scene.h

   1 #ifndef SCENE_H
   2 #define SCENE_H
   3
   4 #include "common.h"
   5 #include "model.h"
   6
   7 typedef struct scene scene;
   8 typedef struct bvh_node bvh_node;
   9
  10 struct scene
  11 {
  12    glmesh mesh;
  13
  14    model_vert *verts;
  15    u32 *indices;
  16
  17    struct
  18    {
  19       bvh_node *nodes;
  20       u32 node_count;
  21    }
  22    bvh;
  23
  24    u32 vertex_count,
  25        indice_count,
  26        vertex_cap,
  27        indice_cap;
  28
  29    boxf bbx;
  30
  31    u32 shadower_count,
  32        shadower_cap;
  33
  34    submodel submesh;
  35 };
  36
  37 GLuint tex_dual_noise;
  38
  39 static void scene_init( scene *pscene )
  40 {
  41    pscene->verts = NULL;
  42    pscene->indices = NULL;
  43    pscene->vertex_count = 0;
  44    pscene->indice_count = 0;
  45    pscene->shadower_count = 0;
  46    pscene->shadower_cap = 0;
  47    pscene->submesh.indice_start = 0;
  48    pscene->submesh.indice_count = 0;
  49
  50    v3_fill( pscene->bbx[0],  999999.9f );
  51    v3_fill( pscene->bbx[1], -999999.9f );
  52
  53    static int noise_ready = 0;
  54    if( !noise_ready )
  55    {
  56       noise_ready = 1;
  57
  58       u8 *buf = malloc( 256*256*2 );
  59
  60       for( int i=0; i<256*256; i++ )
  61       {
  62          u8 val = rand()&0xff;
  63          buf[i*2] = val;
  64       }
  65
  66       for( int y=0; y<256; y++ )
  67       {
  68          for( int x=0; x<256; x++ )
  69          {
  70             u8 *pr = &buf[(y*256+x)*2],
  71                *pg = &buf[(((y+17)&0xff)*256+((x+37)&0xff))*2+1];
  72             *pg = *pr;
  73          }
  74       }
  75
  76       /* TODO: This texture should be delted somewhere */
  77       glGenTextures( 1, &tex_dual_noise );
  78       glBindTexture( GL_TEXTURE_2D, tex_dual_noise );
  79       glTexImage2D( GL_TEXTURE_2D, 0, GL_RG, 256, 256, 0, GL_RG,
  80             GL_UNSIGNED_BYTE, buf );
  81
  82       vg_tex2d_linear();
  83       vg_tex2d_repeat();
  84
  85       free( buf );
  86    }
  87 }
  88
  89 static void *buffer_reserve( void *buffer, u32 count, u32 *cap, u32 amount,
  90       size_t emsize )
  91 {
  92    if( count+amount > *cap )
  93    {
  94       *cap = VG_MAX( (*cap)*2, (*cap)+amount );
  95
  96       return realloc( buffer, (*cap) * emsize );
  97    }
  98
  99    return buffer;
 100 }
 101
 102 /*
 103  * Append a model into the scene with a given transform
 104  */
 105 static void scene_add_model( scene *pscene, model *mdl, submodel *submodel,
 106       v3f pos, float yaw, float scale )
 107 {
 108    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 109          &pscene->vertex_cap, submodel->vertex_count, sizeof(model_vert) );
 110    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 111          &pscene->indice_cap, submodel->indice_count, sizeof(u32) );
 112
 113    /* Transform and place vertices */
 114    model_vert *src_verts = submodel_vert_data( mdl, submodel );
 115    u32 *src_indices = submodel_indice_data( mdl, submodel );
 116
 117    m4x3f mtx;
 118    m4x3_identity( mtx );
 119    m4x3_translate( mtx, pos );
 120    m4x3_rotate_y( mtx, yaw );
 121    m4x3_scale( mtx, scale );
 122
 123    boxf bbxnew;
 124    box_copy( submodel->bbx, bbxnew );
 125    m4x3_transform_aabb( mtx, bbxnew );
 126    box_concat( pscene->bbx, bbxnew );
 127
 128    m3x3f rotation;
 129    m4x3_to_3x3( mtx, rotation );
 130
 131    float rand_hue = vg_randf();
 132
 133    for( u32 i=0; i<submodel->vertex_count; i++ )
 134    {
 135       model_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
 136                  *src = &src_verts[ i ];
 137
 138       m4x3_mulv( mtx, src->co, pvert->co );
 139       m3x3_mulv( rotation, src->norm, pvert->norm );
