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 static void scene_init( scene *pscene )
  32 {
  33    pscene->verts = NULL;
  34    pscene->indices = NULL;
  35    pscene->vertex_count = 0;
  36    pscene->indice_count = 0;
  37    pscene->shadower_count = 0;
  38    pscene->shadower_cap = 0;
  39    pscene->submesh.indice_start = 0;
  40    pscene->submesh.indice_count = 0;
  41
  42    v3_fill( pscene->bbx[0],  999999.9f );
  43    v3_fill( pscene->bbx[1], -999999.9f );
  44 }
  45
  46 /*
  47  * Append a model into the scene with a given transform
  48  */
  49 static void scene_add_submesh( scene *pscene, mdl_header *mdl,
  50                                mdl_submesh *sm, m4x3f transform )
  51 {
  52    pscene->verts  = buffer_reserve( pscene->verts, pscene->vertex_count,
  53                     &pscene->vertex_cap, sm->vertex_count, sizeof(mdl_vert) );
  54
  55    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
  56                      &pscene->indice_cap, sm->indice_count, sizeof(u32) );
  57
  58    m3x3f normal_matrix;
  59    m3x3_copy( transform, normal_matrix );
  60    v3_normalize( normal_matrix[0] );
  61    v3_normalize( normal_matrix[1] );
  62    v3_normalize( normal_matrix[2] );
  63
  64    /* Transform and place vertices */
  65    mdl_vert *src_verts = mdl_submesh_vertices( mdl, sm );
  66    u32 *src_indices    = mdl_submesh_indices( mdl, sm );
  67
  68    boxf bbxnew;
  69    box_copy( sm->bbx, bbxnew );
  70    m4x3_transform_aabb( transform, bbxnew );
  71    box_concat( pscene->bbx, bbxnew );
  72
  73    for( u32 i=0; i<sm->vertex_count; i++ )
  74    {
  75       mdl_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
  76                *src = &src_verts[ i ];
  77
  78       m4x3_mulv( transform, src->co, pvert->co );
  79       m3x3_mulv( normal_matrix, src->norm, pvert->norm );
  80
  81       pvert->colour[0] = src->colour[0];
  82       pvert->colour[1] = src->colour[1];
  83       pvert->colour[2] = src->colour[2];
  84       pvert->colour[3] = src->colour[3];
  85       v2_copy( src->uv, pvert->uv );
  86    }
  87
  88    for( u32 i=0; i<sm->indice_count; i++ )
  89    {
  90       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
  91       *pidx = src_indices[i] + pscene->vertex_count;
  92    }
  93
  94    pscene->vertex_count += sm->vertex_count;
  95    pscene->indice_count += sm->indice_count;
  96 }
  97
  98 /*
  99  * One by one adders for simplified access (mostly procedural stuff)
 100  */
 101 static void scene_push_tri( scene *pscene, u32 tri[3] )
 102 {
 103    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 104                                     &pscene->indice_cap, 3, sizeof(u32) );
 105
 106    u32 *dst = &pscene->indices[pscene->indice_count];
 107    dst[0] = tri[0];
 108    dst[1] = tri[1];
 109    dst[2] = tri[2];
 110
 111    pscene->indice_count += 3;
 112 }
 113
 114 static void scene_push_vert( scene *pscene, mdl_vert *v )
 115 {
 116    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 117                                   &pscene->vertex_cap, 1, sizeof(mdl_vert) );
 118    pscene->verts[pscene->vertex_count ++] = *v;
 119 }
 120
 121 static void scene_copy_slice( scene *pscene, mdl_submesh *sm )
 122 {
 123    sm->indice_start = pscene->submesh.indice_start;
 124    sm->indice_count = pscene->indice_count - sm->indice_start;
 125
 126    sm->vertex_start = pscene->submesh.vertex_start;
 127    sm->vertex_count = pscene->vertex_count - sm->vertex_start;
 128
 129    pscene->submesh.indice_start = pscene->indice_count;
 130    pscene->submesh.vertex_start = pscene->vertex_count;
 131 }
 132
 133 static void scene_fix( scene *pscene )
 134 {
 135    buffer_fix( pscene->verts, pscene->vertex_count,
 136          &pscene->vertex_cap, sizeof( mdl_vert ));
 137
 138    buffer_fix( pscene->indices, pscene->indice_count,
 139          &pscene->indice_cap, sizeof( mdl_vert ));
 140 }
 141
 142 static void scene_upload( scene *pscene )
 143 {
 144    mesh_upload( &pscene->mesh,
 145                 pscene->verts, pscene->vertex_count,
