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
 170    ent_gate *rendering_gate;
 171
 172    /* logic
 173     * ----------------------------------------------------
 174     */
 175
 176    /* world geometry */
 177    scene *scene_geo,
 178          *scene_no_collide,
 179          *scene_lines;
 180
 181    /* spacial mappings */
 182    bh_tree *audio_bh,
 183            *volume_bh,
 184            *geo_bh;
 185
 186    /* graphics */
 187    glmesh mesh_route_lines;
 188    glmesh mesh_geo,
 189           mesh_no_collide,
 190           mesh_water;
 191
 192    rb_object rb_geo;
 193 };
 194
 195 struct world_global{
 196    /*
 197     * Allocated as system memory
 198     * --------------------------------------------------------------------------
 199     */
 200    void *heap;
 201
 202    /* rendering */
 203    glmesh skydome;
 204    glmesh mesh_gate;
 205    mdl_submesh sm_gate_surface,
 206                sm_gate_marker[4];
 207
 208    double sky_time, sky_rate, sky_target_rate;
 209
 210    u32 current_run_version;
 211    double time, rewind_from, rewind_to, last_use;
 212
 213    /* water rendering */
 214    struct{
 215       struct framebuffer fbreflect, fbdepth;
 216    }
 217    water;
 218
 219    /* split flap display */
 220    struct{
 221       glmesh mesh_base, mesh_display;
 222       mdl_submesh sm_base;
 223       u32 active_route_board;
 224
 225       u32 w, h;
 226       float *buffer;
 227    }
 228    sfd;
 229
 230    v3f render_gate_pos;
 231    int in_volume;
 232
 233    int switching_to_new_world;
 234
 235    world_instance worlds[4];
 236    u32            world_count;
 237    u32            active_world;
 238
 239    /* text particles */
 240    font3d font;
 241
 242    struct timer_text{
 243       char text[8];
 244       m4x3f transform;
 245       ent_gate *gate;
 246       ent_route *route;
 247    }
 248    timer_texts[4];
 249    u32 timer_text_count;
 250
 251    struct text_particle{
 252       rb_object obj;
 253       m4x3f mlocal;
 254       ent_glyph *glyph;
 255       v4f colour;
 256
 257       m4x3f mdl;
 258    }
 259    text_particles[6*4];
 260    u32 text_particle_count;
 261 }
 262 static world_global;
 263
 264 VG_STATIC world_instance *get_active_world( void )
 265 {
 266    return &world_global.worlds[ world_global.active_world ];
 267 }
 268
 269 /*
 270  * API
 271  */
 272
 273 VG_STATIC
 274 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 275
 276 VG_STATIC
 277 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 278
 279 VG_STATIC
 280 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 281
 282 VG_STATIC
 283 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 284
 285 VG_STATIC
 286 ent_spawn *world_find_closest_spawn( world_instance *world, v3f position )
 287 {
 288    ent_spawn *rp = NULL, *r;
 289    float min_dist = INFINITY;
 290
 291    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 292       r = mdl_arritm( &world->ent_spawn, i );
 293       float d = v3_dist2( r->transform.co, position );
 294
 295       if( d < min_dist ){
 296          min_dist = d;
 297          rp = r;
 298       }
 299    }
 300
 301    if( !rp ){
 302       if( mdl_arrcount(&world->ent_spawn) ){
 303          vg_warn( "Invalid distances to spawns.. defaulting to first one.\n" );
 304          return mdl_arritm( &world->ent_spawn, 0 );
 305       }
 306       else{
 307          vg_error( "There are no spawns in the level!\n" );
 308       }
 309    }
 310
 311    return rp;
 312 }
 313
 314 VG_STATIC
 315 ent_spawn *world_find_spawn_by_name( world_instance *world, const char *name )
 316 {
 317    ent_spawn *rp = NULL, *r;
 318    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 319       r = mdl_arritm( &world->ent_spawn, i );
 320       if( !strcmp( mdl_pstr(&world->meta, r->pstr_name), name ) ){
 321          rp = r;
 322          break;
 323       }
 324    }
 325
 326    if( !rp )
 327       vg_warn( "No spawn named '%s'\n", name );
 328
 329    return rp;
 330 }
 331
 332 /*
