scene.h

   1 #ifndef SCENE_H
   2 #define SCENE_H
   3
   4 #include "common.h"
   5 #include "model.h"
   6 #include "bvh.h"
   7 #include "distq.h"
   8
   9 typedef struct scene scene;
  10
  11 struct scene
  12 {
  13    mdl_vert *arrvertices;
  14    u32 *arrindices;
  15
  16    u32 vertex_count, indice_count,
  17        max_vertices, max_indices;
  18
  19    boxf bbx;
  20    mdl_submesh submesh;
  21 };
  22
  23 /* Initialize a scene description with bounded buffers */
  24 VG_STATIC scene *scene_init( void *lin_alloc, u32 max_verts, u32 max_indices )
  25 {
  26    u32 vertex_length = max_verts   * sizeof(mdl_vert),
  27        index_length  = max_indices * sizeof(u32),
  28        tot_size = sizeof(scene) + vertex_length + index_length;
  29
  30    scene *pscene = vg_linear_alloc( lin_alloc, tot_size );
  31
  32    pscene->arrvertices = (mdl_vert *)(pscene+1);
  33    pscene->arrindices  = (u32 *)( pscene->arrvertices + max_verts );
  34
  35    pscene->vertex_count = 0;
  36    pscene->indice_count = 0;
  37    pscene->max_vertices = max_verts;
  38    pscene->max_indices  = max_indices;
  39
  40    memset( &pscene->submesh, 0, sizeof(mdl_submesh) );
  41
  42    v3_fill( pscene->bbx[0],  999999.9f );
  43    v3_fill( pscene->bbx[1], -999999.9f );
  44
  45    return pscene;
  46 }
  47
  48 /*
  49  * Append a model into the scene with a given transform
  50  */
  51 VG_STATIC void scene_add_submesh( scene *pscene, mdl_context *mdl,
  52                                   mdl_submesh *sm, m4x3f transform )
  53 {
  54    if( pscene->vertex_count + sm->vertex_count > pscene->max_vertices )
  55    {
  56       vg_error( "%u(current) + %u > %u\n", pscene->vertex_count,
  57                                            sm->vertex_count,
  58                                            pscene->max_vertices );
  59
  60       vg_warn( "%p ... %p\n", pscene, sm );
  61       vg_fatal_exit_loop( "Scene vertex buffer overflow" );
  62    }
  63
  64    if( pscene->indice_count + sm->indice_count > pscene->max_indices )
  65    {
  66       vg_error( "%u(current) + %u > %u\n", pscene->indice_count,
  67                                            sm->indice_count,
  68                                            pscene->max_indices );
  69       vg_warn( "%p ... %p\n", pscene, sm );
  70
  71       vg_fatal_exit_loop( "Scene index buffer overflow" );
  72    }
  73
  74    mdl_vert *src_verts =  mdl_submesh_vertices( mdl, sm ),
  75             *dst_verts = &pscene->arrvertices[ pscene->vertex_count ];
  76
  77    u32 *src_indices    =  mdl_submesh_indices( mdl, sm ),
  78        *dst_indices    = &pscene->arrindices[ pscene->indice_count ];
  79
  80    /* Transform and place vertices */
  81    boxf bbxnew;
  82    box_copy( sm->bbx, bbxnew );
  83    m4x3_transform_aabb( transform, bbxnew );
  84    box_concat( pscene->bbx, bbxnew );
  85
  86    m3x3f normal_matrix;
  87    m3x3_copy( transform, normal_matrix );
  88    v3_normalize( normal_matrix[0] );
  89    v3_normalize( normal_matrix[1] );
  90    v3_normalize( normal_matrix[2] );
  91
  92    for( u32 i=0; i<sm->vertex_count; i++ )
  93    {
  94       mdl_vert *pvert = &dst_verts[ i ],
  95                *src = &src_verts[ i ];
  96
  97       m4x3_mulv( transform, src->co, pvert->co );
  98       m3x3_mulv( normal_matrix, src->norm, pvert->norm );
  99
 100       pvert->colour[0] = src->colour[0];
 101       pvert->colour[1] = src->colour[1];
 102       pvert->colour[2] = src->colour[2];
 103       pvert->colour[3] = src->colour[3];
 104       pvert->weights[0] = src->weights[0];
 105       pvert->weights[1] = src->weights[1];
 106       pvert->weights[2] = src->weights[2];
 107       pvert->weights[3] = src->weights[3];
 108       v2_copy( src->uv, pvert->uv );
 109    }
 110
