[C++&OpenCv]两点距离、三点角度的计算

#include
#include
#include
//#include
#include
#include //opencv申明
#include
#include
#include
#include
#include "cstring"
using namespace cv;
using namespace std;
vector points;
IplImage* src = 0;
IplImage* dst = 0;
int i = 0 ,j=0;
//两点间距离公式
float getDistance(CvPoint pointO, CvPoint pointA)
{
float distance;
distance = powf((pointO.x - pointA.x), 2) + powf((pointO.y - pointA.y), 2);
distance = sqrtf(distance);
//屏幕分辨率为1366*768，一个像素约为0.214mm，所以这里乘以0.214转化为实际尺寸，当然分辨率不同，一个像素表示的实际长度也不同
return distance;
}
//两条直线间的夹角
float angle(Point pt1, Point pt0, Point pt2)
{
double dx1 = (pt1.x - pt0.x);
double dy1 = (pt1.y - pt0.y);
double dx2 = (pt2.x - pt0.x);
double dy2 = (pt2.y - pt0.y);
double angle_line = (dx1*dx2 + dy1 * dy2) / sqrt((dx1*dx1 + dy1 * dy1)*(dx2*dx2 + dy2 * dy2) + 1e-10);
double a = acos(angle_line) * 180 / 3.141592653;
return a;
}
void on_mouse( int event, int x, int y, int flags, void* ustc)
{
static CvPoint pre_pt = (-1,-1);
static CvPoint cur_pt = (-1,-1);
CvFont font;
cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);
char temp[16];
if( event == CV_EVENT_LBUTTONDOWN )
{
cvCopy(dst,src);
sprintf(temp,"(%d,%d)",x,y);
pre_pt = cvPoint(x,y);
points.push_back(pre_pt);
//cvPutText(src,temp, pre_pt, &font, cvScalar(0,0,255));
cvCircle( src, pre_pt,3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
int k = points.size();
if(k>1)
{
cvLine(src,points.at(i),points.at(i+1),cvScalar(0,255,60),1,8,0);
float Dis = getDistance(points.at(i),points.at(i+1));
//转换字节数组到float数据
char m_Dis[50];
sprintf(m_Dis,"%.2f",Dis);//如果用sprintf函数小数点后会有6位
cvPutText(src,m_Dis,(points.at(i)+points.at(i+1))/2, &font, cvScalar(0,0,255));
i++;
}
if(k>2)
{
float m_angle = angle(points.at(j), points.at(j+1), points.at(j+2));
char m_angle1[50];
sprintf(m_angle1,"%.2f",m_angle);//如果用sprintf函数小数点后会有6位
//将角度保留两位小数
// double # = floor(m_angle * 100.000f + 0.5) / 100.000f;
cvPutText(src,m_angle1,points.at(j+1), &font, cvScalar(255,0,255));
j++;
}
cvShowImage( "src", src );
cvCopy(src,dst);
}
else if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))
{
cvCopy(dst,src);
sprintf(temp,"(%d,%d)",x,y);
cur_pt = cvPoint(x,y);
cvPutText(src,temp, cur_pt, &font, cvScalar(255,0,255));
cvShowImage( "src", src );
}
}
int main()
{
src=cvLoadImage("D:\\Data\\1.jpg",1);
dst=cvCloneImage(src);
cvNamedWindow("src",1);
cvSetMouseCallback( "src", on_mouse, 0 );
cvShowImage("src",src);
cvWaitKey(0);
cvDestroyAllWindows();
cvReleaseImage(&src);
cvReleaseImage(&dst);
return 0;
}