sah_builder.h

/*
 * Copyright (c) 2010-2011, NVIDIA Corporation
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 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright
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 *     notice, this list of conditions and the following disclaimer in the
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 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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#pragma once

#include <nih/bvh/bvh.h>
#include <nih/linalg/vector.h>
#include <nih/linalg/bbox.h>
#include <nih/bintree/bintree_node.h>
#include <nih/bintree/cuda/bintree_gen_context.h>
#include <thrust/device_vector.h>

namespace nih {
namespace cuda {

struct Sah_builder
{
    Sah_builder(
        thrust::device_vector<Bvh_node>&         nodes,
        thrust::device_vector<uint2>&            leaves,
        thrust::device_vector<uint32>&           index) :
        m_nodes( &nodes ), m_leaves( &leaves ), m_index( &index )
    {
        m_init_bins_time          = 0.0f;
        m_update_bins_time        = 0.0f;
        m_sah_split_time          = 0.0f;
        m_distribute_objects_time = 0.0f;
    }

    template <typename Iterator>
    void build(
        const uint32    BINS,
        const Bbox3f    bbox,
        const Iterator  bbox_begin,
        const Iterator  bbox_end,
        const uint32    max_leaf_size,
        const float     max_cost = 1.8f);

    thrust::device_vector<Bvh_node>*    m_nodes;
    thrust::device_vector<uint2>*       m_leaves;
    thrust::device_vector<uint32>*      m_index;
    uint32                              m_levels[128];
    uint32                              m_level_count;
    Bbox3f                              m_bbox;
    uint32                              m_node_count;
    uint32                              m_leaf_count;

    float m_init_bins_time;
    float m_update_bins_time;
    float m_sah_split_time;
    float m_distribute_objects_time;

    struct Bin
    {
        float4 bmin;
        float4 bmax;

        FORCE_INLINE NIH_HOST_DEVICE int32 get_size() const { return binary_cast<int32>( bmin.w ); }
        FORCE_INLINE NIH_HOST_DEVICE void  set_size(const int32 x) { bmin.w = binary_cast<float>(x); }
    };
    struct Split
    {
        NIH_HOST_DEVICE Split() {}
        NIH_HOST_DEVICE Split(int32 id, int32 plane) : task_id(id), best_plane(plane) {}

        int32 task_id;
        int32 best_plane;
    };
    struct Queue
    {
        Bin*    bins;
        Split*  splits;
        uint32* offsets;
        int32   size;
    };
    struct Objects
    {
        int4*       bin_ids;
        int32*      split_ids;
        int32*      node_ids;
        uint32*     index;
    };
    struct Bbox
    {
        float3 bmin;
        float3 bmax;
    };
    struct Bins
    {
        float3* bmin;
        float3* bmax;
        volatile int32* size;
    };

    thrust::device_vector<float3> m_bin_bmin;
    thrust::device_vector<float3> m_bin_bmax;
    thrust::device_vector<int32>  m_bin_size;
    thrust::device_vector<Bin>    m_queue_bins;
    thrust::device_vector<Split>  m_queue_splits;
    thrust::device_vector<uint32> m_queue_offsets;

    thrust::device_vector<int4>   m_bin_ids;
    thrust::device_vector<int32>  m_split_ids;
    thrust::device_vector<int32>  m_node_ids;
    thrust::device_vector<uint32> m_new_pos;
    thrust::device_vector<uint32> m_counters;
};

} // namespace cuda
} // namespace nih

#include <nih/bvh/cuda/sah_builder_inline.h>