->clip, sound_co,
 473                               audio->transform.s[0],
 474                               audio->volume );
 475          }
 476          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 477             audio_channel *ch =
 478                audio_get_group_idle_channel( audio->group,
 479                                              audio->max_channels );
 480
 481             if( ch ){
 482                audio_channel_init( ch, &clip->clip, audio->flags );
 483                audio_channel_group( ch, audio->group );
 484                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 485                audio_channel_edit_volume( ch, audio->volume, 1 );
 486                ch = audio_relinquish_channel( ch );
 487             }
 488          }
 489          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 490             audio_channel *ch =
 491                audio_get_group_idle_channel( audio->group,
 492                                              audio->max_channels );
 493
 494             /* group is full */
 495             if( !ch ){
 496                audio_channel *existing =
 497                   audio_get_group_first_active_channel( audio->group );
 498
 499                if( existing ){
 500                   if( existing->source == &clip->clip ){
 501                      audio_unlock();
 502                      return;
 503                   }
 504
 505                   existing->group = 0;
 506                   existing = audio_channel_fadeout(existing, audio->crossfade);
 507                }
 508
 509                ch = audio_get_first_idle_channel();
 510             }
 511
 512             if( ch ){
 513                audio_channel_init( ch, &clip->clip, audio->flags );
 514                audio_channel_group( ch, audio->group );
 515                audio_channel_fadein( ch, audio->crossfade );
 516                ch = audio_relinquish_channel( ch );
 517             }
 518          }
 519
 520          audio_unlock();
 521          return;
 522       }
 523    }
 524 }
 525
 526 VG_STATIC void world_update( world_instance *world, v3f pos )
 527 {
 528    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 529    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 530                                     world_global.sky_target_rate,
 531                                     vg.time_delta * 5.0 );
 532
 533    world_routes_update_timer_texts( world );
 534    world_routes_update( world );
 535    //world_routes_debug( world );
 536
 537    /* ---- traffic -------- */
 538
 539    for( u32 i=0; i<mdl_arrcount( &world->ent_traffic ); i++ ){
 540       ent_traffic *traffic = mdl_arritm( &world->ent_traffic, i );
 541
 542       u32 i1 = traffic->index,
 543           i0,
 544           i2 = i1+1;
 545
 546       if( i1 == 0 ) i0 = traffic->node_count-1;
 547       else i0 = i1-1;
 548
 549       if( i2 >= traffic->node_count ) i2 = 0;
 550
 551       i0 += traffic->start_node;
 552       i1 += traffic->start_node;
 553       i2 += traffic->start_node;
 554
 555       v3f h[3];
 556
 557       ent_route_node *rn0 = mdl_arritm( &world->ent_route_node, i0 ),
 558                      *rn1 = mdl_arritm( &world->ent_route_node, i1 ),
 559                      *rn2 = mdl_arritm( &world->ent_route_node, i2 );
 560
 561       v3_copy( rn1->co, h[1] );
 562       v3_lerp( rn0->co, rn1->co, 0.5f, h[0] );
 563       v3_lerp( rn1->co, rn2->co, 0.5f, h[2] );
 564
 565       float const k_sample_dist = 0.0025f;
 566       v3f pc, pd;
 567       eval_bezier3( h[0], h[1], h[2], traffic->t, pc );
 568       eval_bezier3( h[0], h[1], h[2], traffic->t+k_sample_dist, pd );
 569
 570       v3f v0;
 571       v3_sub( pd, pc, v0 );
 572       float length = vg_maxf( 0.0001f, v3_length( v0 ) );
 573       v3_muls( v0, 1.0f/length, v0 );
 574
 575       float mod = k_sample_dist / length;
 576
 577       traffic->t += traffic->speed * vg.time_delta * mod;
 578
 579       if( traffic->t > 1.0f ){
 580          traffic->t -= 1.0f;
 581
 582          if( traffic->t > 1.0f ) traffic->t = 0.0f;
 583
 584          traffic->index ++;
 585
 586          if( traffic->index >= traffic->node_count )
 587             traffic->index = 0;
 588       }
 589
 590       v3_copy( pc, traffic->transform.co );
 591
 592       float a = atan2f( -v0[0], v0[2] );
 593       q_axis_angle( traffic->transform.q, (v3f){0.0f,1.0f,0.0f}, -a );
 594
 595       vg_line_pt3( traffic->transform.co, 0.3f, VG__BLUE );
 596    }
 597
 598    /* ---- SFD ------------ */
 599
 600    if( mdl_arrcount( &world->ent_route ) ){
 601       u32 closest = 0;
 602       float min_dist = INFINITY;
 603
 604       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 605          ent_route *route = mdl_arritm( &world->ent_route, i );
 606          float dist = v3_dist2( route->board_transform[3], pos );
 607
 608          if( dist < min_dist ){
 609             min_dist = dist;
 610             closest = i;
 611          }
 612       }
 613
 614       if( (world_global.sfd.active_route_board != closest)
 615           || network_scores_updated )
 616       {
 617          network_scores_updated = 0;
 618          world_global.sfd.active_route_board = closest;
