OpenCV学习记录 鼠标操作

#include<opencv2/opencv.hpp>
using namespace cv;
#define WINDOW_NAME "【程序窗口】"

//-------------【全局函数声明部分】----------------------------
//描述：全局函数声明
//-------------------------------------------------------------
void on_MouseHandle(int event, int x, int y, int flags, void* param);
void DrawRectangle(cv::Mat&img, cv::Rect box);
void ShowHelpText();

//------------------【全局变量声明部分】-----------------------
//描述：全局变量声明
//-------------------------------------------------------------

Rect g_rectangle;
bool g_bDrawingBox = false;//是否进行绘制
RNG g_rng(12345);
//------------------【主函数】-----------------------
//描述：控制台应用程序的入口函数
//-------------------------------------------------------------
int main(int argc, char** argv) {
//【1】准备参数
g_rectangle = Rect(-1, -1, 0, 0);
Mat srcImage(600, 800, CV_8UC3), tempImage;
srcImage.copyTo(tempImage);
g_rectangle = Rect(-1, -1, 0, 0);
srcImage = Scalar::all(0);

//【2】设置鼠标操作回调函数
namedWindow(WINDOW_NAME);
setMouseCallback(WINDOW_NAME, on_MouseHandle, (void*)&srcImage);

//【3】程序主循环，当进行绘制的标识符为真时，进行绘制
while (1)
{
srcImage.copyTo(tempImage);//复制图到临时变量
if (g_bDrawingBox)
DrawRectangle(tempImage, g_rectangle);//当进行的绘制标识符为真时，则进行绘制
imshow(WINDOW_NAME, tempImage);
if (waitKey(10) == 27)
break;//按下esc键，程序退出
}
return 0;
}

//------------------【on_MouseHandle()函数】-----------------------
//描述：鼠标回调函数，根据不同的鼠标事件进行不同操作
//-------------------------------------------------------------

void on_MouseHandle(int event, int x, int y, int flags, void*param)
{
Mat& image = *(cv::Mat*)param;
switch (event)
{
//鼠标移动消息
case EVENT_MOUSEMOVE:
{
if (g_bDrawingBox)
{
g_rectangle.width = x - g_rectangle.x;
g_rectangle.height = y - g_rectangle.y;
}
}
break;
//左键按下消息
case EVENT_LBUTTONDOWN:
{
g_bDrawingBox = true;
g_rectangle = Rect(x, y, 0, 0);//记录起点
}
break;
//左键抬起的消息
case EVENT_LBUTTONUP:
{
g_bDrawingBox = false;//标识符记为false
//对宽和长小于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;
}
}

//------------------【DrawRectangle()函数】-----------------------
//描述：自定义的矩形绘制函数
//-------------------------------------------------------------
void DrawRectangle(cv::Mat& img, cv::Rect box)
{
rectangle(img, box.tl(), box.br(), Scalar(g_rng.uniform(0, 255), g_rng.uniform(0, 255), g_rng.uniform(0, 255)));//随机颜色
}