//main.cpp檔案

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <stdio.h>
using namespace cv;
cv::Mat org, dst, img, tmp;
void on_mouse(int event, int x, int y, int flags, void *ustc)//event滑鼠事件代號，x,y滑鼠座標，flags拖拽和鍵盤操作的代號 
{
 static Point pre_pt = (-1, -1);//初始座標 
 static Point cur_pt = (-1, -1);//實時座標
 Point cirpoint = (-1, -1);//圓心座標
 int r = 0;



 char temp[16];
 if (event == CV_EVENT_LBUTTONDOWN)//左鍵按下，讀取初始座標，並在影象上該點處劃圓 
 {
  org.copyTo(img);//將原始圖片複製到img中 
  sprintf(temp, "(%d,%d)", x, y);
  pre_pt = Point(x, y);
  putText(img, temp, pre_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255), 1, 8);//在視窗上顯示座標 
  circle(img, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);//劃圓 
  imshow("img", img);
 }
 else if (event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))//左鍵沒有按下的情況下滑鼠移動的處理函式 
 {
  img.copyTo(tmp);//將img複製到臨時影象tmp上，用於顯示實時座標 
  sprintf(temp, "(%d,%d)", x, y);
  cur_pt = Point(x, y);
  putText(tmp, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));//只是實時顯示滑鼠移動的座標 
  imshow("img", tmp);
 }
 else if (event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))//左鍵按下時，滑鼠移動，則在影象上劃矩形 
 {
  img.copyTo(tmp);
  sprintf(temp, "(%d,%d)", x, y);
  cur_pt = Point(x, y);
  putText(tmp, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
  rectangle(tmp, pre_pt, cur_pt, Scalar(0, 255, 0, 0), 1, 8, 0);//在臨時影象上實時顯示滑鼠拖動時形成的矩形 
  imshow("img", tmp);
 }
 else if (event == CV_EVENT_LBUTTONUP)//左鍵鬆開，將在影象上劃矩形 
 {
  org.copyTo(img);
  sprintf(temp, "(%d,%d)", x, y);
  cur_pt = Point(x, y);
  putText(img, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
  //circle(img, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
  //rectangle(img, pre_pt, cur_pt, Scalar(0, 255, 0, 0), 1, 8, 0);//根據初始點和結束點，將矩形畫到img上 
  cirpoint.x = (pre_pt.x + cur_pt.x) / 2;
  cirpoint.y = (pre_pt.y + cur_pt.y) / 2;
  r = min(abs(pre_pt.x - cur_pt.x), abs(pre_pt.y - cur_pt.y));
  r = r / 2.0;



  circle(img, cirpoint, r, Scalar(0, 0, 225, 0), 1, 8, 0);//繪製第一個圓，半徑為100，圓心（350，300），線寬為7
  imshow("img", img);



  img.copyTo(tmp);
  //擷取矩形包圍的影象，並儲存到dst中 
  int width = abs(pre_pt.x - cur_pt.x);
  int height = abs(pre_pt.y - cur_pt.y);
  if (width == 0 || height == 0)
  {
   printf("width == 0 || height == 0");
   return;
  }



  dst = org(Rect(min(cur_pt.x, pre_pt.x), min(cur_pt.y, pre_pt.y), width, height));



  namedWindow("dst");
  imshow("dst", dst);
  waitKey(0);
 }
}



void main()
{
 org = imread("1.jpg");
 org.copyTo(img);
 org.copyTo(tmp);
 namedWindow("img");//定義一個img視窗 
 setMouseCallback("img", on_mouse, 0);//呼叫回撥函式 

 imshow("img", img);
 cv::waitKey(0);
}