 140
 141       v4_copy( src->colour, pvert->colour );
 142       v2_copy( src->uv, pvert->uv );
 143
 144       float rel_y = src->co[1] / submodel->bbx[1][1];
 145       pvert->colour[0] = rel_y;
 146       pvert->colour[2] = rand_hue;
 147    }
 148
 149    for( u32 i=0; i<submodel->indice_count; i++ )
 150    {
 151       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
 152       *pidx = src_indices[i] + pscene->vertex_count;
 153    }
 154
 155    pscene->vertex_count += submodel->vertex_count;
 156    pscene->indice_count += submodel->indice_count;
 157 }
 158
 159 static void scene_add_foliage( scene *pscene, model *mdl, submodel *submodel,
 160       m4x3f transform )
 161 {
 162    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 163          &pscene->vertex_cap, submodel->vertex_count, sizeof(model_vert) );
 164    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 165          &pscene->indice_cap, submodel->indice_count, sizeof(u32) );
 166
 167    /* Transform and place vertices */
 168    model_vert *src_verts = submodel_vert_data( mdl, submodel );
 169    u32 *src_indices = submodel_indice_data( mdl, submodel );
 170
 171    boxf bbxnew;
 172    box_copy( submodel->bbx, bbxnew );
 173    m4x3_transform_aabb( transform, bbxnew );
 174    box_concat( pscene->bbx, bbxnew );
 175
 176    float rand_hue = vg_randf();
 177    for( u32 i=0; i<submodel->vertex_count; i++ )
 178    {
 179       model_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
 180                  *src = &src_verts[ i ];
 181
 182       m4x3_mulv( transform, src->co, pvert->co );
 183       m3x3_mulv( transform, src->norm, pvert->norm );
 184
 185       v4_copy( src->colour, pvert->colour );
 186       v2_copy( src->uv, pvert->uv );
 187
 188       float rel_y = src->co[1] / submodel->bbx[1][1];
 189       pvert->colour[0] = rel_y;
 190       pvert->colour[2] = rand_hue;
 191    }
 192
 193    for( u32 i=0; i<submodel->indice_count; i++ )
 194    {
 195       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
 196       *pidx = src_indices[i] + pscene->vertex_count;
 197    }
 198
 199    pscene->vertex_count += submodel->vertex_count;
 200    pscene->indice_count += submodel->indice_count;
 201 }
 202
 203 static void scene_copy_slice( scene *pscene, submodel *sm )
 204 {
 205    sm->indice_start = pscene->submesh.indice_start;
 206    sm->indice_count = pscene->indice_count - sm->indice_start;
 207
 208    sm->vertex_start = pscene->submesh.vertex_start;
 209    sm->vertex_count = pscene->vertex_count - sm->vertex_start;
 210
 211    pscene->submesh.indice_start = pscene->indice_count;
 212    pscene->submesh.vertex_start = pscene->vertex_count;
 213 }
 214
 215 static void scene_upload( scene *pscene )
 216 {
 217    mesh_upload( &pscene->mesh,
 218          pscene->verts, pscene->vertex_count,
 219          pscene->indices, pscene->indice_count );
 220
 221    vg_info( "Scene upload\n" );
 222    vg_info( "   indices:%u\n", pscene->indice_count );
 223    vg_info( "   verts:%u\n", pscene->vertex_count );
 224 }
 225
 226 float scene_tree_sway = 0.1f;
 227
 228 #if 0
 229 static void scene_foliage_shader_use(void)
 230 {
 231    SHADER_USE( shader_debug_vcol );
 232
 233         glUniformMatrix4fv( SHADER_UNIFORM( shader_debug_vcol, "uPv" ),
 234          1, GL_FALSE, (float *)vg_pv );
 235
 236    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uMode" ), debugview );
 237    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexMain" ), 0 );
 238
 239    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexGradients" ), 1 );
 240    vg_tex2d_bind( &tex_gradients, 1 );
 241
 242    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexNoise" ), 2 );
