scene.h

   1 #ifndef SCENE_H
   2 #define SCENE_H
   3
   4 #include "vg/vg.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    struct shadower
  32    {
  33       sdf_primative sdf;
  34       esdf_type sdf_type;
  35    }
  36    *shadowers;
  37
  38    u32 shadower_count,
  39        shadower_cap;
  40
  41    submodel submesh;
  42 };
  43
  44 GLuint tex_dual_noise;
  45
  46 static void scene_init( scene *pscene )
  47 {
  48    pscene->verts = NULL;
  49    pscene->indices = NULL;
  50    pscene->vertex_count = 0;
  51    pscene->indice_count = 0;
  52    pscene->shadowers = NULL;
  53    pscene->shadower_count = 0;
  54    pscene->shadower_cap = 0;
  55    pscene->submesh.indice_start = 0;
  56    pscene->submesh.indice_count = 0;
  57
  58    v3_fill( pscene->bbx[0],  999999.9f );
  59    v3_fill( pscene->bbx[1], -999999.9f );
  60
  61    static int noise_ready = 0;
  62    if( !noise_ready )
  63    {
  64       noise_ready = 1;
  65
  66       u8 *buf = malloc( 256*256*2 );
  67
  68       for( int i=0; i<256*256; i++ )
  69       {
  70          u8 val = rand()&0xff;
  71          buf[i*2] = val;
  72       }
  73
  74       for( int y=0; y<256; y++ )
  75       {
  76          for( int x=0; x<256; x++ )
  77          {
  78             u8 *pr = &buf[(y*256+x)*2],
  79                *pg = &buf[(((y+17)&0xff)*256+((x+37)&0xff))*2+1];
  80             *pg = *pr;
  81          }
  82       }
  83
  84       /* TODO: This texture should be delted somewhere */
  85       glGenTextures( 1, &tex_dual_noise );
  86       glBindTexture( GL_TEXTURE_2D, tex_dual_noise );
  87       glTexImage2D( GL_TEXTURE_2D, 0, GL_RG, 256, 256, 0, GL_RG,
  88             GL_UNSIGNED_BYTE, buf );
  89
  90       vg_tex2d_linear();
  91       vg_tex2d_repeat();
  92
  93       free( buf );
  94    }
  95 }
  96
  97 /* https://www.shadertoy.com/view/4sfGzS */
  98 #define SHADER_VALUE_NOISE_3D                         \
  99 "uniform sampler2D uTexNoise;"                        \
 100 ""                                                    \
 101 "float noise( vec3 x )"                               \
 102 "{"                                                   \
 103    "vec3 i = floor(x);"                               \
 104    "vec3 f = fract(x);"                               \
 105    "f = f*f*(3.0-2.0*f);"                             \
 106    "vec2 uv = (i.xy+vec2(37.0,17.0)*i.z) + f.xy;"     \
 107    "vec2 rg = texture( uTexNoise, (uv+0.5)/256.0).yx;"\
 108    "return mix( rg.x, rg.y, f.z );"                   \
 109 "}"                                                   \
 110 ""                                                    \
 111 "const mat3 m = mat3( 0.00,  0.80,  0.60,"            \
 112                     "-0.80,  0.36, -0.48,"            \
 113                     "-0.60, -0.48,  0.64 );"          \
 114 ""                                                    \
 115 "float fractalNoise( vec3 x )"                        \
 116 "{"                                                   \
 117    "vec3 q = 8.0*x;"                                  \
 118    "float f;"                                         \
 119    "f  = 0.5000*noise( q ); q = m*q*2.01;"            \
 120    "f += 0.2500*noise( q ); q = m*q*2.02;"            \
 121    "f += 0.1250*noise( q ); q = m*q*2.03;"            \
 122    "f += 0.0625*noise( q ); q = m*q*2.01;"            \
 123    "return f;"                                        \
 124 "}"
 125
 126 SHADER_DEFINE( shader_debug_vcol,
 127
 128    /*Include*/ VERTEX_STANDARD_ATTRIBUTES
 129
 130         "uniform mat4 uPv;"
 131    "uniform mat4x3 uMdl;"
 132    "uniform float uTime;"
 133    "uniform float uSwayAmt;"
 134    ""
 135    "out vec4 aColour;"
 136    "out vec2 aUv;"
 137    "out vec3 aNorm;"
 138    "out vec3 aCo;"
 139    ""
 140    "vec3 compute_sway( vec3 pos )"
 141    "{"
 142       "vec4 sines = vec4( sin(uTime + pos.x)*1.0,"
 143                          "sin(uTime*1.2 + pos.z*2.0)*1.1,"
 144                          "sin(uTime*2.33)*0.5,"
 145                          "sin(uTime*0.6 + pos.x*0.3)*1.3 );"
 146
 147       "vec3 offset = vec3( sines.x+sines.y*sines.w, 0.0, sines.x+sines.z );"
 148       "return pos + offset*a_colour.r*uSwayAmt;"
 149    "}"
 150         ""
 151         "void main()"
 152         "{"
 153       "vec3 swaypos = compute_sway( a_co );"
 154                 "gl_Position = uPv * vec4(uMdl * vec4(swaypos,1.0), 1.0 );"
 155       "aColour = a_colour;"
 156       "aUv = a_uv;"
 157       "aNorm = normalize(mat3(uMdl) * a_norm);"
 158       "aCo = a_co;"
 159         "}",
 160    /* Fragment */
 161         "out vec4 FragColor;"
 162         ""
 163    "uniform int uMode;"
 164    "uniform sampler2D uTexMain;"
 165    "uniform sampler2D uTexGradients;"
 166    ""
 167    /*Include*/ SHADER_VALUE_NOISE_3D
