/**
 * $Id$
 *
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include "DNA_meshdata_types.h"
#include "DNA_mesh_types.h"
#include "DNA_object_types.h"

#include "MEM_guardedalloc.h"

#include "BLI_math.h"
#include "BLI_ghash.h"
#include "BLI_pbvh.h"

#include "BKE_DerivedMesh.h"
#include "BKE_dmgrid.h"
#include "BKE_mesh.h" /* for mesh_calc_normals */
#include "BKE_global.h" /* for mesh_calc_normals */
#include "BKE_paint.h"

#include "GPU_buffers.h"

static void pbvh_free_nodes(PBVH *bvh);

//#define PERFCNTRS

/* Bitmap */
typedef char* BLI_bitmap;

BLI_bitmap BLI_bitmap_new(int tot)
{
	return MEM_callocN((tot >> 3) + 1, "BLI bitmap");
}

int BLI_bitmap_get(BLI_bitmap b, int index)
{
	return b[index >> 3] & (1 << (index & 7));
}

void BLI_bitmap_set(BLI_bitmap b, int index)
{
	b[index >> 3] |= (1 << (index & 7));
}

void BLI_bitmap_clear(BLI_bitmap b, int index)
{
	b[index >> 3] &= ~(1 << (index & 7));
}

/* Axis-aligned bounding box */
typedef struct {
	float bmin[3], bmax[3];
} BB;

/* Axis-aligned bounding box with centroid */
typedef struct {
	float bmin[3], bmax[3], bcentroid[3];
} BBC;

struct PBVHNode {
	/* Opaque handle for drawing code */
	void *draw_buffers;

	int *vert_indices;

	/* Voxel bounds */
	BB vb;
	BB orig_vb;

	/* For internal nodes */
	int children_offset;

	/* Pointer into bvh prim_indices */
	int *prim_indices;
	int *face_vert_indices;

	unsigned int totprim;
	unsigned int uniq_verts, face_verts;

	char flag;

	float tmin; // used for raycasting, is how close bb is to the ray point

	int proxy_count;
	PBVHProxyNode* proxies;
};

struct PBVH {
	PBVHNode *nodes;
	int node_mem_count, totnode;

	int *prim_indices;
	int totprim;
	int totvert;

	int leaf_limit;

	/* Mesh data */
	MVert *verts;
	MFace *faces;

	/* Grid Data */
	DMGridData **grids;
	DMGridAdjacency *gridadj;
	void **gridfaces;
	int totgrid;
	int gridsize;
	struct GridKey *gridkey;
	struct GridToFace *grid_face_map;

	/* Used by both mesh and grid type */
	CustomData *vdata;

	/* For vertex paint */
	CustomData *fdata;

	/* Only used during BVH build and update,
	   don't need to remain valid after */
	BLI_bitmap vert_bitmap;

#ifdef PERFCNTRS
	int perf_modified;
#endif

	/* flag are verts/faces deformed */
	int deformed;
};

#define STACK_FIXED_DEPTH	100

typedef struct PBVHStack {
	PBVHNode *node;
	int revisiting;
} PBVHStack;

typedef struct PBVHIter {
	PBVH *bvh;
	BLI_pbvh_SearchCallback scb;
	void *search_data;

	PBVHStack *stack;
	int stacksize;

	PBVHStack stackfixed[STACK_FIXED_DEPTH];
	int stackspace;
} PBVHIter;

/* Test AABB against sphere */
int BLI_pbvh_search_sphere_cb(PBVHNode *node, void *data_v)
{
	PBVHSearchSphereData *data = data_v;
	float nearest[3];
	float t[3], bb_min[3], bb_max[3];
	int i;

	if(data->original)
		BLI_pbvh_node_get_original_BB(node, bb_min, bb_max);
	else
		BLI_pbvh_node_get_BB(node, bb_min, bb_max);
	
	for(i = 0; i < 3; ++i) {
		if(bb_min[i] > data->center[i])
			nearest[i] = bb_min[i];
		else if(bb_max[i] < data->center[i])
			nearest[i] = bb_max[i];
		else
			nearest[i] = data->center[i]; 
	}
	
	sub_v3_v3v3(t, data->center, nearest);

	return t[0] * t[0] + t[1] * t[1] + t[2] * t[2] < data->radius_squared;
}

/* Adapted from:
   http://www.gamedev.net/community/forums/topic.asp?topic_id=512123
   Returns true if the AABB is at least partially within the frustum
   (ok, not a real frustum), false otherwise.
*/
static int pbvh_planes_contain_AABB(float bb_min[3], float bb_max[3], float (*planes)[4])
{
	int i, axis;
	float vmin[3], vmax[3];

	for(i = 0; i < 4; ++i) { 
		for(axis = 0; axis < 3; ++axis) {
			if(planes[i][axis] > 0) { 
				vmin[axis] = bb_min[axis];
				vmax[axis] = bb_max[axis];
			}
			else {
				vmin[axis] = bb_max[axis];
				vmax[axis] = bb_min[axis];
			}
		}
		
		if(dot_v3v3(planes[i], vmin) + planes[i][3] > 0)
			return 0;
	} 

	return 1;
}

static void BB_reset(BB *bb)
{
	bb->bmin[0] = bb->bmin[1] = bb->bmin[2] = FLT_MAX;
	bb->bmax[0] = bb->bmax[1] = bb->bmax[2] = -FLT_MAX;
}

/* Expand the bounding box to include a new coordinate */
static void BB_expand(BB *bb, float co[3])
{
	int i;
	for(i = 0; i < 3; ++i) {
		bb->bmin[i] = MIN2(bb->bmin[i], co[i]);
		bb->bmax[i] = MAX2(bb->bmax[i], co[i]);
	}
}

/* Expand the bounding box to include another bounding box */
static void BB_expand_with_bb(BB *bb, BB *bb2)
{
	int i;
	for(i = 0; i < 3; ++i) {
		bb->bmin[i] = MIN2(bb->bmin[i], bb2->bmin[i]);
		bb->bmax[i] = MAX2(bb->bmax[i], bb2->bmax[i]);
	}
}

/* Return 0, 1, or 2 to indicate the widest axis of the bounding box */
static int BB_widest_axis(BB *bb)
{
	float dim[3];
	int i;

	for(i = 0; i < 3; ++i)
		dim[i] = bb->bmax[i] - bb->bmin[i];

	if(dim[0] > dim[1]) {
		if(dim[0] > dim[2])
			return 0;
		else
			return 2;
	}
	else {
		if(dim[1] > dim[2])
			return 1;
		else
			return 2;
	}
}

static void BBC_update_centroid(BBC *bbc)
{
	int i;
	for(i = 0; i < 3; ++i)
		bbc->bcentroid[i] = (bbc->bmin[i] + bbc->bmax[i]) * 0.5f;
}

/* Not recursive */
static void update_node_vb(PBVH *bvh, PBVHNode *node)
{
	BB vb;

	BB_reset(&vb);
	
	if(node->flag & PBVH_Leaf) {
		PBVHVertexIter vd;