 619
 620          ent_route *route = mdl_arritm( &world->ent_route, closest );
 621          u32 id = route->official_track_id;
 622
 623          if( id != 0xffffffff ){
 624             struct netmsg_board *local_board =
 625                &scoreboard_client_data.boards[id];
 626
 627             for( int i=0; i<13; i++ ){
 628                sfd_encode( i, &local_board->data[27*i] );
 629             }
 630          }else{
 631             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 632             sfd_encode( 1, "No data" );
 633          }
 634       }
 635    }
 636    sfd_update();
 637
 638    static float random_accum = 0.0f;
 639    random_accum += vg.time_delta;
 640
 641    u32 random_ticks = 0;
 642
 643    while( random_accum > 0.1f ){
 644       random_accum -= 0.1f;
 645       random_ticks ++;
 646    }
 647
 648    float radius = 25.0f;
 649    boxf volume_proximity;
 650    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 651    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 652
 653    bh_iter it;
 654    bh_iter_init( 0, &it );
 655    int idx;
 656
 657    int in_volume = 0;
 658
 659    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 660       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 661
 662       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 663
 664       if( volume->type == k_volume_subtype_trigger ){
 665          v3f local;
 666          m4x3_mulv( volume->to_local, pos, local );
 667
 668          if( (fabsf(local[0]) <= 1.0f) &&
 669              (fabsf(local[1]) <= 1.0f) &&
 670              (fabsf(local[2]) <= 1.0f) )
 671          {
 672             in_volume = 1;
 673             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 674
 675             if( !world_global.in_volume ){
 676                ent_call basecall;
 677                basecall.function = k_ent_function_trigger;
 678                basecall.id = mdl_entity_id( k_ent_volume, idx );
 679                basecall.data = NULL;
 680
 681                entity_call( world, &basecall );
 682             }
 683          }
 684          else
 685             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 686       }
 687       else if( volume->type == k_volume_subtype_particle ){
 688          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 689
 690          for( int j=0; j<random_ticks; j++ ){
 691             ent_call basecall;
 692             basecall.id = mdl_entity_id( k_ent_volume, idx );
 693             basecall.data = NULL;
 694
 695             entity_call( world, &basecall );
 696          }
 697       }
 698    }
 699    world_global.in_volume = in_volume;
 700
 701 #if 0
 702    if( k_debug_light_indices )
 703    {
 704       for( int i=0; i<world->light_count; i++ ){
 705          struct world_light *light = &world->lights[i];
 706          struct classtype_world_light *inf = light->inf;
 707
 708          u32 colour = 0xff000000;
 709          u8 r = inf->colour[0] * 255.0f,
 710             g = inf->colour[1] * 255.0f,
 711             b = inf->colour[2] * 255.0f;
 712
 713          colour |= r;
 714          colour |= g << 8;
 715          colour |= b << 16;
 716
 717          vg_line_pt3( light->node->co, 0.25f, colour );
 718       }
 719    }
 720
 721 #endif
 722 }
 723
 724 /*
 725  * -----------------------------------------------------------------------------
 726  *                              API implementation
 727  * -----------------------------------------------------------------------------
 728  */
 729
 730 VG_STATIC void ray_world_get_tri( world_instance *world,
 731                                   ray_hit *hit, v3f tri[3] )
 732 {
 733    for( int i=0; i<3; i++ )
 734       v3_copy( world->scene_geo.arrvertices[ hit->tri[i] ].co, tri[i] );
 735 }
 736
 737 VG_STATIC int ray_world( world_instance *world,
 738                          v3f pos, v3f dir, ray_hit *hit )
 739 {
 740    return scene_raycast( &world->scene_geo, world->geo_bh, pos, dir, hit );
 741 }
 742
 743 /*
 744  * Cast a sphere from a to b and see what time it hits
 745  */
 746 VG_STATIC int spherecast_world( world_instance *world,
 747                                 v3f pa, v3f pb, float r, float *t, v3f n )
 748 {
 749    bh_iter it;
 750    bh_iter_init( 0, &it );
 751
 752    boxf region;
 753    box_init_inf( region );
 754    box_addpt( region, pa );
 755    box_addpt( region, pb );
 756
 757    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 758    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 759
 760    v3f dir;
 761    v3_sub( pb, pa, dir );
 762
 763    v3f dir_inv;
 764    dir_inv[0] = 1.0f/dir[0];
 765    dir_inv[1] = 1.0f/dir[1];
 766    dir_inv[2] = 1.0f/dir[2];
 767
 768    int hit = -1;
 769    float min_t = 1.0f;
 770
 771    int idx;
 772    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 773       u32 *ptri = &world->scene_geo.arrindices[ idx*3 ];
 774       v3f tri[3];
 775
 776       boxf box;
 777       box_init_inf( box );
 778
 779       for( int j=0; j<3; j++ ){
 780          v3_copy( world->scene_geo.arrvertices[ptri[j]].co, tri[j] );
 781          box_addpt( box, tri[j] );
 782       }
