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_context 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       scene_context scene;
 225
 226       u32 w, h;
 227       float *buffer;
 228    }
 229    sfd;
 230
 231    v3f render_gate_pos;
 232    int in_volume;
 233
 234    int switching_to_new_world;
 235
 236    world_instance worlds[4];
 237    u32            world_count;
 238    u32            active_world;
 239
 240    /* text particles */
 241    font3d font;
 242
 243    struct timer_text{
 244       char text[8];
 245       m4x3f transform;
 246       ent_gate *gate;
 247       ent_route *route;
 248    }
 249    timer_texts[4];
 250    u32 timer_text_count;
 251
 252    struct text_particle{
 253       rb_object obj;
 254       m4x3f mlocal;
 255       ent_glyph *glyph;
 256       v4f colour;
 257
 258       m4x3f mdl;
 259    }
 260    text_particles[6*4];
 261    u32 text_particle_count;
 262 }
 263 static world_global;
 264
 265 VG_STATIC world_instance *get_active_world( void )
 266 {
 267    return &world_global.worlds[ world_global.active_world ];
 268 }
 269
 270 /*
 271  * API
 272  */
 273
 274 VG_STATIC
 275 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 276
 277 VG_STATIC
 278 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 279
 280 VG_STATIC
 281 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 282
 283 VG_STATIC
 284 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 285
 286 VG_STATIC
 287 ent_spawn *world_find_closest_spawn( world_instance *world, v3f position )
 288 {
 289    ent_spawn *rp = NULL, *r;
 290    float min_dist = INFINITY;
 291
 292    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 293       r = mdl_arritm( &world->ent_spawn, i );
 294       float d = v3_dist2( r->transform.co, position );
 295
 296       if( d < min_dist ){
 297          min_dist = d;
 298          rp = r;
 299       }
 300    }
 301
 302    if( !rp ){
 303       if( mdl_arrcount(&world->ent_spawn) ){
 304          vg_warn( "Invalid distances to spawns.. defaulting to first one.\n" );
 305          return mdl_arritm( &world->ent_spawn, 0 );
 306       }
 307       else{
 308          vg_error( "There are no spawns in the level!\n" );
 309       }
 310    }
 311
 312    return rp;
 313 }
 314
 315 VG_STATIC
 316 ent_spawn *world_find_spawn_by_name( world_instance *world, const char *name )
 317 {
 318    ent_spawn *rp = NULL, *r;
 319    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 320       r = mdl_arritm( &world->ent_spawn, i );
 321       if( !strcmp( mdl_pstr(&world->meta, r->pstr_name), name ) ){
 322          rp = r;
 323          break;
 324       }
 325    }
 326
 327    if( !rp )
 328       vg_warn( "No spawn named '%s'\n", name );
 329
 330    return rp;
 331 }
 332
 333 /*
 334  * Submodules
 335  */
 336
 337 VG_STATIC float
 338    k_day_length            = 30.0f; /* minutes */
 339
 340 VG_STATIC int   k_debug_light_indices = 0,
 341                 k_debug_light_complexity = 0,
 342                 k_light_preview = 0;
 343
 344 #include "world_routes.h"
 345 #include "world_sfd.h"
 346 #include "world_render.h"
 347 #include "world_water.h"
 348 #include "world_volumes.h"
 349 #include "world_gen.h"
 350 #include "world_gate.h"
 351
 352 /*
 353  * -----------------------------------------------------------------------------
 354  *                                    Events
 355  * -----------------------------------------------------------------------------
 356  */
 357
 358 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 359 {
 360    world_instance *world = get_active_world();
 361    return 0;
 362 }
 363
 364 VG_STATIC void world_init(void)
 365 {
 366    VG_VAR_F32( k_day_length );
 367    VG_VAR_I32( k_debug_light_indices );
 368    VG_VAR_I32( k_debug_light_complexity );
 369    VG_VAR_I32( k_light_preview );
 370
 371    world_global.sky_rate = 1.0;
 372    world_global.sky_target_rate = 1.0;
 373
 374    shader_scene_standard_register();
 375    shader_scene_standard_alphatest_register();
 376    shader_scene_vertex_blend_register();
 377    shader_scene_terrain_register();
 378    shader_scene_depth_register();
 379    shader_scene_position_register();
 380
 381    shader_model_sky_register();
 382
 383    vg_info( "Loading world resources\n" );
 384
 385    vg_linear_clear( vg_mem.scratch );
 386
 387    mdl_context msky;
 388    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 389    mdl_load_metadata_block( &msky, vg_mem.scratch );
 390    mdl_async_load_glmesh( &msky, &world_global.skydome );
 391    mdl_close( &msky );
 392
 393    /* Other systems */
