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
  60    /* Fixed items
  61     * -------------------------------------------------------
  62     */
  63
  64    void *heap;
  65    char  world_name[ 64 ];
  66    enum world_status{
  67       k_world_status_unloaded = 0,
  68       k_world_status_loading = 1,
  69       k_world_status_loaded = 2
  70    }
  71    status;
  72
  73    struct{
  74       boxf depthbounds;
  75       int depth_computed;
  76
  77       float height;
  78       int enabled;
  79       v4f plane;
  80    }
  81    water;
  82
  83    f64 time;
  84
  85    /* STD140 */
  86    struct ub_world_lighting{
  87       v4f g_cube_min,
  88           g_cube_inv_range;
  89
  90       v4f g_water_plane,
  91           g_depth_bounds;
  92
  93       v4f g_daysky_colour;
  94       v4f g_nightsky_colour;
  95       v4f g_sunset_colour;
  96       v4f g_ambient_colour;
  97       v4f g_sunset_ambient;
  98       v4f g_sun_colour;
  99       v4f g_sun_dir;
 100       v4f g_board_0;
 101       v4f g_board_1;
 102
 103       float g_water_fog;
 104       float g_time;
 105       float g_realtime;
 106       float g_shadow_length;
 107       float g_shadow_spread;
 108
 109       float g_time_of_day;
 110       float g_day_phase;
 111       float g_sunset_phase;
 112
 113       int g_light_preview;
 114       int g_shadow_samples;
 115
 116       int g_debug_indices;
 117       int g_debug_complexity;
 118    }
 119    ub_lighting;
 120    GLuint ubo_lighting;
 121    int    ubo_bind_point;
 122
 123    GLuint tbo_light_entities,
 124           tex_light_entities,
 125           tex_light_cubes;
 126
 127    float probabilities[3];
 128
 129    v3i light_cubes;
 130
 131    struct framebuffer heightmap;
 132
 133    /*
 134     * Dynamically allocated when world_load is called.
 135     *
 136     *                  the following arrays index somewhere into this linear
 137     *                  allocator
 138     *
 139     * (world_gen.h)
 140     * --------------------------------------------------------------------------
 141     */
 142
 143    /*
 144     * Main world .mdl
 145     */
 146    mdl_context meta;
 147
 148    GLuint *textures;
 149    u32 texture_count;
 150
 151    struct world_surface{
 152       mdl_material info;
 153       mdl_submesh sm_geo,
 154                   sm_no_collide;
 155    }
 156    * surfaces;
 157    u32 surface_count;
 158
 159    ent_worldinfo info;
 160    mdl_array_ptr ent_spawn,
 161                  ent_gate,
 162                  ent_light,
 163                  ent_route_node,
 164                  ent_path_index,
 165                  ent_checkpoint,
 166                  ent_route,
 167                  ent_water,
 168
 169                  ent_audio_clip,
 170                  ent_audio,
 171                  ent_volume,
 172                  ent_traffic,
 173                  ent_skateshop,
 174                  ent_marker,
 175                  ent_camera,
 176                  ent_swspreview;
 177
 178    ent_gate *rendering_gate;
 179
 180    /* logic
 181     * ----------------------------------------------------
 182     */
 183
 184    /* world geometry */
 185    scene_context scene_geo,
 186                  scene_no_collide,
 187                  scene_lines;
 188
 189    /* spacial mappings */
 190    bh_tree *audio_bh,
 191            *volume_bh,
 192            *geo_bh;
 193
 194    /* graphics */
 195    glmesh mesh_route_lines;
 196    glmesh mesh_geo,
 197           mesh_no_collide,
 198           mesh_water;
 199
 200    rb_object rb_geo;
 201 };
 202
 203 struct world_global{
 204    /*
 205     * Allocated as system memory
 206     * --------------------------------------------------------------------------
 207     */
 208    void *heap;
 209
 210    /* rendering */
 211    glmesh skydome;
 212    glmesh mesh_gate;
