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
 110 static void scene_add_submesh( scene *pscene, mdl_header *mdl,
 111       mdl_submesh *sm, m4x3f transform )
 112 {
 113    pscene->verts = buffer_reserve( pscene->verts, pscene->vertex_count,
 114          &pscene->vertex_cap, sm->vertex_count, sizeof(mdl_vert) );
 115    pscene->indices = buffer_reserve( pscene->indices, pscene->indice_count,
 116          &pscene->indice_cap, sm->indice_count, sizeof(u32) );
 117
 118    m3x3f normal_matrix;
 119    m3x3_copy( transform, normal_matrix );
 120    v3_normalize( normal_matrix[0] );
 121    v3_normalize( normal_matrix[1] );
 122    v3_normalize( normal_matrix[2] );
 123
 124    /* Transform and place vertices */
 125    mdl_vert *src_verts = mdl_submesh_vertices( mdl, sm );
 126    u32 *src_indices    = mdl_submesh_indices( mdl, sm );
 127
 128    boxf bbxnew;
 129    box_copy( sm->bbx, bbxnew );
 130    m4x3_transform_aabb( transform, bbxnew );
 131    box_concat( pscene->bbx, bbxnew );
 132
 133    for( u32 i=0; i<sm->vertex_count; i++ )
 134    {
 135       mdl_vert *pvert = &pscene->verts[ pscene->vertex_count+i ],
 136                *src = &src_verts[ i ];
 137
 138       m4x3_mulv( transform, src->co, pvert->co );
 139       m3x3_mulv( normal_matrix, src->norm, pvert->norm );
 140
 141       v4_copy( src->colour, pvert->colour );
 142       v2_copy( src->uv, pvert->uv );
 143    }
 144
 145    for( u32 i=0; i<sm->indice_count; i++ )
 146    {
 147       u32 *pidx = &pscene->indices[ pscene->indice_count+i ];
 148       *pidx = src_indices[i] + pscene->vertex_count;
 149    }
 150
 151    pscene->vertex_count += sm->vertex_count;
 152    pscene->indice_count += sm->indice_count;
 153 }
 154
 155 static void scene_copy_slice( scene *pscene, mdl_submesh *sm )
 156 {
 157    sm->indice_start = pscene->submesh.indice_start;
 158    sm->indice_count = pscene->indice_count - sm->indice_start;
 159
 160    sm->vertex_start = pscene->submesh.vertex_start;
 161    sm->vertex_count = pscene->vertex_count - sm->vertex_start;
 162
 163    pscene->submesh.indice_start = pscene->indice_count;
 164    pscene->submesh.vertex_start = pscene->vertex_count;
 165 }
 166
 167 static void scene_fix( scene *pscene )
 168 {
 169    buffer_fix( pscene->verts, pscene->vertex_count,
 170          &pscene->vertex_cap, sizeof( mdl_vert ));
 171
 172    buffer_fix( pscene->indices, pscene->indice_count,
 173          &pscene->indice_cap, sizeof( mdl_vert ));
 174 }
 175
 176 static void scene_upload( scene *pscene )
 177 {
 178    mesh_upload( &pscene->mesh,
 179          pscene->verts, pscene->vertex_count,
 180          pscene->indices, pscene->indice_count );
 181
 182    vg_info( "Scene upload\n" );
 183    vg_info( "   indices:%u\n", pscene->indice_count );
 184    vg_info( "   verts:%u\n", pscene->vertex_count );
 185 }
 186
 187 static void scene_bind( scene *pscene )
 188 {
 189    mesh_bind( &pscene->mesh );
 190 }
 191
 192 static void scene_draw( scene *pscene )
 193 {
 194    mesh_drawn( 0, pscene->indice_count );
 195 }
 196
 197 static void scene_free( scene *pscene )
 198 {
 199    free( pscene->verts );
 200    free( pscene->indices );
 201
 202    /* TODO: bvh */
 203 }
 204
 205 static void scene_register(void)
 206 {
 207 }
 208
 209 /*
 210  * BVH implementation
 211  */
 212
