scene.h

   1 #ifndef SCENE_H
   2 #define SCENE_H
   3
   4 #include "common.h"
   5 #include "model.h"
   6 #include "bvh.h"
   7
   8 typedef struct scene_context scene_context;
   9 typedef struct scene_vert scene_vert;
  10
  11 #pragma pack(push,1)
  12
  13 /* 32 byte vertexs, we don't care about the normals too much,
  14  *    maybe possible to bring down uv to i16s too */
  15 struct scene_vert
  16 {
  17    v3f co;        /* 3*32 */
  18    v2f uv;        /* 2*32 */
  19    i8  norm[4];   /* 4*8 */
  20    u16 flags; /* only for the cpu. its junk on the gpu */
  21    u16 unused[3];
  22 };
  23
  24 #pragma pack(pop)
  25
  26 /*
  27  * 1. this should probably be a CONTEXT based approach unlike this mess.
  28  * take a bit of the mdl_context ideas and redo this header. its messed up
  29  * pretty bad right now.
  30  */
  31
  32 struct scene_context
  33 {
  34    scene_vert *arrvertices;
  35    u32 *arrindices;
  36
  37    u32 vertex_count, indice_count,
  38        max_vertices, max_indices;
  39
  40    boxf bbx;
  41    mdl_submesh submesh;
  42 };
  43
  44 static u32 scene_mem_required( scene_context *ctx )
  45 {
  46    u32 vertex_length = vg_align8(ctx->max_vertices * sizeof(scene_vert)),
  47        index_length  = vg_align8(ctx->max_indices  * sizeof(u32));
  48
  49    return vertex_length + index_length;
  50 }
  51
  52 static
  53 void scene_init( scene_context *ctx, u32 max_vertices, u32 max_indices )
  54 {
  55    ctx->vertex_count = 0;
  56    ctx->indice_count = 0;
  57    ctx->max_vertices = max_vertices;
  58    ctx->max_indices = max_indices;
  59    ctx->arrindices = NULL; /* must be filled out by user */
  60    ctx->arrvertices = NULL;
  61
  62    memset( &ctx->submesh, 0, sizeof(mdl_submesh) );
  63
  64    v3_fill( ctx->bbx[0],  999999.9f );
  65    v3_fill( ctx->bbx[1], -999999.9f );
  66 }
  67
  68 void scene_supply_buffer( scene_context *ctx, void *buffer )
  69 {
  70    u32 vertex_length = vg_align8( ctx->max_vertices * sizeof(scene_vert) );
  71
  72    ctx->arrvertices = buffer;
  73    ctx->arrindices  = (u32*)(((u8*)buffer) + vertex_length);
  74 }
  75
  76 static void scene_vert_pack_norm( scene_vert *vert, v3f norm, f32 blend ){
  77    v3f n;
  78    v3_muls( norm, 127.0f, n );
  79    v3_minv( n, (v3f){  127.0f,  127.0f,  127.0f }, n );
  80    v3_maxv( n, (v3f){ -127.0f, -127.0f, -127.0f }, n );
  81    vert->norm[0] = n[0];
  82    vert->norm[1] = n[1];
  83    vert->norm[2] = n[2];
  84    vert->norm[3] = blend * 127.0f;
  85 }
  86
  87 /*
  88  * Append a model into the scene with a given transform
  89  */
  90 static void scene_add_mdl_submesh( scene_context *ctx, mdl_context *mdl,
  91                                       mdl_submesh *sm, m4x3f transform )
  92 {
  93    if( ctx->vertex_count + sm->vertex_count > ctx->max_vertices ){
  94       vg_fatal_error( "Scene vertex buffer overflow (%u exceeds %u)\n",
  95                         ctx->vertex_count + sm->vertex_count,
  96                         ctx->max_vertices );
  97    }
  98
  99    if( ctx->indice_count + sm->indice_count > ctx->max_indices ){
 100       vg_fatal_error( "Scene index buffer overflow (%u exceeds %u)\n",
 101                         ctx->indice_count + sm->indice_count,
 102                         ctx->max_indices );
 103    }
 104
 105    mdl_vert   *src_verts = mdl_arritm( &mdl->verts, sm->vertex_start );
 106    scene_vert *dst_verts = &ctx->arrvertices[ ctx->vertex_count ];
 107
 108    u32 *src_indices    =  mdl_arritm( &mdl->indices, sm->indice_start ),
