dont remember

[carveJwlIkooP6JGAAIwe30JlM.git] / bvh.h

diff --git a/bvh.h b/bvh.h
index 41a4108c908ff345a06978c39c313b06a06bc27a..23f8a564d54cd7ce1b7830457da97ce15ad790d7 100644 (file)
--- a/bvh.h
+++ b/bvh.h
@@ -5,7 +5,6 @@
 #ifndef BVH_H
 #define BVH_H
 #include "common.h"
-#include "distq.h"
 
 /*
  * Usage:
@@ -91,7 +90,6 @@ 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++ )
    {
@@ -99,9 +97,9 @@ 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;
    
@@ -145,16 +143,9 @@ 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);
+   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;
@@ -169,16 +160,39 @@ VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system,
    root->start = 0;
 
    bh_update_bounds( bh, 0 );
-   bh_subdivide( bh, 0 );
+
+   if( item_count > 2 )
+      bh_subdivide( bh, 0 );
 
    totsize = 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 ];
 
@@ -189,21 +203,13 @@ VG_STATIC void bh_debug_node( bh_tree *bh, u32 inode, v3f pos, u32 colour )
       {
          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 );
-
          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 );
       }
    }
 }
@@ -220,11 +226,16 @@ 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)
    {
       bh_node *inode = &bh->nodes[ stack[depth] ];
-      if( ray_aabb( inode->bbx, co, dir, hit->dist ) )
+      if( ray_aabb1( inode->bbx, co, dir_inv, hit->dist ) )
       {
          if( inode->count )
          {
@@ -288,39 +299,39 @@ VG_STATIC int bh_next( bh_tree *bh, bh_iter *it, boxf box, int *em )
    {
       bh_node *inode = &bh->nodes[ it->stack[it->depth].id ];
       
-      if( box_overlap( inode->bbx, box ) )
+      /* Only process overlapping nodes */
+      if( !box_overlap( inode->bbx, box ) )
       {
-         if( inode->count )
+         it->depth --;
+         continue;
+      }
+
+      if( inode->count )
+      {
+         if( it->i < inode->count )
          {
-            if( it->i < inode->count )
-            {
-               *em = inode->start+it->i;
-               it->i ++;
-               return 1;
-            }
-            else
-            {
-               it->depth --;
-               it->i = 0;
-            }
+            *em = inode->start+it->i;
+            it->i ++;
+            return 1;
          }
          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->depth --;
             it->i = 0;
          }
       }
       else
       {
-         it->depth --;
+         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;
       }
    }