 213 static void scene_bh_expand_bound( void *user, boxf bound, u32 item_index )
 214 {
 215    scene *s = user;
 216    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 217             *pb = &s->verts[ s->indices[item_index*3+1] ],
 218             *pc = &s->verts[ s->indices[item_index*3+2] ];
 219
 220   box_addpt( bound, pa->co );
 221   box_addpt( bound, pb->co );
 222   box_addpt( bound, pc->co );
 223 }
 224
 225 static float scene_bh_centroid( void *user, u32 item_index, int axis )
 226 {
 227    scene *s = user;
 228    mdl_vert *pa = &s->verts[ s->indices[item_index*3+0] ],
 229             *pb = &s->verts[ s->indices[item_index*3+1] ],
 230             *pc = &s->verts[ s->indices[item_index*3+2] ];
 231
 232    return (pa->co[axis] + pb->co[axis] + pc->co[axis]) * (1.0f/3.0f);
 233 }
 234
 235 static void scene_bh_swap( void *user, u32 ia, u32 ib )
 236 {
 237    scene *s = user;
 238
 239    u32 *ti = &s->indices[ia*3];
 240    u32 *tj = &s->indices[ib*3];
 241
 242    u32 temp[3];
 243    temp[0] = ti[0];
 244    temp[1] = ti[1];
 245    temp[2] = ti[2];
 246
 247    ti[0] = tj[0];
 248    ti[1] = tj[1];
 249    ti[2] = tj[2];
 250
 251    tj[0] = temp[0];
 252    tj[1] = temp[1];
 253    tj[2] = temp[2];
 254 }
 255
 256 static void scene_bh_debug( void *user, u32 item_index )
 257 {
 258    scene *s = user;
 259    u32 idx = item_index*3;
 260    mdl_vert *pa = &s->verts[ s->indices[ idx+0 ] ],
 261             *pb = &s->verts[ s->indices[ idx+1 ] ],
 262             *pc = &s->verts[ s->indices[ idx+2 ] ];
 263
 264    vg_line( pa->co, pb->co, 0xff0000ff );
 265    vg_line( pb->co, pc->co, 0xff0000ff );
 266    vg_line( pc->co, pa->co, 0xff0000ff );
 267 }
 268
 269 static int scene_bh_ray( void *user, u32 index, v3f co, v3f dir, ray_hit *hit )
 270 {
 271    scene *s = user;
 272    v3f positions[3];
 273
 274    u32 *tri = &s->indices[ index*3 ];
 275
 276    for( int i=0; i<3; i++ )
 277       v3_copy( s->verts[tri[i]].co, positions[i] );
 278
 279    float t;
 280    if(ray_tri( positions, co, dir, &t ))
 281    {
 282       if( t < hit->dist )
 283       {
 284          hit->dist = t;
 285          hit->tri = tri;
 286          return 1;
 287       }
 288    }
 289
 290    return 0;
 291 }
 292
 293 static bh_system bh_system_scene =
 294 {
 295    .expand_bound = scene_bh_expand_bound,
 296    .item_centroid = scene_bh_centroid,
 297    .item_swap = scene_bh_swap,
 298    .item_debug = scene_bh_debug,
 299    .cast_ray = scene_bh_ray
 300 };
 301
 302 /*
 303  * An extra step is added onto the end to calculate the hit normal
 304  */
 305 static int scene_raycast( scene *s, v3f co, v3f dir, ray_hit *hit )
 306 {
 307    int count = bh_ray( &s->bhtris, 0, co, dir, hit );
 308
 309    if( count )
 310    {
 311       v3f v0, v1;
 312
 313       float *pa = s->verts[hit->tri[0]].co,
 314             *pb = s->verts[hit->tri[1]].co,
 315             *pc = s->verts[hit->tri[2]].co;
 316
 317       v3_sub( pa, pb, v0 );
 318       v3_sub( pc, pb, v1 );
 319       v3_cross( v1, v0, hit->normal );
 320       v3_normalize( hit->normal );
 321       v3_muladds( co, dir, hit->dist, hit->pos );
 322    }
 323
 324    return count;
 325 }
 326
 327 static void scene_bh_create( scene *s )
 328 {
 329    u32 triangle_count = s->indice_count / 3;
 330    bh_create( &s->bhtris, &bh_system_scene, s, triangle_count );
 331 }
 332
 333 #endif