AdventuresInLestoria/Adventures in Lestoria/Pathfinding.h

#pragma region License
/*
License (OLC-3)
~~~~~~~~~~~~~~~

Copyright 2024 Joshua Sigona <sigonasr2@gmail.com>

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

1. Redistributions or derivations of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

2. Redistributions or derivative works in binary form must reproduce the above
copyright notice. This list of conditions and the following	disclaimer must be
reproduced 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.

Portions of this software are copyright © 2023 The FreeType
Project (www.freetype.org). Please see LICENSE_FT.txt for more information.
All rights reserved.
*/
#pragma endregion
#pragma once
#include "olcUTIL_Geometry2D.h"
#include <set>
#include <vector>
#include <map>

struct Pathfinding{
    struct sNode
	{
		int x=0;							// Nodes position in 2D space
		int y=0;
		bool bObstacle = false;			// Is the node an obstruction?
		bool bObstacleUpper = false;	// Is the node an obstruction on the upper level?
		bool bVisited = false;			// Have we searched this node before?
		float fGlobalGoal=0;				// Distance to goal so far
		float fLocalGoal=0;				// Distance to goal if we took the alternative route
		std::vector<sNode*> vecNeighbours;	// Connections to neighbours
		sNode* parent=nullptr;					// Node connecting to this node that offers shortest parent
	};

	struct sPoint2D
	{
		vf2d pos;
		float length;
	};
	struct sSpline
	{
		std::vector<sPoint2D> points;
		float fTotalSplineLength = 0.0f;

		void Initialize(const std::vector<vf2d>&points);
		sPoint2D GetSplinePoint(float t, bool bLooped = true);
		sPoint2D GetSplineGradient(float t, bool bLooped = true);
		float CalculateSegmentLength(int node, bool bLooped = true);
		float GetNormalisedOffset(float p);
	};

	std::map<vi2d,sNode>nodes;

	sNode *nodeStart = nullptr;
	sNode *nodeEnd = nullptr;

	const static vi2d gridSpacing; //Decrease this for more precision

    void Initialize();
	//maxRange in tiles. Returns the path as points.
	[[nodiscard]]
    std::vector<vf2d> Solve_AStar(vf2d startPos,vf2d endPos,float maxRange=8,bool upperLevel=false);
	sSpline Solve_WalkPath(vf2d startPos,vf2d endPos,float maxRange=8,bool upperLevel=false);
};