#include <iostream>
#include "opencv2/opencv.hpp"
using namespace cv;

void contours_basic() {
	Mat src = imread("../../resources/images/contours.bmp", IMREAD_GRAYSCALE);

	std::vector<std::vector<Point>> contours;
	findContours(src, contours, RETR_LIST, CHAIN_APPROX_NONE);

	Mat dst;
	cvtColor(src, dst, COLOR_GRAY2BGR);

	for (int i = 0; i < contours.size(); i++) {
		Scalar c(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst, contours, i, c, 2);
	}

	imshow("src", src);
	imshow("dst", dst);

	waitKey();
	destroyAllWindows();
}

void contours_hier() {
	Mat src = imread("../../resources/images/contours.bmp", IMREAD_GRAYSCALE);

	std::vector<std::vector<Point>> contours;
	std::vector<Vec4i> hirarchy;
	findContours(src, contours, hirarchy, RETR_CCOMP, CHAIN_APPROX_NONE);

	Mat dst;
	cvtColor(src, dst, COLOR_GRAY2BGR);

	for (int i = 0; i >= 0; i = hirarchy[i][0]) {
		Scalar c(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst, contours, i, c, -1, LINE_8, hirarchy);
	}

	for (int i = 0; i < contours.size(); i++) {
		std::cout << "Hirarchy of contour index: " << i << "-->" << hirarchy[i] << std::endl;
	}

	imshow("src", src);
	imshow("dst", dst);

	waitKey();
	destroyAllWindows();
}

void contour_apps() {
	Mat src = imread("../../resources/images/beta.png", IMREAD_GRAYSCALE);

	Mat bin;
	std::vector<std::vector<Point>> contours;
	std::vector<Vec4i> hirarchy;
	threshold(src, bin, 128, 255, THRESH_BINARY | THRESH_OTSU);
	morphologyEx(bin, bin, MORPH_OPEN, Mat(), Point(-1, -1), 1);

	findContours(bin, contours, hirarchy, RETR_TREE, CHAIN_APPROX_NONE);

	Mat dst;
	cvtColor(src, dst, COLOR_GRAY2BGR); 
	
	for (int idx = 0; idx >= 0; idx = hirarchy[idx][0]) {
		Scalar c(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst, contours, idx, c, 2, LINE_AA, hirarchy, 2, Point(0, 0));

		Rect rect = boundingRect(contours[idx]);
		rectangle(dst, rect, Scalar(0, 0, 255), 2, LINE_AA, 0);

		RotatedRect rrect = minAreaRect(contours[idx]);
		Point2f vertices[4];
		rrect.points(vertices);
		for (int i = 0; i < 4; i++)
			line(dst, vertices[i], vertices[(i + 1 & 3)], Scalar(255, 0, 0), 2, LINE_AA, 0);
		float angle = rrect.angle;
		std::cout << "\nrotated angle: " << cvRound(angle) << std::endl;

		Point2f center;
		float radius;
		minEnclosingCircle(contours[idx], center, radius);
		circle(dst, center, radius, Scalar(0, 255, 255), 2, LINE_AA, 0);

		double len = arcLength(contours[idx], true);
		std::cout << "\nlength of contour: " << cvRound(len) << std::endl;

		double area = contourArea(contours[idx], false);
		std::cout << "\narea of contour: " << cvRound(area) << std::endl;
	}

	imshow("dst", dst);

	waitKey();
	destroyAllWindows();
}

void contour_approximation() {
	Mat src = imread("../../resources/images/kmap_simple.jpg", IMREAD_GRAYSCALE);

	Mat bin;
	std::vector<std::vector<Point>> contours;
	std::vector<Vec4i> hirarchy;
	threshold(src, bin, 128, 255, THRESH_BINARY | THRESH_OTSU);
	findContours(bin, contours, hirarchy, RETR_TREE, CHAIN_APPROX_NONE);
	Mat dst;
	cvtColor(src, dst, COLOR_GRAY2BGR);
	for (int idx = 0; idx >= 0; idx = hirarchy[idx][0]) {
		Scalar c(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst, contours, idx, c, 2, LINE_AA, hirarchy, 2, Point(0, 0));

		std::vector<Point> approxCurve;
		approxPolyDP(contours[idx], approxCurve, arcLength(contours[idx], true) * 0.005, true);
		int no_vertex = approxCurve.size();
		std::cout << "The nimber of vertex: " << no_vertex << std::endl;
		for (int v = 0; v < no_vertex; v++) {
			circle(dst, approxCurve[v], 3, Scalar(0, 0, 255), 2);
			line(dst, approxCurve[v], approxCurve[(v+1) % no_vertex], Scalar(255, 255, 0), 2);
		}

	}

	imshow("src", src);
	imshow("dst", dst);

	waitKey();
	destroyAllWindows();
}

int main() {
	contour_approximation();
}