 213    mdl_submesh sm_gate_surface,
 214                sm_gate_marker[4];
 215
 216    double sky_time, sky_rate, sky_target_rate;
 217
 218    u32 current_run_version;
 219    double time, rewind_from, rewind_to, last_use;
 220
 221    /* water rendering */
 222    struct{
 223       struct framebuffer fbreflect, fbdepth;
 224    }
 225    water;
 226
 227    /* split flap display */
 228    struct{
 229       glmesh mesh_base, mesh_display;
 230       mdl_submesh sm_base;
 231       u32 active_route_board;
 232       scene_context scene;
 233
 234       u32 w, h;
 235       float *buffer;
 236    }
 237    sfd;
 238
 239    v3f render_gate_pos;
 240    int in_volume;
 241
 242    int switching_to_new_world;
 243
 244    world_instance worlds[4];
 245    u32            active_world;
 246
 247    /* text particles */
 248    font3d font;
 249
 250    struct timer_text{
 251       char text[8];
 252       m4x3f transform;
 253       ent_gate *gate;
 254       ent_route *route;
 255    }
 256    timer_texts[4];
 257    u32 timer_text_count;
 258
 259    struct text_particle{
 260       rb_object obj;
 261       m4x3f mlocal;
 262       ent_glyph *glyph;
 263       v4f colour;
 264
 265       m4x3f mdl;
 266    }
 267    text_particles[6*4];
 268    u32 text_particle_count;
 269 }
 270 static world_global;
 271 VG_STATIC void entity_call( world_instance *world, ent_call *call );
 272
 273 VG_STATIC world_instance *get_active_world( void )
 274 {
 275    return &world_global.worlds[ world_global.active_world ];
 276 }
 277
 278 /*
 279  * API
 280  */
 281
 282 VG_STATIC
 283 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 284
 285 VG_STATIC
 286 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 287
 288 VG_STATIC
 289 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 290
 291 VG_STATIC
 292 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 293
 294 VG_STATIC
 295 ent_spawn *world_find_closest_spawn( world_instance *world, v3f position )
 296 {
 297    ent_spawn *rp = NULL, *r;
 298    float min_dist = INFINITY;
 299
 300    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 301       r = mdl_arritm( &world->ent_spawn, i );
 302       float d = v3_dist2( r->transform.co, position );
 303
 304       if( d < min_dist ){
 305          min_dist = d;
 306          rp = r;
 307       }
 308    }
 309
 310    if( !rp ){
 311       if( mdl_arrcount(&world->ent_spawn) ){
 312          vg_warn( "Invalid distances to spawns.. defaulting to first one.\n" );
 313          return mdl_arritm( &world->ent_spawn, 0 );
 314       }
 315       else{
 316          vg_error( "There are no spawns in the level!\n" );
 317       }
 318    }
 319
 320    return rp;
 321 }
 322
 323 VG_STATIC
 324 ent_spawn *world_find_spawn_by_name( world_instance *world, const char *name )
 325 {
 326    ent_spawn *rp = NULL, *r;
 327    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 328       r = mdl_arritm( &world->ent_spawn, i );
 329       if( !strcmp( mdl_pstr(&world->meta, r->pstr_name), name ) ){
 330          rp = r;
 331          break;
 332       }
 333    }
 334
 335    if( !rp )
 336       vg_warn( "No spawn named '%s'\n", name );
 337
 338    return rp;
 339 }
 340
 341 /*
 342  * Submodules
 343  */
 344
 345 VG_STATIC float
 346    k_day_length            = 30.0f; /* minutes */
 347
 348 VG_STATIC int   k_debug_light_indices = 0,
 349                 k_debug_light_complexity = 0,
 350                 k_light_preview = 0;
 351
 352 #include "world_routes.h"
 353 #include "world_sfd.h"
 354 #include "world_render.h"
 355 #include "world_water.h"
 356 #include "world_volumes.h"
 357 #include "world_gen.h"
 358 #include "world_gate.h"
 359
 360 /*
 361  * -----------------------------------------------------------------------------
 362  *                                    Events
 363  * -----------------------------------------------------------------------------
