opencv利用鼠标滑动画出多彩的形状

// opencvMouse.cpp : 定义控制台应用程序的入口点。
//
 
#include "stdafx.h"
#include <iostream>
#include <opencv2/opencv.hpp>
 
using namespace cv;
using namespace std;
 
#define WINDOW_NAME "【窗口程序】"
 
void on_MouseHandle(int event,int x, int y, int flages, void * param);
void DrawRectangle(cv::Mat & img, cv::Rect box);
 
//全局变量
Rect g_rectangle;
bool g_bDrawingBox = false; //是否进行绘制
RNG rng(12345);
 
int main()
{
 //【1】准备参数
 Mat srcImage(600,800,CV_8UC3), tempImage;
 srcImage.copyTo(tempImage);
 g_rectangle = Rect(-1, -1, 0, 0);
 srcImage = Scalar::all(0);
 
 //【2】设置鼠标操作做回调函数
 namedWindow(WINDOW_NAME);
 setMouseCallback(WINDOW_NAME, on_MouseHandle, (void*)&srcImage);
 
 //【3】程序主循环，当进程绘制的标识符为真时，进行绘制
 while (true)
 {
 srcImage.copyTo(tempImage); //复制源图到临时变量
 if (g_bDrawingBox)
 {
 DrawRectangle(tempImage, g_rectangle);
 }
 imshow(WINDOW_NAME, tempImage);
 if (waitKey(10) == 27) //按下ESC建，程序退出
 {
 break;
 }
 }
 return 0;
}
 
void on_MouseHandle(int event, int x, int y, int flages, void * param)
{
 Mat & image = *(cv::Mat*)param;
 switch (event)
 {
 //鼠标移动消息
 case EVENT_MOUSEMOVE:
 {
 if (g_bDrawingBox) //如果是否进行绘制的标识符为真，则记录下长和宽到RECT型变量中
 {
 g_rectangle.width = x - g_rectangle.x;
 g_rectangle.height = y - g_rectangle.y;
 }
 break;
 }
 case EVENT_LBUTTONDOWN: //按左键消息
 {
 g_bDrawingBox = true;
 g_rectangle = Rect(x,y,0,0); //记录起始点
 }
 break;
 case EVENT_LBUTTONUP: //左键松开消息
 {
 g_bDrawingBox = false;
 //对宽和高小于0的处理
 if (g_rectangle.width < 0)
 {
 g_rectangle.x += g_rectangle.width;
 g_rectangle.width *= -1;
 }
 if (g_rectangle.height < 0)
 {
 g_rectangle.y += g_rectangle.height;
 g_rectangle.height *= -1;
 }
 //调用函数进行绘制
 DrawRectangle(image, g_rectangle);
 }
 break;
 }
}
 
void DrawRectangle(cv::Mat & img, cv::Rect box)
{
 rectangle(img, box.tl(), box.br(), Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255))); //随机颜色
}