X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=bvh.h;h=ddc81ca7c1ad5793d45d72ca579aeccab7e85657;hb=bc40c302f1b8313bdd3c773fcfa2f850511c4634;hp=9e4528604d59c8cf205f20d3d172b671102085e1;hpb=a3c10b9dec1ed7136721695033ebeef30717f249;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/bvh.h b/bvh.h
index 9e45286..ddc81ca 100644
--- a/bvh.h
+++ b/bvh.h
@@ -26,6 +26,13 @@ typedef struct bh_node bh_node;
 typedef struct bh_tree bh_tree;
 typedef struct bh_system bh_system;
 
+typedef struct ray_hit ray_hit;
+struct ray_hit{
+   float dist;
+   u32 *tri;
+   v3f pos, normal;
+};
+
 struct bh_tree
 {
    u32 node_count;
@@ -39,8 +46,8 @@ struct bh_tree
       boxf bbx;
 
       /* if il is 0, this is a leaf */
-      u32 il, count;
-      union{ u32 ir, start; };
+      int il, count;
+      union{ int ir, start; };
    } 
    nodes[];
 };
@@ -49,6 +56,7 @@ struct bh_system
 {
    void  (*expand_bound)( void *user, boxf bound, u32 item_index );
    float (*item_centroid)( void *user, u32 item_index, int axis );
+   void  (*item_closest)( void *user, u32 item_index, v3f point, v3f closest );
    void  (*item_swap)( void *user, u32 ia, u32 ib );
 
    /*
@@ -67,8 +75,7 @@ VG_STATIC void bh_update_bounds( bh_tree *bh, u32 inode )
    bh_node *node = &bh->nodes[ inode ];
 
    box_init_inf( node->bbx );
-   for( u32 i=0; i<node->count; i++ )
-   {
+   for( u32 i=0; i<node->count; i++ ){
       u32 idx = node->start+i;
       bh->system->expand_bound( bh->user, node->bbx, idx );
    }
@@ -89,7 +96,6 @@ VG_STATIC void bh_subdivide( bh_tree *bh, u32 inode )
    if( extent[2] > extent[axis] ) axis = 2;
 
    float split = node->bbx[0][axis] + extent[axis]*0.5f;
-
    float avg = 0.0;
    for( u32 t=0; t<node->count; t++ )
    {
@@ -97,18 +103,16 @@ VG_STATIC void bh_subdivide( bh_tree *bh, u32 inode )
       avg += bh->system->item_centroid( bh->user, idx, axis );
    }
    avg /= (float)node->count;
-
    split = avg;
 
+
    i32 i = node->start,
        j = i + node->count-1;
    
-   while( i <= j )
-   {
+   while( i <= j ){
       if( bh->system->item_centroid( bh->user, i, axis ) < split )
          i ++;
-      else
-      {
+      else{
          bh->system->item_swap( bh->user, i, j );
          j --;
       }
@@ -143,17 +147,10 @@ VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system,
 {
    assert( max_per_leaf > 0 );
 
-   if( item_count == 0 )
-   {
-      bh_tree *bh = vg_linear_alloc( lin_alloc, sizeof(bh_tree) );
-      bh->node_count = 0;
-      bh->system = system;
-      bh->user = user;
-      return bh;
-   }
+   u32 alloc_count = VG_MAX( 1, item_count );
 
-   u32 totsize = sizeof(bh_tree) + sizeof(bh_node)*(item_count*2-1);
-   bh_tree *bh = vg_linear_alloc( lin_alloc, totsize );
+   u32 totsize = sizeof(bh_tree) + sizeof(bh_node)*(alloc_count*2-1);
+   bh_tree *bh = vg_linear_alloc( lin_alloc, vg_align8(totsize) );
    bh->system = system;
    bh->user = user;
    bh->max_per_leaf = max_per_leaf;
@@ -167,41 +164,52 @@ VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system,
    root->start = 0;
 
    bh_update_bounds( bh, 0 );
-   bh_subdivide( bh, 0 );
 