 333  * Submodules
 334  */
 335
 336 VG_STATIC float
 337    k_day_length            = 30.0f; /* minutes */
 338
 339 VG_STATIC int   k_debug_light_indices = 0,
 340                 k_debug_light_complexity = 0,
 341                 k_light_preview = 0;
 342
 343 #include "world_routes.h"
 344 #include "world_sfd.h"
 345 #include "world_render.h"
 346 #include "world_water.h"
 347 #include "world_volumes.h"
 348 #include "world_gen.h"
 349 #include "world_gate.h"
 350
 351 /*
 352  * -----------------------------------------------------------------------------
 353  *                                    Events
 354  * -----------------------------------------------------------------------------
 355  */
 356
 357 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 358 {
 359    world_instance *world = get_active_world();
 360    return 0;
 361 }
 362
 363 VG_STATIC void world_init(void)
 364 {
 365    VG_VAR_F32( k_day_length );
 366    VG_VAR_I32( k_debug_light_indices );
 367    VG_VAR_I32( k_debug_light_complexity );
 368    VG_VAR_I32( k_light_preview );
 369
 370    world_global.sky_rate = 1.0;
 371    world_global.sky_target_rate = 1.0;
 372
 373    shader_scene_standard_register();
 374    shader_scene_standard_alphatest_register();
 375    shader_scene_vertex_blend_register();
 376    shader_scene_terrain_register();
 377    shader_scene_depth_register();
 378    shader_scene_position_register();
 379
 380    shader_model_sky_register();
 381
 382    vg_info( "Loading world resources\n" );
 383
 384    vg_linear_clear( vg_mem.scratch );
 385
 386    mdl_context msky;
 387    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 388    mdl_load_metadata_block( &msky, vg_mem.scratch );
 389    mdl_load_mesh_block( &msky, vg_mem.scratch );
 390    mdl_close( &msky );
 391
 392    vg_acquire_thread_sync();
 393    {
 394       mdl_unpack_glmesh( &msky, &world_global.skydome );
 395    }
 396    vg_release_thread_sync();
 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 typedef struct ent_call ent_call;
 414 struct ent_call{
 415    ent_index ent;
 416    u32 function;
 417    void *data;
 418 };
 419
 420 VG_STATIC void entity_call( world_instance *world, ent_call *call );
 421
 422 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 423 {
 424    ent_volume *volume = mdl_arritm( &world->ent_volume, call->ent.index );
 425    if( !volume->target.type ) return;
 426
 427    if( call->function == k_ent_function_trigger ){
 428       call->ent = volume->target;
 429
 430       if( volume->type == k_volume_subtype_particle ){
 431          float *co = alloca( sizeof(float)*3 );
 432          co[0] = vg_randf()*2.0f-1.0f;
 433          co[1] = vg_randf()*2.0f-1.0f;
 434          co[2] = vg_randf()*2.0f-1.0f;
 435          m4x3_mulv( volume->to_world, co, co );
 436
 437          call->function = k_ent_function_particle_spawn;
 438          call->data = co;
 439          entity_call( world, call );
 440       }
 441       else
 442          entity_call( world, call );
 443    }
 444 }
 445
 446 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 447 {
 448    ent_audio *audio = mdl_arritm( &world->ent_audio, call->ent.index );
 449
 450    v3f sound_co;
 451
 452    if( call->function == k_ent_function_particle_spawn ){
 453       v3_copy( call->data, sound_co );
 454    }
 455    else if( call->function == k_ent_function_trigger ){
 456       v3_copy( audio->transform.co, sound_co );
 457    }
 458    else
 459       vg_fatal_exit_loop( "ent_audio_call (invalid function id)" );
 460
 461    float chance = vg_randf()*100.0f,
 462          bar = 0.0f;
 463
 464    for( u32 i=0; i<audio->clip_count; i++ ){
 465       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 466                                           audio->clip_start+i );
 467
 468       float mod = world->probabilities[ audio->probability_curve ],
 469             p   = clip->probability * mod;
 470
 471       bar += p;
 472
 473       if( chance < bar ){
 474
 475          audio_lock();
 476