 243    glActiveTexture( GL_TEXTURE2 );
 244    glBindTexture( GL_TEXTURE_2D, tex_dual_noise );
 245
 246    glUniform1f( SHADER_UNIFORM( shader_debug_vcol, "uTime" ), vg_time );
 247    glUniform1f( SHADER_UNIFORM( shader_debug_vcol, "uSwayAmt" ),
 248          scene_tree_sway );
 249 }
 250 #endif
 251
 252 static void scene_bind( scene *pscene )
 253 {
 254    mesh_bind( &pscene->mesh );
 255 }
 256
 257 static void scene_draw( scene *pscene )
 258 {
 259    mesh_drawn( 0, pscene->indice_count );
 260 }
 261
 262 static void scene_register(void)
 263 {
 264 }
 265
 266
 267 /* Physics segment */
 268
 269 static int triangle_raycast2d( v3f pA, v3f pB, v3f pC, v3f ray, float *height )
 270 {
 271         v2f v0, v1, v2, vp, vp2;
 272         float d, bca = 0.f, bcb = 0.f, bcc = 0.f;
 273
 274    v0[0] = pB[0] - pA[0];
 275    v0[1] = pB[2] - pA[2];
 276    v1[0] = pC[0] - pA[0];
 277    v1[1] = pC[2] - pA[2];
 278    v2[0] = pB[0] - pC[0];
 279    v2[1] = pB[2] - pC[2];
 280
 281         d = 1.f / (v0[0]*v1[1] - v1[0]*v0[1]);
 282
 283 #if 0
 284         /* Backface culling */
 285         if( v2_cross( v0, v1 ) > 0.f )
 286                 return;
 287 #endif
 288
 289    vp[0] = ray[0] - pA[0];
 290    vp[1] = ray[2] - pA[2];
 291
 292    if( v2_cross( v0, vp ) > 0.f ) return 0;
 293    if( v2_cross( vp, v1 ) > 0.f ) return 0;
 294
 295    vp2[0] = ray[0] - pB[0];
 296    vp2[1] = ray[2] - pB[2];
 297
 298    if( v2_cross( vp2, v2 ) > 0.f ) return 0;
 299
 300    bcb = (vp[0]*v1[1] - v1[0]*vp[1]) * d;
 301    bcc = (v0[0]*vp[1] - vp[0]*v0[1]) * d;
 302    bca = 1.f - bcb - bcc;
 303
 304    *height = pA[1]*bca + pB[1]*bcb + pC[1]*bcc;
 305    return 1;
 306 }
 307
 308 /* Temporary */
 309 static int sample_scene_height( scene *pscene, v3f pos, v3f norm )
 310 {
 311    for( int i=0; i<pscene->indice_count/3; i++ )
 312    {
 313       u32 *tri = &pscene->indices[i*3];
 314
 315       float *pA = pscene->verts[tri[0]].co,
 316             *pB = pscene->verts[tri[1]].co,
 317             *pC = pscene->verts[tri[2]].co;
 318
 319       float height;
 320       if( triangle_raycast2d( pA, pB, pC, pos, &height ))
 321       {
 322          pos[1] = height;
 323
 324          if( norm )
 325          {
 326             v3f v0, v1;
 327             v3_sub( pA, pB, v0 );
 328             v3_sub( pC, pB, v1 );
 329             v3_cross( v1, v0, norm );
 330             v3_normalize( norm );
 331          }
 332
 333          return 1;
 334       }
 335    }
 336    return 0;
 337 }
 338
 339 static void sample_scene_normal( scene *pscene, v3f pos, v3f normal )
 340 {
 341    for( int i=0; i<pscene->indice_count/3; i++ )
 342    {
 343       u32 *tri = &pscene->indices[i*3];
 344
 345       float height;
 346       if( triangle_raycast2d(
 347             pscene->verts[ tri[0] ].co,
 348             pscene->verts[ tri[1] ].co,
 349             pscene->verts[ tri[2] ].co, pos, &height ))
 350       {
 351          v3f v0, v1;
 352
 353          v3_sub( pscene->verts[ tri[1] ].co,
 354                  pscene->verts[ tri[0] ].co,
 355                  v0 );
 356
 357          v3_sub( pscene->verts[ tri[2] ].co,
 358                  pscene->verts[ tri[0] ].co,
 359                  v1 );
 360
 361          v3_cross( v0, v1, normal );
 362          v3_normalize( normal );
 363          return;
 364       }
 365    }
 366
 367    normal[0] = 0.0f;
 368    normal[1] = 1.0f;
 369    normal[2] = 0.0f;
 370 }
 371
 372
 373 /*
 374  *
 375  *
 376  *            TODO: THIS SHIT IS DEPRECATED FOR THE NEW SHIT IN BVH.H
 377  *
 378  *
 379  */
 380
 381 struct bvh_node
 382 {
 383    boxf bbx;
 384
 385    /* if il is 0, this is a leaf */
 386    u32 il, count;
 387    union{ u32 ir, start; };
 388 };
 389
