lighting.h

   1 #ifndef LIGHTING_H
   2 #define LIGHTING_H
   3
   4 #include "common.h"
   5 #include "scene.h"
   6
   7 static int ray_world( v3f pos, v3f dir, ray_hit *hit );
   8
   9 typedef struct voxel_gi voxel_gi;
  10
  11 struct voxel_gi
  12 {
  13    GLuint hw_texture,
  14           pt_texture;
  15
  16    v3i pt_dims;      /* Page table dimentions */
  17    i32 page_size;
  18
  19    v3f origin;
  20 };
  21
  22 static void voxel_gi_setup( voxel_gi *gi, scene *sc,
  23                             i32 page_size, float voxel_res )
  24 {
  25    v3_copy( sc->bbx[0], gi->origin );
  26    gi->page_size = page_size;
  27
  28    v3f extent;
  29    v3_sub( sc->bbx[1], sc->bbx[0], extent );
  30
  31    float fpage_size = voxel_res * (float)page_size;
  32
  33    for( int i=0; i<3; i++ )
  34    {
  35       i32 voxel_count = extent[i] / voxel_res;
  36       gi->pt_dims[i] = (voxel_count+page_size-1) / page_size;
  37    }
  38
  39    i32 pt_capacity = gi->pt_dims[0]*gi->pt_dims[1]*gi->pt_dims[2];
  40    vg_info( "Page table size: %dkb\n", (pt_capacity*2*2)/1024 );
  41
  42    u16 *page_table = malloc( pt_capacity*sizeof(u16)*3 );
  43
  44
  45    u32 active_count = 0;
  46
  47    for( int z=0; z<gi->pt_dims[2]; z++ )
  48    {
  49       for( int y=0; y<gi->pt_dims[1]; y++ )
  50       {
  51          for( int x=0; x<gi->pt_dims[0]; x++ )
  52          {
  53             v3f base = {x,y,z},
  54                 end  = {x+1,y+1,z+1};
  55
  56             boxf page_region;
  57
  58             v3_muladds( sc->bbx[0], base, ((float)page_size)*voxel_res, base );
  59             v3_muladds( sc->bbx[0], end,  ((float)page_size)*voxel_res, end  );
  60             v3_copy( base, page_region[0] );
  61             v3_copy( end,  page_region[1] );
  62
  63             u32 nothing[2];
  64             if( bh_select( &sc->bhtris, page_region, nothing, 2 ))
  65             {
  66                active_count ++;
  67
  68                /* Calculate lighting */
  69             }
  70          }
  71       }
  72    }
  73
  74    /* Calculate physical storage size */
  75    vg_info( "Hardware texture required size: %dmb\n",
  76          ((active_count*page_size*page_size*page_size*1)/1024)/1024 );
  77    vg_info( "Required physical blocks: %d\n", active_count );
  78
  79    free( page_table );
  80 }
  81
  82 static void compute_lighting_vertex( scene *sc )
  83 {
  84    v3f light_dir = { 0.2f, 1.0f, 1.0f };
  85    v3_normalize( light_dir );
  86
  87    for( int i=0; i<sc->vertex_count; i++ )
  88    {
  89       model_vert *mv = &sc->verts[i];
  90
  91       ray_hit hit;
  92       hit.dist = 100.0f;
  93
  94       ray_world( mv->co, light_dir, &hit );
  95       float amt = hit.dist / 100.0f;
  96
  97       mv->colour[0] = amt;
  98       mv->colour[1] = amt;
  99       mv->colour[2] = amt;
 100       mv->colour[3] = 1.0f;
 101    }
 102 }
 103
 104 #endif /* LIGHTING_H */