OpenCV 鼠标事件

#include"OpenCVLib.hpp"
#define WINDOW_NAME "TEST"
using namespace cv;

void on_MouseHandle(int event,int x,int y,int flags,void *param);
void DrawRectangle(Mat& img,Rect box);
void ShowHelpText();

Rect g_rectangle;
bool g_bDrawingBox = false;
RNG g_rng(12345);

int main(){
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);
namedWindow(WINDOW_NAME);
setMouseCallback(WINDOW_NAME,on_MouseHandle,(void*)&srcImage);
while(true){
srcImage.copyTo(tempImage);
if(g_bDrawingBox) DrawRectangle(tempImage,g_rectangle);
imshow(WINDOW_NAME,tempImage);
if(waitKey(10) == 27)break;
}

}

void on_MouseHandle(int event,int x,int y,int flags,void * param){
Mat & image = *(Mat*)param;
switch(event){
case EVENT_MOUSEMOVE:
{
if(g_bDrawingBox){
g_rectangle.width = x-g_rectangle.x;
g_rectangle.height = y-g_rectangle.y;
}
}
break;
case EVENT_LBUTTONDOWN:
{
g_bDrawingBox = true;
g_rectangle = Rect(x,y,0,0);
}
break;
case EVENT_LBUTTONUP:
{
g_bDrawingBox = false;
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;
}

}
break;
}
}
void DrawRectangle(Mat &img,Rect box){
//tl : top and left ? ; br : bottom and right ? ;random -- uniform?
rectangle(img,box.tl(),box.br(),Scalar(g_rng.uniform(0,255),g_rng.uniform(0,255),g_rng.uniform(0,255)));
}