		BLI_pbvh_vertex_iter_begin(bvh, node, vd, PBVH_ITER_ALL) {
			BB_expand(&vb, vd.co);
		}
		BLI_pbvh_vertex_iter_end;
	}
	else {
		BB_expand_with_bb(&vb,
				  &bvh->nodes[node->children_offset].vb);
		BB_expand_with_bb(&vb,
				  &bvh->nodes[node->children_offset + 1].vb);
	}

	node->vb= vb;
}

//void BLI_pbvh_node_BB_reset(PBVHNode* node)
//{
//	BB_reset(&node->vb);
//}
//
//void BLI_pbvh_node_BB_expand(PBVHNode* node, float co[3])
//{
//	BB_expand(&node->vb, co);
//}


/* Adapted from BLI_kdopbvh.c */
/* Returns the index of the first element on the right of the partition */
static int partition_indices(int *prim_indices, int lo, int hi, int axis,
				 float mid, BBC *prim_bbc)
{
	int i=lo, j=hi;
	for(;;) {
		for(; prim_bbc[prim_indices[i]].bcentroid[axis] < mid; i++);
		for(; mid < prim_bbc[prim_indices[j]].bcentroid[axis]; j--);
		
		if(!(i < j))
			return i;
		
		SWAP(int, prim_indices[i], prim_indices[j]);
		i++;
	}
}

void check_partitioning(int *prim_indices, int lo, int hi, int axis,
				   float mid, BBC *prim_bbc, int index_of_2nd_partition)
{
	int i;
	for(i = lo; i <= hi; ++i) {
		const float c = prim_bbc[prim_indices[i]].bcentroid[axis];

		if((i < index_of_2nd_partition && c > mid) ||
		   (i > index_of_2nd_partition && c < mid)) {
			printf("fail\n");
		}
	}
}

static void grow_nodes(PBVH *bvh, int totnode)
{
	if(totnode > bvh->node_mem_count) {
		PBVHNode *prev = bvh->nodes;
		bvh->node_mem_count *= 1.33;
		if(bvh->node_mem_count < totnode)
			bvh->node_mem_count = totnode;
		bvh->nodes = MEM_callocN(sizeof(PBVHNode) * bvh->node_mem_count,
					 "bvh nodes");
		memcpy(bvh->nodes, prev, bvh->totnode * sizeof(PBVHNode));
		MEM_freeN(prev);
	}

	bvh->totnode = totnode;
}

/* Add a vertex to the map, with a positive value for unique vertices and
   a negative value for additional vertices */
static int map_insert_vert(PBVH *bvh, GHash *map,
				unsigned int *face_verts,
				unsigned int *uniq_verts, int vertex)
{
	void *value, *key = SET_INT_IN_POINTER(vertex);

	if(!BLI_ghash_haskey(map, key)) {
		if(BLI_bitmap_get(bvh->vert_bitmap, vertex)) {
			value = SET_INT_IN_POINTER(-(*face_verts) - 1);
			++(*face_verts);
		}
		else {
			BLI_bitmap_set(bvh->vert_bitmap, vertex);
			value = SET_INT_IN_POINTER(*uniq_verts);
			++(*uniq_verts);
		}
		
		BLI_ghash_insert(map, key, value);
		return GET_INT_FROM_POINTER(value);
	}
	else
		return GET_INT_FROM_POINTER(BLI_ghash_lookup(map, key));
}

/* Find vertices used by the faces in this node and update the draw buffers */
static void build_mesh_leaf_node(PBVH *bvh, PBVHNode *node)
{
	GHashIterator *iter;
	GHash *map;
	int i, j, totface;

	map = BLI_ghash_new(BLI_ghashutil_inthash, BLI_ghashutil_intcmp, "build_mesh_leaf_node gh");
	
	node->uniq_verts = node->face_verts = 0;
	totface= node->totprim;

	node->face_vert_indices = MEM_callocN(sizeof(int) *
					 4*totface, "bvh node face vert indices");

	for(i = 0; i < totface; ++i) {
		MFace *f = bvh->faces + node->prim_indices[i];
		int sides = f->v4 ? 4 : 3;

		for(j = 0; j < sides; ++j) {
			node->face_vert_indices[i*4 + j]= 
				map_insert_vert(bvh, map, &node->face_verts,
						&node->uniq_verts, (&f->v1)[j]);
		}
	}

	node->vert_indices = MEM_callocN(sizeof(int) *
					 (node->uniq_verts + node->face_verts),
					 "bvh node vert indices");

	/* Build the vertex list, unique verts first */
	for(iter = BLI_ghashIterator_new(map), i = 0;
		!BLI_ghashIterator_isDone(iter);
		BLI_ghashIterator_step(iter), ++i) {
		void *value = BLI_ghashIterator_getValue(iter);
		int ndx = GET_INT_FROM_POINTER(value);

		if(ndx < 0)
			ndx = -ndx + node->uniq_verts - 1;

		node->vert_indices[ndx] =
			GET_INT_FROM_POINTER(BLI_ghashIterator_getKey(iter));
	}

	BLI_ghashIterator_free(iter);

	for(i = 0; i < totface*4; ++i)
		if(node->face_vert_indices[i] < 0)
			node->face_vert_indices[i]= -node->face_vert_indices[i] + node->uniq_verts - 1;

	if(!G.background) {
		node->draw_buffers =
			GPU_build_mesh_buffers(map, bvh->verts, bvh->faces,
				  bvh->vdata,
				  bvh->fdata,
				  node->prim_indices,
				  node->totprim, node->vert_indices,
				  node->uniq_verts,
				  node->uniq_verts + node->face_verts);
	}

	node->flag |= PBVH_UpdateVertBuffers|PBVH_UpdateColorBuffers;

	BLI_ghash_free(map, NULL, NULL);
}

static void build_grids_leaf_node(PBVH *bvh, PBVHNode *node)
{
	if(!G.background) {
		node->draw_buffers =
			GPU_build_grid_buffers(bvh->gridsize);
	}
	node->flag |= PBVH_UpdateVertBuffers|PBVH_UpdateColorBuffers;
}

/* Recursively build a node in the tree

   vb is the voxel box around all of the primitives contained in
   this node.

   cb is the bounding box around all the centroids of the primitives
   contained in this node

   offset and start indicate a range in the array of primitive indices
*/

void build_sub(PBVH *bvh, int node_index, BB *cb, BBC *prim_bbc,
		   int offset, int count)
{
	int i, axis, end;
	BB cb_backing;

	/* Decide whether this is a leaf or not */
	// XXX adapt leaf limit for grids
	if(count <= bvh->leaf_limit) {
		bvh->nodes[node_index].flag |= PBVH_Leaf;

		bvh->nodes[node_index].prim_indices = bvh->prim_indices + offset;
		bvh->nodes[node_index].totprim = count;

		/* Still need vb for searches */
		BB_reset(&bvh->nodes[node_index].vb);
		for(i = offset + count - 1; i >= offset; --i) {
			BB_expand_with_bb(&bvh->nodes[node_index].vb,
					  (BB*)(prim_bbc +
						bvh->prim_indices[i]));
		}
		
		if(bvh->faces)
			build_mesh_leaf_node(bvh, bvh->nodes + node_index);
		else
			build_grids_leaf_node(bvh, bvh->nodes + node_index);
		bvh->nodes[node_index].orig_vb= bvh->nodes[node_index].vb;