 364  */
 365
 366 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 367 {
 368    world_instance *world = get_active_world();
 369    return 0;
 370 }
 371
 372 VG_STATIC void world_init(void)
 373 {
 374    VG_VAR_F32( k_day_length );
 375    VG_VAR_I32( k_debug_light_indices );
 376    VG_VAR_I32( k_debug_light_complexity );
 377    VG_VAR_I32( k_light_preview );
 378
 379    world_global.sky_rate = 1.0;
 380    world_global.sky_target_rate = 1.0;
 381
 382    shader_scene_standard_register();
 383    shader_scene_standard_alphatest_register();
 384    shader_scene_vertex_blend_register();
 385    shader_scene_terrain_register();
 386    shader_scene_depth_register();
 387    shader_scene_position_register();
 388
 389    shader_model_sky_register();
 390
 391    vg_info( "Loading world resources\n" );
 392
 393    vg_linear_clear( vg_mem.scratch );
 394
 395    mdl_context msky;
 396    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 397    mdl_load_metadata_block( &msky, vg_mem.scratch );
 398    mdl_async_load_glmesh( &msky, &world_global.skydome );
 399    mdl_close( &msky );
 400
 401    /* Other systems */
 402    vg_info( "Loading other world systems\n" );
 403
 404    vg_loader_step( world_render_init, NULL );
 405    vg_loader_step( world_sfd_init, NULL );
 406    vg_loader_step( world_water_init, NULL );
 407    vg_loader_step( world_gates_init, NULL );
 408    vg_loader_step( world_routes_init, NULL );
 409
 410    /* Allocate dynamic world memory arena */
 411    u32 max_size = 76*1024*1024;
 412    world_global.heap = vg_create_linear_allocator( vg_mem.rtmemory, max_size,
 413                                                    VG_MEMORY_SYSTEM );
 414 }
 415
 416 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 417 {
 418    u32 index = mdl_entity_id_id( call->id );
 419    ent_volume *volume = mdl_arritm( &world->ent_volume, index );
 420    if( !volume->target ) return;
 421
 422    if( call->function == k_ent_function_trigger ){
 423       call->id = volume->target;
 424
 425       if( volume->type == k_volume_subtype_particle ){
 426          float *co = alloca( sizeof(float)*3 );
 427          co[0] = vg_randf64()*2.0f-1.0f;
 428          co[1] = vg_randf64()*2.0f-1.0f;
 429          co[2] = vg_randf64()*2.0f-1.0f;
 430          m4x3_mulv( volume->to_world, co, co );
 431
 432          call->function = k_ent_function_particle_spawn;
 433          call->data = co;
 434          entity_call( world, call );
 435       }
 436       else{
 437          entity_call( world, call );
 438       }
 439    }
 440 }
 441
 442 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 443 {
 444    u32 index = mdl_entity_id_id( call->id );
 445    ent_audio *audio = mdl_arritm( &world->ent_audio, index );
 446
 447    v3f sound_co;
 448
 449    if( call->function == k_ent_function_particle_spawn ){
 450       v3_copy( call->data, sound_co );
 451    }
 452    else if( call->function == k_ent_function_trigger ){
 453       v3_copy( audio->transform.co, sound_co );
 454    }
 455    else
 456       vg_fatal_error( "ent_audio_call (invalid function id)" );
 457
 458    float chance = vg_randf64()*100.0f,
 459          bar = 0.0f;
 460
 461    for( u32 i=0; i<audio->clip_count; i++ ){
 462       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 463                                           audio->clip_start+i );
 464
 465       float mod = world->probabilities[ audio->probability_curve ],
 466             p   = clip->probability * mod;
 467
 468       bar += p;
 469
 470       if( chance < bar ){
 471
 472          audio_lock();
 473
 474          if( audio->behaviour == k_channel_behaviour_unlimited ){
 475             audio_oneshot_3d( &clip->clip, sound_co,
 476                               audio->transform.s[0],
 477                               audio->volume );