 109        *dst_indices    = &ctx->arrindices[ ctx->indice_count ];
 110
 111    /* Transform and place vertices */
 112    boxf bbxnew;
 113    box_init_inf( bbxnew );
 114    m4x3_expand_aabb_aabb( transform, bbxnew, sm->bbx );
 115    box_concat( ctx->bbx, bbxnew );
 116
 117    m3x3f normal_matrix;
 118    m3x3_copy( transform, normal_matrix );
 119    v3_normalize( normal_matrix[0] );
 120    v3_normalize( normal_matrix[1] );
 121    v3_normalize( normal_matrix[2] );
 122
 123    for( u32 i=0; i<sm->vertex_count; i++ ){
 124       mdl_vert   *src   = &src_verts[i];
 125       scene_vert *pvert = &dst_verts[i];
 126
 127       m4x3_mulv( transform, src->co, pvert->co );
 128
 129       v3f normal;
 130       m3x3_mulv( normal_matrix, src->norm, normal );
 131       scene_vert_pack_norm( pvert, normal, src->colour[0]*(1.0f/255.0f) );
 132
 133       v2_copy( src->uv, pvert->uv );
 134    }
 135
 136    u32 real_indices = 0;
 137    for( u32 i=0; i<sm->indice_count/3; i++ ){
 138       u32 *src = &src_indices[i*3],
 139           *dst = &dst_indices[real_indices];
 140
 141       v3f ab, ac, tn;
 142       v3_sub( src_verts[src[2]].co, src_verts[src[0]].co, ab );
 143       v3_sub( src_verts[src[1]].co, src_verts[src[0]].co, ac );
 144       v3_cross( ac, ab, tn );
 145
 146 #if 0
 147       if( v3_length2( tn ) <= 0.00001f )
 148          continue;
 149 #endif
 150
 151       dst[0] = src[0] + ctx->vertex_count;
 152       dst[1] = src[1] + ctx->vertex_count;
 153       dst[2] = src[2] + ctx->vertex_count;
 154
 155       real_indices += 3;
 156    }
 157
 158    if( real_indices != sm->indice_count )
 159       vg_warn( "Zero area triangles in model\n" );
 160
 161    ctx->vertex_count += sm->vertex_count;
 162    ctx->indice_count += real_indices;
 163 }
 164
 165 /*
 166  * One by one adders for simplified access (mostly procedural stuff)
 167  */
 168 static void scene_push_tri( scene_context *ctx, u32 tri[3] )
 169 {
 170    if( ctx->indice_count + 3 > ctx->max_indices )
 171       vg_fatal_error( "Scene indice buffer overflow (%u exceeds %u)\n",
 172                         ctx->indice_count+3, ctx->max_indices );
 173
 174    u32 *dst = &ctx->arrindices[ ctx->indice_count ];
 175
 176    dst[0] = tri[0];
 177    dst[1] = tri[1];
 178    dst[2] = tri[2];
 179
 180    ctx->indice_count += 3;
 181 }
 182
 183 static void scene_push_vert( scene_context *ctx, scene_vert *v )
 184 {
 185    if( ctx->vertex_count + 1 > ctx->max_vertices )
 186       vg_fatal_error( "Scene vertex buffer overflow (%u exceeds %u)\n",
 187                         ctx->vertex_count+1, ctx->max_vertices );
 188
 189    scene_vert *dst = &ctx->arrvertices[ ctx->vertex_count ];
 190    *dst = *v;
 191
 192    ctx->vertex_count ++;
 193 }
 194
 195 static void scene_copy_slice( scene_context *ctx, mdl_submesh *sm )
 196 {
 197    sm->indice_start = ctx->submesh.indice_start;
 198    sm->indice_count = ctx->indice_count - sm->indice_start;
 199
 200    sm->vertex_start = ctx->submesh.vertex_start;
 201    sm->vertex_count = ctx->vertex_count - sm->vertex_start;
 202
 203    ctx->submesh.indice_start = ctx->indice_count;
 204    ctx->submesh.vertex_start = ctx->vertex_count;
 205 }
 206
 207 static void scene_set_vertex_flags( scene_context *ctx,
 208                                        u32 start, u32 count, u16 flags ){
 209    for( u32 i=0; i<count; i++ )
 210       ctx->arrvertices[ start + i ].flags = flags;
 211 }
 212
 213 struct scene_upload_info{
 214    scene_context *ctx;
 215    glmesh *mesh;
 216 };
 217
