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 scene;
   9
  10 struct scene
  11 {
  12    glmesh mesh;
  13
  14    mdl_vert *verts;
  15    u32 *indices;
  16
  17    bh_tree bhtris;
  18    u32 vertex_count,
  19        indice_count,
  20        vertex_cap,
  21        indice_cap;
  22
  23    boxf bbx;
  24
  25    u32 shadower_count,
  26        shadower_cap;
  27
  28    mdl_submesh submesh;
  29 };
  30
  31 #if 0
  32 GLuint tex_dual_noise;
  33 #endif
  34
  35 static void scene_init( scene *pscene )
  36 {
  37    pscene->verts = NULL;
  38    pscene->indices = NULL;
  39    pscene->vertex_count = 0;
  40    pscene->indice_count = 0;
  41    pscene->shadower_count = 0;
  42    pscene->shadower_cap = 0;
  43    pscene->submesh.indice_start = 0;
  44    pscene->submesh.indice_count = 0;
  45
  46    v3_fill( pscene->bbx[0],  999999.9f );
  47    v3_fill( pscene->bbx[1], -999999.9f );
  48
  49 #if 0
  50    static int noise_ready = 0;
  51    if( !noise_ready )
  52    {
  53       noise_ready = 1;
  54
  55       u8 *buf = malloc( 256*256*2 );
  56
  57       for( int i=0; i<256*256; i++ )
  58       {
  59          u8 val = rand()&0xff;
  60          buf[i*2] = val;
  61       }
  62
  63       for( int y=0; y<256; y++ )
  64       {
  65          for( int x=0; x<256; x++ )
  66          {
  67             u8 *pr = &buf[(y*256+x)*2],
  68                *pg = &buf[(((y+17)&0xff)*256+((x+37)&0xff))*2+1];
  69             *pg = *pr;
  70          }
  71       }
  72
  73       /* TODO: This texture should be delted somewhere */
  74       glGenTextures( 1, &tex_dual_noise );
  75       glBindTexture( GL_TEXTURE_2D, tex_dual_noise );
  76       glTexImage2D( GL_TEXTURE_2D, 0, GL_RG, 256, 256, 0, GL_RG,
  77             GL_UNSIGNED_BYTE, buf );
  78
  79       vg_tex2d_linear();
  80       vg_tex2d_repeat();
  81
  82       free( buf );
  83    }
  84 #endif
  85 }
  86
  87 static void *buffer_reserve( void *buffer, u32 count, u32 *cap, u32 amount,
  88       size_t emsize )
  89 {
  90    if( count+amount > *cap )
  91    {
  92       *cap = VG_MAX( (*cap)*2, (*cap)+amount );
  93
  94       return realloc( buffer, (*cap) * emsize );
  95    }
  96
  97    return buffer;
  98 }
  99
 100 static void *buffer_fix( void *buffer, u32 count, u32 *cap, size_t emsize )
 101 {
 102    *cap = count;
 103    return realloc( buffer, (*cap) * emsize );
 104 }
 105
 106 /*
 107  * Append a model into the scene with a given transform
 108  */
 109 static void scene_add_submesh( scene *pscene, mdl_header *mdl,
 110       mdl_submesh *sm, m4x3f transform )
 111 {
 112    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 113          &pscene->vertex_cap, sm->vertex_count, sizeof(mdl_vert) );
 114    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 115          &pscene->indice_cap, sm->indice_count, sizeof(u32) );
 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    /* Transform and place vertices */
 124    mdl_vert *src_verts = mdl_submesh_vertices( mdl, sm );
 125    u32 *src_indices    = mdl_submesh_indices( mdl, sm );
 126
 127    boxf bbxnew;
 128    box_copy( sm->bbx, bbxnew );
 129    m4x3_transform_aabb( transform, bbxnew );
 130    box_concat( pscene->bbx, bbxnew );
 131
 132    for( u32 i=0; i<sm->vertex_count; i++ )
 133    {
 134       mdl_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
 135                *src = &src_verts[ i ];
 136
 137       m4x3_mulv( transform, src->co, pvert->co );
 138       m3x3_mulv( normal_matrix, src->norm, pvert->norm );
 139
 140       v4_copy( src->colour, pvert->colour );
 141       v2_copy( src->uv, pvert->uv );
 142    }
 143
 144    for( u32 i=0; i<sm->indice_count; i++ )
 145    {
 146       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
 147       *pidx = src_indices[i] + pscene->vertex_count;
 148    }
 149
 150    pscene->vertex_count += sm->vertex_count;
 151    pscene->indice_count += sm->indice_count;
 152 }
 153
 154 /*
 155  * One by one adders for simplified access (mostly procedural stuff)
 156  */
 157 static void scene_push_tri( scene *pscene, u32 tri[3] )
 158 {
 159    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 160          &pscene->indice_cap, 3, sizeof(u32) );
 161
 162    u32 *dst = &pscene->indices[pscene->indice_count];
 163    dst[0] = tri[0];
 164    dst[1] = tri[1];
 165    dst[2] = tri[2];
 166
 167    pscene->indice_count += 3;
 168 }
 169
 170 static void scene_push_vert( scene *pscene, mdl_vert *v )
 171 {
 172    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 173          &pscene->vertex_cap, 1, sizeof(mdl_vert) );
 174
 175    pscene->verts[pscene->vertex_count ++] = *v;
 176 }
 177
 178 static void scene_copy_slice( scene *pscene, mdl_submesh *sm )
 179 {
 180    sm->indice_start = pscene->submesh.indice_start;
 181    sm->indice_count = pscene->indice_count - sm->indice_start;
 182
