bvh_params.h

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/*
 * Adapted from code copyright 2009-2010 NVIDIA Corporation
 * Modifications Copyright 2011, Blender Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __BVH_PARAMS_H__
#define __BVH_PARAMS_H__

CCL_NAMESPACE_BEGIN

/* BVH Parameters */

class BVHParams
{
public:
    /* spatial split area threshold */
    int use_spatial_split;
    float spatial_split_alpha;

    /* SAH costs */
    float sah_node_cost;
    float sah_triangle_cost;

    /* number of triangles in leaf */
    int min_leaf_size;
    int max_leaf_size;

    /* object or mesh level bvh */
    int top_level;

    /* disk cache */
    int use_cache;

    /* QBVH */
    int use_qbvh;

    int pad;

    /* fixed parameters */
    enum {
        MAX_DEPTH = 64,
        MAX_SPATIAL_DEPTH = 48,
        NUM_SPATIAL_BINS = 32
    };

    BVHParams()
    {
        use_spatial_split = true;
        spatial_split_alpha = 1e-5f;

        sah_node_cost = 1.0f;
        sah_triangle_cost = 1.0f;

        min_leaf_size = 1;
        max_leaf_size = 0x7FFFFFF;

        top_level = false;
        use_cache = false;
        use_qbvh = false;
        pad = false;
    }

    /* SAH costs */
    float cost(int num_nodes, int num_tris) const
    { return node_cost(num_nodes) + triangle_cost(num_tris); }

    float triangle_cost(int n) const
    { return n*sah_triangle_cost; }

    float node_cost(int n) const
    { return n*sah_node_cost; }
};

CCL_NAMESPACE_END

#endif /* __BVH_PARAMS_H__ */