 218 static void async_scene_upload( void *payload, u32 size )
 219 {
 220    struct scene_upload_info *info = payload;
 221
 222    //assert( mesh->loaded == 0 );
 223
 224    glmesh *mesh = info->mesh;
 225    scene_context *ctx = info->ctx;
 226
 227    glGenVertexArrays( 1, &mesh->vao );
 228    glGenBuffers( 1, &mesh->vbo );
 229    glGenBuffers( 1, &mesh->ebo );
 230    glBindVertexArray( mesh->vao );
 231
 232    size_t stride = sizeof(scene_vert);
 233
 234    glBindBuffer( GL_ARRAY_BUFFER, mesh->vbo );
 235    glBufferData( GL_ARRAY_BUFFER, ctx->vertex_count*stride,
 236                  ctx->arrvertices, GL_STATIC_DRAW );
 237
 238    glBindVertexArray( mesh->vao );
 239    glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, mesh->ebo );
 240    glBufferData( GL_ELEMENT_ARRAY_BUFFER, ctx->indice_count*sizeof(u32),
 241                  ctx->arrindices, GL_STATIC_DRAW );
 242
 243    /* 0: coordinates */
 244    glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, stride, (void*)0 );
 245    glEnableVertexAttribArray( 0 );
 246
 247    /* 1: normal */
 248    glVertexAttribPointer( 1, 4, GL_BYTE, GL_TRUE,
 249          stride, (void *)offsetof(scene_vert, norm) );
 250    glEnableVertexAttribArray( 1 );
 251
 252    /* 2: uv */
 253    glVertexAttribPointer( 2, 2, GL_FLOAT, GL_FALSE,
 254          stride, (void *)offsetof(scene_vert, uv) );
 255    glEnableVertexAttribArray( 2 );
 256
 257    VG_CHECK_GL_ERR();
 258
 259    mesh->indice_count = ctx->indice_count;
 260    mesh->loaded = 1;
 261
 262    vg_info( "Scene upload ( XYZ_f32 UV_f32 XYZW_i8 )[ u32 ]\n" );
 263    vg_info( "   indices:%u\n", ctx->indice_count );
 264    vg_info( "   verts:%u\n",   ctx->vertex_count );
 265 }
 266
 267 static void scene_upload_async( scene_context *ctx, glmesh *mesh )
 268 {
 269    vg_async_item *call = vg_async_alloc( sizeof(struct scene_upload_info) );
 270
 271    struct scene_upload_info *info = call->payload;
 272    info->mesh = mesh;
 273    info->ctx = ctx;
 274
 275    vg_async_dispatch( call, async_scene_upload );
 276 }
 277
 278 static
 279 vg_async_item *scene_alloc_async( scene_context *scene, glmesh *mesh,
 280                                   u32 max_vertices, u32 max_indices )
 281 {
 282    scene_init( scene, max_vertices, max_indices );
 283    u32 buf_size = scene_mem_required( scene );
 284
 285    u32 hdr_size = vg_align8(sizeof(struct scene_upload_info));
 286    vg_async_item *call = vg_async_alloc( hdr_size + buf_size );
 287
 288    struct scene_upload_info *info = call->payload;
 289
 290    info->mesh = mesh;
 291    info->ctx = scene;
 292
 293    void *buffer = ((u8*)call->payload)+hdr_size;
 294    scene_supply_buffer( scene, buffer );
 295
 296    return call;
 297 }
 298
 299
 300 /*
 301  * BVH implementation
 302  */
 303
 304 static void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
 305 {
 306    scene_context *s = user;
 307    scene_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
 308               *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
 309               *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
 310
 311   box_addpt( bound, pa->co );
 312   box_addpt( bound, pb->co );
 313   box_addpt( bound, pc->co );
 314 }
 315
 316 static float scene_bh_centroid( void *user, u32 item_index, int axis )
 317 {
 318    scene_context *s = user;
 319    scene_vert *pa = &s->arrvertices[ s->arrindices[item_index*3+0] ],
 320               *pb = &s->arrvertices[ s->arrindices[item_index*3+1] ],
 321               *pc = &s->arrvertices[ s->arrindices[item_index*3+2] ];
 322
