Spatial_SimpleSpatialIndex.h

/*
 * Gamedev Framework (gf)
 * Copyright (C) 2016-2021 Julien Bernard
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 */
#ifndef GF_SPATIAL_SIMPLE_SPATIAL_INDEX_H
#define GF_SPATIAL_SIMPLE_SPATIAL_INDEX_H

#include <vector>

#include "CoreApi.h"
#include "Handle.h"
#include "Rect.h"
#include "SpatialTypes.h"

namespace gf {
#ifndef DOXYGEN_SHOULD_SKIP_THIS
inline namespace v1 {
#endif

  class GF_CORE_API SimpleSpatialIndex {
  public:
    SimpleSpatialIndex();

    SpatialId insert(Handle handle, const RectF& bounds);

    void modify(SpatialId id, RectF bounds);

    std::size_t query(const RectF& bounds, SpatialQueryCallback callback, SpatialQuery kind = SpatialQuery::Intersect);

    void remove(SpatialId id);

    void clear();

    Handle operator[](SpatialId id);

  private:
    static constexpr std::size_t Null = static_cast<std::size_t>(-1);
    static constexpr std::size_t Occupied = static_cast<std::size_t>(-2);

    struct Entry {
      Handle handle;
      RectF bounds;
      std::size_t next;
    };

    std::vector<Entry> m_entries;
    std::size_t m_firstFreeEntry;
  };

#ifndef DOXYGEN_SHOULD_SKIP_THIS
}
#endif
}

#endif // GF_SPATIAL_SIMPLE_SPATIAL_INDEX_H