 478          }
 479          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 480             audio_channel *ch =
 481                audio_get_group_idle_channel( audio->group,
 482                                              audio->max_channels );
 483
 484             if( ch ){
 485                audio_channel_init( ch, &clip->clip, audio->flags );
 486                audio_channel_group( ch, audio->group );
 487                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 488                audio_channel_edit_volume( ch, audio->volume, 1 );
 489                ch = audio_relinquish_channel( ch );
 490             }
 491          }
 492          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 493             audio_channel *ch =
 494                audio_get_group_idle_channel( audio->group,
 495                                              audio->max_channels );
 496
 497             /* group is full */
 498             if( !ch ){
 499                audio_channel *existing =
 500                   audio_get_group_first_active_channel( audio->group );
 501
 502                if( existing ){
 503                   if( existing->source == &clip->clip ){
 504                      audio_unlock();
 505                      return;
 506                   }
 507
 508                   existing->group = 0;
 509                   existing = audio_channel_fadeout(existing, audio->crossfade);
 510                }
 511
 512                ch = audio_get_first_idle_channel();
 513             }
 514
 515             if( ch ){
 516                audio_channel_init( ch, &clip->clip, audio->flags );
 517                audio_channel_group( ch, audio->group );
 518                audio_channel_fadein( ch, audio->crossfade );
 519                ch = audio_relinquish_channel( ch );
 520             }
 521          }
 522
 523          audio_unlock();
 524          return;
 525       }
 526    }
 527 }
 528
 529 VG_STATIC void world_update( world_instance *world, v3f pos )
 530 {
 531    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 532    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 533                                     world_global.sky_target_rate,
 534                                     vg.time_delta * 5.0 );
 535
 536    world_routes_update_timer_texts( world );
 537    world_routes_update( world );
 538    //world_routes_debug( world );
 539
 540    /* ---- traffic -------- */
 541
 542    for( u32 i=0; i<mdl_arrcount( &world->ent_traffic ); i++ ){
 543       ent_traffic *traffic = mdl_arritm( &world->ent_traffic, i );
 544
 545       u32 i1 = traffic->index,
 546           i0,
 547           i2 = i1+1;
 548
 549       if( i1 == 0 ) i0 = traffic->node_count-1;
 550       else i0 = i1-1;
 551
 552       if( i2 >= traffic->node_count ) i2 = 0;
 553
 554       i0 += traffic->start_node;
 555       i1 += traffic->start_node;
 556       i2 += traffic->start_node;
 557
 558       v3f h[3];
 559
 560       ent_route_node *rn0 = mdl_arritm( &world->ent_route_node, i0 ),
 561                      *rn1 = mdl_arritm( &world->ent_route_node, i1 ),
 562                      *rn2 = mdl_arritm( &world->ent_route_node, i2 );
 563
 564       v3_copy( rn1->co, h[1] );
 565       v3_lerp( rn0->co, rn1->co, 0.5f, h[0] );
 566       v3_lerp( rn1->co, rn2->co, 0.5f, h[2] );
 567
 568       float const k_sample_dist = 0.0025f;
 569       v3f pc, pd;
 570       eval_bezier3( h[0], h[1], h[2], traffic->t, pc );
 571       eval_bezier3( h[0], h[1], h[2], traffic->t+k_sample_dist, pd );
 572
 573       v3f v0;
 574       v3_sub( pd, pc, v0 );
 575       float length = vg_maxf( 0.0001f, v3_length( v0 ) );
 576       v3_muls( v0, 1.0f/length, v0 );
 577
 578       float mod = k_sample_dist / length;
 579
 580       traffic->t += traffic->speed * vg.time_delta * mod;
 581
 582       if( traffic->t > 1.0f ){