 394    vg_info( "Loading other world systems\n" );
 395
 396    vg_loader_step( world_render_init, NULL );
 397    vg_loader_step( world_sfd_init, NULL );
 398    vg_loader_step( world_water_init, NULL );
 399    vg_loader_step( world_gates_init, NULL );
 400    vg_loader_step( world_routes_init, NULL );
 401
 402    /* Allocate dynamic world memory arena */
 403    u32 max_size = 76*1024*1024;
 404    world_global.heap = vg_create_linear_allocator( vg_mem.rtmemory, max_size,
 405                                                    VG_MEMORY_SYSTEM );
 406 }
 407
 408 typedef struct ent_call ent_call;
 409 struct ent_call{
 410    ent_index ent;
 411    u32 function;
 412    void *data;
 413 };
 414
 415 VG_STATIC void entity_call( world_instance *world, ent_call *call );
 416
 417 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 418 {
 419    ent_volume *volume = mdl_arritm( &world->ent_volume, call->ent.index );
 420    if( !volume->target.type ) return;
 421
 422    if( call->function == k_ent_function_trigger ){
 423       call->ent = volume->target;
 424
 425       if( volume->type == k_volume_subtype_particle ){
 426          float *co = alloca( sizeof(float)*3 );
 427          co[0] = vg_randf()*2.0f-1.0f;
 428          co[1] = vg_randf()*2.0f-1.0f;
 429          co[2] = vg_randf()*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 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 442 {
 443    ent_audio *audio = mdl_arritm( &world->ent_audio, call->ent.index );
 444
 445    v3f sound_co;
 446
 447    if( call->function == k_ent_function_particle_spawn ){
 448       v3_copy( call->data, sound_co );
 449    }
 450    else if( call->function == k_ent_function_trigger ){
 451       v3_copy( audio->transform.co, sound_co );
 452    }
 453    else
 454       vg_fatal_error( "ent_audio_call (invalid function id)" );
 455
 456    float chance = vg_randf()*100.0f,
 457          bar = 0.0f;
 458
 459    for( u32 i=0; i<audio->clip_count; i++ ){
 460       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 461                                           audio->clip_start+i );
 462
 463       float mod = world->probabilities[ audio->probability_curve ],
 464             p   = clip->probability * mod;
 465
 466       bar += p;
 467
 468       if( chance < bar ){
 469
 470          audio_lock();
 471
 472          if( audio->behaviour == k_channel_behaviour_unlimited ){
 473             audio_oneshot_3d( &clip->clip, sound_co,
 474                               audio->transform.s[0],
 475                               audio->volume );
 476          }
 477          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 478             audio_channel *ch =
 479                audio_get_group_idle_channel( audio->group,
 480                                              audio->max_channels );
 481
 482             if( ch ){
 483                audio_channel_init( ch, &clip->clip, audio->flags );
 484                audio_channel_group( ch, audio->group );
 485                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 486                audio_channel_edit_volume( ch, audio->volume, 1 );
 487                ch = audio_relinquish_channel( ch );
 488             }
 489          }
 490          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 491             audio_channel *ch =
 492                audio_get_group_idle_channel( audio->group,
 493                                              audio->max_channels );
 494
 495             /* group is full */
 496             if( !ch ){
 497                audio_channel *existing =
 498                   audio_get_group_first_active_channel( audio->group );
 499
 500                if( existing ){
 501                   if( existing->source == &clip->clip ){
 502                      audio_unlock();
 503                      return;
 504                   }
 505
 506                   existing->group = 0;
 507                   existing = audio_channel_fadeout(existing, audio->crossfade);
 508                }
 509
 510                ch = audio_get_first_idle_channel();
 511             }
 512
 513             if( ch ){
 514                audio_channel_init( ch, &clip->clip, audio->flags );
 515                audio_channel_group( ch, audio->group );
 516                audio_channel_fadein( ch, audio->crossfade );
 517                ch = audio_relinquish_channel( ch );
 518             }
 519          }
 520
 521          audio_unlock();
 522          return;
 523       }
 524    }
 525 }
 526
 527 VG_STATIC void entity_call( world_instance *world, ent_call *call )
 528 {