		/* Done with this subtree */
		return;
	}
	else {
		BB_reset(&bvh->nodes[node_index].vb);
		bvh->nodes[node_index].children_offset = bvh->totnode;
		grow_nodes(bvh, bvh->totnode + 2);

		if(!cb) {
			cb = &cb_backing;
			BB_reset(cb);
			for(i = offset + count - 1; i >= offset; --i)
				BB_expand(cb, prim_bbc[bvh->prim_indices[i]].bcentroid);
		}
	}

	axis = BB_widest_axis(cb);

	for(i = offset + count - 1; i >= offset; --i) {
		BB_expand_with_bb(&bvh->nodes[node_index].vb,
				  (BB*)(prim_bbc + bvh->prim_indices[i]));
	}

	bvh->nodes[node_index].orig_vb= bvh->nodes[node_index].vb;

	end = partition_indices(bvh->prim_indices, offset, offset + count - 1,
				axis,
				(cb->bmax[axis] + cb->bmin[axis]) * 0.5f,
				prim_bbc);
	check_partitioning(bvh->prim_indices, offset, offset + count - 1,
			   axis,
			   (cb->bmax[axis] + cb->bmin[axis]) * 0.5f,
			   prim_bbc, end);

	build_sub(bvh, bvh->nodes[node_index].children_offset, NULL,
		  prim_bbc, offset, end - offset);
	build_sub(bvh, bvh->nodes[node_index].children_offset + 1, NULL,
		  prim_bbc, end, offset + count - end);
}

/* Returns 0 if the primitive should be hidden, 1 otherwise */
static int test_prim_against_hidden_areas(BBC *prim_bbc, ListBase *hidden_areas)
{
	HiddenArea *area;

	for(area = hidden_areas->first; area; area = area->next) {
		int prim_inside_planes = pbvh_planes_contain_AABB(prim_bbc->bmin, prim_bbc->bmax, area->clip_planes);
		if((prim_inside_planes && area->hide_inside) || (!prim_inside_planes && !area->hide_inside))
			return 0;
	}

	return 1;
}

/* Initially, the root node contains all primitives in
   their original order.

   If we are clipping, exclude primitives outside the
   clip planes from the primitive list
*/
static int pbvh_initialize_prim_indices(PBVH *bvh, BBC *prim_bbc, int totprim, ListBase *hidden_areas)
{
	int prim, index;
	int *prim_indices;

	prim_indices = MEM_callocN(sizeof(int) * totprim, "bvh prim indices");

	for(prim= 0, index = 0; prim < totprim; ++prim) {
		if(!hidden_areas || test_prim_against_hidden_areas(&prim_bbc[prim], hidden_areas)) {
			prim_indices[index] = prim;
			++index;
		}
	}
	
	if(index == prim) {
		bvh->prim_indices = prim_indices;
		return totprim;
	}
	else {
		bvh->prim_indices = MEM_callocN(sizeof(int) * index, "bvh prim indices");
		memcpy(bvh->prim_indices, prim_indices, sizeof(int) * index);
		MEM_freeN(prim_indices);
		return index;
	}
}

static void pbvh_build(PBVH *bvh, BB *cb, BBC *prim_bbc, int totprim, ListBase *hidden_areas)
{
	int max_prim_index;

	if(totprim != bvh->totprim) {
		/* Initialize the nodes */
		bvh->totprim = totprim;
		if(bvh->nodes)
			pbvh_free_nodes(bvh);
		if(bvh->prim_indices) MEM_freeN(bvh->prim_indices);

		max_prim_index = pbvh_initialize_prim_indices(bvh, prim_bbc, totprim, hidden_areas);

		bvh->totnode = 0;
		if(bvh->node_mem_count < 100)
			bvh->node_mem_count = 100;

		bvh->nodes = MEM_callocN(sizeof(PBVHNode) *
					 bvh->node_mem_count,
					 "bvh initial nodes");
	}

	bvh->totnode = 1;
	build_sub(bvh, 0, cb, prim_bbc, 0, max_prim_index);
}

void pbvh_begin_build(PBVH *bvh, int totprim, ListBase *hidden_areas)
{
	int i, j;
	int totgridelem;
	BBC *prim_bbc;
	BB cb;

	/* cb will be the bounding box around all primitives' centroids */
	BB_reset(&cb);

	if(bvh->faces)
		bvh->vert_bitmap = BLI_bitmap_new(bvh->totvert);
	else
		totgridelem = bvh->gridsize*bvh->gridsize;

	/* For each primitive, store the AABB and the AABB centroid */
	prim_bbc = MEM_mallocN(sizeof(BBC) * totprim, "prim_bbc");

	for(i = 0; i < totprim; ++i) {
		BBC *bbc = prim_bbc + i;

		BB_reset((BB*)bbc);

		if(bvh->faces) {
			/* For regular mesh */
			MFace *f = bvh->faces + i;
			const int sides = f->v4 ? 4 : 3;
			for(j = 0; j < sides; ++j)
				BB_expand((BB*)bbc, bvh->verts[(&f->v1)[j]].co);
		}
		else {
			/* For multires */
			DMGridData *grid= bvh->grids[i];
			for(j = 0; j < totgridelem; ++j)
				BB_expand((BB*)bbc, GRIDELEM_CO_AT(grid, j, bvh->gridkey));
		}

		BBC_update_centroid(bbc);
		BB_expand(&cb, bbc->bcentroid);
	}

	pbvh_build(bvh, &cb, prim_bbc, totprim, hidden_areas);

	MEM_freeN(prim_bbc);
	if(bvh->faces)
		MEM_freeN(bvh->vert_bitmap);
}

/* Do a full rebuild with on Mesh data structure */
void BLI_pbvh_build_mesh(PBVH *bvh, MFace *faces, MVert *verts,
			 CustomData *vdata, CustomData *fdata,
			 int totface, int totvert,
			 ListBase *hidden_areas)
{
	bvh->faces = faces;
	bvh->verts = verts;
	bvh->vdata = vdata;
	bvh->fdata = fdata;
	bvh->totvert = totvert;

	if(totface)
		pbvh_begin_build(bvh, totface, hidden_areas);
}

/* Do a full rebuild with on Grids data structure */
void BLI_pbvh_build_grids(PBVH *bvh, DMGridData **grids,
			  DMGridAdjacency *gridadj,
			  int totgrid, int gridsize, GridKey *gridkey,
			  void **gridfaces, GridToFace *grid_face_map,
			  CustomData *vdata, CustomData *fdata,
			  ListBase *hidden_areas)
{
	bvh->grids= grids;
	bvh->gridadj= gridadj;
	bvh->gridfaces= gridfaces;
	bvh->totgrid= totgrid;
	bvh->gridsize= gridsize;
	bvh->gridkey= gridkey;
	bvh->vdata= vdata;
	bvh->fdata= fdata;
	bvh->leaf_limit = MAX2(bvh->leaf_limit/((gridsize-1)*(gridsize-1)), 1);
	bvh->grid_face_map = grid_face_map;

	if(totgrid)
		pbvh_begin_build(bvh, totgrid, hidden_areas);
}

PBVH *BLI_pbvh_new(int leaf_limit)
{
	PBVH *bvh = MEM_callocN(sizeof(PBVH), "pbvh");

	bvh->leaf_limit = leaf_limit;

	return bvh;
}

static void pbvh_free_nodes(PBVH *bvh)
{
	PBVHNode *node;
	int i;

	for(i = 0; i < bvh->totnode; ++i) {
		node= &bvh->nodes[i];

		if(node->flag & PBVH_Leaf) {
			if(node->draw_buffers)
				GPU_free_buffers(node->draw_buffers);
			if(node->vert_indices)
				MEM_freeN(node->vert_indices);
			if(node->face_vert_indices)
				MEM_freeN(node->face_vert_indices);
		}
	}

	if (bvh->deformed) {
		if (bvh->verts) {
			/* if pbvh was deformed, new memory was allocated for verts/faces -- free it */

