scene.c

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