 183    sm->vertex_start = pscene->submesh.vertex_start;
 184    sm->vertex_count = pscene->vertex_count - sm->vertex_start;
 185
 186    pscene->submesh.indice_start = pscene->indice_count;
 187    pscene->submesh.vertex_start = pscene->vertex_count;
 188 }
 189
 190 static void scene_fix( scene *pscene )
 191 {
 192    buffer_fix( pscene->verts, pscene->vertex_count,
 193          &pscene->vertex_cap, sizeof( mdl_vert ));
 194
 195    buffer_fix( pscene->indices, pscene->indice_count,
 196          &pscene->indice_cap, sizeof( mdl_vert ));
 197 }
 198
 199 static void scene_upload( scene *pscene )
 200 {
 201    mesh_upload( &pscene->mesh,
 202          pscene->verts, pscene->vertex_count,
 203          pscene->indices, pscene->indice_count );
 204
 205    vg_info( "Scene upload\n" );
 206    vg_info( "   indices:%u\n", pscene->indice_count );
 207    vg_info( "   verts:%u\n", pscene->vertex_count );
 208 }
 209
 210 static void scene_bind( scene *pscene )
 211 {
 212    mesh_bind( &pscene->mesh );
 213 }
 214
 215 static void scene_draw( scene *pscene )
 216 {
 217    mesh_drawn( 0, pscene->indice_count );
 218 }
 219
 220 static void scene_free_offline_buffers( scene *pscene )
 221 {
 222    free( pscene->verts );
 223    free( pscene->indices );
 224 }
 225
 226 static void scene_free( scene *pscene )
 227 {
 228    scene_free_offline_buffers( pscene );
 229    /* TODO: bvh */
 230 }
 231
 232 static void scene_register(void)
 233 {
 234 }
 235
 236 /*
 237  * BVH implementation
 238  */
 239
 240 static void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
 241 {
 242    scene *s = user;
 243    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 244             *pb = &s->verts[ s->indices[item_index*3+1] ],
 245             *pc = &s->verts[ s->indices[item_index*3+2] ];
 246
 247   box_addpt( bound, pa->co );
 248   box_addpt( bound, pb->co );
 249   box_addpt( bound, pc->co );
 250 }
 251
 252 static float scene_bh_centroid( void *user, u32 item_index, int axis )
 253 {
 254    scene *s = user;
 255    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 256             *pb = &s->verts[ s->indices[item_index*3+1] ],
 257             *pc = &s->verts[ s->indices[item_index*3+2] ];
 258
 259    return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
 260 }
 261
 262 static void scene_bh_swap( void *user, u32 ia, u32 ib )
 263 {
 264    scene *s = user;
 265
 266    u32 *ti = &s->indices[ia*3];
 267    u32 *tj = &s->indices[ib*3];
 268
 269    u32 temp[3];
 270    temp[0] = ti[0];
 271    temp[1] = ti[1];
 272    temp[2] = ti[2];
 273
 274    ti[0] = tj[0];
 275    ti[1] = tj[1];
 276    ti[2] = tj[2];
 277
 278    tj[0] = temp[0];
 279    tj[1] = temp[1];
 280    tj[2] = temp[2];
 281 }
 282
 283 static void scene_bh_debug( void *user, u32 item_index )
 284 {
 285    scene *s = user;
 286    u32 idx = item_index*3;
 287    mdl_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
 288             *pb = &s->verts[ s->indices[ idx+1 ] ],
 289             *pc = &s->verts[ s->indices[ idx+2 ] ];
 290
 291    vg_line( pa->co, pb->co, 0xff0000ff );
 292    vg_line( pb->co, pc->co, 0xff0000ff );
 293    vg_line( pc->co, pa->co, 0xff0000ff );
 294 }
 295
 296 static int scene_bh_ray( void *user, u32 index, v3f co, v3f dir, ray_hit *hit )
 297 {
 298    scene *s = user;
 299    v3f positions[3];
 300
 301    u32 *tri = &s->indices[ index*3 ];
 302
 303    for( int i=0; i<3; i++ )
 304       v3_copy( s->verts[tri[i]].co, positions[i] );
 305
 306    float t;
 307    if(ray_tri( positions, co, dir, &t ))
 308    {
 309       if( t < hit->dist )
 310       {
 311          hit->dist = t;
 312          hit->tri = tri;
 313          return 1;
 314       }
 315    }
 316
 317    return 0;
 318 }
 319
 320 static bh_system bh_system_scene =
 321 {
 322    .expand_bound = scene_bh_expand_bound,
 323    .item_centroid = scene_bh_centroid,
 324    .item_swap = scene_bh_swap,
 325    .item_debug = scene_bh_debug,
 326    .cast_ray = scene_bh_ray
 327 };
 328
 329 /*
 330  * An extra step is added onto the end to calculate the hit normal
 331  */
 332 static int scene_raycast( scene *s, v3f co, v3f dir, ray_hit *hit )
 333 {
 334    int count = bh_ray( &s->bhtris, 0, co, dir, hit );
 335
 336    if( count )
 337    {
 338       v3f v0, v1;
 339
 340       float *pa = s->verts[hit->tri[0]].co,
 341             *pb = s->verts[hit->tri[1]].co,
 342             *pc = s->verts[hit->tri[2]].co;
 343
 344       v3_sub( pa, pb, v0 );
 345       v3_sub( pc, pb, v1 );
 346       v3_cross( v1, v0, hit->normal );
 347       v3_normalize( hit->normal );
 348       v3_muladds( co, dir, hit->dist, hit->pos );
 349    }
 350
 351    return count;
 352 }
 353
 354 static void scene_bh_create( scene *s )
 355 {
 356    u32 triangle_count = s->indice_count / 3;
 357    bh_create( &s->bhtris, &bh_system_scene, s, triangle_count );
 358 }
 359
 360 #endif