 323    #if 0
 324
 325    float min, max;
 326
 327    min = vg_minf( pa->co[axis], pb->co[axis] );
 328    max = vg_maxf( pa->co[axis], pb->co[axis] );
 329    min = vg_minf( min, pc->co[axis] );
 330    max = vg_maxf( max, pc->co[axis] );
 331
 332    return (min+max) * 0.5f;
 333
 334    #else
 335    return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
 336    #endif
 337 }
 338
 339 static void scene_bh_swap( void *user, u32 ia, u32 ib )
 340 {
 341    scene_context *s = user;
 342
 343    u32 *ti = &s->arrindices[ia*3];
 344    u32 *tj = &s->arrindices[ib*3];
 345
 346    u32 temp[3];
 347    temp[0] = ti[0];
 348    temp[1] = ti[1];
 349    temp[2] = ti[2];
 350
 351    ti[0] = tj[0];
 352    ti[1] = tj[1];
 353    ti[2] = tj[2];
 354
 355    tj[0] = temp[0];
 356    tj[1] = temp[1];
 357    tj[2] = temp[2];
 358 }
 359
 360 static void scene_bh_debug( void *user, u32 item_index )
 361 {
 362    scene_context *s = user;
 363    u32 idx = item_index*3;
 364    scene_vert *pa = &s->arrvertices[ s->arrindices[ idx+0 ] ],
 365               *pb = &s->arrvertices[ s->arrindices[ idx+1 ] ],
 366               *pc = &s->arrvertices[ s->arrindices[ idx+2 ] ];
 367
 368    vg_line( pa->co, pb->co, 0xff0000ff );
 369    vg_line( pb->co, pc->co, 0xff0000ff );
 370    vg_line( pc->co, pa->co, 0xff0000ff );
 371 }
 372
 373 static void scene_bh_closest( void *user, u32 index, v3f point, v3f closest )
 374 {
 375    scene_context *s = user;
 376
 377    v3f positions[3];
 378    u32 *tri = &s->arrindices[ index*3 ];
 379    for( int i=0; i<3; i++ )
 380       v3_copy( s->arrvertices[tri[i]].co, positions[i] );
 381
 382    closest_on_triangle_1( point, positions, closest );
 383 }
 384
 385 static bh_system bh_system_scene =
 386 {
 387    .expand_bound = scene_bh_expand_bound,
 388    .item_centroid = scene_bh_centroid,
 389    .item_closest = scene_bh_closest,
 390    .item_swap = scene_bh_swap,
 391    .item_debug = scene_bh_debug,
 392    .system_type = 0x1
 393 };
 394
 395 /*
 396  * An extra step is added onto the end to calculate the hit normal
 397  */
 398 static int scene_raycast( scene_context *s, bh_tree *bh,
 399                              v3f co, v3f dir, ray_hit *hit, u16 ignore )
 400 {
 401    hit->tri = NULL;
 402
 403    bh_iter it;
 404    bh_iter_init_ray( 0, &it, co, dir, hit->dist );
 405    i32 idx;
 406
 407    while( bh_next( bh, &it, &idx ) ){
 408       u32 *tri = &s->arrindices[ idx*3 ];
 409
 410       if( s->arrvertices[tri[0]].flags & ignore )  continue;
 411
 412       v3f vs[3];
 413       for( u32 i=0; i<3; i++ )
 414          v3_copy( s->arrvertices[tri[i]].co, vs[i] );
 415
 416       f32 t;
 417       if( ray_tri( vs, co, dir, &t, 0 ) ){
 418          if( t < hit->dist ){
 419             hit->dist = t;
 420             hit->tri = tri;
 421          }
 422       }
 423    }
 424
 425    if( hit->tri ){
 426       v3f v0, v1;
 427
 428       float *pa = s->arrvertices[hit->tri[0]].co,
 429             *pb = s->arrvertices[hit->tri[1]].co,
 430             *pc = s->arrvertices[hit->tri[2]].co;
 431
 432       v3_sub( pa, pb, v0 );
 433       v3_sub( pc, pb, v1 );
 434       v3_cross( v1, v0, hit->normal );
 435       v3_normalize( hit->normal );
 436       v3_muladds( co, dir, hit->dist, hit->pos );
 437    }
 438
 439    return hit->tri?1:0;
 440 }
 441
 442 static bh_tree *scene_bh_create( void *lin_alloc, scene_context *s )
 443 {
 444    u32 triangle_count = s->indice_count / 3;
 445    return bh_create( lin_alloc, &bh_system_scene, s, triangle_count, 2 );
 446 }
 447
 448 #endif