 168    ""
 169    "in vec4 aColour;"
 170    "in vec2 aUv;"
 171    "in vec3 aNorm;"
 172    "in vec3 aCo;"
 173    ""
 174         "void main()"
 175         "{"
 176       "vec4 colour = vec4(1.0,0.0,0.5,1.0);"
 177       "vec4 diffuse = texture( uTexMain, aUv );"
 178
 179       "if( uMode == 1 )"
 180       "{"
 181          "colour = vec4(aNorm * 0.5 + 0.5, 1.0);"
 182       "}"
 183       "if( uMode == 2 )"
 184       "{"
 185          "colour = aColour;"
 186       "}"
 187       "if( uMode == 3 )"
 188       "{"
 189          "float light = dot(aNorm, vec3(0.2,0.8,0.1));"
 190          "vec3 grid3 = fract(aCo);"
 191
 192          "colour = vec4(vec3(light)*(1.0-grid3*0.3),1.0);"
 193       "}"
 194       "if( uMode == 4 )"
 195       "{"
 196          "colour = vec4( aUv, 0.0, 1.0 );"
 197       "}"
 198       "if( uMode == 5 )"
 199       "{"
 200          "if( diffuse.a < 0.45 ) discard;"
 201          "colour = diffuse;"
 202       "}"
 203       "if( uMode == 6 )"
 204       "{"
 205          "float r1 = fractalNoise(aCo);"
 206          "colour = vec4( vec3(r1), 1.0 );"
 207       "}"
 208       "if( uMode == 7 )"
 209       "{"
 210          "if( diffuse.a < 0.2 ) discard;"
 211          "float lighting = 1.0 - aColour.g*0.8;"
 212
 213          "float light1 = max(0.0,dot(-vec3(0.5,-0.8,0.25), aNorm));"
 214          "float light2 = max(0.0,dot(-vec3(-0.8,0.5,-0.25), aNorm));"
 215          "vec3 lt = vec3(0.2,0.2,0.2 ) + "
 216                    "vec3(1.0,1.0,0.9)*light1 + "
 217                    "vec3(0.1,0.3,0.4 )*light2;"
 218
 219
 220          "colour = vec4(vec3(pow(lighting,1.6)*(diffuse.r*0.7+0.5)),1.0);"
 221          "colour = vec4(colour.rgb*lt,1.0);"
 222
 223          "vec2 gradUV = vec2(lighting*1.9,aColour.b*0.8);"
 224          "vec4 gradient_sample = texture( uTexGradients, gradUV );"
 225          "colour = colour*gradient_sample;"
 226       "}"
 227       "if( uMode == 8 )"
 228       "{"
 229          "if( diffuse.a < 0.45 ) discard;"
 230          "float light = 1.0 - aColour.g;"
 231          "light = pow(light,1.6)*(diffuse.r*0.7+0.5);"
 232          "float r1 = fractalNoise(aCo*0.01);"
 233
 234          "vec2 gradUV = vec2(light*1.9,r1+aColour.b);"
 235          "vec4 gradient_sample = texture( uTexGradients, gradUV );"
 236          "colour = gradient_sample*light;"
 237       "}"
 238
 239                 "FragColor = colour;"
 240         "}"
 241         ,
 242         UNIFORMS({ "uPv", "uMode", "uTexMain", "uTexGradients", "uTexNoise", \
 243               "uTime", "uSwayAmt", "uMdl" })
 244 )
 245
 246 SHADER_DEFINE( shader_standard_lit,
 247
 248    /*Include*/ VERTEX_STANDARD_ATTRIBUTES
 249
 250         "uniform mat4 uPv;"
 251    "uniform mat4x3 uMdl;"
 252    ""
 253    "out vec4 aColour;"
 254    "out vec2 aUv;"
 255    "out vec3 aNorm;"
 256    "out vec3 aCo;"
 257    ""
 258         "void main()"
 259         "{"
 260                 "gl_Position = uPv * vec4( uMdl * vec4(a_co,1.0), 1.0 );"
 261       "aColour = a_colour;"
 262       "aUv = a_uv;"
 263       "aNorm = mat3(uMdl) * a_norm;"
 264       "aCo = a_co;"
 265         "}",
 266    /* Fragment */
 267         "out vec4 FragColor;"
 268         ""
 269    "uniform sampler2D uTexMain;"
 270    "uniform vec4 uColour;"
 271    ""
 272    "in vec4 aColour;"
 273    "in vec2 aUv;"
 274    "in vec3 aNorm;"
 275    "in vec3 aCo;"
 276    ""
 277         "void main()"
 278         "{"
 279       "vec3 diffuse = texture( uTexMain, aUv ).rgb;"
 280
 281       "float light1 = max(0.0,dot(-vec3(0.5,-0.8,0.25), aNorm));"
 282       "float light2 = max(0.0,dot(-vec3(-0.8,0.5,-0.25), aNorm));"
 283       "diffuse += vec3(0.2,0.2,0.2) + "
 284                  "vec3(1.0,1.0,0.9)*light1 + "
 285                  "vec3(0.1,0.3,0.4)*light2;"
 286
 287                 "FragColor = vec4(diffuse*uColour.rgb, aColour.a*uColour.a);"
 288         "}"
 289         ,
 290         UNIFORMS({ "uColour","uTexMain","uPv","uMdl" })
 291 )
 292
 293 SHADER_DEFINE( shader_unlit,
 294
 295    /*Include*/ VERTEX_STANDARD_ATTRIBUTES
 296
 297         "uniform mat4 uPv;"
 298    "uniform mat4x3 uMdl;"
 299    ""
 300    "out vec4 aColour;"
 301    "out vec2 aUv;"
 302    "out vec3 aNorm;"
 303    "out vec3 aCo;"
 304    ""
 305         "void main()"
 306         "{"
 307                 "gl_Position = uPv * vec4(uMdl * vec4(a_co,1.0), 1.0);"
 308       "aColour = a_colour;"
 309       "aUv = a_uv;"
 310       "aNorm = mat3(uMdl) * a_norm;"
 311       "aCo = a_co;"
 312         "}",
 313    /* Fragment */
 314         "out vec4 FragColor;"
 315         ""
 316    "uniform sampler2D uTexMain;"
 317    "uniform vec4 uColour;"
 318    ""
 319    "in vec4 aColour;"
 320    "in vec2 aUv;"
 321    "in vec3 aNorm;"
 322    "in vec3 aCo;"
 323    ""
 324         "void main()"
 325         "{"