 583          traffic->t -= 1.0f;
 584
 585          if( traffic->t > 1.0f ) traffic->t = 0.0f;
 586
 587          traffic->index ++;
 588
 589          if( traffic->index >= traffic->node_count )
 590             traffic->index = 0;
 591       }
 592
 593       v3_copy( pc, traffic->transform.co );
 594
 595       float a = atan2f( -v0[0], v0[2] );
 596       q_axis_angle( traffic->transform.q, (v3f){0.0f,1.0f,0.0f}, -a );
 597
 598       vg_line_pt3( traffic->transform.co, 0.3f, VG__BLUE );
 599    }
 600
 601    /* ---- SFD ------------ */
 602
 603    if( mdl_arrcount( &world->ent_route ) ){
 604       u32 closest = 0;
 605       float min_dist = INFINITY;
 606
 607       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 608          ent_route *route = mdl_arritm( &world->ent_route, i );
 609          float dist = v3_dist2( route->board_transform[3], pos );
 610
 611          if( dist < min_dist ){
 612             min_dist = dist;
 613             closest = i;
 614          }
 615       }
 616
 617       if( (world_global.sfd.active_route_board != closest)
 618           || network_scores_updated )
 619       {
 620          network_scores_updated = 0;
 621          world_global.sfd.active_route_board = closest;
 622
 623          ent_route *route = mdl_arritm( &world->ent_route, closest );
 624          u32 id = route->official_track_id;
 625
 626          if( id != 0xffffffff ){
 627             struct netmsg_board *local_board =
 628                &scoreboard_client_data.boards[id];
 629
 630             for( int i=0; i<13; i++ ){
 631                sfd_encode( i, &local_board->data[27*i] );
 632             }
 633          }else{
 634             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 635             sfd_encode( 1, "No data" );
 636          }
 637       }
 638    }
 639    sfd_update();
 640
 641    static float random_accum = 0.0f;
 642    random_accum += vg.time_delta;
 643
 644    u32 random_ticks = 0;
 645
 646    while( random_accum > 0.1f ){
 647       random_accum -= 0.1f;
 648       random_ticks ++;
 649    }
 650
 651    float radius = 25.0f;
 652    boxf volume_proximity;
 653    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 654    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 655
 656    bh_iter it;
 657    bh_iter_init( 0, &it );
 658    int idx;
 659
 660    int in_volume = 0;
 661
 662    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 663       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 664
 665       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 666
 667       if( volume->type == k_volume_subtype_trigger ){
 668          v3f local;
 669          m4x3_mulv( volume->to_local, pos, local );
 670
 671          if( (fabsf(local[0]) <= 1.0f) &&
 672              (fabsf(local[1]) <= 1.0f) &&
 673              (fabsf(local[2]) <= 1.0f) )
 674          {
 675             in_volume = 1;
 676             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 677
 678             if( !world_global.in_volume ){
 679                ent_call basecall;
 680                basecall.function = k_ent_function_trigger;
 681                basecall.id = mdl_entity_id( k_ent_volume, idx );
 682                basecall.data = NULL;
 683
 684                entity_call( world, &basecall );
 685             }
 686          }
 687          else
 688             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 689       }
 690       else if( volume->type == k_volume_subtype_particle ){
 691          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 692
 693          for( int j=0; j<random_ticks; j++ ){
 694             ent_call basecall;
 695             basecall.id = mdl_entity_id( k_ent_volume, idx );
 696             basecall.data = NULL;
 697
 698             entity_call( world, &basecall );
 699          }
 700       }
 701    }