-   totsize = sizeof(bh_tree) + sizeof(bh_node) * bh->node_count;
+   if( item_count > 2 )
+      bh_subdivide( bh, 0 );
+
+   totsize = vg_align8(sizeof(bh_tree) + sizeof(bh_node) * bh->node_count);
    bh = vg_linear_resize( lin_alloc, bh, totsize );
 
-   vg_success( "BVH done, size: %u/%u\n", bh->node_count, (item_count*2-1) );
+   vg_success( "BVH done, size: %u/%u\n", bh->node_count, (alloc_count*2-1) );
    return bh;
 }
 
-VG_STATIC void bh_debug_node( bh_tree *bh, u32 inode, v3f pos, u32 colour )
+/*
+ * Draw items in this leaf node.
+ * *item_debug() must be set!
+ */
+VG_STATIC void bh_debug_leaf( bh_tree *bh, bh_node *node )
+{
+   vg_line_boxf( node->bbx, 0xff00ff00 );
+
+   if( bh->system->item_debug ){
+      for( u32 i=0; i<node->count; i++ ){
+         u32 idx = node->start+i;
+         bh->system->item_debug( bh->user, idx );
+      }
+   }
+}
+
+/*
+ * Trace the bh tree all the way down to the leaf nodes where pos is inside
+ */
+VG_STATIC void bh_debug_trace( bh_tree *bh, u32 inode, v3f pos, u32 colour )
 {
    bh_node *node = &bh->nodes[ inode ];
 
    if( (pos[0] >= node->bbx[0][0] && pos[0] <= node->bbx[1][0]) &&
        (pos[2] >= node->bbx[0][2] && pos[2] <= node->bbx[1][2]) )
    {
-      if( !node->count )
-      {
+      if( !node->count ){
          vg_line_boxf( node->bbx, colour );
 
-         bh_debug_node( bh, node->il, pos, colour );
-         bh_debug_node( bh, node->ir, pos, colour );
+         bh_debug_trace( bh, node->il, pos, colour );
+         bh_debug_trace( bh, node->ir, pos, colour );
       }
-      else
-      {
-         vg_line_boxf( node->bbx, 0xff00ff00 );
-
+      else{
          if( bh->system->item_debug )
-         {
-            for( u32 i=0; i<node->count; i++ )
-            {
-               u32 idx = node->start+i;
-               bh->system->item_debug( bh->user, idx );
-            }
-         }
+            bh_debug_leaf( bh, node );
       }
    }
 }
@@ -218,16 +226,17 @@ VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
    stack[0] = 0;
    stack[1] = bh->nodes[0].il;
    stack[2] = bh->nodes[0].ir;
+
+   v3f dir_inv;
+   dir_inv[0] = 1.0f/dir[0];
+   dir_inv[1] = 1.0f/dir[1];
+   dir_inv[2] = 1.0f/dir[2];
    
-   while(depth)
-   {
+   while(depth){
       bh_node *inode = &bh->nodes[ stack[depth] ];
-      if( ray_aabb( inode->bbx, co, dir, hit->dist ) )
-      {
-         if( inode->count )
-         {
-            for( u32 i=0; i<inode->count; i++ )
-            {
+      if( ray_aabb1( inode->bbx, co, dir_inv, hit->dist ) ){
+         if( inode->count ){
+            for( u32 i=0; i<inode->count; i++ ){
                u32 idx = inode->start+i;
 
                if( bh->system->cast_ray )
@@ -238,10 +247,8 @@ VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
 
             depth --;
          }
-         else
-         {
-            if( depth+1 >= vg_list_size(stack) )
-            {
+         else{
+            if( depth+1 >= vg_list_size(stack) ){
                vg_error( "Maximum stack reached!\n" );
                return count;
             }
@@ -251,8 +258,7 @@ VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
             depth ++;
          }
       }
-      else
-      {
+      else{
          depth --;
       }
    }
@@ -260,54 +266,114 @@ VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
    return count;
 }
 