 326       "vec3 diffuse = texture( uTexMain, aUv ).rgb;"
 327       "FragColor = vec4(pow(diffuse,vec3(1.0)),1.0);"
 328         "}"
 329         ,
 330         UNIFORMS({ "uTexMain", "uPv", "uMdl" })
 331 )
 332
 333 static void *buffer_reserve( void *buffer, u32 count, u32 *cap, u32 amount,
 334       size_t emsize )
 335 {
 336    if( count+amount > *cap )
 337    {
 338       *cap = VG_MAX( (*cap)*2, (*cap)+amount );
 339
 340       return realloc( buffer, (*cap) * emsize );
 341    }
 342
 343    return buffer;
 344 }
 345
 346 /*
 347  * Append a model into the scene with a given transform
 348  */
 349 static void scene_add_model( scene *pscene, model *mdl, submodel *submodel,
 350       v3f pos, float yaw, float scale )
 351 {
 352    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 353          &pscene->vertex_cap, submodel->vertex_count, sizeof(model_vert) );
 354    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 355          &pscene->indice_cap, submodel->indice_count, sizeof(u32) );
 356
 357    if( submodel->sdf_type )
 358    {
 359       pscene->shadowers = buffer_reserve( pscene->shadowers,
 360             pscene->shadower_count, &pscene->shadower_cap, 1,
 361             sizeof( struct shadower ));
 362
 363       struct shadower *shadower =
 364          &pscene->shadowers[ pscene->shadower_count ++ ];
 365
 366       shadower->sdf = submodel->sdf;
 367       shadower->sdf_type = submodel->sdf_type;
 368
 369       v2_muls( shadower->sdf.info, scale, shadower->sdf.info );
 370       v3_muls( shadower->sdf.origin, scale, shadower->sdf.origin );
 371       v3_add( pos, shadower->sdf.origin, shadower->sdf.origin );
 372    }
 373
 374    /* Transform and place vertices */
 375    model_vert *src_verts = submodel_vert_data( mdl, submodel );
 376    u32 *src_indices = submodel_indice_data( mdl, submodel );
 377
 378    m4x3f mtx;
 379    m4x3_identity( mtx );
 380    m4x3_translate( mtx, pos );
 381    m4x3_rotate_y( mtx, yaw );
 382    m4x3_scale( mtx, scale );
 383
 384    boxf bbxnew;
 385    box_copy( submodel->bbx, bbxnew );
 386    m4x3_transform_aabb( mtx, bbxnew );
 387    box_concat( pscene->bbx, bbxnew );
 388
 389    m3x3f rotation;
 390    m4x3_to_3x3( mtx, rotation );
 391
 392    float rand_hue = vg_randf();
 393
 394    for( u32 i=0; i<submodel->vertex_count; i++ )
 395    {
 396       model_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
 397                  *src = &src_verts[ i ];
 398
 399       m4x3_mulv( mtx, src->co, pvert->co );
 400       m3x3_mulv( rotation, src->norm, pvert->norm );
 401
 402       v4_copy( src->colour, pvert->colour );
 403       v2_copy( src->uv, pvert->uv );
 404
 405       float rel_y = src->co[1] / submodel->bbx[1][1];
 406       pvert->colour[0] = rel_y;
 407       pvert->colour[2] = rand_hue;
 408    }
 409
 410    for( u32 i=0; i<submodel->indice_count; i++ )
 411    {
 412       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
 413       *pidx = src_indices[i] + pscene->vertex_count;
 414    }
 415
 416    pscene->vertex_count += submodel->vertex_count;
 417    pscene->indice_count += submodel->indice_count;
 418 }
 419
 420 static void scene_copy_slice( scene *pscene, submodel *sm )
 421 {
 422    sm->indice_start = pscene->submesh.indice_start;
 423    sm->indice_count = pscene->indice_count - sm->indice_start;
 424
 425    pscene->submesh.indice_start = pscene->indice_count;
 426 }
 427
 428 static void scene_shadow_sphere( scene *pscene, v3f sphere,
 429       v4f params, v3f lightdir )
 430 {
 431    for( int i=0; i<pscene->vertex_count; i++ )
 432    {
 433       model_vert *vert = &pscene->verts[i];
 434
 435       v3f delta;
 436       v3_sub( sphere, vert->co, delta );
 437
 438       float d = v3_dot( lightdir, delta );
 439       v3f closest;
 440
 441       v3_muls( lightdir, d, closest );
 442       float dist = v3_dist( closest, delta ),
 443             shading = vg_maxf( dist - params[0], 0.0f );
 444
 445       shading = vg_minf( shading * params[1], 1.0f );
 446       vert->colour[1] *= shading;
 447    }
 448 }
 449
 450 static void scene_shadow_gradient( scene *pscene, int comp,
 451       float start, float length )
 452 {
 453    float scale = 1.0f / length;
 454
 455    for( int i=0; i<pscene->vertex_count; i++ )
 456    {
 457       model_vert *vert = &pscene->verts[i];
 458       float shading = start + vert->co[comp] * scale;
 459
 460       vert->colour[1] = shading;
 461    }
 462 }
 463
 464
 465 /*
 466  * Experimental SDF based shadows
 467  *
 468  * https://iquilezles.org/articles/distfunctions/
 469  */
 470 static float sd_cone( v3f co, sdf_primative *prim )
 471 {
 472    float bound = prim->info[1]*1.75f;
 473    if( v3_dist2( prim->origin, co ) > bound*bound )
 474       return 999999.9f;
 475
 476    v3f p;
 477    v3_sub( co, prim->origin, p );