 390 static void bvh_update_bounds( scene *s, u32 inode )
 391 {
 392    bvh_node *node = &s->bvh.nodes[ inode ];
 393
 394    box_init_inf( node->bbx );
 395    for( u32 i=0; i<node->count; i++ )
 396    {
 397       u32 idx = node->start+i;
 398       model_vert *pa = &s->verts[ s->indices[idx*3+0] ],
 399                  *pb = &s->verts[ s->indices[idx*3+1] ],
 400                  *pc = &s->verts[ s->indices[idx*3+2] ];
 401
 402      box_addpt( node->bbx, pa->co );
 403      box_addpt( node->bbx, pb->co );
 404      box_addpt( node->bbx, pc->co );
 405    }
 406 }
 407
 408 static void bvh_subdiv( scene *s, u32 inode )
 409 {
 410    bvh_node *node = &s->bvh.nodes[ inode ];
 411
 412    v3f extent;
 413    v3_sub( node->bbx[1], node->bbx[0], extent );
 414
 415    int axis = 0;
 416    if( extent[1] > extent[0] ) axis = 1;
 417    if( extent[2] > extent[axis] ) axis = 2;
 418
 419    float split = node->bbx[0][axis] + extent[axis]*0.5f;
 420
 421    float avg = 0.0;
 422    for( u32 t=0; t<node->count; t++ )
 423    {
 424       u32 *ti = &s->indices[(node->start+t)*3];
 425       float a = s->verts[ti[0]].co[axis],
 426             b = s->verts[ti[1]].co[axis],
 427             c = s->verts[ti[2]].co[axis];
 428       avg += (a+b+c) * (1.0f/3.0f);
 429    }
 430    avg /= (float)node->count;
 431
 432    split = avg;
 433
 434    i32 i = node->start,
 435        j = i + node->count-1;
 436
 437    while( i <= j )
 438    {
 439       u32 *ti = &s->indices[i*3];
 440
 441       float a = s->verts[ti[0]].co[axis],
 442             b = s->verts[ti[1]].co[axis],
 443             c = s->verts[ti[2]].co[axis];
 444
 445       if( (a+b+c) * (1.0f/3.0f) < split )
 446          i ++;
 447       else
 448       {
 449          /* Swap triangle indices */
 450          u32 *tj = &s->indices[j*3];
 451          u32 temp[3];
 452          temp[0] = ti[0];
 453          temp[1] = ti[1];
 454          temp[2] = ti[2];
 455
 456          ti[0] = tj[0];
 457          ti[1] = tj[1];
 458          ti[2] = tj[2];
 459
 460          tj[0] = temp[0];
 461          tj[1] = temp[1];
 462          tj[2] = temp[2];
 463
 464          j --;
 465       }
 466    }
 467
 468    u32 left_count = i - node->start;
 469    if( left_count == 0 || left_count == node->count ) return;
 470
 471    u32 il = s->bvh.node_count ++,
 472        ir = s->bvh.node_count ++;
 473
 474    struct bvh_node *lnode = &s->bvh.nodes[il],
 475                    *rnode = &s->bvh.nodes[ir];
 476
 477    lnode->start = node->start;
 478    lnode->count = left_count;
 479    rnode->start = i;
 480    rnode->count = node->count - left_count;
 481
 482    node->il = il;
 483    node->ir = ir;
 484    node->count = 0;
 485
 486    bvh_update_bounds( s, il );
 487    bvh_update_bounds( s, ir );
 488    bvh_subdiv( s, il );
 489    bvh_subdiv( s, ir );
 490 }
 491
 492 static void bvh_create( scene *s )
 493 {
 494    u32 triangle_count = s->indice_count / 3;
 495    s->bvh.nodes = malloc( sizeof(struct bvh_node) * (triangle_count*2-1) );
 496
 497    bvh_node *root = &s->bvh.nodes[0];
 498    s->bvh.node_count = 1;
 499
 500    root->il = 0;
 501    root->ir = 0;
 502    root->count = triangle_count;
 503    root->start = 0;
 504
 505    bvh_update_bounds( s, 0 );
 506    bvh_subdiv( s, 0 );
 507
 508    s->bvh.nodes =
 509       realloc( s->bvh.nodes, sizeof(struct bvh_node) * s->bvh.node_count );
 510
 511    vg_success( "BVH done, size: %u/%u\n", s->bvh.node_count,
 512                                           (triangle_count*2-1) );
 513 }
 514
 515 static void bvh_debug_node( scene *s, u32 inode, v3f pos, u32 colour )
 516 {
 517    struct bvh_node *node = &s->bvh.nodes[ inode ];
 518
 519    if( (pos[0] >= node->bbx[0][0] && pos[0] <= node->bbx[1][0]) &&
