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
 269 VG_STATIC world_instance *get_active_world( void )
 270 {
 271    return &world_global.worlds[ world_global.active_world ];
 272 }
 273
 274 /*
 275  * API
 276  */
 277
 278 VG_STATIC
 279 int ray_hit_is_ramp( world_instance *world, ray_hit *hit );
 280
 281 VG_STATIC
 282 struct world_surface *ray_hit_surface( world_instance *world, ray_hit *hit );
 283
 284 VG_STATIC
 285 void ray_world_get_tri( world_instance *world, ray_hit *hit, v3f tri[3] );
 286
 287 VG_STATIC
 288 int ray_world( world_instance *world, v3f pos, v3f dir, ray_hit *hit );
 289
 290 VG_STATIC
 291 ent_spawn *world_find_closest_spawn( world_instance *world, v3f position )
 292 {
 293    ent_spawn *rp = NULL, *r;
 294    float min_dist = INFINITY;
 295
 296    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 297       r = mdl_arritm( &world->ent_spawn, i );
 298       float d = v3_dist2( r->transform.co, position );
 299
 300       if( d < min_dist ){
 301          min_dist = d;
 302          rp = r;
 303       }
 304    }
 305
 306    if( !rp ){
 307       if( mdl_arrcount(&world->ent_spawn) ){
 308          vg_warn( "Invalid distances to spawns.. defaulting to first one.\n" );
 309          return mdl_arritm( &world->ent_spawn, 0 );
 310       }
 311       else{
 312          vg_error( "There are no spawns in the level!\n" );
 313       }
 314    }
 315
 316    return rp;
 317 }
 318
 319 VG_STATIC
 320 ent_spawn *world_find_spawn_by_name( world_instance *world, const char *name )
 321 {
 322    ent_spawn *rp = NULL, *r;
 323    for( u32 i=0; i<mdl_arrcount(&world->ent_spawn); i++ ){
 324       r = mdl_arritm( &world->ent_spawn, i );
 325       if( !strcmp( mdl_pstr(&world->meta, r->pstr_name), name ) ){
 326          rp = r;
 327          break;
 328       }
 329    }
 330
 331    if( !rp )
 332       vg_warn( "No spawn named '%s'\n", name );
 333
 334    return rp;
 335 }
 336
 337 /*
 338  * Submodules
 339  */
 340
 341 VG_STATIC float
 342    k_day_length            = 30.0f; /* minutes */
 343
 344 VG_STATIC int   k_debug_light_indices = 0,
 345                 k_debug_light_complexity = 0,
 346                 k_light_preview = 0;
 347
 348 #include "world_routes.h"
 349 #include "world_sfd.h"
 350 #include "world_render.h"
 351 #include "world_water.h"
 352 #include "world_volumes.h"
 353 #include "world_gen.h"
 354 #include "world_gate.h"
 355
 356 /*
 357  * -----------------------------------------------------------------------------
 358  *                                    Events
 359  * -----------------------------------------------------------------------------
 360  */
 361
 362 VG_STATIC int world_stop_sound( int argc, const char *argv[] )
 363 {
 364    world_instance *world = get_active_world();
 365    return 0;
 366 }
 367
 368 VG_STATIC void world_init(void)
 369 {
 370    VG_VAR_F32( k_day_length );
 371    VG_VAR_I32( k_debug_light_indices );
 372    VG_VAR_I32( k_debug_light_complexity );
 373    VG_VAR_I32( k_light_preview );
 374
 375    world_global.sky_rate = 1.0;
 376    world_global.sky_target_rate = 1.0;
 377
 378    shader_scene_standard_register();
 379    shader_scene_standard_alphatest_register();
 380    shader_scene_vertex_blend_register();
 381    shader_scene_terrain_register();
 382    shader_scene_depth_register();
 383    shader_scene_position_register();
 384
 385    shader_model_sky_register();
 386
 387    vg_info( "Loading world resources\n" );
 388
 389    vg_linear_clear( vg_mem.scratch );
 390
 391    mdl_context msky;
 392    mdl_open( &msky, "models/rs_skydome.mdl", vg_mem.scratch );
 393    mdl_load_metadata_block( &msky, vg_mem.scratch );