 477          if( audio->behaviour == k_channel_behaviour_unlimited ){
 478             audio_oneshot_3d( &clip->clip, sound_co,
 479                               audio->transform.s[0],
 480                               audio->volume );
 481          }
 482          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 483             audio_channel *ch =
 484                audio_get_group_idle_channel( audio->group,
 485                                              audio->max_channels );
 486
 487             if( ch ){
 488                audio_channel_init( ch, &clip->clip, audio->flags );
 489                audio_channel_group( ch, audio->group );
 490                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 491                audio_channel_edit_volume( ch, audio->volume, 1 );
 492                ch = audio_relinquish_channel( ch );
 493             }
 494          }
 495          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 496             audio_channel *ch =
 497                audio_get_group_idle_channel( audio->group,
 498                                              audio->max_channels );
 499
 500             /* group is full */
 501             if( !ch ){
 502                audio_channel *existing =
 503                   audio_get_group_first_active_channel( audio->group );
 504
 505                if( existing ){
 506                   if( existing->source == &clip->clip ){
 507                      audio_unlock();
 508                      return;
 509                   }
 510
 511                   existing->group = 0;
 512                   existing = audio_channel_fadeout(existing, audio->crossfade);
 513                }
 514
 515                ch = audio_get_first_idle_channel();
 516             }
 517
 518             if( ch ){
 519                audio_channel_init( ch, &clip->clip, audio->flags );
 520                audio_channel_group( ch, audio->group );
 521                audio_channel_fadein( ch, audio->crossfade );
 522                ch = audio_relinquish_channel( ch );
 523             }
 524          }
 525
 526          audio_unlock();
 527          return;
 528       }
 529    }
 530 }
 531
 532 VG_STATIC void entity_call( world_instance *world, ent_call *call )
 533 {
 534    if( call->ent.type == k_ent_volume ){
 535       ent_volume_call( world, call );
 536    } else if( call->ent.type == k_ent_audio ){
 537       ent_audio_call( world, call );
 538    }
 539 }
 540
 541 VG_STATIC void world_update( world_instance *world, v3f pos )
 542 {
 543    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 544    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 545                                     world_global.sky_target_rate,
 546                                     vg.time_delta * 5.0 );
 547
 548    world_routes_update_timer_texts( world );
 549    world_routes_update( world );
 550    //world_routes_debug( world );
 551
 552    /* ---- traffic -------- */
 553
 554    for( u32 i=0; i<mdl_arrcount( &world->ent_traffic ); i++ ){
 555       ent_traffic *traffic = mdl_arritm( &world->ent_traffic, i );
 556
 557       u32 i1 = traffic->index,
 558           i0,
 559           i2 = i1+1;
 560
 561       if( i1 == 0 ) i0 = traffic->node_count-1;
 562       else i0 = i1-1;
 563
 564       if( i2 >= traffic->node_count ) i2 = 0;
 565
 566       i0 += traffic->start_node;
 567       i1 += traffic->start_node;
 568       i2 += traffic->start_node;
 569
 570       v3f h[3];
 571
 572       ent_route_node *rn0 = mdl_arritm( &world->ent_route_node, i0 ),
 573                      *rn1 = mdl_arritm( &world->ent_route_node, i1 ),
 574                      *rn2 = mdl_arritm( &world->ent_route_node, i2 );
 575
 576       v3_copy( rn1->co, h[1] );
 577       v3_lerp( rn0->co, rn1->co, 0.5f, h[0] );
 578       v3_lerp( rn1->co, rn2->co, 0.5f, h[2] );
 579
 580       float const k_sample_dist = 0.0025f;
 581       v3f pc, pd;
 582       eval_bezier3( h[0], h[1], h[2], traffic->t, pc );