 520        (pos[2] >= node->bbx[0][2] && pos[2] <= node->bbx[1][2]) )
 521    {
 522       if( !node->count )
 523       {
 524          vg_line_boxf( node->bbx, colour );
 525
 526          bvh_debug_node( s, node->il, pos, colour );
 527          bvh_debug_node( s, node->ir, pos, colour );
 528       }
 529       else
 530       {
 531          vg_line_boxf( node->bbx, 0xff00ff00 );
 532          for( u32 i=0; i<node->count; i++ )
 533          {
 534             u32 idx = (node->start+i)*3;
 535
 536             model_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
 537                        *pb = &s->verts[ s->indices[ idx+1 ] ],
 538                        *pc = &s->verts[ s->indices[ idx+2 ] ];
 539
 540             vg_line( pa->co, pb->co, 0xff0000ff );
 541             vg_line( pb->co, pc->co, 0xff0000ff );
 542             vg_line( pc->co, pa->co, 0xff0000ff );
 543          }
 544       }
 545    }
 546 }
 547
 548 static void bvh_debug( scene *s, v3f pos )
 549 {
 550    bvh_debug_node( s, 0, pos, 0x4000ffa8 );
 551 }
 552
 553 static int bvh_ray_tri( scene *sc, u32 *tri, v3f co, v3f dir, ray_hit *hit )
 554 {
 555    v3f positions[3];
 556    for( int i=0; i<3; i++ )
 557       v3_copy( sc->verts[tri[i]].co, positions[i] );
 558
 559    float t;
 560    if(ray_tri( positions, co, dir, &t ))
 561    {
 562       if( t < hit->dist )
 563       {
 564          hit->dist = t;
 565          hit->tri = tri;
 566          return 1;
 567       }
 568    }
 569
 570    return 0;
 571 }
 572
 573 static int bvh_ray( scene *s, u32 inode, v3f co, v3f dir, ray_hit *hit )
 574 {
 575 #if 0
 576    bvh_node *node = &s->bvh.nodes[ inode ];
 577
 578    if( !ray_aabb( node->bbx, co, dir, hit->dist ))
 579       return 0;
 580
 581    int count = 0;
 582
 583    if( node->count )
 584    {
 585       for( u32 i=0; i<node->count; i++ )
 586       {
 587          u32 *indices = &s->indices[ (node->start+i)*3 ];
 588          count += bvh_ray_tri( s, indices, co, dir, hit );
 589       }
 590    }
 591    else
 592    {
 593       count += bvh_ray( s, node->il, co, dir, hit );
 594       count += bvh_ray( s, node->ir, co, dir, hit );
 595    }
 596
 597    return count;
 598 #endif
 599
 600    int count = 0;
 601    u32 stack[100];
 602    u32 depth = 2;
 603
 604    stack[0] = 0;
 605    stack[1] = s->bvh.nodes[0].il;
 606    stack[2] = s->bvh.nodes[0].ir;
 607
 608    while(depth)
 609    {
 610       bvh_node *inode = &s->bvh.nodes[ stack[depth] ];
 611       if( ray_aabb( inode->bbx, co, dir, hit->dist ) )
 612       {
 613          if( inode->count )
 614          {
 615             for( u32 i=0; i<inode->count; i++ )
 616             {
 617                u32 *indices = &s->indices[ (inode->start+i)*3 ];
 618                count += bvh_ray_tri( s, indices, co, dir, hit );
 619             }
 620
 621             depth --;
 622          }
 623          else
 624          {
 625             if( depth+1 >= vg_list_size(stack) )
 626             {
 627                vg_error( "Maximum stack reached!\n" );
 628                return count;
 629             }
 630
 631             stack[depth] = inode->il;
 632             stack[depth+1] = inode->ir;
 633             depth ++;
 634          }
 635       }
 636       else
 637       {
 638          depth --;
 639       }
 640    }
 641
 642    return count;
 643 }
 644
 645 static int bvh_raycast( scene *s, v3f co, v3f dir, ray_hit *hit )
 646 {
 647    v3f pb;
 648    v3_muladds( co, dir, hit->dist, pb );
 649
 650    int count = bvh_ray( s, 0, co, dir, hit );
 651
 652    if( count )
 653    {
 654       //vg_line( co, pb, 0xff00ffff );
 655
 656       v3f v0, v1;
 657
 658       float *pa = s->verts[hit->tri[0]].co,
 659             *pb = s->verts[hit->tri[1]].co,