			MEM_freeN(bvh->verts);
			MEM_freeN(bvh->faces);
		}
	}

	MEM_freeN(bvh->nodes);
}

void BLI_pbvh_free(PBVH *bvh)
{
	pbvh_free_nodes(bvh);

	MEM_freeN(bvh->prim_indices);
	MEM_freeN(bvh);
}

static void pbvh_iter_begin(PBVHIter *iter, PBVH *bvh, BLI_pbvh_SearchCallback scb, void *search_data)
{
	iter->bvh= bvh;
	iter->scb= scb;
	iter->search_data= search_data;

	iter->stack= iter->stackfixed;
	iter->stackspace= STACK_FIXED_DEPTH;

	iter->stack[0].node= bvh->nodes;
	iter->stack[0].revisiting= 0;
	iter->stacksize= 1;
}

static void pbvh_iter_end(PBVHIter *iter)
{
	if(iter->stackspace > STACK_FIXED_DEPTH)
		MEM_freeN(iter->stack);
}

static void pbvh_stack_push(PBVHIter *iter, PBVHNode *node, int revisiting)
{
	if(iter->stacksize == iter->stackspace) {
		PBVHStack *newstack;

		iter->stackspace *= 2;
		newstack= MEM_callocN(sizeof(PBVHStack)*iter->stackspace, "PBVHStack");
		memcpy(newstack, iter->stack, sizeof(PBVHStack)*iter->stacksize);

		if(iter->stackspace > STACK_FIXED_DEPTH)
			MEM_freeN(iter->stack);
		iter->stack= newstack;
	}

	iter->stack[iter->stacksize].node= node;
	iter->stack[iter->stacksize].revisiting= revisiting;
	iter->stacksize++;
}

static PBVHNode *pbvh_iter_next(PBVHIter *iter)
{
	PBVHNode *node;
	int revisiting;

	/* purpose here is to traverse tree, visiting child nodes before their
	   parents, this order is necessary for e.g. computing bounding boxes */

	while(iter->stacksize) {
                /* pop node */
		iter->stacksize--;
		node= iter->stack[iter->stacksize].node;

		/* on a mesh with no faces this can happen
		 * can remove this check if we know meshes have at least 1 face */
		if(node==NULL)
			return NULL;

		revisiting= iter->stack[iter->stacksize].revisiting;

		/* revisiting node already checked */
		if(revisiting)
			return node;

		if(iter->scb && !iter->scb(node, iter->search_data))
			continue; /* don't traverse, outside of search zone */

		if(node->flag & PBVH_Leaf) {
			/* immediately hit leaf node */
			return node;
		}
		else {
			/* come back later when children are done */
			pbvh_stack_push(iter, node, 1);

			/* push two child nodes on the stack */
			pbvh_stack_push(iter, iter->bvh->nodes+node->children_offset+1, 0);
			pbvh_stack_push(iter, iter->bvh->nodes+node->children_offset, 0);
		}
	}

	return NULL;
}

static PBVHNode *pbvh_iter_next_occluded(PBVHIter *iter)
{
    PBVHNode *node;

    while(iter->stacksize) {
        /* pop node */
        iter->stacksize--;
        node= iter->stack[iter->stacksize].node;

        /* on a mesh with no faces this can happen
        * can remove this check if we know meshes have at least 1 face */
        if(node==NULL) return NULL;

        if(iter->scb && !iter->scb(node, iter->search_data)) continue; /* don't traverse, outside of search zone */

        if(node->flag & PBVH_Leaf) {
            /* immediately hit leaf node */
            return node;
        }
        else {
            pbvh_stack_push(iter, iter->bvh->nodes+node->children_offset+1, 0);
            pbvh_stack_push(iter, iter->bvh->nodes+node->children_offset, 0);
        }
    }

    return NULL;
}

void BLI_pbvh_search_gather(PBVH *bvh,
	BLI_pbvh_SearchCallback scb, void *search_data,
	PBVHNode ***r_array, int *r_tot)
{
	PBVHIter iter;
	PBVHNode **array= NULL, **newarray, *node;
	int tot= 0, space= 0;

	pbvh_iter_begin(&iter, bvh, scb, search_data);

	while((node=pbvh_iter_next(&iter))) {
		if(node->flag & PBVH_Leaf) {
			if(tot == space) {
				/* resize array if needed */
				space= (tot == 0)? 32: space*2;
				newarray= MEM_callocN(sizeof(PBVHNode)*space, "PBVHNodeSearch");

				if(array) {
					memcpy(newarray, array, sizeof(PBVHNode)*tot);
					MEM_freeN(array);
				}

				array= newarray;
			}

			array[tot]= node;
			tot++;
		}
	}

	pbvh_iter_end(&iter);

	if(tot == 0 && array) {
		MEM_freeN(array);
		array= NULL;
	}

	*r_array= array;
	*r_tot= tot;
}

void BLI_pbvh_search_callback(PBVH *bvh,
	BLI_pbvh_SearchCallback scb, void *search_data,
	BLI_pbvh_HitCallback hcb, void *hit_data)
{
	PBVHIter iter;
	PBVHNode *node;

	pbvh_iter_begin(&iter, bvh, scb, search_data);

	while((node=pbvh_iter_next(&iter)))
		if (node->flag & PBVH_Leaf)
			hcb(node, hit_data);

	pbvh_iter_end(&iter);
}

typedef struct node_tree {
    PBVHNode* data;

    struct node_tree* left;
    struct node_tree* right;
} node_tree;

static void node_tree_insert(node_tree* tree, node_tree* new_node)
{
    if (new_node->data->tmin < tree->data->tmin) {
        if (tree->left) {
            node_tree_insert(tree->left, new_node);
        }
        else {
            tree->left = new_node;
        }
    }
    else {
        if (tree->right) {
            node_tree_insert(tree->right, new_node);
        }
        else {
            tree->right = new_node;
        }
    }
}

static void traverse_tree(node_tree* tree, BLI_pbvh_HitOccludedCallback hcb, void* hit_data, float* tmin)
{
    if (tree->left) traverse_tree(tree->left, hcb, hit_data, tmin);

    hcb(tree->data, hit_data, tmin);