 111    for( u32 i=0; i<sm->indice_count; i++ )
 112    {
 113       dst_indices[i] = src_indices[i] + pscene->vertex_count;
 114    }
 115
 116    pscene->vertex_count += sm->vertex_count;
 117    pscene->indice_count += sm->indice_count;
 118
 119 }
 120
 121 /*
 122  * One by one adders for simplified access (mostly procedural stuff)
 123  */
 124 VG_STATIC void scene_push_tri( scene *pscene, u32 tri[3] )
 125 {
 126    if( pscene->indice_count + 3 > pscene->max_indices )
 127       vg_fatal_exit_loop( "Scene vertex buffer overflow" );
 128
 129    u32 *dst = &pscene->arrindices[ pscene->indice_count ];
 130
 131    dst[0] = tri[0];
 132    dst[1] = tri[1];
 133    dst[2] = tri[2];
 134
 135    pscene->indice_count += 3;
 136 }
 137
 138 VG_STATIC void scene_push_vert( scene *pscene, mdl_vert *v )
 139 {
 140    if( pscene->vertex_count + 1 > pscene->max_vertices )
 141       vg_fatal_exit_loop( "Scene vertex buffer overflow" );
 142
 143    mdl_vert *dst = &pscene->arrvertices[ pscene->vertex_count ];
 144    *dst = *v;
 145
 146    pscene->vertex_count ++;
 147 }
 148
 149 VG_STATIC void scene_copy_slice( scene *pscene, mdl_submesh *sm )
 150 {
 151    sm->indice_start = pscene->submesh.indice_start;
 152    sm->indice_count = pscene->indice_count - sm->indice_start;
 153
 154    sm->vertex_start = pscene->submesh.vertex_start;
 155    sm->vertex_count = pscene->vertex_count - sm->vertex_start;
 156
 157    pscene->submesh.indice_start = pscene->indice_count;
 158    pscene->submesh.vertex_start = pscene->vertex_count;
 159 }
 160
 161 /* finalization: tightly pack data */
 162 __attribute__((warn_unused_result))
 163 VG_STATIC scene *scene_fix( void *lin_alloc, scene *pscene )
 164 {
 165    return pscene;
 166    u32 vertex_count  = pscene->vertex_count,
 167        indice_count  = pscene->indice_count,
 168        vertex_length = vertex_count * sizeof(mdl_vert),
 169        index_length  = indice_count * sizeof(u32),
 170        tot_size = sizeof(scene) + vertex_length + index_length;
 171
 172    /* copy down index data */
 173    void *dst_indices = pscene->arrvertices + vertex_length;
 174    memmove( dst_indices, pscene->arrindices, index_length );
 175
 176    /* realloc */
 177    pscene = vg_linear_resize( lin_alloc, pscene, tot_size );
 178
 179    pscene->arrvertices = (mdl_vert *)(pscene+1);
 180    pscene->arrindices  = (u32 *)(pscene->arrvertices+vertex_count);
 181    pscene->max_vertices = vertex_count;
 182    pscene->max_indices  = indice_count;
 183
 184    return pscene;
 185 }
 186
 187 #if 0
 188 /* finalization: delete any offline buffers and reduce size */
 189 __attribute__((warn_unused_result))
 190 VG_STATIC scene *scene_free_offline_buffers( void *lin_alloc, scene *pscene )
 191 {
 192    u32 tot_size = sizeof(scene);
 193
 194    scene    *src_scene   = pscene;
 195    mdl_vert *src_verts   = pscene->arrvertices;
 196    u32      *src_indices = pscene->arrindices;
 197
 198    scene *dst_scene = vg_linear_resize( lin_alloc, pscene, tot_size );
 199    memcpy( dst_scene, src_scene, sizeof(scene) );
 200
 201    dst_scene->arrindices = NULL;
 202    dst_scene->arrvertices = NULL;
 203
 204    return dst_scene;
 205 }
 206 #endif
 207
 208 VG_STATIC void scene_upload( scene *pscene, glmesh *mesh )
 209 {
 210    mesh_upload( mesh,
 211                 pscene->arrvertices, pscene->vertex_count,
 212                 pscene->arrindices,  pscene->indice_count );
 213
 214    vg_info( "Scene upload\n" );
 215    vg_info( "   indices:%u\n", pscene->indice_count );
 216    vg_info( "   verts:%u\n", pscene->vertex_count );
 217 }
 218
 219 /*
 220  * BVH implementation
 221  */
 222
 223 VG_STATIC void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
 224 {
 225    scene *s = user;
 226    mdl_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
