#ifndef BVH_H
#define BVH_H
-#include "common.h"
+
+#include "vg/vg_mem.h"
+#include "vg/vg_m.h"
+#include "vg/vg_lines.h"
/*
* Usage:
typedef struct bh_tree bh_tree;
typedef struct bh_system bh_system;
-struct bh_tree
-{
+typedef struct ray_hit ray_hit;
+struct ray_hit{
+ float dist;
+ u32 *tri;
+ v3f pos, normal;
+};
+
+struct bh_tree{
u32 node_count;
bh_system *system;
nodes[];
};
-struct bh_system
-{
+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 );
int (*cast_ray)( void *user, u32 index, v3f co, v3f dir, ray_hit *hit );
};
-VG_STATIC void bh_update_bounds( bh_tree *bh, u32 inode )
-{
+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 );
}
}
-VG_STATIC void bh_subdivide( bh_tree *bh, u32 inode )
-{
+VG_STATIC void bh_subdivide( bh_tree *bh, u32 inode ){
bh_node *node = &bh->nodes[ inode ];
if( node->count <= bh->max_per_leaf )
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++ )
{
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 --;
}
}
VG_STATIC bh_tree *bh_create( void *lin_alloc, bh_system *system,
- void *user, u32 item_count, u32 max_per_leaf )
-{
+ void *user, u32 item_count, u32 max_per_leaf ){
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;
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;
}
* Draw items in this leaf node.
* *item_debug() must be set!
*/
-VG_STATIC void bh_debug_leaf( bh_tree *bh, bh_node *node )
-{
+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++ )
- {
+ 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 )
-{
+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_trace( bh, node->il, pos, colour );
bh_debug_trace( bh, node->ir, pos, colour );
}
- else
- {
+ else{
if( bh->system->item_debug )
bh_debug_leaf( bh, node );
}
}
}
-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;
-
- 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_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 )
- count += bh->system->cast_ray( bh->user, idx, co, dir, hit );
- else
- count ++;
- }
+typedef struct bh_iter bh_iter;
+struct bh_iter{
+ struct {
+ i32 id, depth;
+ }
+ stack[64];
- depth --;
- }
- else
- {
- if( depth+1 >= vg_list_size(stack) )
- {
- vg_error( "Maximum stack reached!\n" );
- return count;
- }
+ enum bh_query_type{
+ k_bh_query_box,
+ k_bh_query_ray,
+ k_bh_query_range
+ }
+ query;
- stack[depth] = inode->il;
- stack[depth+1] = inode->ir;
- depth ++;
- }
+ union{
+ struct{
+ boxf box;
}
- else
- {
- depth --;
- }
- }
+ box;
- return count;
-}
+ struct{
+ v3f co, inv_dir;
+ f32 max_dist;
+ }
+ ray;
-typedef struct bh_iter bh_iter;
-struct bh_iter
-{
- struct
- {
- int id, depth;
- }
- stack[64];
+ struct {
+ v3f co;
+ f32 dist_sqr;
+ }
+ range;
+ };
- int depth, i;
+ i32 depth, i;
};
-VG_STATIC void bh_iter_init( int root, bh_iter *it )
-{
+VG_STATIC void bh_iter_init_generic( i32 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 )
- {
+VG_STATIC void bh_iter_init_box( i32 root, bh_iter *it, boxf box ){
+ bh_iter_init_generic( root, it );
+ it->query = k_bh_query_box;
+
+ box_copy( box, it->box.box );
+}
+
+VG_STATIC void bh_iter_init_ray( i32 root, bh_iter *it, v3f co,
+ v3f dir, f32 max_dist ){
+ bh_iter_init_generic( root, it );
+ it->query = k_bh_query_ray;
+
+ v3_div( (v3f){1.0f,1.0f,1.0f}, dir, it->ray.inv_dir );
+ v3_copy( co, it->ray.co );
+ it->ray.max_dist = max_dist;
+}
+
+VG_STATIC void bh_iter_init_range( i32 root, bh_iter *it, v3f co, f32 range ){
+ bh_iter_init_generic( root, it );
+ it->query = k_bh_query_range;
+
+ v3_copy( co, it->range.co );
+ it->range.dist_sqr = range*range;
+}
+
+/* NOTE: does not compute anything beyond the leaf level. element level tests
+ * should be implemented by the users code.
+ *
+ * this is like a 'broad phase only' deal.
+ */
+VG_STATIC i32 bh_next( bh_tree *bh, bh_iter *it, i32 *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 ) )
- {
+ i32 q = 0;
+
+ if( it->i ) /* already checked */
+ q = 1;
+ else{
+ if( it->query == k_bh_query_box )
+ q = box_overlap( inode->bbx, it->box.box );
+ else if( it->query == k_bh_query_ray )
+ q = ray_aabb1( inode->bbx, it->ray.co,
+ it->ray.inv_dir, it->ray.max_dist );
+ else {
+ v3f nearest;
+ closest_point_aabb( it->range.co, inode->bbx, nearest );
+
+ if( v3_dist2( nearest, it->range.co ) <= it->range.dist_sqr )
+ q = 1;
+ }
+ }
+
+ if( !q ){
it->depth --;
continue;
}
- if( inode->count )
- {
- if( it->i < inode->count )
- {
+ if( inode->count ){
+ if( it->i < inode->count ){
*em = inode->start+it->i;
it->i ++;
return 1;
}
- else
- {
+ else{
it->depth --;
it->i = 0;
}
}
- else
- {
- if( it->depth+1 >= vg_list_size(it->stack) )
- {
+ else{
+ if( it->depth+1 >= vg_list_size(it->stack) ){
vg_error( "Maximum stack reached!\n" );
return 0;
}
queue[0] = 0;
- while( depth >= 0 )
- {
+ while( depth >= 0 ){
bh_node *inode = &bh->nodes[ queue[depth] ];
v3f p1;
/* 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++ )
- {
+ 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 )
- {
+ if( item_dist < max_dist ){
max_dist = item_dist;
v3_copy( p2, closest );
best_item = inode->start+i;
depth --;
}
- else
- {
+ else{
queue[depth] = inode->il;
queue[depth+1] = inode->ir;