 702    world_global.in_volume = in_volume;
 703
 704 #if 0
 705    if( k_debug_light_indices )
 706    {
 707       for( int i=0; i<world->light_count; i++ ){
 708          struct world_light *light = &world->lights[i];
 709          struct classtype_world_light *inf = light->inf;
 710
 711          u32 colour = 0xff000000;
 712          u8 r = inf->colour[0] * 255.0f,
 713             g = inf->colour[1] * 255.0f,
 714             b = inf->colour[2] * 255.0f;
 715
 716          colour |= r;
 717          colour |= g << 8;
 718          colour |= b << 16;
 719
 720          vg_line_pt3( light->node->co, 0.25f, colour );
 721       }
 722    }
 723
 724 #endif
 725 }
 726
 727 /*
 728  * -----------------------------------------------------------------------------
 729  *                              API implementation
 730  * -----------------------------------------------------------------------------
 731  */
 732
 733 VG_STATIC void ray_world_get_tri( world_instance *world,
 734                                   ray_hit *hit, v3f tri[3] )
 735 {
 736    for( int i=0; i<3; i++ )
 737       v3_copy( world->scene_geo.arrvertices[ hit->tri[i] ].co, tri[i] );
 738 }
 739
 740 VG_STATIC int ray_world( world_instance *world,
 741                          v3f pos, v3f dir, ray_hit *hit )
 742 {
 743    return scene_raycast( &world->scene_geo, world->geo_bh, pos, dir, hit );
 744 }
 745
 746 /*
 747  * Cast a sphere from a to b and see what time it hits
 748  */
 749 VG_STATIC int spherecast_world( world_instance *world,
 750                                 v3f pa, v3f pb, float r, float *t, v3f n )
 751 {
 752    bh_iter it;
 753    bh_iter_init( 0, &it );
 754
 755    boxf region;
 756    box_init_inf( region );
 757    box_addpt( region, pa );
 758    box_addpt( region, pb );
 759
 760    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 761    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 762
 763    v3f dir;
 764    v3_sub( pb, pa, dir );
 765
 766    v3f dir_inv;
 767    dir_inv[0] = 1.0f/dir[0];
 768    dir_inv[1] = 1.0f/dir[1];
 769    dir_inv[2] = 1.0f/dir[2];
 770
 771    int hit = -1;
 772    float min_t = 1.0f;
 773
 774    int idx;
 775    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 776       u32 *ptri = &world->scene_geo.arrindices[ idx*3 ];
 777       v3f tri[3];
 778
 779       boxf box;
 780       box_init_inf( box );
 781
 782       for( int j=0; j<3; j++ ){
 783          v3_copy( world->scene_geo.arrvertices[ptri[j]].co, tri[j] );
 784          box_addpt( box, tri[j] );
 785       }
 786
 787       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 788       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 789
 790       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 791          continue;
 792
 793       float t;
 794       v3f n1;
 795       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 796          if( t < min_t ){
 797             min_t = t;
 798             hit = idx;
 799             v3_copy( n1, n );
 800          }
 801       }
 802    }
 803
 804    *t = min_t;
 805    return hit;
 806 }
 807
 808 VG_STATIC
 809 struct world_surface *world_tri_index_surface( world_instance *world,
 810                                                  u32 index )
 811 {
 812    for( int i=1; i<world->surface_count; i++ ){
 813       struct world_surface *surf = &world->surfaces[i];
 814
 815       if( (index >= surf->sm_geo.vertex_start) &&
 816           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 817       {
 818          return surf;
 819       }
 820    }
 821
 822    return &world->surfaces[0];
 823 }
 824
 825 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 826                                                          rb_ct *ct )
 827 {
 828    return world_tri_index_surface( world, ct->element_id );
 829 }
 830
