rayobject_blibvh.cpp

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/*
 * ***** 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.
 *
 * The Original Code is Copyright (C) 2009 Blender Foundation.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): André Pinto.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#include <assert.h>

#include "MEM_guardedalloc.h"

#include "BLI_kdopbvh.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "rayintersection.h"
#include "rayobject.h"

static int  RE_rayobject_blibvh_intersect(RayObject *o, Isect *isec);
static void RE_rayobject_blibvh_add(RayObject *o, RayObject *ob);
static void RE_rayobject_blibvh_done(RayObject *o);
static void RE_rayobject_blibvh_free(RayObject *o);
static void RE_rayobject_blibvh_bb(RayObject *o, float *min, float *max);

static float RE_rayobject_blibvh_cost(RayObject *UNUSED(o))
{
    //TODO calculate the expected cost to raycast on this structure
    return 1.0;
}

static void RE_rayobject_blibvh_hint_bb(RayObject *UNUSED(o), RayHint *UNUSED(hint),
                                        float *UNUSED(min), float *UNUSED(max))
{
    return;
}

static RayObjectAPI bvh_api =
{
    RE_rayobject_blibvh_intersect,
    RE_rayobject_blibvh_add,
    RE_rayobject_blibvh_done,
    RE_rayobject_blibvh_free,
    RE_rayobject_blibvh_bb,
    RE_rayobject_blibvh_cost,
    RE_rayobject_blibvh_hint_bb
};

typedef struct BVHObject
{
    RayObject rayobj;
    RayObject **leafs, **next_leaf;
    BVHTree *bvh;
    float bb[2][3];
} BVHObject;

RayObject *RE_rayobject_blibvh_create(int size)
{
    BVHObject *obj= (BVHObject*)MEM_callocN(sizeof(BVHObject), "BVHObject");
    assert(RE_rayobject_isAligned(obj)); /* RayObject API assumes real data to be 4-byte aligned */ 
    
    obj->rayobj.api = &bvh_api;
    obj->bvh = BLI_bvhtree_new(size, 0.0, 4, 6);
    obj->next_leaf = obj->leafs = (RayObject**)MEM_callocN(size*sizeof(RayObject*), "BVHObject leafs");
    
    INIT_MINMAX(obj->bb[0], obj->bb[1]);
    return RE_rayobject_unalignRayAPI((RayObject*) obj);
}

struct BVHCallbackUserData
{
    Isect *isec;
    RayObject **leafs;
};

static void bvh_callback(void *userdata, int index, const BVHTreeRay *UNUSED(ray), BVHTreeRayHit *hit)
{
    struct BVHCallbackUserData *data = (struct BVHCallbackUserData*)userdata;
    Isect *isec = data->isec;
    RayObject *face = data->leafs[index];
    
    if(RE_rayobject_intersect(face,isec))
    {
        hit->index = index;

        if(isec->mode == RE_RAY_SHADOW)
            hit->dist = 0;
        else
            hit->dist = isec->dist;
    }
}

static int  RE_rayobject_blibvh_intersect(RayObject *o, Isect *isec)
{
    BVHObject *obj = (BVHObject*)o;
    BVHTreeRayHit hit;
    float dir[3];
    struct BVHCallbackUserData data;
    data.isec = isec;
    data.leafs = obj->leafs;

    copy_v3_v3(dir, isec->dir);

    hit.index = 0;
    hit.dist = isec->dist;
    
    return BLI_bvhtree_ray_cast(obj->bvh, isec->start, dir, 0.0, &hit, bvh_callback, (void*)&data);
}

static void RE_rayobject_blibvh_add(RayObject *o, RayObject *ob)
{
    BVHObject *obj = (BVHObject*)o;
    float min_max[6];
    INIT_MINMAX(min_max, min_max+3);
    RE_rayobject_merge_bb(ob, min_max, min_max+3);

    DO_MIN(min_max  , obj->bb[0]);
    DO_MAX(min_max+3, obj->bb[1]);
    
    BLI_bvhtree_insert(obj->bvh, obj->next_leaf - obj->leafs, min_max, 2);  
    *(obj->next_leaf++) = ob;
}

static void RE_rayobject_blibvh_done(RayObject *o)
{
    BVHObject *obj = (BVHObject*)o;
    BLI_bvhtree_balance(obj->bvh);
}

static void RE_rayobject_blibvh_free(RayObject *o)
{
    BVHObject *obj = (BVHObject*)o;

    if(obj->bvh)
        BLI_bvhtree_free(obj->bvh);

    if(obj->leafs)
        MEM_freeN(obj->leafs);

    MEM_freeN(obj);
}

static void RE_rayobject_blibvh_bb(RayObject *o, float *min, float *max)
{
    BVHObject *obj = (BVHObject*)o;
    DO_MIN(obj->bb[0], min);
    DO_MAX(obj->bb[1], max);
}