 478
 479    float h = prim->info[1];
 480    v2f c = { prim->info[2], prim->info[3] };
 481
 482    v2f q, w, a, b;
 483    v2_muls( (v2f){ c[0]/c[1], -1.0f }, h, q );
 484
 485    w[0] = v2_length( (v2f){ p[0], p[2] } );
 486    w[1] = p[1];
 487
 488    v2_muladds( w, q, -vg_clampf( v2_dot(w,q)/v2_dot(q,q), 0.0f, 1.0f ), a );
 489    v2_muladd( w, q, (v2f){ vg_clampf( w[0]/q[0], 0.0f, 1.0f ), 1.0f }, b );
 490
 491    float k = vg_signf( q[1] ),
 492          d = vg_minf( v2_dot( a,a ), v2_dot( b,b ) ),
 493          s = vg_maxf( k*(w[0]*q[1]-w[1]*q[0]), k*(w[1]-q[1]) );
 494
 495    return sqrtf(d)*vg_signf(s);
 496 }
 497
 498 #define CACHE_AMBIENT_SHAPES
 499
 500 static float scene_ambient_sample( scene *pscene, v3f pos, v3f dir )
 501 {
 502    float accum = 0.0f;
 503
 504 #ifdef CACHE_AMBIENT_SHAPES
 505    static struct shadower *local_shadowers[32];
 506    static int local_shadower_count = 0;
 507    static v3f local_shadower_last = { -99999.9f, -999999.9f, -9999999.9f };
 508
 509    if( v3_dist2( pos, local_shadower_last ) > 10.0f*10.0f )
 510    {
 511       local_shadower_count = 0;
 512       v3_copy( pos, local_shadower_last );
 513
 514       for( int k=0; k<pscene->shadower_count; k++ )
 515       {
 516          struct shadower *shadower = &pscene->shadowers[k];
 517
 518          if( sd_cone( pos, &shadower->sdf ) <= 20.0f )
 519          {
 520             local_shadowers[ local_shadower_count ++ ] = shadower;
 521             if( local_shadower_count == vg_list_size( local_shadowers ) )
 522                break;
 523          }
 524       }
 525    }
 526 #endif
 527
 528    for( int j=0; j<5; j++ )
 529    {
 530       v3f tracepos;
 531       v3_muladds( pos, dir, 1.5f*(float)j, tracepos );
 532
 533       float mindist = 99999.9f;
 534
 535 #ifndef CACHE_AMBIENT_SHAPES
 536
 537       for( int k=0; k<pscene->shadower_count; k++ ){
 538          struct shadower *shadower = &pscene->shadowers[k];
 539 #else
 540
 541       for( int k=0; k<local_shadower_count; k++ ){
 542          struct shadower *shadower = local_shadowers[k];
 543 #endif
 544
 545          float dist = vg_maxf( 0.0f, sd_cone( tracepos, &shadower->sdf ));
 546          mindist = vg_minf( mindist, dist );
 547       }
 548
 549
 550       accum += vg_clampf( 1.0f - mindist, 0.0f, 1.0f )*0.2f;
 551    }
 552
 553    return accum;
 554 }
 555
 556 #define DYNAMIC_GRID
 557 #define JUST_DO_EVERY_VERT
 558
 559 static void scene_compute_occlusion( scene *pscene )
 560 {
 561    v3f sundir = { 0.2f, 0.9f, 0.2f };
 562    v3_normalize( sundir );
 563
 564    /* TODO: Make this sample grid be dynamically required.
 565     *
 566     *   1. Only resample the light grid (1x1x1), when a vertex is outside the
 567     *      current cube
 568     *
 569     *   2. Reorder all vertices so that each group of vertices that fit in a
 570     *      cube are next to eachother in the buffer. This will save cache
 571     *      misses.
 572     *
 573     *      for the sorting algorithm, i think we can already assume that *most
 574     *      vertices will be quite close to eachother. so instead of doing an
 575     *      exhaustive search we can reorder 1k chunks at a time.
 576     */
 577
 578    v3f sample_area;
 579    v3_sub( pscene->bbx[1], pscene->bbx[0], sample_area );
 580    v3_ceil( sample_area, sample_area );
 581    int ax = sample_area[0],
 582        ay = sample_area[1],
 583        az = sample_area[2];
 584
 585 #ifndef DYNAMIC_GRID
 586    float *samplegrid = malloc( ax*ay*az* sizeof(float) );
 587
 588    for( int x=0; x<ax; x++ ){
 589    for( int y=0; y<ay; y++ ){
 590    for( int z=0; z<az; z++ )
 591    {
 592       v3f sample_pos = { x,y,z };
 593       v3_add( pscene->bbx[0], sample_pos, sample_pos );
 594       float accum = scene_ambient_sample( pscene, sample_pos, sundir );
 595
 596       samplegrid[x + y*ax + z*ax*ay] = accum;
 597    }}}
 598 #else
 599    v3i cube_pos = { -999999, -999999, -999999 };
 600    int cube_resamples = 0, hits = 0, misses = 0;
 601
 602    float s0=0.0f,s1=0.0f,s2=0.0f,s3=0.0f,s4=0.0f,s5=0.0f,s6=0.0f,s7=0.0f;
 603 #endif
 604
 605    for( int i=0; i<pscene->vertex_count; i++ )
 606    {
 607       model_vert *vert = &pscene->verts[i];
 608       v3f rel, q;
 609
 610 #ifndef DYNAMIC_GRID
 611       v3_sub( vert->co, pscene->bbx[0], q );
 612 #else
 613       v3_copy( vert->co, q );
 614 #endif
 615
 616       v3_floor( q, rel );
 617       v3_sub( q, rel, q );
 618
 619       int x=rel[0],
 620           y=rel[1],
 621           z=rel[2];
 622
 623 #ifndef JUST_DO_EVERY_VERT
 624 #ifndef DYNAMIC_GRID
 625       x = VG_MIN(x,ax-2);
 626       y = VG_MIN(y,ay-2);
 627       z = VG_MIN(z,az-2);
 628       x = VG_MAX(x,0);
 629       y = VG_MAX(y,0);
 630       z = VG_MAX(z,0);
 631
 632       float