 660             *pc = s->verts[hit->tri[2]].co;
 661
 662       v3_sub( pa, pb, v0 );
 663       v3_sub( pc, pb, v1 );
 664       v3_cross( v1, v0, hit->normal );
 665       v3_normalize( hit->normal );
 666       v3_muladds( co, dir, hit->dist, hit->pos );
 667    }
 668    else
 669    {
 670       //vg_line( co, pb, 0xff0000ff );
 671    }
 672
 673    return count;
 674 }
 675
 676 static int bvh_select_triangles( scene *s, boxf box, u32 *triangles, int len )
 677 {
 678    /* TODO: use this stack system on the raycast function */
 679    int count = 0;
 680    u32 stack[100];
 681    u32 depth = 2;
 682
 683    stack[0] = 0;
 684    stack[1] = s->bvh.nodes[0].il;
 685    stack[2] = s->bvh.nodes[0].ir;
 686
 687    while(depth)
 688    {
 689       bvh_node *inode = &s->bvh.nodes[ stack[depth] ];
 690       if( box_overlap( inode->bbx, box ) )
 691       {
 692          if( inode->count )
 693          {
 694             if( count + inode->count >= len )
 695             {
 696                vg_error( "Maximum buffer reached!\n" );
 697                return count;
 698             }
 699
 700             for( u32 i=0; i<inode->count; i++ )
 701                triangles[ count ++ ] = (inode->start+i)*3;
 702
 703             depth --;
 704          }
 705          else
 706          {
 707             if( depth+1 >= vg_list_size(stack) )
 708             {
 709                vg_error( "Maximum stack reached!\n" );
 710                return count;
 711             }
 712
 713             stack[depth] = inode->il;
 714             stack[depth+1] = inode->ir;
 715             depth ++;
 716          }
 717       }
 718       else
 719       {
 720          depth --;
 721       }
 722    }
 723
 724    return count;
 725 }
 726
 727 static int bvh_scene_sample_node_h( scene *s, u32 inode, v3f pos, v3f norm )
 728 {
 729    bvh_node *node = &s->bvh.nodes[ inode ];
 730
 731    if( (pos[0] >= node->bbx[0][0] && pos[0] <= node->bbx[1][0]) &&
 732        (pos[2] >= node->bbx[0][2] && pos[2] <= node->bbx[1][2]) )
 733    {
 734       if( !node->count )
 735       {
 736          if( bvh_scene_sample_node_h( s, node->il, pos, norm )) return 1;
 737          if( bvh_scene_sample_node_h( s, node->ir, pos, norm )) return 1;
 738       }
 739       else
 740       {
 741          for( u32 i=0; i<node->count; i++ )
 742          {
 743             u32 idx = (node->start+i)*3;
 744             model_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
 745                        *pb = &s->verts[ s->indices[ idx+1 ] ],
 746                        *pc = &s->verts[ s->indices[ idx+2 ] ];
 747
 748             float height;
 749             if( triangle_raycast2d( pa->co, pb->co, pc->co, pos, &height ))
 750             {
 751                pos[1] = height;
 752
 753                if( norm )
 754                {
 755                   v3f v0, v1;
 756                   v3_sub( pa->co, pb->co, v0 );
 757                   v3_sub( pc->co, pb->co, v1 );
 758                   v3_cross( v1, v0, norm );
 759                   v3_normalize( norm );
 760                }
 761
 762                return 1;
 763             }
 764          }
 765       }
 766    }
 767
 768    return 0;
 769 }
 770
 771 static int bvh_scene_sample_h( scene *s, v3f pos, v3f norm)
 772 {
 773    return bvh_scene_sample_node_h( s, 0, pos, norm );
 774 }
 775
 776 static int bvh_scene_sample( scene *s, v3f pos, ray_hit *hit )
 777 {
 778    hit->dist = INFINITY;
 779
 780    v3f ray_pos;
 781    v3_add( pos, (v3f){0.0f,4.0f,0.0f}, ray_pos );
 782
 783    if( bvh_raycast( s, ray_pos, (v3f){0.0f,-1.0f,0.0f}, hit ))
 784    {
 785       pos[1] = hit->pos[1];
 786       return 1;
 787    }
 788
 789    return 0;
 790 }
 791
 792 #endif