 394    mdl_async_load_glmesh( &msky, &world_global.skydome );
 395    mdl_close( &msky );
 396
 397    /* Other systems */
 398    vg_info( "Loading other world systems\n" );
 399
 400    vg_loader_step( world_render_init, NULL );
 401    vg_loader_step( world_sfd_init, NULL );
 402    vg_loader_step( world_water_init, NULL );
 403    vg_loader_step( world_gates_init, NULL );
 404    vg_loader_step( world_routes_init, NULL );
 405
 406    /* Allocate dynamic world memory arena */
 407    u32 max_size = 76*1024*1024;
 408    world_global.heap = vg_create_linear_allocator( vg_mem.rtmemory, max_size,
 409                                                    VG_MEMORY_SYSTEM );
 410 }
 411
 412 VG_STATIC void ent_volume_call( world_instance *world, ent_call *call )
 413 {
 414    u32 index = mdl_entity_id_id( call->id );
 415    ent_volume *volume = mdl_arritm( &world->ent_volume, index );
 416    if( !volume->target ) return;
 417
 418    if( call->function == k_ent_function_trigger ){
 419       call->id = volume->target;
 420
 421       if( volume->type == k_volume_subtype_particle ){
 422          float *co = alloca( sizeof(float)*3 );
 423          co[0] = vg_randf()*2.0f-1.0f;
 424          co[1] = vg_randf()*2.0f-1.0f;
 425          co[2] = vg_randf()*2.0f-1.0f;
 426          m4x3_mulv( volume->to_world, co, co );
 427
 428          call->function = k_ent_function_particle_spawn;
 429          call->data = co;
 430          entity_call( world, call );
 431       }
 432       else{
 433          entity_call( world, call );
 434       }
 435    }
 436 }
 437
 438 VG_STATIC void ent_audio_call( world_instance *world, ent_call *call )
 439 {
 440    u32 index = mdl_entity_id_id( call->id );
 441    ent_audio *audio = mdl_arritm( &world->ent_audio, index );
 442
 443    v3f sound_co;
 444
 445    if( call->function == k_ent_function_particle_spawn ){
 446       v3_copy( call->data, sound_co );
 447    }
 448    else if( call->function == k_ent_function_trigger ){
 449       v3_copy( audio->transform.co, sound_co );
 450    }
 451    else
 452       vg_fatal_error( "ent_audio_call (invalid function id)" );
 453
 454    float chance = vg_randf()*100.0f,
 455          bar = 0.0f;
 456
 457    for( u32 i=0; i<audio->clip_count; i++ ){
 458       ent_audio_clip *clip = mdl_arritm( &world->ent_audio_clip,
 459                                           audio->clip_start+i );
 460
 461       float mod = world->probabilities[ audio->probability_curve ],
 462             p   = clip->probability * mod;
 463
 464       bar += p;
 465
 466       if( chance < bar ){
 467
 468          audio_lock();
 469
 470          if( audio->behaviour == k_channel_behaviour_unlimited ){
 471             audio_oneshot_3d( &clip->clip, sound_co,
 472                               audio->transform.s[0],
 473                               audio->volume );
 474          }
 475          else if( audio->behaviour == k_channel_behaviour_discard_if_full ){
 476             audio_channel *ch =
 477                audio_get_group_idle_channel( audio->group,
 478                                              audio->max_channels );
 479
 480             if( ch ){
 481                audio_channel_init( ch, &clip->clip, audio->flags );
 482                audio_channel_group( ch, audio->group );
 483                audio_channel_set_spacial( ch, sound_co, audio->transform.s[0] );
 484                audio_channel_edit_volume( ch, audio->volume, 1 );
 485                ch = audio_relinquish_channel( ch );
 486             }
 487          }
 488          else if( audio->behaviour == k_channel_behaviour_crossfade_if_full){
 489             audio_channel *ch =
 490                audio_get_group_idle_channel( audio->group,