 633          s0 = samplegrid[ x    +  y*ax    + z*ax*ay],
 634          s1 = samplegrid[(x+1) +  y*ax    + z*ax*ay],
 635          s2 = samplegrid[ x    + (y+1)*ax + z*ax*ay],
 636          s3 = samplegrid[(x+1) + (y+1)*ax + z*ax*ay],
 637          s4 = samplegrid[ x    +  y*ax    + (z+1)*ax*ay],
 638          s5 = samplegrid[(x+1) +  y*ax    + (z+1)*ax*ay],
 639          s6 = samplegrid[ x    + (y+1)*ax + (z+1)*ax*ay],
 640          s7 = samplegrid[(x+1) + (y+1)*ax + (z+1)*ax*ay],
 641 #else
 642       if( x!=cube_pos[0] || y!=cube_pos[1] || z!=cube_pos[2] )
 643       {
 644          cube_pos[0] = x;
 645          cube_pos[1] = y;
 646          cube_pos[2] = z;
 647
 648          s0 = scene_ambient_sample( pscene, (v3f){ x,y,z }, sundir );
 649          s1 = scene_ambient_sample( pscene, (v3f){ x+1,y,z }, sundir );
 650          s2 = scene_ambient_sample( pscene, (v3f){ x,y+1,z }, sundir );
 651          s3 = scene_ambient_sample( pscene, (v3f){ x+1,y+1,z }, sundir );
 652          s4 = scene_ambient_sample( pscene, (v3f){ x,y,z+1 }, sundir );
 653          s5 = scene_ambient_sample( pscene, (v3f){ x+1,y,z+1 }, sundir );
 654          s6 = scene_ambient_sample( pscene, (v3f){ x,y+1,z+1 }, sundir );
 655          s7 = scene_ambient_sample( pscene, (v3f){ x+1,y+1,z+1 }, sundir );
 656
 657          cube_resamples += 8;
 658          misses ++;
 659       }
 660       else
 661          hits ++;
 662
 663       float
 664 #endif
 665
 666          s0_s1 = vg_lerpf( s0, s1, q[0] ),
 667          s2_s3 = vg_lerpf( s2, s3, q[0] ),
 668          s4_s5 = vg_lerpf( s4, s5, q[0] ),
 669          s6_s7 = vg_lerpf( s6, s7, q[0] ),
 670
 671          s0s1_s2s3 = vg_lerpf( s0_s1, s2_s3, q[1] ),
 672          s4s5_s6s7 = vg_lerpf( s4_s5, s6_s7, q[1] ),
 673          s0s1s2s3_s4s5s6s7 = vg_lerpf( s0s1_s2s3, s4s5_s6s7, q[2] );
 674
 675       vert->colour[1] = s0s1s2s3_s4s5s6s7;
 676 #else
 677       vert->colour[1] = scene_ambient_sample( pscene, vert->co, sundir );
 678 #endif
 679    }
 680
 681 #ifndef DYNAMIC_GRID
 682    int cube_resamples = -1, misses = 0, hits = 0;
 683 #endif
 684
 685    int static_samples = ax*ay*az,
 686        vertex_samples = pscene->vertex_count;
 687
 688    if( cube_resamples < static_samples )
 689       vg_success( "Walking cube beat static grid (%d<%d. %d)!\n",
 690          cube_resamples, static_samples, vertex_samples );
 691    else
 692       vg_warn( "Walking cube was worse than static grid (%d<%d. %d).\n",
 693          cube_resamples, static_samples, vertex_samples );
 694
 695    vg_info( "Hits; %d, misses: %d\n", hits, misses );
 696
 697 #ifndef DYNAMIC_GRID
 698    free( samplegrid );
 699 #endif
 700
 701    return;
 702
 703    for( int i=0; i<pscene->vertex_count; i++ )
 704    {
 705       model_vert *vert = &pscene->verts[i];
 706       float accum = 0.0f;
 707
 708       for( int j=0; j<5; j++ )
 709       {
 710          v3f tracepos;
 711          v3_copy( vert->co, tracepos );
 712          v3_muladds( tracepos, sundir, 1.5f*(float)j, tracepos );
 713
 714          float mindist = 99999.9f;
 715
 716          for( int k=0; k<pscene->shadower_count; k++ )
 717          {
 718             struct shadower *shadower = &pscene->shadowers[k];
 719             float dist = vg_maxf( 0.0f, sd_cone( tracepos, &shadower->sdf ));
 720             mindist = vg_minf( mindist, dist );
 721          }
 722
 723          accum += vg_clampf( 1.0f - mindist, 0.0f, 1.0f )*0.2f;
 724       }
 725
 726       vert->colour[1] = vg_minf( accum, 1.0f );
 727    }
 728 }
 729
 730 static void scene_upload( scene *pscene )
 731 {
 732    mesh_upload( &pscene->mesh,
 733          pscene->verts, pscene->vertex_count,
 734          pscene->indices, pscene->indice_count );
 735
 736    vg_info( "Scene upload\n" );
 737    vg_info( "   indices:%u\n", pscene->indice_count );
 738    vg_info( "   verts:%u\n", pscene->vertex_count );
 739 }
 740
 741 float scene_tree_sway = 0.1f;
 742
 743 #if 0
 744 static void scene_foliage_shader_use(void)
 745 {
 746    SHADER_USE( shader_debug_vcol );
 747
 748         glUniformMatrix4fv( SHADER_UNIFORM( shader_debug_vcol, "uPv" ),
 749          1, GL_FALSE, (float *)vg_pv );
 750
 751    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uMode" ), debugview );
 752    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexMain" ), 0 );
 753
 754    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexGradients" ), 1 );
 755    vg_tex2d_bind( &tex_gradients, 1 );
 756
 757    glUniform1i( SHADER_UNIFORM( shader_debug_vcol, "uTexNoise" ), 2 );
 758    glActiveTexture( GL_TEXTURE2 );
 759    glBindTexture( GL_TEXTURE_2D, tex_dual_noise );
 760
 761    glUniform1f( SHADER_UNIFORM( shader_debug_vcol, "uTime" ), vg_time );
 762    glUniform1f( SHADER_UNIFORM( shader_debug_vcol, "uSwayAmt" ),
 763          scene_tree_sway );
 764 }