    if (tree->right) traverse_tree(tree->right, hcb, hit_data, tmin);
}

static void free_tree(node_tree* tree)
{
    if (tree->left) {
        free_tree(tree->left);
        tree->left = 0;
    }

    if (tree->right) {
        free_tree(tree->right);
        tree->right = 0;
    }

    free(tree);
}

float BLI_pbvh_node_get_tmin(PBVHNode* node)
{
    return node->tmin;
}

void BLI_pbvh_search_callback_occluded(PBVH *bvh,
	BLI_pbvh_SearchCallback scb, void *search_data,
	BLI_pbvh_HitOccludedCallback hcb, void *hit_data)
{
	PBVHIter iter;
	PBVHNode *node;
	node_tree *tree = 0;

	pbvh_iter_begin(&iter, bvh, scb, search_data);

	while((node=pbvh_iter_next_occluded(&iter))) {
		if(node->flag & PBVH_Leaf) {
			node_tree* new_node = malloc(sizeof(node_tree));

			new_node->data = node;

			new_node->left  = NULL;
			new_node->right = NULL;

			if (tree) {
				node_tree_insert(tree, new_node);
			}
			else {
				tree = new_node;
			}
		}
	}

	pbvh_iter_end(&iter);

	if (tree) {
		float tmin = FLT_MAX;
		traverse_tree(tree, hcb, hit_data, &tmin);
		free_tree(tree);
	}
}

static int update_search_cb(PBVHNode *node, void *data_v)
{
	int flag= GET_INT_FROM_POINTER(data_v);

	if(node->flag & PBVH_Leaf)
		return (node->flag & flag);
	
	return 1;
}

static void pbvh_update_normals(PBVH *bvh, PBVHNode **nodes,
	int totnode, float (*face_nors)[3])
{
	float (*vnor)[3];
	int n;

	if(bvh->grids)
		return;

	/* could be per node to save some memory, but also means
	   we have to store for each vertex which node it is in */
	vnor= MEM_callocN(sizeof(float)*3*bvh->totvert, "bvh temp vnors");

	/* subtle assumptions:
	   - We know that for all edited vertices, the nodes with faces
		 adjacent to these vertices have been marked with PBVH_UpdateNormals.
		 This is true because if the vertex is inside the brush radius, the
		 bounding box of it's adjacent faces will be as well.
	   - However this is only true for the vertices that have actually been
		 edited, not for all vertices in the nodes marked for update, so we
		 can only update vertices marked with ME_VERT_PBVH_UPDATE.
	*/

	#pragma omp parallel for private(n) schedule(static)
	for(n = 0; n < totnode; n++) {
		PBVHNode *node= nodes[n];

		if((node->flag & PBVH_UpdateNormals)) {
			int i, j, totface, *faces;

			faces= node->prim_indices;
			totface= node->totprim;

			for(i = 0; i < totface; ++i) {
				MFace *f= bvh->faces + faces[i];
				float fn[3];
				unsigned int *fv = &f->v1;
				int sides= (f->v4)? 4: 3;

				if(f->v4)
					normal_quad_v3(fn, bvh->verts[f->v1].co, bvh->verts[f->v2].co,
								   bvh->verts[f->v3].co, bvh->verts[f->v4].co);
				else
					normal_tri_v3(fn, bvh->verts[f->v1].co, bvh->verts[f->v2].co,
								  bvh->verts[f->v3].co);

				for(j = 0; j < sides; ++j) {
					int v= fv[j];

					if(bvh->verts[v].flag & ME_VERT_PBVH_UPDATE) {
						/* this seems like it could be very slow but profile
						   does not show this, so just leave it for now? */
						#pragma omp atomic
						vnor[v][0] += fn[0];
						#pragma omp atomic
						vnor[v][1] += fn[1];
						#pragma omp atomic
						vnor[v][2] += fn[2];
					}
				}

				if(face_nors)
					copy_v3_v3(face_nors[faces[i]], fn);
			}
		}
	}

	#pragma omp parallel for private(n) schedule(static)
	for(n = 0; n < totnode; n++) {
		PBVHNode *node= nodes[n];

		if(node->flag & PBVH_UpdateNormals) {
			int i, *verts, totvert;

			verts= node->vert_indices;
			totvert= node->uniq_verts;

			for(i = 0; i < totvert; ++i) {
				const int v = verts[i];
				MVert *mvert= &bvh->verts[v];

				if(mvert->flag & ME_VERT_PBVH_UPDATE) {
					float no[3];

					copy_v3_v3(no, vnor[v]);
					normalize_v3(no);
					
					mvert->no[0] = (short)(no[0]*32767.0f);
					mvert->no[1] = (short)(no[1]*32767.0f);
					mvert->no[2] = (short)(no[2]*32767.0f);
					
					mvert->flag &= ~ME_VERT_PBVH_UPDATE;
				}
			}

			node->flag &= ~PBVH_UpdateNormals;
		}
	}

	MEM_freeN(vnor);
}

static void pbvh_update_BB_redraw(PBVH *bvh, PBVHNode **nodes,
	int totnode, int flag)
{
	int n;

	/* update BB, redraw flag */
	#pragma omp parallel for private(n) schedule(static)
	for(n = 0; n < totnode; n++) {
		PBVHNode *node= nodes[n];

		if((flag & PBVH_UpdateBB) && (node->flag & PBVH_UpdateBB))
			/* don't clear flag yet, leave it for flushing later */
			update_node_vb(bvh, node);

		if((flag & PBVH_UpdateOriginalBB) && (node->flag & PBVH_UpdateOriginalBB))
			node->orig_vb= node->vb;

		if((flag & PBVH_UpdateRedraw) && (node->flag & PBVH_UpdateRedraw))
			node->flag &= ~PBVH_UpdateRedraw;
	}
}

static void pbvh_update_draw_buffers(PBVH *bvh, PBVHNode **nodes, int totnode, DMDrawFlags flags)
{
	PBVHNode *node;
	int n;

	/* can't be done in parallel with OpenGL */
	for(n = 0; n < totnode; n++) {
		node= nodes[n];

		if(node->flag & PBVH_UpdateVertBuffers) {
			if(bvh->grids) {
				GPU_update_grid_vert_buffers(node->draw_buffers,
							     bvh->grids,
							     node->prim_indices,
							     node->totprim,
							     bvh->gridsize,
							     bvh->gridkey,
							     flags & DM_DRAW_FULLY_SMOOTH);
			}
			else {
				GPU_update_mesh_vert_buffers(node->draw_buffers,
							     bvh->verts,
							     node->vert_indices,
							     node->uniq_verts +
							     node->face_verts);
			}

			node->flag &= ~PBVH_UpdateVertBuffers;
		}
		
		if(node->flag & PBVH_UpdateColorBuffers) {
			if(bvh->grids) {
				if(flags & DM_DRAW_PTEX) {
					GPU_update_ptex(node->draw_buffers, bvh, node);
					/* TODO: should only do this after ptex
					   res change */
					GPU_update_grid_uv_buffer(node->draw_buffers,
								  bvh, node, flags);
				}
				else if(flags & DM_DRAW_PAINT_MASK) {
					GPU_update_grid_color_buffers(node->draw_buffers,
								      bvh->grids,
								      node->prim_indices,
								      node->totprim,
								      bvh->gridsize,
								      bvh->gridkey,
								      bvh->vdata,
								      flags);
				}
			}
			else {
				if(flags & DM_DRAW_PAINT_MASK) {
					GPU_update_mesh_color_buffers(node->draw_buffers,
								      bvh, node, flags);
				}
			}

			node->flag &= ~PBVH_UpdateColorBuffers;
		}
	}
}

static int pbvh_flush_bb(PBVH *bvh, PBVHNode *node, int flag)
{
	int update= 0;