 491                                              audio->max_channels );
 492
 493             /* group is full */
 494             if( !ch ){
 495                audio_channel *existing =
 496                   audio_get_group_first_active_channel( audio->group );
 497
 498                if( existing ){
 499                   if( existing->source == &clip->clip ){
 500                      audio_unlock();
 501                      return;
 502                   }
 503
 504                   existing->group = 0;
 505                   existing = audio_channel_fadeout(existing, audio->crossfade);
 506                }
 507
 508                ch = audio_get_first_idle_channel();
 509             }
 510
 511             if( ch ){
 512                audio_channel_init( ch, &clip->clip, audio->flags );
 513                audio_channel_group( ch, audio->group );
 514                audio_channel_fadein( ch, audio->crossfade );
 515                ch = audio_relinquish_channel( ch );
 516             }
 517          }
 518
 519          audio_unlock();
 520          return;
 521       }
 522    }
 523 }
 524
 525 VG_STATIC void world_update( world_instance *world, v3f pos )
 526 {
 527    world_global.sky_time += world_global.sky_rate * vg.time_delta;
 528    world_global.sky_rate = vg_lerp( world_global.sky_rate,
 529                                     world_global.sky_target_rate,
 530                                     vg.time_delta * 5.0 );
 531
 532    world_routes_update_timer_texts( world );
 533    world_routes_update( world );
 534    //world_routes_debug( world );
 535
 536    /* ---- traffic -------- */
 537
 538    for( u32 i=0; i<mdl_arrcount( &world->ent_traffic ); i++ ){
 539       ent_traffic *traffic = mdl_arritm( &world->ent_traffic, i );
 540
 541       u32 i1 = traffic->index,
 542           i0,
 543           i2 = i1+1;
 544
 545       if( i1 == 0 ) i0 = traffic->node_count-1;
 546       else i0 = i1-1;
 547
 548       if( i2 >= traffic->node_count ) i2 = 0;
 549
 550       i0 += traffic->start_node;
 551       i1 += traffic->start_node;
 552       i2 += traffic->start_node;
 553
 554       v3f h[3];
 555
 556       ent_route_node *rn0 = mdl_arritm( &world->ent_route_node, i0 ),
 557                      *rn1 = mdl_arritm( &world->ent_route_node, i1 ),
 558                      *rn2 = mdl_arritm( &world->ent_route_node, i2 );
 559
 560       v3_copy( rn1->co, h[1] );
 561       v3_lerp( rn0->co, rn1->co, 0.5f, h[0] );
 562       v3_lerp( rn1->co, rn2->co, 0.5f, h[2] );
 563
 564       float const k_sample_dist = 0.0025f;
 565       v3f pc, pd;
 566       eval_bezier3( h[0], h[1], h[2], traffic->t, pc );
 567       eval_bezier3( h[0], h[1], h[2], traffic->t+k_sample_dist, pd );
 568
 569       v3f v0;
 570       v3_sub( pd, pc, v0 );
 571       float length = vg_maxf( 0.0001f, v3_length( v0 ) );
 572       v3_muls( v0, 1.0f/length, v0 );
 573
 574       float mod = k_sample_dist / length;
 575
 576       traffic->t += traffic->speed * vg.time_delta * mod;
 577
 578       if( traffic->t > 1.0f ){
 579          traffic->t -= 1.0f;
 580
 581          if( traffic->t > 1.0f ) traffic->t = 0.0f;
 582
 583          traffic->index ++;
 584
 585          if( traffic->index >= traffic->node_count )
 586             traffic->index = 0;
 587       }
 588
 589       v3_copy( pc, traffic->transform.co );
 590
 591       float a = atan2f( -v0[0], v0[2] );
 592       q_axis_angle( traffic->transform.q, (v3f){0.0f,1.0f,0.0f}, -a );
 593
 594       vg_line_pt3( traffic->transform.co, 0.3f, VG__BLUE );
 595    }
 596
 597    /* ---- SFD ------------ */
 598
 599    if( mdl_arrcount( &world->ent_route ) ){
 600       u32 closest = 0;