 765 #endif
 766
 767 static void scene_bind( scene *pscene )
 768 {
 769    mesh_bind( &pscene->mesh );
 770 }
 771
 772 static void scene_draw( scene *pscene )
 773 {
 774    mesh_drawn( 0, pscene->indice_count );
 775 }
 776
 777 static void scene_debugsdf( scene *pscene )
 778 {
 779    for( int i=0; i<pscene->shadower_count; i++ )
 780    {
 781       struct shadower *shadower = &pscene->shadowers[i];
 782
 783       v3f base, side;
 784       v3_copy( shadower->sdf.origin, base );
 785       base[1] -= shadower->sdf.info[1];
 786       v3_copy( base, side );
 787       side[0] += shadower->sdf.info[0];
 788
 789       vg_line2( shadower->sdf.origin, base, 0xff00ff00, 0xff0000ff );
 790       vg_line2( side, base, 0xff00ff00, 0xff0000ff );
 791       vg_line( side, shadower->sdf.origin, 0xff00ff00 );
 792    }
 793
 794    v3f p0 = { pscene->bbx[0][0], pscene->bbx[0][1], pscene->bbx[0][2] },
 795        p1 = { pscene->bbx[0][0], pscene->bbx[1][1], pscene->bbx[0][2] },
 796        p2 = { pscene->bbx[1][0], pscene->bbx[1][1], pscene->bbx[0][2] },
 797        p3 = { pscene->bbx[1][0], pscene->bbx[0][1], pscene->bbx[0][2] },
 798
 799        p4 = { pscene->bbx[0][0], pscene->bbx[0][1], pscene->bbx[1][2] },
 800        p5 = { pscene->bbx[0][0], pscene->bbx[1][1], pscene->bbx[1][2] },
 801        p6 = { pscene->bbx[1][0], pscene->bbx[1][1], pscene->bbx[1][2] },
 802        p7 = { pscene->bbx[1][0], pscene->bbx[0][1], pscene->bbx[1][2] };
 803
 804    u32 col = 0xffff00c8;
 805    vg_line( p0, p1, col );
 806    vg_line( p1, p2, col );
 807    vg_line( p2, p3, col );
 808    vg_line( p3, p0, col );
 809
 810    vg_line( p4, p5, col );
 811    vg_line( p5, p6, col );
 812    vg_line( p6, p7, col );
 813    vg_line( p7, p4, col );
 814
 815    vg_line( p0, p4, col );
 816    vg_line( p1, p5, col );
 817    vg_line( p2, p6, col );
 818    vg_line( p3, p7, col );
 819 }
 820
 821 static void scene_register(void)
 822 {
 823    SHADER_INIT( shader_debug_vcol );
 824    SHADER_INIT( shader_standard_lit );
 825    SHADER_INIT( shader_unlit );
 826 }
 827
 828
 829 /* Physics segment */
 830
 831 static int triangle_raycast2d( v3f pA, v3f pB, v3f pC, v3f ray, float *height )
 832 {
 833         v2f v0, v1, v2, vp, vp2;
 834         float d, bca = 0.f, bcb = 0.f, bcc = 0.f;
 835
 836    v0[0] = pB[0] - pA[0];
 837    v0[1] = pB[2] - pA[2];
 838    v1[0] = pC[0] - pA[0];
 839    v1[1] = pC[2] - pA[2];
 840    v2[0] = pB[0] - pC[0];
 841    v2[1] = pB[2] - pC[2];
 842
 843         d = 1.f / (v0[0]*v1[1] - v1[0]*v0[1]);
 844
 845 #if 0
 846         /* Backface culling */
 847         if( v2_cross( v0, v1 ) > 0.f )
 848                 return;
 849 #endif
 850
 851    vp[0] = ray[0] - pA[0];
 852    vp[1] = ray[2] - pA[2];
 853
 854    if( v2_cross( v0, vp ) > 0.f ) return 0;
 855    if( v2_cross( vp, v1 ) > 0.f ) return 0;
 856
 857    vp2[0] = ray[0] - pB[0];
 858    vp2[1] = ray[2] - pB[2];
 859
 860    if( v2_cross( vp2, v2 ) > 0.f ) return 0;
 861
 862    bcb = (vp[0]*v1[1] - v1[0]*vp[1]) * d;
 863    bcc = (v0[0]*vp[1] - vp[0]*v0[1]) * d;
 864    bca = 1.f - bcb - bcc;
 865
 866    *height = pA[1]*bca + pB[1]*bcb + pC[1]*bcc;
 867    return 1;
 868 }
 869
 870 /* Temporary */
 871 static int sample_scene_height( scene *pscene, v3f pos, v3f norm )
 872 {
 873    for( int i=0; i<pscene->indice_count/3; i++ )
 874    {
 875       u32 *tri = &pscene->indices[i*3];
 876
 877       float *pA = pscene->verts[tri[0]].co,
 878             *pB = pscene->verts[tri[1]].co,
 879             *pC = pscene->verts[tri[2]].co;
 880
 881       float height;
 882       if( triangle_raycast2d( pA, pB, pC, pos, &height ))
 883       {
 884          pos[1] = height;
 885
 886          if( norm )
 887          {
 888             v3f v0, v1;
 889             v3_sub( pA, pB, v0 );
 890             v3_sub( pC, pB, v1 );
 891             v3_cross( v1, v0, norm );
 892             v3_normalize( norm );
 893          }
 894
 895          return 1;
 896       }
 897    }
 898    return 0;
 899 }
 900
 901 static void sample_scene_normal( scene *pscene, v3f pos, v3f normal )
 902 {
 903    for( int i=0; i<pscene->indice_count/3; i++ )
 904    {
 905       u32 *tri = &pscene->indices[i*3];
 906
 907       float height;
 908       if( triangle_raycast2d(
 909             pscene->verts[ tri[0] ].co,
 910             pscene->verts[ tri[1] ].co,
 911             pscene->verts[ tri[2] ].co, pos, &height ))
 912       {
 913          v3f v0, v1;
 914
 915          v3_sub( pscene->verts[ tri[1] ].co,
 916                  pscene->verts[ tri[0] ].co,
 917                  v0 );
 918
 919          v3_sub( pscene->verts[ tri[2] ].co,
 920                  pscene->verts[ tri[0] ].co,
 921                  v1 );
 922
 923          v3_cross( v0, v1, normal );
 924          v3_normalize( normal );
 925          return;
