McRogueFace/deps_linux/libtcod/pathfinder_frontier.h

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/* BSD 3-Clause License
*
* Copyright © 2008-2022, Jice and the libtcod contributors.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the 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 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef TCOD_PATHFINDER_FRONTIER_H
#define TCOD_PATHFINDER_FRONTIER_H
#include <stdint.h>
#include "config.h"
#include "error.h"
#include "heapq.h"
#define TCOD_PATHFINDER_MAX_DIMENSIONS 4
struct TCOD_Frontier {
int8_t ndim;
int active_dist;
int active_index[TCOD_PATHFINDER_MAX_DIMENSIONS];
struct TCOD_Heap heap;
};
#ifdef __cplusplus
extern "C" {
#endif // __cplusplus
/**
Create a new pathfinder frontier.
`ndim` is the number of dimensions. Must be in the range `1 <= n <= 4`.
*/
TCOD_PUBLIC TCOD_NODISCARD struct TCOD_Frontier* TCOD_frontier_new(int ndim);
/**
Delete a pathfinder frontier.
*/
TCOD_PUBLIC void TCOD_frontier_delete(struct TCOD_Frontier* frontier);
/**
Pop the next node from this frontier.
The popped node variables will placed in the `active_dist` and
`active_index` attributes.
*/
TCOD_PUBLIC TCOD_Error TCOD_frontier_pop(struct TCOD_Frontier* frontier);
/**
Add a node to this frontier.
`index[frontier->ndim]` is the position of the node to add to the frontier.
`dist` is the total distance of the node. This should be a low number
like 0, but can also be a negative number such as `INT_MIN`.
When adding a node as an edge then `dist` is `frontier->active_dist` plus
the cost of the edge.
`heuristic` is the true priority of the node, used to affect node order.
For Dijkstra-like algorithms this should be the same as `dist`.
For A* this should be `dist` plus the maximum possible distance to the
goal.
*/
TCOD_PUBLIC TCOD_Error
TCOD_frontier_push(struct TCOD_Frontier* __restrict frontier, const int* __restrict index, int dist, int heuristic);
/**
Return the current number of nodes in this frontier.
*/
TCOD_PUBLIC TCOD_NODISCARD int TCOD_frontier_size(const struct TCOD_Frontier* frontier);
/**
Remove all nodes from this frontier.
*/
TCOD_PUBLIC TCOD_Error TCOD_frontier_clear(struct TCOD_Frontier* frontier);
#ifdef __cplusplus
} // extern "C"
#endif // __cplusplus
#endif // TCOD_PATHFINDER_FRONTIER_H