 601       float min_dist = INFINITY;
 602
 603       for( u32 i=0; i<mdl_arrcount( &world->ent_route ); i++ ){
 604          ent_route *route = mdl_arritm( &world->ent_route, i );
 605          float dist = v3_dist2( route->board_transform[3], pos );
 606
 607          if( dist < min_dist ){
 608             min_dist = dist;
 609             closest = i;
 610          }
 611       }
 612
 613       if( (world_global.sfd.active_route_board != closest)
 614           || network_scores_updated )
 615       {
 616          network_scores_updated = 0;
 617          world_global.sfd.active_route_board = closest;
 618
 619          ent_route *route = mdl_arritm( &world->ent_route, closest );
 620          u32 id = route->official_track_id;
 621
 622          if( id != 0xffffffff ){
 623             struct netmsg_board *local_board =
 624                &scoreboard_client_data.boards[id];
 625
 626             for( int i=0; i<13; i++ ){
 627                sfd_encode( i, &local_board->data[27*i] );
 628             }
 629          }else{
 630             sfd_encode( 0, mdl_pstr( &world->meta, route->pstr_name ) );
 631             sfd_encode( 1, "No data" );
 632          }
 633       }
 634    }
 635    sfd_update();
 636
 637    static float random_accum = 0.0f;
 638    random_accum += vg.time_delta;
 639
 640    u32 random_ticks = 0;
 641
 642    while( random_accum > 0.1f ){
 643       random_accum -= 0.1f;
 644       random_ticks ++;
 645    }
 646
 647    float radius = 25.0f;
 648    boxf volume_proximity;
 649    v3_add( pos, (v3f){ radius, radius, radius }, volume_proximity[1] );
 650    v3_sub( pos, (v3f){ radius, radius, radius }, volume_proximity[0] );
 651
 652    bh_iter it;
 653    bh_iter_init( 0, &it );
 654    int idx;
 655
 656    int in_volume = 0;
 657
 658    while( bh_next( world->volume_bh, &it, volume_proximity, &idx ) ){
 659       ent_volume *volume = mdl_arritm( &world->ent_volume, idx );
 660
 661       boxf cube = {{-1.0f,-1.0f,-1.0f},{1.0f,1.0f,1.0f}};
 662
 663       if( volume->type == k_volume_subtype_trigger ){
 664          v3f local;
 665          m4x3_mulv( volume->to_local, pos, local );
 666
 667          if( (fabsf(local[0]) <= 1.0f) &&
 668              (fabsf(local[1]) <= 1.0f) &&
 669              (fabsf(local[2]) <= 1.0f) )
 670          {
 671             in_volume = 1;
 672             vg_line_boxf_transformed( volume->to_world, cube, 0xff00ff00 );
 673
 674             if( !world_global.in_volume ){
 675                ent_call basecall;
 676                basecall.function = k_ent_function_trigger;
 677                basecall.id = mdl_entity_id( k_ent_volume, idx );
 678                basecall.data = NULL;
 679
 680                entity_call( world, &basecall );
 681             }
 682          }
 683          else
 684             vg_line_boxf_transformed( volume->to_world, cube, 0xff0000ff );
 685       }
 686       else if( volume->type == k_volume_subtype_particle ){
 687          vg_line_boxf_transformed( volume->to_world, cube, 0xff00c0ff );
 688
 689          for( int j=0; j<random_ticks; j++ ){
 690             ent_call basecall;
 691             basecall.id = mdl_entity_id( k_ent_volume, idx );
 692             basecall.data = NULL;
 693
 694             entity_call( world, &basecall );
 695          }
 696       }
 697    }
 698    world_global.in_volume = in_volume;
 699
 700 #if 0
 701    if( k_debug_light_indices )
 702    {
 703       for( int i=0; i<world->light_count; i++ ){
 704          struct world_light *light = &world->lights[i];
 705          struct classtype_world_light *inf = light->inf;
 706
 707          u32 colour = 0xff000000;
 708          u8 r = inf->colour[0] * 255.0f,
 709             g = inf->colour[1] * 255.0f,