 926       }
 927    }
 928
 929    normal[0] = 0.0f;
 930    normal[1] = 1.0f;
 931    normal[2] = 0.0f;
 932 }
 933
 934 struct bvh_node
 935 {
 936    boxf bbx;
 937
 938    /* if il is 0, this is a leaf */
 939    u32 il, count;
 940    union{ u32 ir, start; };
 941 };
 942
 943 static void bvh_update_bounds( scene *s, u32 inode )
 944 {
 945    bvh_node *node = &s->bvh.nodes[ inode ];
 946
 947    box_init_inf( node->bbx );
 948    for( u32 i=0; i<node->count; i++ )
 949    {
 950       u32 idx = node->start+i;
 951       model_vert *pa = &s->verts[ s->indices[idx*3+0] ],
 952                  *pb = &s->verts[ s->indices[idx*3+1] ],
 953                  *pc = &s->verts[ s->indices[idx*3+2] ];
 954
 955      box_addpt( node->bbx, pa->co );
 956      box_addpt( node->bbx, pb->co );
 957      box_addpt( node->bbx, pc->co );
 958    }
 959 }
 960
 961 static void bvh_subdiv( scene *s, u32 inode )
 962 {
 963    bvh_node *node = &s->bvh.nodes[ inode ];
 964
 965    v3f extent;
 966    v3_sub( node->bbx[1], node->bbx[0], extent );
 967
 968    int axis = 0;
 969    if( extent[1] > extent[0] ) axis = 1;
 970    if( extent[2] > extent[axis] ) axis = 2;
 971
 972    float split = node->bbx[0][axis] + extent[axis]*0.5f;
 973
 974    i32 i = node->start,
 975        j = i + node->count-1;
 976
 977    while( i <= j )
 978    {
 979       u32 *ti = &s->indices[i*3];
 980
 981       float a = s->verts[ti[0]].co[axis],
 982             b = s->verts[ti[1]].co[axis],
 983             c = s->verts[ti[2]].co[axis];
 984
 985       if( ((a+b+c) / 3.0f) < split )
 986          i ++;
 987       else
 988       {
 989          /* Swap triangle indices */
 990          u32 *tj = &s->indices[j*3];
 991          u32 temp[3];
 992          temp[0] = ti[0];
 993          temp[1] = ti[1];
 994          temp[2] = ti[2];
 995
 996          ti[0] = tj[0];
 997          ti[1] = tj[1];
 998          ti[2] = tj[2];
 999
1000          tj[0] = temp[0];
1001          tj[1] = temp[1];
1002          tj[2] = temp[2];
1003
1004          j --;
1005       }
1006    }
1007
1008    u32 left_count = i - node->start;
1009    if( left_count == 0 || left_count == node->count ) return;
1010
1011    u32 il = s->bvh.node_count ++,
1012        ir = s->bvh.node_count ++;
1013
1014    struct bvh_node *lnode = &s->bvh.nodes[il],
1015                    *rnode = &s->bvh.nodes[ir];
1016
1017    lnode->start = node->start;
1018    lnode->count = left_count;
1019    rnode->start = i;
1020    rnode->count = node->count - left_count;
1021
1022    node->il = il;
1023    node->ir = ir;
1024    node->count = 0;
1025
1026    bvh_update_bounds( s, il );
1027    bvh_update_bounds( s, ir );
1028    bvh_subdiv( s, il );
1029    bvh_subdiv( s, ir );
1030 }
1031
1032 static void bvh_create( scene *s )
1033 {
1034    u32 triangle_count = s->indice_count / 3;
1035    s->bvh.nodes = malloc( sizeof(struct bvh_node) * (triangle_count*2-1) );
1036
1037    bvh_node *root = &s->bvh.nodes[0];
1038    s->bvh.node_count = 1;
1039
1040    root->il = 0;
1041    root->ir = 0;
1042    root->count = triangle_count;
1043    root->start = 0;
1044
1045    bvh_update_bounds( s, 0 );
1046    bvh_subdiv( s, 0 );
1047
1048    s->bvh.nodes =
1049       realloc( s->bvh.nodes, sizeof(struct bvh_node) * s->bvh.node_count );
1050
1051    vg_success( "BVH done, size: %u/%u\n", s->bvh.node_count,
1052                                           (triangle_count*2-1) );
1053 }
1054
1055 static void bvh_debug_node( scene *s, u32 inode, v3f pos, u32 colour )
1056 {
1057    struct bvh_node *node = &s->bvh.nodes[ inode ];
1058
1059    if( (pos[0] >= node->bbx[0][0] && pos[0] <= node->bbx[1][0]) &&
1060        (pos[2] >= node->bbx[0][2] && pos[2] <= node->bbx[1][2]) )
1061    {
1062       if( !node->count )
1063       {
1064          vg_line_boxf( node->bbx, colour );
1065
1066          bvh_debug_node( s, node->il, pos, colour );
1067          bvh_debug_node( s, node->ir, pos, colour );
1068       }
1069       else
1070       {
1071          vg_line_boxf( node->bbx, 0xff00ff00 );
1072          for( u32 i=0; i<node->count; i++ )
1073          {
1074             u32 idx = (node->start+i)*3;
1075
1076             model_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
1077                        *pb = &s->verts[ s->indices[ idx+1 ] ],
1078                        *pc = &s->verts[ s->indices[ idx+2 ] ];
1079
1080             vg_line( pa->co, pb->co, 0xff0000ff );
1081             vg_line( pb->co, pc->co, 0xff0000ff );
1082             vg_line( pc->co, pa->co, 0xff0000ff );
1083          }
1084       }
1085    }
1086 }
1087
1088 static void bvh_debug( scene *s, v3f pos )
1089 {
1090    bvh_debug_node( s, 0, pos, 0x4000ffa8 );
1091 }
1092
1093 static int bvh_scene_sample_node( scene *s, u32 inode, v3f pos, v3f norm )
1094 {
1095    bvh_node *node = &s->bvh.nodes[ inode ];