	/* difficult to multithread well, we just do single threaded recursive */
	if(node->flag & PBVH_Leaf) {
		if(flag & PBVH_UpdateBB) {
			update |= (node->flag & PBVH_UpdateBB);
			node->flag &= ~PBVH_UpdateBB;
		}

		if(flag & PBVH_UpdateOriginalBB) {
			update |= (node->flag & PBVH_UpdateOriginalBB);
			node->flag &= ~PBVH_UpdateOriginalBB;
		}

		return update;
	}
	else {
		update |= pbvh_flush_bb(bvh, bvh->nodes + node->children_offset, flag);
		update |= pbvh_flush_bb(bvh, bvh->nodes + node->children_offset + 1, flag);

		if(update & PBVH_UpdateBB)
			update_node_vb(bvh, node);
		if(update & PBVH_UpdateOriginalBB)
			node->orig_vb= node->vb;
	}

	return update;
}

void BLI_pbvh_update(PBVH *bvh, int flag, float (*face_nors)[3])
{
	PBVHNode **nodes;
	int totnode;

	BLI_pbvh_search_gather(bvh, update_search_cb, SET_INT_IN_POINTER(flag),
		&nodes, &totnode);

	if(flag & PBVH_UpdateNormals)
		pbvh_update_normals(bvh, nodes, totnode, face_nors);

	if(flag & (PBVH_UpdateBB|PBVH_UpdateOriginalBB|PBVH_UpdateRedraw))
		pbvh_update_BB_redraw(bvh, nodes, totnode, flag);

	if(flag & (PBVH_UpdateBB|PBVH_UpdateOriginalBB))
		pbvh_flush_bb(bvh, bvh->nodes, flag);

	if(nodes) MEM_freeN(nodes);
}

/* get the object-space bounding box containing all the nodes that
   have been marked with PBVH_UpdateRedraw */
void BLI_pbvh_redraw_BB(PBVH *bvh, float bb_min[3], float bb_max[3])
{
	PBVHIter iter;
	PBVHNode *node;
	BB bb;

	BB_reset(&bb);

	pbvh_iter_begin(&iter, bvh, NULL, NULL);

	while((node=pbvh_iter_next(&iter)))
		if(node->flag & PBVH_UpdateRedraw)
			BB_expand_with_bb(&bb, &node->vb);

	pbvh_iter_end(&iter);

	copy_v3_v3(bb_min, bb.bmin);
	copy_v3_v3(bb_max, bb.bmax);
}

void BLI_pbvh_get_grid_updates(PBVH *bvh, int clear, void ***gridfaces, int *totface)
{
	PBVHIter iter;
	PBVHNode *node;
	GHashIterator *hiter;
	GHash *map;
	void *face, **faces;
	unsigned i;
        int tot;

	map = BLI_ghash_new(BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "pbvh_get_grid_updates gh");

	pbvh_iter_begin(&iter, bvh, NULL, NULL);

	while((node=pbvh_iter_next(&iter))) {
		if(node->flag & (PBVH_UpdateNormals)) {
			for(i = 0; i < node->totprim; ++i) {
				face= bvh->gridfaces[node->prim_indices[i]];
				if(!BLI_ghash_lookup(map, face))
					BLI_ghash_insert(map, face, face);
			}

			if(clear)
				node->flag &= ~PBVH_UpdateNormals;
		}
	}

	pbvh_iter_end(&iter);
	
	tot= BLI_ghash_size(map);
	if(tot == 0) {
		*totface= 0;
		*gridfaces= NULL;
		BLI_ghash_free(map, NULL, NULL);
		return;
	}

	faces= MEM_callocN(sizeof(void*)*tot, "PBVH Grid Faces");

	for(hiter = BLI_ghashIterator_new(map), i = 0;
		!BLI_ghashIterator_isDone(hiter);
		BLI_ghashIterator_step(hiter), ++i)
		faces[i]= BLI_ghashIterator_getKey(hiter);

	BLI_ghashIterator_free(hiter);

	BLI_ghash_free(map, NULL, NULL);

	*totface= tot;
	*gridfaces= faces;
}

/**** Access to mesh/grid data ****/
int BLI_pbvh_uses_grids(PBVH *bvh)
{
	return !!bvh->grids;
}

void BLI_pbvh_get_customdata(PBVH *bvh, CustomData **vdata, CustomData **fdata)
{
	if(vdata) *vdata = bvh->vdata;
	if(fdata) *fdata = bvh->fdata;
}

GridToFace *BLI_pbvh_get_grid_face_map(PBVH *pbvh)
{
	return pbvh->grid_face_map;
}


/***************************** Node Access ***********************************/

void BLI_pbvh_node_mark_update(PBVHNode *node)
{
	node->flag |= PBVH_UpdateNormals|PBVH_UpdateBB|PBVH_UpdateOriginalBB|PBVH_UpdateVertBuffers|PBVH_UpdateRedraw;
}

void BLI_pbvh_node_set_flags(PBVHNode *node, void *data)
{
	node->flag |= GET_INT_FROM_POINTER(data);
}

void BLI_pbvh_node_get_verts(PBVH *bvh, PBVHNode *node, int **vert_indices, MVert **verts)
{
	if(vert_indices) *vert_indices= node->vert_indices;
	if(verts) *verts= bvh->verts;
}

void BLI_pbvh_node_num_verts(PBVH *bvh, PBVHNode *node, int *uniquevert, int *totvert)
{
	if(bvh->grids) {
		if(totvert) *totvert= node->totprim*bvh->gridsize*bvh->gridsize;
		if(uniquevert) *uniquevert= node->totprim*bvh->gridsize*bvh->gridsize;
	}
	else {
		if(totvert) *totvert= node->uniq_verts + node->face_verts;
		if(uniquevert) *uniquevert= node->uniq_verts;
	}
}

void BLI_pbvh_node_get_faces(PBVH *bvh, PBVHNode *node,
			     MFace **mface,
			     int **face_indices, int **face_vert_indices,
			     int *totnode)
{
	if(bvh->grids) {
		if(mface) *mface= NULL;
		if(face_indices) *face_indices= NULL;
		if(face_vert_indices) *face_vert_indices= NULL;
		if(totnode) *totnode= 0;
	}
	else {
		if(mface) *mface= bvh->faces;
		if(face_indices) *face_indices= node->prim_indices;
		if(face_vert_indices) *face_vert_indices= node->face_vert_indices;
		if(totnode) *totnode= node->totprim;
	}
}