 583       eval_bezier3( h[0], h[1], h[2], traffic->t+k_sample_dist, pd );
 584
 585       v3f v0;
 586       v3_sub( pd, pc, v0 );
 587       float length = vg_maxf( 0.0001f, v3_length( v0 ) );
 588       v3_muls( v0, 1.0f/length, v0 );
 589
 590       float mod = k_sample_dist / length;
 591
 592       traffic->t += traffic->speed * vg.time_delta * mod;
 593
 594       if( traffic->t > 1.0f ){
 595          traffic->t -= 1.0f;
 596
 597          if( traffic->t > 1.0f ) traffic->t = 0.0f;
 598
 599          traffic->index ++;
 600
 601          if( traffic->index >= traffic->node_count )
 602             traffic->index = 0;
 603       }
 604
 605       v3_copy( pc, traffic->transform.co );
 606
 607       float a = atan2f( -v0[0], v0[2] );
 608       q_axis_angle( traffic->transform.q, (v3f){0.0f,1.0f,0.0f}, -a );
 609
 610       vg_line_pt3( traffic->transform.co, 0.3f, VG__BLUE );
 611    }
 612
 613    /* ---- SFD ------------ */
 614
 615    if( mdl_arrcount( &world->ent_route ) ){
 616       u32 closest = 0;
 617       float min_dist = INFINITY;
 618
 619       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 620          ent_route *route = mdl_arritm( &world->ent_route, i );
 621          float dist = v3_dist2( route->board_transform[3], pos );
 622
 623          if( dist < min_dist ){
 624             min_dist = dist;
 625             closest = i;
 626          }
 627       }
 628
 629       if( (world_global.sfd.active_route_board != closest)
 630           || network_scores_updated )
 631       {
 632          network_scores_updated = 0;
 633          world_global.sfd.active_route_board = closest;
 634
 635          ent_route *route = mdl_arritm( &world->ent_route, closest );
 636          u32 id = route->official_track_id;
 637
 638          if( id != 0xffffffff ){
 639             struct netmsg_board *local_board =
 640                &scoreboard_client_data.boards[id];
 641
 642             for( int i=0; i<13; i++ ){
 643                sfd_encode( i, &local_board->data[27*i] );
 644             }
 645          }else{
 646             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 647             sfd_encode( 1, "No data" );
 648          }
 649       }
 650    }
 651    sfd_update();
 652
 653    static float random_accum = 0.0f;
 654    random_accum += vg.time_delta;
 655
 656    u32 random_ticks = 0;
 657
 658    while( random_accum > 0.1f ){
 659       random_accum -= 0.1f;
 660       random_ticks ++;
 661    }
 662
 663    float radius = 25.0f;
 664    boxf volume_proximity;
 665    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 666    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 667
 668    bh_iter it;
 669    bh_iter_init( 0, &it );
 670    int idx;
 671
 672    int in_volume = 0;
 673
 674    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 675       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 676
 677       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 678
 679       if( volume->type == k_volume_subtype_trigger ){
 680          v3f local;
 681          m4x3_mulv( volume->to_local, pos, local );
 682
 683          if( (fabsf(local[0]) <= 1.0f) &&
 684              (fabsf(local[1]) <= 1.0f) &&
 685              (fabsf(local[2]) <= 1.0f) )
 686          {
 687             in_volume = 1;
 688             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 689
 690             if( !world_global.in_volume ){
 691                ent_call basecall;
 692                basecall.ent.index = idx;
 693                basecall.ent.type = k_ent_volume;
 694                basecall.function = k_ent_function_trigger;
 695                basecall.data = NULL;
 696
 697                entity_call( world, &basecall );
 698             }
 699          }
 700          else
 701             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 702       }
 703       else if( volume->type == k_volume_subtype_particle ){
 704          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 705
 706          for( int j=0; j<random_ticks; j++ ){