1096
1097    if( (pos[0] >= node->bbx[0][0] && pos[0] <= node->bbx[1][0]) &&
1098        (pos[2] >= node->bbx[0][2] && pos[2] <= node->bbx[1][2]) )
1099    {
1100       if( !node->count )
1101       {
1102          if( bvh_scene_sample_node( s, node->il, pos, norm )) return 1;
1103          if( bvh_scene_sample_node( s, node->ir, pos, norm )) return 1;
1104       }
1105       else
1106       {
1107          for( u32 i=0; i<node->count; i++ )
1108          {
1109             u32 idx = (node->start+i)*3;
1110             model_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
1111                        *pb = &s->verts[ s->indices[ idx+1 ] ],
1112                        *pc = &s->verts[ s->indices[ idx+2 ] ];
1113
1114             float height;
1115             if( triangle_raycast2d( pa->co, pb->co, pc->co, pos, &height ))
1116             {
1117                pos[1] = height;
1118
1119                if( norm )
1120                {
1121                   v3f v0, v1;
1122                   v3_sub( pa->co, pb->co, v0 );
1123                   v3_sub( pc->co, pb->co, v1 );
1124                   v3_cross( v1, v0, norm );
1125                   v3_normalize( norm );
1126                }
1127
1128                return 1;
1129             }
1130          }
1131       }
1132    }
1133
1134    return 0;
1135 }
1136
1137 static int bvh_scene_sample( scene *s, v3f pos, v3f norm)
1138 {
1139    return bvh_scene_sample_node( s, 0, pos, norm );
1140 }
1141
1142 typedef struct ray_hit ray_hit;
1143 struct ray_hit
1144 {
1145    float dist;
1146    u32 *tri;
1147    v3f pos, normal;
1148 };
1149
1150 int ray_aabb( boxf box, v3f co, v3f dir, float dist )
1151 {
1152    v3f v0, v1;
1153    float tmin, tmax;
1154
1155    v3_sub( box[0], co, v0 );
1156    v3_sub( box[1], co, v1 );
1157    v3_div( v0, dir, v0 );
1158    v3_div( v1, dir, v1 );
1159
1160    tmin = vg_minf( v0[0], v1[0] );
1161    tmax = vg_maxf( v0[0], v1[0] );
1162    tmin = vg_maxf( tmin, vg_minf( v0[1], v1[1] ));
1163    tmax = vg_minf( tmax, vg_maxf( v0[1], v1[1] ));
1164    tmin = vg_maxf( tmin, vg_minf( v0[2], v1[2] ));
1165    tmax = vg_minf( tmax, vg_maxf( v0[2], v1[2] ));
1166
1167    return tmax >= tmin && tmin < dist && tmax > 0;
1168 }
1169
1170 static int bvh_ray_tri( scene *sc, u32 *tri, v3f co, v3f dir, ray_hit *hit )
1171 {
1172    float const kEpsilon = 0.00001f;
1173
1174    v3f v0, v1, h, s, q, n;
1175    float a,f,u,v,t;
1176
1177    float *pa = sc->verts[tri[0]].co,
1178          *pb = sc->verts[tri[1]].co,
1179          *pc = sc->verts[tri[2]].co;
1180
1181    v3_sub( pb, pa, v0 );
1182    v3_sub( pc, pa, v1 );
1183    v3_cross( dir, v1, h );
1184    v3_cross( v0, v1, n );
1185
1186    if( v3_dot( n, dir ) > 0.0f ) /* Backface culling */
1187       return 0;
1188
1189    /* Parralel */
1190    a = v3_dot( v0, h );
1191    if( a > -kEpsilon && a < kEpsilon )
1192       return 0;
1193
1194    f = 1.0f/a;
1195    v3_sub( co, pa, s );
1196
1197    u = f * v3_dot(s, h);
1198    if( u < 0.0f || u > 1.0f )
1199       return 0;
1200
1201    v3_cross( s, v0, q );
1202    v = f * v3_dot( dir, q );
1203    if( v < 0.0f || u+v > 1.0f )
1204       return 0;
1205
1206    t = f * v3_dot(v1, q);
1207    if( t > kEpsilon && t < hit->dist )
1208    {
1209       hit->dist = t;
1210       hit->tri = tri;
1211       return 1;
1212    }
1213    else return 0;
1214 }
1215
1216 static int bvh_ray( scene *s, u32 inode, v3f co, v3f dir, ray_hit *hit )
1217 {
1218    bvh_node *node = &s->bvh.nodes[ inode ];
1219
1220    if( !ray_aabb( node->bbx, co, dir, hit->dist ))
1221       return 0;
1222
1223    int count = 0;
1224
1225    if( node->count )
1226    {
1227       for( u32 i=0; i<node->count; i++ )
1228       {
1229          u32 *indices = &s->indices[ (node->start+i)*3 ];
1230          count += bvh_ray_tri( s, indices, co, dir, hit );
1231       }
1232    }
1233    else
1234    {
1235       count += bvh_ray( s, node->il, co, dir, hit );
1236       count += bvh_ray( s, node->ir, co, dir, hit );
1237    }
1238
1239    return count;
1240 }
1241
1242 static int bvh_raycast( scene *s, v3f co, v3f dir, ray_hit *hit )
1243 {
1244    v3f pb;
1245    v3_muladds( co, dir, hit->dist, pb );
1246
1247    int count = bvh_ray( s, 0, co, dir, hit );
1248
1249    if( count )
1250    {
1251       vg_line( co, pb, 0xff00ffff );
1252
1253       v3f v0, v1;
1254
1255       float *pa = s->verts[hit->tri[0]].co,
1256             *pb = s->verts[hit->tri[1]].co,
1257             *pc = s->verts[hit->tri[2]].co;
1258
1259       v3_sub( pa, pb, v0 );
1260       v3_sub( pc, pb, v1 );
1261       v3_cross( v1, v0, hit->normal );
1262       v3_normalize( hit->normal );
1263       v3_muladds( co, dir, hit->dist, hit->pos );
1264    }
1265    else
1266       vg_line( co, pb, 0xff0000ff );
1267
1268    return count;
1269 }
1270
1271 #endif