void BLI_pbvh_node_get_grids(PBVH *bvh, PBVHNode *node, int **grid_indices, int *totgrid, int *maxgrid, int *gridsize, DMGridData ***griddata, DMGridAdjacency **gridadj, GridKey **gridkey)
{
	if(bvh->grids) {
		if(grid_indices) *grid_indices= node->prim_indices;
		if(totgrid) *totgrid= node->totprim;
		if(maxgrid) *maxgrid= bvh->totgrid;
		if(gridsize) *gridsize= bvh->gridsize;
		if(griddata) *griddata= bvh->grids;
		if(gridadj) *gridadj= bvh->gridadj;
		if(gridkey) *gridkey= bvh->gridkey;
	}
	else {
		if(grid_indices) *grid_indices= NULL;
		if(totgrid) *totgrid= 0;
		if(maxgrid) *maxgrid= 0;
		if(gridsize) *gridsize= 0;
		if(griddata) *griddata= NULL;
		if(gridadj) *gridadj= NULL;
		if(gridkey) *gridkey= NULL;
	}
}

void BLI_pbvh_node_get_BB(PBVHNode *node, float bb_min[3], float bb_max[3])
{
	copy_v3_v3(bb_min, node->vb.bmin);
	copy_v3_v3(bb_max, node->vb.bmax);
}

void BLI_pbvh_node_get_original_BB(PBVHNode *node, float bb_min[3], float bb_max[3])
{
	copy_v3_v3(bb_min, node->orig_vb.bmin);
	copy_v3_v3(bb_max, node->orig_vb.bmax);
}

void BLI_pbvh_node_get_proxies(PBVHNode* node, PBVHProxyNode** proxies, int* proxy_count)
{
	if (node->proxy_count > 0) {
		if (proxies) *proxies = node->proxies;
		if (proxy_count) *proxy_count = node->proxy_count;
	}
	else {
		if (proxies) *proxies = 0;
		if (proxy_count) *proxy_count = 0;
	}
}

/********************************* Raycast ***********************************/

typedef struct {
	/* Ray */
	float start[3];
	int sign[3];
	float inv_dir[3];
	int original;
} RaycastData;

/* Adapted from here: http://www.gamedev.net/community/forums/topic.asp?topic_id=459973 */
static int ray_aabb_intersect(PBVHNode *node, void *data_v)
{
	RaycastData *ray = data_v;
	float bbox[2][3];
	float tmin, tmax, tymin, tymax, tzmin, tzmax;

	if(ray->original)
		BLI_pbvh_node_get_original_BB(node, bbox[0], bbox[1]);
	else
		BLI_pbvh_node_get_BB(node, bbox[0], bbox[1]);

	tmin = (bbox[ray->sign[0]][0] - ray->start[0]) * ray->inv_dir[0];
	tmax = (bbox[1-ray->sign[0]][0] - ray->start[0]) * ray->inv_dir[0];

	tymin = (bbox[ray->sign[1]][1] - ray->start[1]) * ray->inv_dir[1];
	tymax = (bbox[1-ray->sign[1]][1] - ray->start[1]) * ray->inv_dir[1];

	if((tmin > tymax) || (tymin > tmax))
		return 0;

	if(tymin > tmin)
		tmin = tymin;

	if(tymax < tmax)
		tmax = tymax;

	tzmin = (bbox[ray->sign[2]][2] - ray->start[2]) * ray->inv_dir[2];
	tzmax = (bbox[1-ray->sign[2]][2] - ray->start[2]) * ray->inv_dir[2];

	if((tmin > tzmax) || (tzmin > tmax))
		return 0;

	if(tzmin > tmin)
		tmin = tzmin;

	// XXX jwilkins: tmax does not need to be updated since we don't use it
	// keeping this here for future reference
	//if(tzmax < tmax) tmax = tzmax; 

	node->tmin = tmin;

	return 1;
}

void BLI_pbvh_raycast(PBVH *bvh, BLI_pbvh_HitOccludedCallback cb, void *data,
			  float ray_start[3], float ray_normal[3], int original)
{
	RaycastData rcd;

	copy_v3_v3(rcd.start, ray_start);
	rcd.inv_dir[0] = 1.0f / ray_normal[0];
	rcd.inv_dir[1] = 1.0f / ray_normal[1];
	rcd.inv_dir[2] = 1.0f / ray_normal[2];
	rcd.sign[0] = rcd.inv_dir[0] < 0;
	rcd.sign[1] = rcd.inv_dir[1] < 0;
	rcd.sign[2] = rcd.inv_dir[2] < 0;
	rcd.original = original;

	BLI_pbvh_search_callback_occluded(bvh, ray_aabb_intersect, &rcd, cb, data);
}

static int ray_face_intersection(float ray_start[3], float ray_normal[3],
				 float *t0, float *t1, float *t2, float *t3,
				 float *fdist)
{
    float dist;

    if ((isect_ray_tri_epsilon_v3(ray_start, ray_normal, t0, t1, t2, &dist, NULL, 0.1f) && dist < *fdist) ||
        (t3 && isect_ray_tri_epsilon_v3(ray_start, ray_normal, t0, t2, t3, &dist, NULL, 0.1f) && dist < *fdist))
    {
        *fdist = dist;
        return 1;
    }
    else {
        return 0;
    }
}

int BLI_pbvh_node_raycast(PBVH *bvh, PBVHNode *node, float (*origco)[3],
			  float ray_start[3], float ray_normal[3], float *dist,
			  int *hit_index, int *grid_hit_index)
{
	int hit= 0;

	if(hit_index) *hit_index = -1;
	if(grid_hit_index) *grid_hit_index = -1;

	if(bvh->faces) {
		MVert *vert = bvh->verts;
		int *faces= node->prim_indices;
		int *face_verts= node->face_vert_indices;
		int totface= node->totprim;
		int i;

		for(i = 0; i < totface; ++i) {
			MFace *f = bvh->faces + faces[i];
			int lhit = 0;

			if(origco) {
				/* intersect with backuped original coordinates */
				lhit = ray_face_intersection(ray_start, ray_normal,
							 origco[face_verts[i*4+0]],
							 origco[face_verts[i*4+1]],
							 origco[face_verts[i*4+2]],
							 f->v4? origco[face_verts[i*4+3]]: NULL,
							 dist);
			}
			else {
				/* intersect with current coordinates */
				lhit = ray_face_intersection(ray_start, ray_normal,
							 vert[f->v1].co,
							 vert[f->v2].co,
							 vert[f->v3].co,
							 f->v4 ? vert[f->v4].co : NULL,
							 dist);
			}

			if(lhit && hit_index)
				*hit_index = i;

			hit |= lhit;
		}
	}
	else {
		int totgrid= node->totprim;
		int gridsize= bvh->gridsize;
		int i, x, y;

		for(i = 0; i < totgrid; ++i) {
			DMGridData *grid= bvh->grids[node->prim_indices[i]];

			if (!grid)
				continue;

			for(y = 0; y < gridsize-1; ++y) {
				for(x = 0; x < gridsize-1; ++x) {
					int lhit = 0;