 146                 pscene->indices, pscene->indice_count );
 147
 148    vg_info( "Scene upload\n" );
 149    vg_info( "   indices:%u\n", pscene->indice_count );
 150    vg_info( "   verts:%u\n", pscene->vertex_count );
 151 }
 152
 153 static void scene_bind( scene *pscene )
 154 {
 155    mesh_bind( &pscene->mesh );
 156 }
 157
 158 static void scene_draw( scene *pscene )
 159 {
 160    mesh_drawn( 0, pscene->indice_count );
 161 }
 162
 163 static void scene_free_offline_buffers( scene *pscene )
 164 {
 165    vg_free( pscene->verts );
 166    vg_free( pscene->indices );
 167 }
 168
 169 static void scene_free( scene *pscene )
 170 {
 171    scene_free_offline_buffers( pscene );
 172 }
 173
 174 /*
 175  * BVH implementation
 176  */
 177
 178 static void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
 179 {
 180    scene *s = user;
 181    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 182             *pb = &s->verts[ s->indices[item_index*3+1] ],
 183             *pc = &s->verts[ s->indices[item_index*3+2] ];
 184
 185   box_addpt( bound, pa->co );
 186   box_addpt( bound, pb->co );
 187   box_addpt( bound, pc->co );
 188 }
 189
 190 static float scene_bh_centroid( void *user, u32 item_index, int axis )
 191 {
 192    scene *s = user;
 193    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 194             *pb = &s->verts[ s->indices[item_index*3+1] ],
 195             *pc = &s->verts[ s->indices[item_index*3+2] ];
 196
 197    return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
 198 }
 199
 200 static void scene_bh_swap( void *user, u32 ia, u32 ib )
 201 {
 202    scene *s = user;
 203
 204    u32 *ti = &s->indices[ia*3];
 205    u32 *tj = &s->indices[ib*3];
 206
 207    u32 temp[3];
 208    temp[0] = ti[0];
 209    temp[1] = ti[1];
 210    temp[2] = ti[2];
 211
 212    ti[0] = tj[0];
 213    ti[1] = tj[1];
 214    ti[2] = tj[2];
 215
 216    tj[0] = temp[0];
 217    tj[1] = temp[1];
 218    tj[2] = temp[2];
 219 }
 220
 221 static void scene_bh_debug( void *user, u32 item_index )
 222 {
 223    scene *s = user;
 224    u32 idx = item_index*3;
 225    mdl_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
 226             *pb = &s->verts[ s->indices[ idx+1 ] ],
 227             *pc = &s->verts[ s->indices[ idx+2 ] ];
 228
 229    vg_line( pa->co, pb->co, 0xff0000ff );
 230    vg_line( pb->co, pc->co, 0xff0000ff );
 231    vg_line( pc->co, pa->co, 0xff0000ff );
 232 }
 233
 234 static int scene_bh_ray( void *user, u32 index, v3f co, v3f dir, ray_hit *hit )
 235 {
 236    scene *s = user;
 237    v3f positions[3];
 238
 239    u32 *tri = &s->indices[ index*3 ];
 240
 241    for( int i=0; i<3; i++ )
 242       v3_copy( s->verts[tri[i]].co, positions[i] );
 243
 244    float t;
 245    if(ray_tri( positions, co, dir, &t ))
 246    {
 247       if( t < hit->dist )
 248       {
 249          hit->dist = t;
 250          hit->tri = tri;
 251          return 1;
 252       }
 253    }
 254
 255    return 0;
 256 }
 257
 258 static bh_system bh_system_scene =
 259 {
 260    .expand_bound = scene_bh_expand_bound,
 261    .item_centroid = scene_bh_centroid,
 262    .item_swap = scene_bh_swap,
 263    .item_debug = scene_bh_debug,
 264    .cast_ray = scene_bh_ray
 265 };
 266
 267 /*
 268  * An extra step is added onto the end to calculate the hit normal
 269  */
 270 static int scene_raycast( scene *s, v3f co, v3f dir, ray_hit *hit )
 271 {
 272    int count = bh_ray( &s->bhtris, 0, co, dir, hit );
 273
 274    if( count )
 275    {
 276       v3f v0, v1;
 277
 278       float *pa = s->verts[hit->tri[0]].co,
 279             *pb = s->verts[hit->tri[1]].co,
 280             *pc = s->verts[hit->tri[2]].co;
 281
 282       v3_sub( pa, pb, v0 );
 283       v3_sub( pc, pb, v1 );
 284       v3_cross( v1, v0, hit->normal );
 285       v3_normalize( hit->normal );
 286       v3_muladds( co, dir, hit->dist, hit->pos );
 287    }
 288
 289    return count;
 290 }
 291
 292 static void scene_bh_create( scene *s )
 293 {
 294    u32 triangle_count = s->indice_count / 3;
 295    bh_create( &s->bhtris, &bh_system_scene, s, triangle_count );
 296 }
 297
 298 #endif