 710             b = inf->colour[2] * 255.0f;
 711
 712          colour |= r;
 713          colour |= g << 8;
 714          colour |= b << 16;
 715
 716          vg_line_pt3( light->node->co, 0.25f, colour );
 717       }
 718    }
 719
 720 #endif
 721 }
 722
 723 /*
 724  * -----------------------------------------------------------------------------
 725  *                              API implementation
 726  * -----------------------------------------------------------------------------
 727  */
 728
 729 VG_STATIC void ray_world_get_tri( world_instance *world,
 730                                   ray_hit *hit, v3f tri[3] )
 731 {
 732    for( int i=0; i<3; i++ )
 733       v3_copy( world->scene_geo.arrvertices[ hit->tri[i] ].co, tri[i] );
 734 }
 735
 736 VG_STATIC int ray_world( world_instance *world,
 737                          v3f pos, v3f dir, ray_hit *hit )
 738 {
 739    return scene_raycast( &world->scene_geo, world->geo_bh, pos, dir, hit );
 740 }
 741
 742 /*
 743  * Cast a sphere from a to b and see what time it hits
 744  */
 745 VG_STATIC int spherecast_world( world_instance *world,
 746                                 v3f pa, v3f pb, float r, float *t, v3f n )
 747 {
 748    bh_iter it;
 749    bh_iter_init( 0, &it );
 750
 751    boxf region;
 752    box_init_inf( region );
 753    box_addpt( region, pa );
 754    box_addpt( region, pb );
 755
 756    v3_add( (v3f){ r, r, r}, region[1], region[1] );
 757    v3_add( (v3f){-r,-r,-r}, region[0], region[0] );
 758
 759    v3f dir;
 760    v3_sub( pb, pa, dir );
 761
 762    v3f dir_inv;
 763    dir_inv[0] = 1.0f/dir[0];
 764    dir_inv[1] = 1.0f/dir[1];
 765    dir_inv[2] = 1.0f/dir[2];
 766
 767    int hit = -1;
 768    float min_t = 1.0f;
 769
 770    int idx;
 771    while( bh_next( world->geo_bh, &it, region, &idx ) ){
 772       u32 *ptri = &world->scene_geo.arrindices[ idx*3 ];
 773       v3f tri[3];
 774
 775       boxf box;
 776       box_init_inf( box );
 777
 778       for( int j=0; j<3; j++ ){
 779          v3_copy( world->scene_geo.arrvertices[ptri[j]].co, tri[j] );
 780          box_addpt( box, tri[j] );
 781       }
 782
 783       v3_add( (v3f){ r, r, r}, box[1], box[1] );
 784       v3_add( (v3f){-r,-r,-r}, box[0], box[0] );
 785
 786       if( !ray_aabb1( box, pa, dir_inv, 1.0f ) )
 787          continue;
 788
 789       float t;
 790       v3f n1;
 791       if( spherecast_triangle( tri, pa, dir, r, &t, n1 ) ){
 792          if( t < min_t ){
 793             min_t = t;
 794             hit = idx;
 795             v3_copy( n1, n );
 796          }
 797       }
 798    }
 799
 800    *t = min_t;
 801    return hit;
 802 }
 803
 804 VG_STATIC
 805 struct world_surface *world_tri_index_surface( world_instance *world,
 806                                                  u32 index )
 807 {
 808    for( int i=1; i<world->surface_count; i++ ){
 809       struct world_surface *surf = &world->surfaces[i];
 810
 811       if( (index >= surf->sm_geo.vertex_start) &&
 812           (index  < surf->sm_geo.vertex_start+surf->sm_geo.vertex_count ) )
 813       {
 814          return surf;
 815       }
 816    }
 817
 818    return &world->surfaces[0];
 819 }
 820
 821 VG_STATIC struct world_surface *world_contact_surface( world_instance *world,
 822                                                          rb_ct *ct )
 823 {
 824    return world_tri_index_surface( world, ct->element_id );
 825 }
 826
 827 VG_STATIC struct world_surface *ray_hit_surface( world_instance *world,
 828                                                  ray_hit *hit )
 829 {
 830    return world_tri_index_surface( world, hit->tri[0] );
 831 }
 832
 833 /*