 707             ent_call basecall;
 708             basecall.ent.index = idx;
 709             basecall.ent.type = k_ent_volume;
 710             basecall.function = k_ent_function_trigger;
 711             basecall.data = NULL;
 712
 713             entity_call( world, &basecall );
 714          }
 715       }
 716    }
 717    world_global.in_volume = in_volume;
 718
 719 #if 0
 720    if( k_debug_light_indices )
 721    {
 722       for( int i=0; i<world->light_count; i++ ){
 723          struct world_light *light = &world->lights[i];
 724          struct classtype_world_light *inf = light->inf;
 725
 726          u32 colour = 0xff000000;
 727          u8 r = inf->colour[0] * 255.0f,
 728             g = inf->colour[1] * 255.0f,
 729             b = inf->colour[2] * 255.0f;
 730
 731          colour |= r;
 732          colour |= g << 8;
 733          colour |= b << 16;
 734
 735          vg_line_pt3( light->node->co, 0.25f, colour );
 736       }
 737    }
 738
 739 #endif
 740 }
 741
 742 /*
 743  * -----------------------------------------------------------------------------
 744  *                              API implementation
 745  * -----------------------------------------------------------------------------
 746  */
 747
 748 VG_STATIC void ray_world_get_tri( world_instance *world,
 749                                   ray_hit *hit, v3f tri[3] )
 750 {
 751    for( int i=0; i<3; i++ )
 752       v3_copy( world->scene_geo->arrvertices[ hit->tri[i] ].co, tri[i] );
 753 }
 754
 755 VG_STATIC int ray_world( world_instance *world,
 756                          v3f pos, v3f dir, ray_hit *hit )
 757 {
 758    return scene_raycast( world->scene_geo, world->geo_bh, pos, dir, hit );
 759 }
 760
 761 /*
 762  * Cast a sphere from a to b and see what time it hits
 763  */
 764 VG_STATIC int spherecast_world( world_instance *world,
 765                                 v3f pa, v3f pb, float r, float *t, v3f n )
 766 {
 767    bh_iter it;
 768    bh_iter_init( 0, &it );
 769
 770    boxf region;
 771    box_init_inf( region );
 772    box_addpt( region, pa );
 773    box_addpt( region, pb );
 774
 775    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 776    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 777
 778    v3f dir;
 779    v3_sub( pb, pa, dir );
 780
 781    v3f dir_inv;
 782    dir_inv[0] = 1.0f/dir[0];
 783    dir_inv[1] = 1.0f/dir[1];
 784    dir_inv[2] = 1.0f/dir[2];
 785
 786    int hit = -1;
 787    float min_t = 1.0f;
 788
 789    int idx;
 790    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 791       u32 *ptri = &world->scene_geo->arrindices[ idx*3 ];
 792       v3f tri[3];
 793
 794       boxf box;
 795       box_init_inf( box );
 796
 797       for( int j=0; j<3; j++ ){
 798          v3_copy( world->scene_geo->arrvertices[ptri[j]].co, tri[j] );
 799          box_addpt( box, tri[j] );
 800       }
 801
 802       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 803       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 804
 805       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 806          continue;
 807
 808       float t;
 809       v3f n1;
 810       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 811          if( t < min_t ){
 812             min_t = t;
 813             hit = idx;
 814             v3_copy( n1, n );
 815          }
 816       }
 817    }
 818
 819    *t = min_t;
 820    return hit;
 821 }
 822
 823 VG_STATIC
 824 struct world_surface *world_tri_index_surface( world_instance *world,
 825                                                  u32 index )
 826 {
 827    for( int i=1; i<world->surface_count; i++ ){
 828       struct world_surface *surf = &world->surfaces[i];
 829
 830       if( (index >= surf->sm_geo.vertex_start) &&
 831           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 832       {
 833          return surf;
 834       }
 835    }
 836
 837    return &world->surfaces[0];
 838 }
 839
 840 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 841                                                          rb_ct *ct )