-VG_STATIC int bh_select( bh_tree *bh, boxf box, u32 *buffer, int len )
+typedef struct bh_iter bh_iter;
+struct bh_iter
+{
+   struct 
+   {
+      int id, depth;
+   }
+   stack[64];
+
+   int depth, i;
+};
+
+VG_STATIC void bh_iter_init( int root, bh_iter *it )
+{
+   it->stack[0].id = root;
+   it->stack[0].depth = 0;
+   it->depth = 0;
+   it->i = 0;
+}
+
+VG_STATIC int bh_next( bh_tree *bh, bh_iter *it, boxf box, int *em )
+{
+   while( it->depth >= 0 ){
+      bh_node *inode = &bh->nodes[ it->stack[it->depth].id ];
+      
+      /* Only process overlapping nodes */
+      if( !box_overlap( inode->bbx, box ) ){
+         it->depth --;
+         continue;
+      }
+
+      if( inode->count ){
+         if( it->i < inode->count ){
+            *em = inode->start+it->i;
+            it->i ++;
+            return 1;
+         }
+         else{
+            it->depth --;
+            it->i = 0;
+         }
+      }
+      else{
+         if( it->depth+1 >= vg_list_size(it->stack) ){
+            vg_error( "Maximum stack reached!\n" );
+            return 0;
+         }
+
+         it->stack[it->depth  ].id = inode->il;
+         it->stack[it->depth+1].id = inode->ir;
+         it->depth ++;
+         it->i = 0;
+      }
+   }
+
+   return 0;
+}
+
+VG_STATIC int bh_closest_point( bh_tree *bh, v3f pos, 
+                                v3f closest, float max_dist )
 {
    if( bh->node_count < 2 )
-      return 0;
+      return -1;
 
-   int count = 0;
-   u32 stack[100];
-   u32 depth = 2;
+   max_dist = max_dist*max_dist;
 
-   stack[0] = 0;
-   stack[1] = bh->nodes[0].il;
-   stack[2] = bh->nodes[0].ir;
-   
-   while(depth)
-   {
-      bh_node *inode = &bh->nodes[ stack[depth] ];
-      if( box_overlap( inode->bbx, box ) )
-      {
-         if( inode->count )
-         {
-            if( count + inode->count >= len )
-               return count;
+   int queue[ 128 ],
+       depth = 0,
+       best_item = -1;
+
+   queue[0] = 0;
+
+   while( depth >= 0 ){
+      bh_node *inode = &bh->nodes[ queue[depth] ];
+
+      v3f p1;
+      closest_point_aabb( pos, inode->bbx, p1 );
 
-            for( u32 i=0; i<inode->count; i++ )
-               buffer[ count ++ ] = inode->start+i;
+      /* branch into node if its closer than current best */
+      float node_dist = v3_dist2( pos, p1 );
+      if( node_dist < max_dist ){
+         if( inode->count ){
+            for( int i=0; i<inode->count; i++ ){
+               v3f p2;
+               bh->system->item_closest( bh->user, inode->start+i, pos, p2 );
+
+               float item_dist = v3_dist2( pos, p2 );
+               if( item_dist < max_dist ){
+                  max_dist = item_dist;
+                  v3_copy( p2, closest );
+                  best_item = inode->start+i;
+               }
+            }
 
             depth --;
          }
-         else
-         {
-            if( depth+1 >= vg_list_size(stack) )
-            {
-               vg_error( "Maximum stack reached!\n" );
-               return count;
-            }
+         else{
+            queue[depth] = inode->il;
+            queue[depth+1] = inode->ir;
 
-            stack[depth] = inode->il;
-            stack[depth+1] = inode->ir;
             depth ++;
          }
       }
       else
-      {
          depth --;
-      }
    }
 
-   return count;
+   return best_item;
 }
 
 #endif /* BVH_H */