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