#include "opencv2/highgui.hpp"

#include "opencv2/imgproc.hpp"

#include <iostream>

using namespace cv;

using namespace std;

static void help()

{

cout << "This program demonstrates finding the minimum enclosing box, triangle or circle of a set\n"

<< "of points using functions: minAreaRect() minEnclosingTriangle() minEnclosingCircle().\n"

<< "Random points are generated and then enclosed.\n\n"

<< "Press ESC, 'q' or 'Q' to exit and any other key to regenerate the set of points.\n\n";

}

int main( int /*argc*/, char** /*argv*/ )

{

help();

Mat img(500, 500, CV_8UC3, Scalar::all(0));

RNG& rng = theRNG();

for(;;)

{

int i, count = rng.uniform(1, 101);

vector<Point> points;

// Generate a random set of points

for( i = 0; i < count; i++ )

{

Point pt;

pt.x = rng.uniform(img.cols/4, img.cols*3/4);

pt.y = rng.uniform(img.rows/4, img.rows*3/4);

points.push_back(pt);

}

// Find the minimum area enclosing bounding box

Point2f vtx[4];

RotatedRect box = minAreaRect(points);

box.points(vtx);

// Find the minimum area enclosing triangle

vector<Point2f> triangle;

minEnclosingTriangle(points, triangle);

// Find the minimum area enclosing circle

Point2f center;

float radius = 0;

minEnclosingCircle(points, center, radius);

img = Scalar::all(0);

// Draw the points

for( i = 0; i < count; i++ )

circle( img, points[i], 3, Scalar(0, 0, 255), FILLED, LINE_AA );

// Draw the bounding box

for( i = 0; i < 4; i++ )

line(img, vtx[i], vtx[(i+1)%4], Scalar(0, 255, 0), 1, LINE_AA);

// Draw the triangle

for( i = 0; i < 3; i++ )

line(img, triangle[i], triangle[(i+1)%3], Scalar(255, 255, 0), 1, LINE_AA);

// Draw the circle

circle(img, center, cvRound(radius), Scalar(0, 255, 255), 1, LINE_AA);

imshow( "Rectangle, triangle & circle", img );

char key = (char)waitKey();

if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'

break;

}

return 0;

}