 783
 784       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 785       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 786
 787       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 788          continue;
 789
 790       float t;
 791       v3f n1;
 792       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 793          if( t < min_t ){
 794             min_t = t;
 795             hit = idx;
 796             v3_copy( n1, n );
 797          }
 798       }
 799    }
 800
 801    *t = min_t;
 802    return hit;
 803 }
 804
 805 VG_STATIC
 806 struct world_surface *world_tri_index_surface( world_instance *world,
 807                                                  u32 index )
 808 {
 809    for( int i=1; i<world->surface_count; i++ ){
 810       struct world_surface *surf = &world->surfaces[i];
 811
 812       if( (index >= surf->sm_geo.vertex_start) &&
 813           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 814       {
 815          return surf;
 816       }
 817    }
 818
 819    return &world->surfaces[0];
 820 }
 821
 822 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 823                                                          rb_ct *ct )
 824 {
 825    return world_tri_index_surface( world, ct->element_id );
 826 }
 827
 828 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 829                                                  ray_hit *hit )
 830 {
 831    return world_tri_index_surface( world, hit->tri[0] );
 832 }
 833
 834 /*
 835  * -----------------------------------------------------------------------------
 836  *                              Audio sampling
 837  * -----------------------------------------------------------------------------
 838  */
 839
 840 VG_STATIC
 841 enum audio_sprite_type world_audio_sample_sprite_kandom(v3f origin, v3f output);
 842 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
 843
 844 #include "audio.h"
 845
 846 /*
 847  * Trace out a random point, near the player to try and determine water areas
 848  */
 849 VG_STATIC
 850 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
 851 {
 852    v3f chance = { (vg_randf64()-0.5f) * 30.0f,
 853                   8.0f,
 854                   (vg_randf64()-0.5f) * 30.0f };
 855
 856    v3f pos;
 857    v3_add( chance, origin, pos );
 858
 859    ray_hit contact;
 860    contact.dist = vg_minf( 16.0f, pos[1] );
 861
 862    world_instance *world = get_active_world();
 863
 864    if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
 865       struct world_surface *mat = ray_hit_surface( world, &contact );
 866
 867       if( mat->info.surface_prop == k_surface_prop_grass){
 868          v3_copy( contact.pos, output );
 869          return k_audio_sprite_type_grass;
 870       }
 871       else{
 872          return k_audio_sprite_type_none;
 873       }
 874    }
 875
 876    output[0] = pos[0];
 877    output[1] = 0.0f;
 878    output[2] = pos[2];
 879
 880    float dist = fabsf(output[1] - origin[1]);
 881
 882    if( world->water.enabled && dist<=40.0f )
 883       return k_audio_sprite_type_water;
 884    else
 885       return k_audio_sprite_type_none;
 886 }
 887
 888 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
 889 {
 890    float inr3 = 0.57735027,
 891          inr2 = 0.70710678118;
 892
 893    v3f sample_directions[] = {
 894       { -1.0f,  0.0f,  0.0f },
 895       {  1.0f,  0.0f,  0.0f },
 896       {  0.0f,  0.0f,  1.0f },
 897       {  0.0f,  0.0f, -1.0f },
 898       {  0.0f,  1.0f,  0.0f },
 899       {  0.0f, -1.0f,  0.0f },
 900       { -inr3,  inr3,  inr3 },
 901       {  inr3,  inr3,  inr3 },
 902       { -inr3,  inr3, -inr3 },
 903       {  inr3,  inr3, -inr3 },
 904       { -inr2,  0.0f,  inr2 },
 905       {  inr2,  0.0f,  inr2 },
 906       { -inr2,  0.0f, -inr2 },
 907       {  inr2,  0.0f, -inr2 },
 908    };
 909
 910    static int si = 0;
 911    static float distances[16];
 912
 913    ray_hit ray;
 914    ray.dist = 5.0f;
 915
 916    v3f rc, rd, ro;
 917    v3_copy( sample_directions[ si ], rd );
 918    v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
 919    v3_copy( ro, rc );
 920
 921    float dist = 200.0f;
 922
 923    for( int i=0; i<10; i++ ){
 924       if( ray_world( get_active_world(), rc, rd, &ray ) ){
 925          dist = (float)i*5.0f + ray.dist;
 926          break;
 927       }
 928       else{
 929          v3_muladds( rc, rd, ray.dist, rc );
 930       }
 931    }
 932
 933    distances[si] = dist;
 934
 935    if( vg_lines.draw ){
 936       for( int i=0; i<14; i++ ){
 937          if( distances[i] != 200.0f ){
 938             u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
 939                               VG__CYAN, VG__YELOW, VG__PINK,
 940                               VG__WHITE };
 941
 942             u32 colour = colours[i%7];
 943
 944             v3f p1;
 945             v3_muladds( ro, sample_directions[i], distances[i], p1 );
 946             vg_line( ro, p1, colour );
 947             vg_line_pt3( p1, 0.1f, colour );
 948          }
 949       }
 950    }
 951
 952    *index = si;
 953    *value = dist;
 954
 955    si ++;
 956    if( si >= 14 )
 957       si = 0;
 958 }
 959
 960 #endif /* WORLD_H */