converted some OpenCV C samples to C++

samples/cpp/convexhull.cpp

@@ -0,0 +1,52 @@
+#include <opencv2/imgproc/imgproc.hpp>
+#include <opencv2/highgui/highgui.hpp>
+
+using namespace cv;
+
+int main( int argc, char** argv )
+{
+    Mat img(500, 500, CV_8UC3);
+    RNG& rng = theRNG();
+
+    for(;;)
+    {
+        char key;
+        int i, count = (unsigned)rng%100 + 1;
+        
+        vector<Point> 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);
+        }
+        
+        vector<int> hull;
+        convexHull(Mat(points), hull, CV_CLOCKWISE);
+        
+        img = Scalar::all(0);
+        for( i = 0; i < count; i++ )
+            circle(img, points[i], 3, Scalar(0, 0, 255), CV_FILLED, CV_AA);
+        
+        int hullcount = (int)hull.size();
+        Point pt0 = points[hull[hullcount-1]];
+        
+        for( i = 0; i < hullcount; i++ )
+        {
+            Point pt = points[hull[i]];
+            line(img, pt0, pt, Scalar(0, 255, 0), 1, CV_AA);
+            pt0 = pt;
+        }
+
+        imshow("hull", img);
+
+        key = (char)waitKey();
+        if( key == 27 || key == 'q' || key == 'Q' ) // 'ESC'
+            break;
+    }
+
+    return 0;
+}