X-Git-Url: https://harrygodden.com/git/?a=blobdiff_plain;f=bvh.h;fp=bvh.h;h=84f4c6b7d675c7b1cfdf9f914722b572424aa347;hb=1f0e3292c021e8263716e5f4544a1efcedf3f03d;hp=9fdbe985040f51e0cadfd0a183b921240c82a036;hpb=be6707a307bfeec1b45cca8b3fb647e81262be87;p=carveJwlIkooP6JGAAIwe30JlM.git

diff --git a/bvh.h b/bvh.h
index 9fdbe98..84f4c6b 100644
--- a/bvh.h
+++ b/bvh.h
@@ -137,6 +137,15 @@ VG_STATIC void bh_subdivide( bh_tree *bh, u32 inode )
 VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system, 
                               void *user, u32 item_count )
 {
+   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 totsize = sizeof(bh_tree) + sizeof(bh_node)*(item_count*2-1);
    bh_tree *bh = vg_linear_alloc( lin_alloc, totsize );
    bh->system = system;
@@ -192,6 +201,9 @@ VG_STATIC void bh_debug_node( bh_tree *bh, u32 inode, v3f pos, u32 colour )
 
 VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
 {
+   if( bh->node_count < 2 )
+      return 0;
+
    int count = 0;
    u32 stack[100];
    u32 depth = 2;
@@ -243,6 +255,9 @@ VG_STATIC int bh_ray( bh_tree *bh, v3f co, v3f dir, ray_hit *hit )
 
 VG_STATIC int bh_select( bh_tree *bh, boxf box, u32 *buffer, int len )
 {
+   if( bh->node_count < 2 )
+      return 0;
+
    int count = 0;
    u32 stack[100];
    u32 depth = 2;