rayobject_vbvh.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 *****
 */

int tot_pushup   = 0;
int tot_pushdown = 0;
int tot_hints    = 0;

#include <assert.h>

#include "MEM_guardedalloc.h"

#include "BKE_global.h"

#include "BLI_math.h"
#include "BLI_memarena.h"
#include "BLI_utildefines.h"

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

#include "reorganize.h"
#include "bvh.h"
#include "vbvh.h"

#include <queue>
#include <algorithm>

#define DFS_STACK_SIZE  256

struct VBVHTree
{
    RayObject rayobj;
    VBVHNode *root;
    MemArena *node_arena;
    float cost;
    RTBuilder *builder;
};

/*
 * Cost to test N childs
 */
struct PackCost
{
    float operator()(int n)
    {
        return n;
    }
};

template<>
void bvh_done<VBVHTree>(VBVHTree *obj)
{
    rtbuild_done(obj->builder, &obj->rayobj.control);
    
    //TODO find a away to exactly calculate the needed memory
    MemArena *arena1 = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, "vbvh arena");
                       BLI_memarena_use_malloc(arena1);
    
    //Build and optimize the tree
    if(1)
    {
        VBVHNode *root = BuildBinaryVBVH<VBVHNode>(arena1,&obj->rayobj.control).transform(obj->builder);
        if(RE_rayobjectcontrol_test_break(&obj->rayobj.control))
        {
            BLI_memarena_free(arena1);
            return;
        }

        if(root) {
            reorganize(root);
            remove_useless(root, &root);
            bvh_refit(root);
        
            pushup(root);
            pushdown(root);
            obj->root = root;
        }
        else
            obj->root = NULL;
    }
    else
    {
/*
    TODO
        MemArena *arena2 = BLI_memarena_new(BLI_MEMARENA_STD_BUFSIZE, "vbvh arena2");
                           BLI_memarena_use_malloc(arena2);
                           
        //Finds the optimal packing of this tree using a given cost model
        //TODO this uses quite a lot of memory, find ways to reduce memory usage during building
        OVBVHNode *root = BuildBinaryVBVH<OVBVHNode>(arena2).transform(obj->builder);           
        VBVH_optimalPackSIMD<OVBVHNode,PackCost>(PackCost()).transform(root);
        obj->root = Reorganize_VBVH<OVBVHNode>(arena1).transform(root);
        
        BLI_memarena_free(arena2);
 */
    }

    //Cleanup
    rtbuild_free( obj->builder );
    obj->builder = NULL;

    obj->node_arena = arena1;
    obj->cost = 1.0;    
}

template<int StackSize>
int intersect(VBVHTree *obj, Isect* isec)
{
    //TODO renable hint support
    if(RE_rayobject_isAligned(obj->root)) {
        if(isec->mode == RE_RAY_SHADOW)
            return bvh_node_stack_raycast<VBVHNode,StackSize,false,true>( obj->root, isec);
        else
            return bvh_node_stack_raycast<VBVHNode,StackSize,false,false>( obj->root, isec);
    }
    else
        return RE_rayobject_intersect( (RayObject*) obj->root, isec );
}

template<class Tree>
void bvh_hint_bb(Tree *tree, LCTSHint *hint, float *UNUSED(min), float *UNUSED(max))
{
    //TODO renable hint support
    {
        hint->size = 0;
        hint->stack[hint->size++] = (RayObject*)tree->root;
    }
}

void bfree(VBVHTree *tree)
{
    if(tot_pushup + tot_pushdown + tot_hints + tot_moves)
    {
        if(G.f & G_DEBUG) {
            printf("tot pushups: %d\n", tot_pushup);
            printf("tot pushdowns: %d\n", tot_pushdown);
            printf("tot moves: %d\n", tot_moves);
            printf("tot hints created: %d\n", tot_hints);
        }

        tot_pushup = 0;
        tot_pushdown = 0;
        tot_hints = 0;
        tot_moves = 0;
    }
    bvh_free(tree);
}

/* the cast to pointer function is needed to workarround gcc bug: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11407 */
template<class Tree, int STACK_SIZE>
RayObjectAPI make_api()
{
    static RayObjectAPI api = 
    {
        (RE_rayobject_raycast_callback) ((int(*)(Tree*,Isect*)) &intersect<STACK_SIZE>),
        (RE_rayobject_add_callback)     ((void(*)(Tree*,RayObject*)) &bvh_add<Tree>),
        (RE_rayobject_done_callback)    ((void(*)(Tree*))       &bvh_done<Tree>),
        (RE_rayobject_free_callback)    ((void(*)(Tree*))       &bvh_free<Tree>),
        (RE_rayobject_merge_bb_callback)((void(*)(Tree*,float*,float*)) &bvh_bb<Tree>),
        (RE_rayobject_cost_callback)    ((float(*)(Tree*))      &bvh_cost<Tree>),
        (RE_rayobject_hint_bb_callback) ((void(*)(Tree*,LCTSHint*,float*,float*)) &bvh_hint_bb<Tree>)
    };
    
    return api;
}

template<class Tree>
RayObjectAPI* bvh_get_api(int maxstacksize)
{
    static RayObjectAPI bvh_api256 = make_api<Tree,1024>();
    
    if(maxstacksize <= 1024) return &bvh_api256;
    assert(maxstacksize <= 256);
    return 0;
}

RayObject *RE_rayobject_vbvh_create(int size)
{
    return bvh_create_tree<VBVHTree,DFS_STACK_SIZE>(size);
}