 842 {
 843    return world_tri_index_surface( world, ct->element_id );
 844 }
 845
 846 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 847                                                  ray_hit *hit )
 848 {
 849    return world_tri_index_surface( world, hit->tri[0] );
 850 }
 851
 852 /*
 853  * -----------------------------------------------------------------------------
 854  *                              Audio sampling
 855  * -----------------------------------------------------------------------------
 856  */
 857
 858 VG_STATIC
 859 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output);
 860 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
 861
 862 #include "audio.h"
 863
 864 /*
 865  * Trace out a random point, near the player to try and determine water areas
 866  */
 867 VG_STATIC
 868 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
 869 {
 870    v3f chance = { (vg_randf()-0.5f) * 30.0f,
 871                   8.0f,
 872                   (vg_randf()-0.5f) * 30.0f };
 873
 874    v3f pos;
 875    v3_add( chance, origin, pos );
 876
 877    ray_hit contact;
 878    contact.dist = vg_minf( 16.0f, pos[1] );
 879
 880    world_instance *world = get_active_world();
 881
 882    if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
 883       struct world_surface *mat = ray_hit_surface( world, &contact );
 884
 885       if( mat->info.surface_prop == k_surface_prop_grass){
 886          v3_copy( contact.pos, output );
 887          return k_audio_sprite_type_grass;
 888       }
 889       else{
 890          return k_audio_sprite_type_none;
 891       }
 892    }
 893
 894    output[0] = pos[0];
 895    output[1] = 0.0f;
 896    output[2] = pos[2];
 897
 898    float dist = fabsf(output[1] - origin[1]);
 899
 900    if( world->water.enabled && dist<=40.0f )
 901       return k_audio_sprite_type_water;
 902    else
 903       return k_audio_sprite_type_none;
 904 }
 905
 906 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
 907 {
 908    float inr3 = 0.57735027,
 909          inr2 = 0.70710678118;
 910
 911    v3f sample_directions[] = {
 912       { -1.0f,  0.0f,  0.0f },
 913       {  1.0f,  0.0f,  0.0f },
 914       {  0.0f,  0.0f,  1.0f },
 915       {  0.0f,  0.0f, -1.0f },
 916       {  0.0f,  1.0f,  0.0f },
 917       {  0.0f, -1.0f,  0.0f },
 918       { -inr3,  inr3,  inr3 },
 919       {  inr3,  inr3,  inr3 },
 920       { -inr3,  inr3, -inr3 },
 921       {  inr3,  inr3, -inr3 },
 922       { -inr2,  0.0f,  inr2 },
 923       {  inr2,  0.0f,  inr2 },
 924       { -inr2,  0.0f, -inr2 },
 925       {  inr2,  0.0f, -inr2 },
 926    };
 927
 928    static int si = 0;
 929    static float distances[16];
 930
 931    ray_hit ray;
 932    ray.dist = 5.0f;
 933
 934    v3f rc, rd, ro;
 935    v3_copy( sample_directions[ si ], rd );
 936    v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
 937    v3_copy( ro, rc );
 938
 939    float dist = 200.0f;
 940
 941    for( int i=0; i<10; i++ ){
 942       if( ray_world( get_active_world(), rc, rd, &ray ) ){
 943          dist = (float)i*5.0f + ray.dist;
 944          break;
 945       }
 946       else{
 947          v3_muladds( rc, rd, ray.dist, rc );
 948       }
 949    }
 950
 951    distances[si] = dist;
 952
 953    if( vg_lines.draw ){
 954       for( int i=0; i<14; i++ ){
 955          if( distances[i] != 200.0f ){
 956             u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
 957                               VG__CYAN, VG__YELOW, VG__PINK,
 958                               VG__WHITE };
 959
 960             u32 colour = colours[i%7];
 961
 962             v3f p1;
 963             v3_muladds( ro, sample_directions[i], distances[i], p1 );
 964             vg_line( ro, p1, colour );
 965             vg_line_pt3( p1, 0.1f, colour );
 966          }
 967       }
 968    }
 969
 970    *index = si;
 971    *value = dist;
 972
 973    si ++;
 974    if( si >= 14 )
 975       si = 0;
 976 }
 977
 978 #endif /* WORLD_H */