 834  * -----------------------------------------------------------------------------
 835  *                              Audio sampling
 836  * -----------------------------------------------------------------------------
 837  */
 838
 839 VG_STATIC
 840 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output);
 841 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value );
 842
 843 #include "audio.h"
 844
 845 /*
 846  * Trace out a random point, near the player to try and determine water areas
 847  */
 848 VG_STATIC
 849 enum audio_sprite_type world_audio_sample_sprite_random(v3f origin, v3f output)
 850 {
 851    v3f chance = { (vg_randf()-0.5f) * 30.0f,
 852                   8.0f,
 853                   (vg_randf()-0.5f) * 30.0f };
 854
 855    v3f pos;
 856    v3_add( chance, origin, pos );
 857
 858    ray_hit contact;
 859    contact.dist = vg_minf( 16.0f, pos[1] );
 860
 861    world_instance *world = get_active_world();
 862
 863    if( ray_world( world, pos, (v3f){0.0f,-1.0f,0.0f}, &contact ) ){
 864       struct world_surface *mat = ray_hit_surface( world, &contact );
 865
 866       if( mat->info.surface_prop == k_surface_prop_grass){
 867          v3_copy( contact.pos, output );
 868          return k_audio_sprite_type_grass;
 869       }
 870       else{
 871          return k_audio_sprite_type_none;
 872       }
 873    }
 874
 875    output[0] = pos[0];
 876    output[1] = 0.0f;
 877    output[2] = pos[2];
 878
 879    float dist = fabsf(output[1] - origin[1]);
 880
 881    if( world->water.enabled && dist<=40.0f )
 882       return k_audio_sprite_type_water;
 883    else
 884       return k_audio_sprite_type_none;
 885 }
 886
 887 VG_STATIC void world_audio_sample_distances( v3f co, int *index, float *value )
 888 {
 889    float inr3 = 0.57735027,
 890          inr2 = 0.70710678118;
 891
 892    v3f sample_directions[] = {
 893       { -1.0f,  0.0f,  0.0f },
 894       {  1.0f,  0.0f,  0.0f },
 895       {  0.0f,  0.0f,  1.0f },
 896       {  0.0f,  0.0f, -1.0f },
 897       {  0.0f,  1.0f,  0.0f },
 898       {  0.0f, -1.0f,  0.0f },
 899       { -inr3,  inr3,  inr3 },
 900       {  inr3,  inr3,  inr3 },
 901       { -inr3,  inr3, -inr3 },
 902       {  inr3,  inr3, -inr3 },
 903       { -inr2,  0.0f,  inr2 },
 904       {  inr2,  0.0f,  inr2 },
 905       { -inr2,  0.0f, -inr2 },
 906       {  inr2,  0.0f, -inr2 },
 907    };
 908
 909    static int si = 0;
 910    static float distances[16];
 911
 912    ray_hit ray;
 913    ray.dist = 5.0f;
 914
 915    v3f rc, rd, ro;
 916    v3_copy( sample_directions[ si ], rd );
 917    v3_add( co, (v3f){0.0f,1.5f,0.0f}, ro );
 918    v3_copy( ro, rc );
 919
 920    float dist = 200.0f;
 921
 922    for( int i=0; i<10; i++ ){
 923       if( ray_world( get_active_world(), rc, rd, &ray ) ){
 924          dist = (float)i*5.0f + ray.dist;
 925          break;
 926       }
 927       else{
 928          v3_muladds( rc, rd, ray.dist, rc );
 929       }
 930    }
 931
 932    distances[si] = dist;
 933
 934    if( vg_lines.draw ){
 935       for( int i=0; i<14; i++ ){
 936          if( distances[i] != 200.0f ){
 937             u32 colours[] = { VG__RED, VG__BLUE, VG__GREEN,
 938                               VG__CYAN, VG__YELOW, VG__PINK,
 939                               VG__WHITE };
 940
 941             u32 colour = colours[i%7];
 942
 943             v3f p1;
 944             v3_muladds( ro, sample_directions[i], distances[i], p1 );
 945             vg_line( ro, p1, colour );
 946             vg_line_pt3( p1, 0.1f, colour );
 947          }
 948       }
 949    }
 950
 951    *index = si;
 952    *value = dist;
 953
 954    si ++;
 955    if( si >= 14 )
 956       si = 0;
 957 }
 958
 959 #endif /* WORLD_H */