 831 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 832                                                  ray_hit *hit )
 833 {
 834    return world_tri_index_surface( world, hit->tri[0] );
 835 }
 836
 837 /*
 838  * -----------------------------------------------------------------------------
 839  *                              Audio sampling
 840  * -----------------------------------------------------------------------------
 841  */
 842
 843 VG_STATIC
 844 enum audio_sprite_type world_audio_sample_sprite_kandom(v3f origin, v3f output);
 845 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
 846
 847 #include "audio.h"
 848
 849 /*
 850  * Trace out a random point, near the player to try and determine water areas
 851  */
 852 VG_STATIC
 853 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
 854 {
 855    v3f chance = { (vg_randf64()-0.5f) * 30.0f,
 856                   8.0f,
 857                   (vg_randf64()-0.5f) * 30.0f };
 858
 859    v3f pos;
 860    v3_add( chance, origin, pos );
 861
 862    ray_hit contact;
 863    contact.dist = vg_minf( 16.0f, pos[1] );
 864
 865    world_instance *world = get_active_world();
 866
 867    if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
 868       struct world_surface *mat = ray_hit_surface( world, &contact );
 869
 870       if( mat->info.surface_prop == k_surface_prop_grass){
 871          v3_copy( contact.pos, output );
 872          return k_audio_sprite_type_grass;
 873       }
 874       else{
 875          return k_audio_sprite_type_none;
 876       }
 877    }
 878
 879    output[0] = pos[0];
 880    output[1] = 0.0f;
 881    output[2] = pos[2];
 882
 883    float dist = fabsf(output[1] - origin[1]);
 884
 885    if( world->water.enabled && dist<=40.0f )
 886       return k_audio_sprite_type_water;
 887    else
 888       return k_audio_sprite_type_none;
 889 }
 890
 891 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
 892 {
 893    float inr3 = 0.57735027,
 894          inr2 = 0.70710678118;
 895
 896    v3f sample_directions[] = {
 897       { -1.0f,  0.0f,  0.0f },
 898       {  1.0f,  0.0f,  0.0f },
 899       {  0.0f,  0.0f,  1.0f },
 900       {  0.0f,  0.0f, -1.0f },
 901       {  0.0f,  1.0f,  0.0f },
 902       {  0.0f, -1.0f,  0.0f },
 903       { -inr3,  inr3,  inr3 },
 904       {  inr3,  inr3,  inr3 },
 905       { -inr3,  inr3, -inr3 },
 906       {  inr3,  inr3, -inr3 },
 907       { -inr2,  0.0f,  inr2 },
 908       {  inr2,  0.0f,  inr2 },
 909       { -inr2,  0.0f, -inr2 },
 910       {  inr2,  0.0f, -inr2 },
 911    };
 912
 913    static int si = 0;
 914    static float distances[16];
 915
 916    ray_hit ray;
 917    ray.dist = 5.0f;
 918
 919    v3f rc, rd, ro;
 920    v3_copy( sample_directions[ si ], rd );
 921    v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
 922    v3_copy( ro, rc );
 923
 924    float dist = 200.0f;
 925
 926    for( int i=0; i<10; i++ ){
 927       if( ray_world( get_active_world(), rc, rd, &ray ) ){
 928          dist = (float)i*5.0f + ray.dist;
 929          break;
 930       }
 931       else{
 932          v3_muladds( rc, rd, ray.dist, rc );
 933       }
 934    }
 935
 936    distances[si] = dist;
 937
 938    if( vg_lines.draw ){
 939       for( int i=0; i<14; i++ ){
 940          if( distances[i] != 200.0f ){
 941             u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
 942                               VG__CYAN, VG__YELOW, VG__PINK,
 943                               VG__WHITE };
 944
 945             u32 colour = colours[i%7];
 946
 947             v3f p1;
 948             v3_muladds( ro, sample_directions[i], distances[i], p1 );
 949             vg_line( ro, p1, colour );
 950             vg_line_pt3( p1, 0.1f, colour );
 951          }
 952       }
 953    }
 954
 955    *index = si;
 956    *value = dist;
 957
 958    si ++;
 959    if( si >= 14 )
 960       si = 0;
 961 }
 962
 963 #endif /* WORLD_H */