 529    if( call->ent.type == k_ent_volume ){
 530       ent_volume_call( world, call );
 531    } else if( call->ent.type == k_ent_audio ){
 532       ent_audio_call( world, call );
 533    }
 534 }
 535
 536 VG_STATIC void world_update( world_instance *world, v3f pos )
 537 {
 538    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 539    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 540                                     world_global.sky_target_rate,
 541                                     vg.time_delta * 5.0 );
 542
 543    world_routes_update_timer_texts( world );
 544    world_routes_update( world );
 545    //world_routes_debug( world );
 546
 547    /* ---- traffic -------- */
 548
 549    for( u32 i=0; i<mdl_arrcount( &world->ent_traffic ); i++ ){
 550       ent_traffic *traffic = mdl_arritm( &world->ent_traffic, i );
 551
 552       u32 i1 = traffic->index,
 553           i0,
 554           i2 = i1+1;
 555
 556       if( i1 == 0 ) i0 = traffic->node_count-1;
 557       else i0 = i1-1;
 558
 559       if( i2 >= traffic->node_count ) i2 = 0;
 560
 561       i0 += traffic->start_node;
 562       i1 += traffic->start_node;
 563       i2 += traffic->start_node;
 564
 565       v3f h[3];
 566
 567       ent_route_node *rn0 = mdl_arritm( &world->ent_route_node, i0 ),
 568                      *rn1 = mdl_arritm( &world->ent_route_node, i1 ),
 569                      *rn2 = mdl_arritm( &world->ent_route_node, i2 );
 570
 571       v3_copy( rn1->co, h[1] );
 572       v3_lerp( rn0->co, rn1->co, 0.5f, h[0] );
 573       v3_lerp( rn1->co, rn2->co, 0.5f, h[2] );
 574
 575       float const k_sample_dist = 0.0025f;
 576       v3f pc, pd;
 577       eval_bezier3( h[0], h[1], h[2], traffic->t, pc );
 578       eval_bezier3( h[0], h[1], h[2], traffic->t+k_sample_dist, pd );
 579
 580       v3f v0;
 581       v3_sub( pd, pc, v0 );
 582       float length = vg_maxf( 0.0001f, v3_length( v0 ) );
 583       v3_muls( v0, 1.0f/length, v0 );
 584
 585       float mod = k_sample_dist / length;
 586
 587       traffic->t += traffic->speed * vg.time_delta * mod;
 588
 589       if( traffic->t > 1.0f ){
 590          traffic->t -= 1.0f;
 591
 592          if( traffic->t > 1.0f ) traffic->t = 0.0f;
 593
 594          traffic->index ++;
 595
 596          if( traffic->index >= traffic->node_count )
 597             traffic->index = 0;
 598       }
 599
 600       v3_copy( pc, traffic->transform.co );
 601
 602       float a = atan2f( -v0[0], v0[2] );
 603       q_axis_angle( traffic->transform.q, (v3f){0.0f,1.0f,0.0f}, -a );
 604
 605       vg_line_pt3( traffic->transform.co, 0.3f, VG__BLUE );
 606    }
 607
 608    /* ---- SFD ------------ */
 609
 610    if( mdl_arrcount( &world->ent_route ) ){
 611       u32 closest = 0;
 612       float min_dist = INFINITY;
 613
 614       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 615          ent_route *route = mdl_arritm( &world->ent_route, i );
 616          float dist = v3_dist2( route->board_transform[3], pos );
 617
 618          if( dist < min_dist ){
 619             min_dist = dist;
 620             closest = i;
 621          }
 622       }
 623
 624       if( (world_global.sfd.active_route_board != closest)
 625           || network_scores_updated )
 626       {
 627          network_scores_updated = 0;
 628          world_global.sfd.active_route_board = closest;
 629
 630          ent_route *route = mdl_arritm( &world->ent_route, closest );
 631          u32 id = route->official_track_id;
 632
 633          if( id != 0xffffffff ){
 634             struct netmsg_board *local_board =
 635                &scoreboard_client_data.boards[id];
 636
 637             for( int i=0; i<13; i++ ){
 638                sfd_encode( i, &local_board->data[27*i] );
 639             }
 640          }else{
 641             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 642             sfd_encode( 1, "No data" );
 643          }
 644       }
 645    }
 646    sfd_update();
 647
 648    static float random_accum = 0.0f;
 649    random_accum += vg.time_delta;
 650
 651    u32 random_ticks = 0;
 652
 653    while( random_accum > 0.1f ){
 654       random_accum -= 0.1f;
 655       random_ticks ++;
 656    }
 657
 658    float radius = 25.0f;
 659    boxf volume_proximity;
 660    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 661    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 662
 663    bh_iter it;
 664    bh_iter_init( 0, &it );
 665    int idx;
 666
 667    int in_volume = 0;
 668
 669    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 670       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 671
