/*
 * © Copyright 2014 – Urheberrechtshinweis
 * Alle Rechte vorbehalten / All Rights Reserved
 *
 * Programmcode ist urheberrechtlich geschuetzt.
 * Das Urheberrecht liegt, soweit nicht ausdruecklich anders gekennzeichnet, bei Frank Ebner.
 * Keine Verwendung ohne explizite Genehmigung.
 * (vgl. § 106 ff UrhG / § 97 UrhG)
 */

#ifndef HELPERPOLY3_H
#define HELPERPOLY3_H

#include "../../../geo/Point2.h"
#include "../../../geo/Point3.h"
#include "../../../geo/BBox2.h"
#include "../../../geo/BBox3.h"
#include "../../../floorplan/v2/Floorplan.h"
#include "../../../grid/Grid.h"

/** helper class for polygon methods */
struct HelperPoly3 {

	BBox2 bbox_cm;
	std::vector<Point2> points_cm;

	/** empty ctor */
	HelperPoly3() {
		;
	}

	/** ctor from floorplan-polygon */
	HelperPoly3(const Floorplan::FloorOutlinePolygon& poly) {
		for (Point2 p : poly.poly.points) { add(p * 100); }
	}

	/** ctor from floorplan-quad */
	HelperPoly3(const Floorplan::Quad3& quad) {
		add(quad.p1*100); add(quad.p2*100); add(quad.p3*100); add(quad.p4*100);
	}

	/** ctor from floorplan-polygon */
	HelperPoly3(const Floorplan::Polygon2& poly) {
		for (Point2 p : poly.points) { add(p * 100); }
	}

	void add(const Point2 p) {
		points_cm.push_back(p);
		bbox_cm.add(p);
	}

	void add(const Point3& p) {
		points_cm.push_back(p.xy());
		bbox_cm.add(p.xy());
	}

	/** does the polygon contain the given point (in cm)? */
	bool contains(const Point2 p_cm) const {

		// not within bbox? -> not within polygon
		if (!bbox_cm.contains(p_cm)) {return false;}

		// ensure the point is at least a bit outside of the polygon
		const float x1_cm = bbox_cm.getMin().x - 17.71920;
		const float y1_cm = bbox_cm.getMin().y - 23.10923891;

		// construct line between point outside of the polygon and the point in question
		const Line2 l(x1_cm, y1_cm, p_cm.x, p_cm.y);

		// determine the number of intersections
		int hits = 0;
		const int cnt = points_cm.size();
		for (int i = 0; i < cnt; ++i) {
			const Point2 p1 = points_cm[(i+0)%cnt];
			const Point2 p2 = points_cm[(i+1)%cnt];
			const Line2 l12(p1, p2);
			if (l12.getSegmentIntersection(l)) {++hits;}
		}

		// inside or outside?
		return ((hits % 2) == 1);

	}

	/** call a user-function for each GRID-ALIGNED point within the polygon */
	void forEachGridPoint(const int gridSize_cm, std::function<void(int x_cm, int y_cm)> callback) const {

		int x1 = std::floor(bbox_cm.getMin().x / gridSize_cm) * gridSize_cm;
		int x2 = std::ceil(bbox_cm.getMax().x / gridSize_cm) * gridSize_cm;

		int y1 = std::floor(bbox_cm.getMin().y / gridSize_cm) * gridSize_cm;
		int y2 = std::ceil(bbox_cm.getMax().y / gridSize_cm) * gridSize_cm;

		// process each point within the (aligned) bbox
		for (int y = y1; y <= y2; y += gridSize_cm) {
			for (int x = x1; x <= x2; x += gridSize_cm) {

				// does this point belong to the polygon?
				if (!contains(Point2(x,y))) {continue;}

				// call the callback
				callback(x,y);

			}
		}

	}

};

#endif // HELPERPOLY3_H