					if(origco) {
						lhit |= ray_face_intersection(ray_start, ray_normal,
									 origco[y*gridsize + x],
									 origco[y*gridsize + x+1],
									 origco[(y+1)*gridsize + x+1],
									 origco[(y+1)*gridsize + x],
									 dist);
					}
					else {
						lhit |= ray_face_intersection(ray_start, ray_normal,
									 GRIDELEM_CO_AT(grid, y*gridsize + x, bvh->gridkey),
									 GRIDELEM_CO_AT(grid, y*gridsize + x+1, bvh->gridkey),
									 GRIDELEM_CO_AT(grid, (y+1)*gridsize + x+1, bvh->gridkey),
									 GRIDELEM_CO_AT(grid, (y+1)*gridsize + x, bvh->gridkey),
									 dist);
					}

					if(lhit) {
						if(hit_index) *hit_index = i;
						if(grid_hit_index) *grid_hit_index = y*gridsize + x;
					}

					hit |= lhit;
				}
			}

			if(origco)
				origco += gridsize*gridsize;
		}
	}

	return hit;
}

//#include <GL/glew.h>

typedef struct {
	PBVH *pbvh;
	DMDrawFlags flags;
} PBVHDrawData;

void BLI_pbvh_node_draw(PBVHNode *node, void *data_v)
{
#if 0
	/* XXX: Just some quick code to show leaf nodes in different colors */
	float col[3]; int i;

	if(0) { //is_partial) {
		col[0] = (rand() / (float)RAND_MAX); col[1] = col[2] = 0.6;
	}
	else {
		srand((long long)node);
		for(i = 0; i < 3; ++i)
			col[i] = (rand() / (float)RAND_MAX) * 0.3 + 0.7;
	}
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, col);

	glColor3f(1, 0, 0);
#endif

	PBVHDrawData *data = data_v;
	GPU_draw_buffers(node->draw_buffers, data->pbvh, node, data->flags);
}

int BLI_pbvh_node_planes_contain_AABB(PBVHNode *node, void *data)
{
	float bb_min[3], bb_max[3];

	BLI_pbvh_node_get_BB(node, bb_min, bb_max);

	return pbvh_planes_contain_AABB(bb_min, bb_max, data);
}

void BLI_pbvh_draw(PBVH *bvh, float (*planes)[4], float (*face_nors)[3], int flags)
{
	PBVHNode **nodes;
	PBVHDrawData draw_data = {bvh, flags};
	int totnode;

	BLI_pbvh_search_gather(bvh, update_search_cb,
			       SET_INT_IN_POINTER(PBVH_UpdateNormals|PBVH_UpdateVertBuffers|PBVH_UpdateColorBuffers),
		&nodes, &totnode);

	pbvh_update_normals(bvh, nodes, totnode, face_nors);
	pbvh_update_draw_buffers(bvh, nodes, totnode, flags);

	if(nodes) MEM_freeN(nodes);

	if(planes) {
		BLI_pbvh_search_callback(bvh, BLI_pbvh_node_planes_contain_AABB,
				planes, BLI_pbvh_node_draw, &draw_data);
	}
	else {
		BLI_pbvh_search_callback(bvh, NULL, NULL, BLI_pbvh_node_draw, &draw_data);
	}
}

void BLI_pbvh_grids_update(PBVH *bvh, DMGridData **grids,
			   DMGridAdjacency *gridadj, void **gridfaces,
			   struct GridKey *gridkey)
{
	bvh->grids= grids;
	bvh->gridadj= gridadj;
	bvh->gridfaces= gridfaces;
	bvh->gridkey= gridkey;
}

float (*BLI_pbvh_get_vertCos(PBVH *pbvh))[3]
{
	int a;
	float (*vertCos)[3]= NULL;

	if (pbvh->verts) {
		float *co;
		MVert *mvert= pbvh->verts;

		vertCos= MEM_callocN(3*pbvh->totvert*sizeof(float), "BLI_pbvh_get_vertCoords");
		co= (float*)vertCos;

		for (a= 0; a<pbvh->totvert; a++, mvert++, co+= 3) {
			copy_v3_v3(co, mvert->co);
		}
	}

	return vertCos;
}

void BLI_pbvh_apply_vertCos(PBVH *pbvh, float (*vertCos)[3])
{
	int a;

	if (!pbvh->deformed) {
		if (pbvh->verts) {
			/* if pbvh is not already deformed, verts/faces points to the */
			/* original data and applying new coords to this arrays would lead to */
			/* unneeded deformation -- duplicate verts/faces to avoid this */

			pbvh->verts= MEM_dupallocN(pbvh->verts);
			pbvh->faces= MEM_dupallocN(pbvh->faces);

			pbvh->deformed= 1;
		}
	}

	if (pbvh->verts) {
		/* copy new verts coords */
		for (a= 0; a < pbvh->totvert; ++a) {
			copy_v3_v3(pbvh->verts[a].co, vertCos[a]);
		}

		/* coordinates are new -- normals should also be updated */
		mesh_calc_normals(pbvh->verts, pbvh->totvert, pbvh->faces, pbvh->totprim, NULL);
	}
}

int BLI_pbvh_isDeformed(PBVH *pbvh)
{
	return pbvh->deformed;
}
/* Proxies */

PBVHProxyNode* BLI_pbvh_node_add_proxy(PBVH* bvh, PBVHNode* node)
{
	int index, totverts;

	#pragma omp critical
	{

		index = node->proxy_count;

		node->proxy_count++;

		if (node->proxies)
			node->proxies= MEM_reallocN(node->proxies, node->proxy_count*sizeof(PBVHProxyNode));
		else
			node->proxies= MEM_mallocN(sizeof(PBVHProxyNode), "PBVHNodeProxy");

		if (bvh->grids)
			totverts = node->totprim*bvh->gridsize*bvh->gridsize;
		else
			totverts = node->uniq_verts;

		node->proxies[index].co= MEM_callocN(sizeof(float[3])*totverts, "PBVHNodeProxy.co");
	}

	return node->proxies + index;
}

void BLI_pbvh_node_free_proxies(PBVHNode* node)
{
	#pragma omp critical
	{
		int p;

		for (p= 0; p < node->proxy_count; p++) {
			MEM_freeN(node->proxies[p].co);
			node->proxies[p].co= 0;
		}

		MEM_freeN(node->proxies);
		node->proxies = 0;

		node->proxy_count= 0;
	}
}

void BLI_pbvh_gather_proxies(PBVH* pbvh, PBVHNode*** r_array,  int* r_tot)
{
	PBVHNode **array= NULL, **newarray, *node;
	int tot= 0, space= 0;
	int n;

	for (n= 0; n < pbvh->totnode; n++) {
		node = pbvh->nodes + n;

		if(node->proxy_count > 0) {
			if(tot == space) {
				/* resize array if needed */
				space= (tot == 0)? 32: space*2;
				newarray= MEM_callocN(sizeof(PBVHNode)*space, "BLI_pbvh_gather_proxies");

				if (array) {
					memcpy(newarray, array, sizeof(PBVHNode)*tot);
					MEM_freeN(array);
				}

				array= newarray;
			}

			array[tot]= node;
			tot++;
		}
	}

	if(tot == 0 && array) {
		MEM_freeN(array);
		array= NULL;
	}

	*r_array= array;
	*r_tot= tot;
}