 672       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 673
 674       if( volume->type == k_volume_subtype_trigger ){
 675          v3f local;
 676          m4x3_mulv( volume->to_local, pos, local );
 677
 678          if( (fabsf(local[0]) <= 1.0f) &&
 679              (fabsf(local[1]) <= 1.0f) &&
 680              (fabsf(local[2]) <= 1.0f) )
 681          {
 682             in_volume = 1;
 683             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 684
 685             if( !world_global.in_volume ){
 686                ent_call basecall;
 687                basecall.ent.index = idx;
 688                basecall.ent.type = k_ent_volume;
 689                basecall.function = k_ent_function_trigger;
 690                basecall.data = NULL;
 691
 692                entity_call( world, &basecall );
 693             }
 694          }
 695          else
 696             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 697       }
 698       else if( volume->type == k_volume_subtype_particle ){
 699          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 700
 701          for( int j=0; j<random_ticks; j++ ){
 702             ent_call basecall;
 703             basecall.ent.index = idx;
 704             basecall.ent.type = k_ent_volume;
 705             basecall.function = k_ent_function_trigger;
 706             basecall.data = NULL;
 707
 708             entity_call( world, &basecall );
 709          }
 710       }
 711    }
 712    world_global.in_volume = in_volume;
 713
 714 #if 0
 715    if( k_debug_light_indices )
 716    {
 717       for( int i=0; i<world->light_count; i++ ){
 718          struct world_light *light = &world->lights[i];
 719          struct classtype_world_light *inf = light->inf;
 720
 721          u32 colour = 0xff000000;
 722          u8 r = inf->colour[0] * 255.0f,
 723             g = inf->colour[1] * 255.0f,
 724             b = inf->colour[2] * 255.0f;
 725
 726          colour |= r;
 727          colour |= g << 8;
 728          colour |= b << 16;
 729
 730          vg_line_pt3( light->node->co, 0.25f, colour );
 731       }
 732    }
 733
 734 #endif
 735 }
 736
 737 /*
 738  * -----------------------------------------------------------------------------
 739  *                              API implementation
 740  * -----------------------------------------------------------------------------
 741  */
 742
 743 VG_STATIC void ray_world_get_tri( world_instance *world,
 744                                   ray_hit *hit, v3f tri[3] )
 745 {
 746    for( int i=0; i<3; i++ )
 747       v3_copy( world->scene_geo.arrvertices[ hit->tri[i] ].co, tri[i] );
 748 }
 749
 750 VG_STATIC int ray_world( world_instance *world,
 751                          v3f pos, v3f dir, ray_hit *hit )
 752 {
 753    return scene_raycast( &world->scene_geo, world->geo_bh, pos, dir, hit );
 754 }
 755
 756 /*
 757  * Cast a sphere from a to b and see what time it hits
 758  */
 759 VG_STATIC int spherecast_world( world_instance *world,
 760                                 v3f pa, v3f pb, float r, float *t, v3f n )
 761 {
 762    bh_iter it;
 763    bh_iter_init( 0, &it );
 764
 765    boxf region;
 766    box_init_inf( region );
 767    box_addpt( region, pa );
 768    box_addpt( region, pb );
 769
 770    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 771    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 772
 773    v3f dir;
 774    v3_sub( pb, pa, dir );
 775
 776    v3f dir_inv;
 777    dir_inv[0] = 1.0f/dir[0];
 778    dir_inv[1] = 1.0f/dir[1];
 779    dir_inv[2] = 1.0f/dir[2];
 780
 781    int hit = -1;
 782    float min_t = 1.0f;
 783
 784    int idx;
 785    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 786       u32 *ptri = &world->scene_geo.arrindices[ idx*3 ];
 787       v3f tri[3];
 788
 789       boxf box;
 790       box_init_inf( box );
 791
 792       for( int j=0; j<3; j++ ){
 793          v3_copy( world->scene_geo.arrvertices[ptri[j]].co, tri[j] );
 794          box_addpt( box, tri[j] );
 795       }
 796
 797       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 798       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 799
 800       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 801          continue;
 802
 803       float t;
 804       v3f n1;
 805       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 806          if( t < min_t ){
 807             min_t = t;
 808             hit = idx;
 809             v3_copy( n1, n );
 810          }
 811       }
 812    }
 813
 814    *t = min_t;
 815    return hit;
 816 }
 817
 818 VG_STATIC