 227             *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
 228             *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
 229
 230   box_addpt( bound, pa->co );
 231   box_addpt( bound, pb->co );
 232   box_addpt( bound, pc->co );
 233 }
 234
 235 VG_STATIC float scene_bh_centroid( void *user, u32 item_index, int axis )
 236 {
 237    scene *s = user;
 238    mdl_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
 239             *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
 240             *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
 241
 242    return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
 243 }
 244
 245 VG_STATIC void scene_bh_swap( void *user, u32 ia, u32 ib )
 246 {
 247    scene *s = user;
 248
 249    u32 *ti = &s->arrindices[ia*3];
 250    u32 *tj = &s->arrindices[ib*3];
 251
 252    u32 temp[3];
 253    temp[0] = ti[0];
 254    temp[1] = ti[1];
 255    temp[2] = ti[2];
 256
 257    ti[0] = tj[0];
 258    ti[1] = tj[1];
 259    ti[2] = tj[2];
 260
 261    tj[0] = temp[0];
 262    tj[1] = temp[1];
 263    tj[2] = temp[2];
 264 }
 265
 266 VG_STATIC void scene_bh_debug( void *user, u32 item_index )
 267 {
 268    scene *s = user;
 269    u32 idx = item_index*3;
 270    mdl_vert *pa = &s->arrvertices[ s->arrindices[ idx+0 ] ],
 271             *pb = &s->arrvertices[ s->arrindices[ idx+1 ] ],
 272             *pc = &s->arrvertices[ s->arrindices[ idx+2 ] ];
 273
 274    vg_line( pa->co, pb->co, 0xff0000ff );
 275    vg_line( pb->co, pc->co, 0xff0000ff );
 276    vg_line( pc->co, pa->co, 0xff0000ff );
 277 }
 278
 279 VG_STATIC int scene_bh_ray( void *user, u32 index, v3f co,
 280                             v3f dir, ray_hit *hit )
 281 {
 282    scene *s = user;
 283    v3f positions[3];
 284
 285    u32 *tri = &s->arrindices[ index*3 ];
 286
 287    for( int i=0; i<3; i++ )
 288       v3_copy( s->arrvertices[tri[i]].co, positions[i] );
 289
 290    float t;
 291    if(ray_tri( positions, co, dir, &t ))
 292    {
 293       if( t < hit->dist )
 294       {
 295          hit->dist = t;
 296          hit->tri = tri;
 297          return 1;
 298       }
 299    }
 300
 301    return 0;
 302 }
 303
 304 VG_STATIC void scene_bh_closest( void *user, u32 index, v3f point, v3f closest )
 305 {
 306    scene *s = user;
 307
 308    v3f positions[3];
 309    u32 *tri = &s->arrindices[ index*3 ];
 310    for( int i=0; i<3; i++ )
 311       v3_copy( s->arrvertices[tri[i]].co, positions[i] );
 312
 313    closest_on_triangle_1( point, positions, closest );
 314 }
 315
 316 VG_STATIC bh_system bh_system_scene =
 317 {
 318    .expand_bound = scene_bh_expand_bound,
 319    .item_centroid = scene_bh_centroid,
 320    .item_closest = scene_bh_closest,
 321    .item_swap = scene_bh_swap,
 322    .item_debug = scene_bh_debug,
 323    .cast_ray = scene_bh_ray
 324 };
 325
 326 /*
 327  * An extra step is added onto the end to calculate the hit normal
 328  */
 329 VG_STATIC int scene_raycast( scene *s, bh_tree *bh,
 330                              v3f co, v3f dir, ray_hit *hit )
 331 {
 332    int count = bh_ray( bh, co, dir, hit );
 333
 334    if( count )
 335    {
 336       v3f v0, v1;
 337
 338       float *pa = s->arrvertices[hit->tri[0]].co,
 339             *pb = s->arrvertices[hit->tri[1]].co,
 340             *pc = s->arrvertices[hit->tri[2]].co;
 341
 342       v3_sub( pa, pb, v0 );
 343       v3_sub( pc, pb, v1 );
 344       v3_cross( v1, v0, hit->normal );
 345       v3_normalize( hit->normal );
 346       v3_muladds( co, dir, hit->dist, hit->pos );
 347    }
 348
 349    return count;
 350 }
 351
 352 VG_STATIC bh_tree *scene_bh_create( void *lin_alloc, scene *s )
 353 {
 354    u32 triangle_count = s->indice_count / 3;
 355    return bh_create( lin_alloc, &bh_system_scene, s, triangle_count, 2 );
 356 }
 357
 358 #endif