 819 struct world_surface *world_tri_index_surface( world_instance *world,
 820                                                  u32 index )
 821 {
 822    for( int i=1; i<world->surface_count; i++ ){
 823       struct world_surface *surf = &world->surfaces[i];
 824
 825       if( (index >= surf->sm_geo.vertex_start) &&
 826           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 827       {
 828          return surf;
 829       }
 830    }
 831
 832    return &world->surfaces[0];
 833 }
 834
 835 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 836                                                          rb_ct *ct )
 837 {
 838    return world_tri_index_surface( world, ct->element_id );
 839 }
 840
 841 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 842                                                  ray_hit *hit )
 843 {
 844    return world_tri_index_surface( world, hit->tri[0] );
 845 }
 846
 847 /*
 848  * -----------------------------------------------------------------------------
 849  *                              Audio sampling
 850  * -----------------------------------------------------------------------------
 851  */
 852
 853 VG_STATIC
 854 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output);
 855 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
 856
 857 #include "audio.h"
 858
 859 /*
 860  * Trace out a random point, near the player to try and determine water areas
 861  */
 862 VG_STATIC
 863 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
 864 {
 865    v3f chance = { (vg_randf()-0.5f) * 30.0f,
 866                   8.0f,
 867                   (vg_randf()-0.5f) * 30.0f };
 868
 869    v3f pos;
 870    v3_add( chance, origin, pos );
 871
 872    ray_hit contact;
 873    contact.dist = vg_minf( 16.0f, pos[1] );
 874
 875    world_instance *world = get_active_world();
 876
 877    if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
 878       struct world_surface *mat = ray_hit_surface( world, &contact );
 879
 880       if( mat->info.surface_prop == k_surface_prop_grass){
 881          v3_copy( contact.pos, output );
 882          return k_audio_sprite_type_grass;
 883       }
 884       else{
 885          return k_audio_sprite_type_none;
 886       }
 887    }
 888
 889    output[0] = pos[0];
 890    output[1] = 0.0f;
 891    output[2] = pos[2];
 892
 893    float dist = fabsf(output[1] - origin[1]);
 894
 895    if( world->water.enabled && dist<=40.0f )
 896       return k_audio_sprite_type_water;
 897    else
 898       return k_audio_sprite_type_none;
 899 }
 900
 901 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
 902 {
 903    float inr3 = 0.57735027,
 904          inr2 = 0.70710678118;
 905
 906    v3f sample_directions[] = {
 907       { -1.0f,  0.0f,  0.0f },
 908       {  1.0f,  0.0f,  0.0f },
 909       {  0.0f,  0.0f,  1.0f },
 910       {  0.0f,  0.0f, -1.0f },
 911       {  0.0f,  1.0f,  0.0f },
 912       {  0.0f, -1.0f,  0.0f },
 913       { -inr3,  inr3,  inr3 },
 914       {  inr3,  inr3,  inr3 },
 915       { -inr3,  inr3, -inr3 },
 916       {  inr3,  inr3, -inr3 },
 917       { -inr2,  0.0f,  inr2 },
 918       {  inr2,  0.0f,  inr2 },
 919       { -inr2,  0.0f, -inr2 },
 920       {  inr2,  0.0f, -inr2 },
 921    };
 922
 923    static int si = 0;
 924    static float distances[16];
 925
 926    ray_hit ray;
 927    ray.dist = 5.0f;
 928
 929    v3f rc, rd, ro;
 930    v3_copy( sample_directions[ si ], rd );
 931    v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
 932    v3_copy( ro, rc );
 933
 934    float dist = 200.0f;
 935
 936    for( int i=0; i<10; i++ ){
 937       if( ray_world( get_active_world(), rc, rd, &ray ) ){
 938          dist = (float)i*5.0f + ray.dist;
 939          break;
 940       }
 941       else{
 942          v3_muladds( rc, rd, ray.dist, rc );
 943       }
 944    }
 945
 946    distances[si] = dist;
 947
 948    if( vg_lines.draw ){
 949       for( int i=0; i<14; i++ ){
 950          if( distances[i] != 200.0f ){
 951             u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
 952                               VG__CYAN, VG__YELOW, VG__PINK,
 953                               VG__WHITE };
 954
 955             u32 colour = colours[i%7];
 956
 957             v3f p1;
 958             v3_muladds( ro, sample_directions[i], distances[i], p1 );
 959             vg_line( ro, p1, colour );
 960             vg_line_pt3( p1, 0.1f, colour );
 961          }
 962       }
 963    }
 964
 965    *index = si;
 966    *value = dist;
 967
 968    si ++;
 969    if( si >= 14 )
 970       si = 0;
 971 }
 972
 973 #endif /* WORLD_H */