OpenCV C++ basic drawing operations

Procedure description

// Program description: OpenCV C++ basic drawing operations
// Reference: Mao Xingyun "Introduction to OpenCV3 Programming"
// Operating system: Windows 10 64bit
// Development language: C++
// IDE version: Visual Studio 2019
// OpenCV version: 4.20

Code

The main function is very simple to write. First create an empty table Mat image, then click the function to draw a chemical atom diagram, then draw a combination diagram, and finally display the image.

//---------------------------------【头文件、命名空间包含部分】----------------------------
//          描述：包含程序所使用的头文件和命名空间
//------------------------------------------------------------------------------------------------
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;

//此程序对于OpenCV4版需要额外包含头文件：
#include <opencv2/imgproc/imgproc.hpp>



//-----------------------------------【宏定义部分】-------------------------------------------- 
//		描述：定义一些辅助宏 
//------------------------------------------------------------------------------------------------ 
#define WINDOW_NAME1 "【绘制图1】"        //为窗口标题定义的宏 
#define WINDOW_NAME2 "【绘制图2】"        //为窗口标题定义的宏 
#define WINDOW_WIDTH 600//定义窗口大小的宏



//--------------------------------【全局函数声明部分】-------------------------------------
//		描述：全局函数声明
//-----------------------------------------------------------------------------------------------
void DrawEllipse(Mat img, double angle);//绘制椭圆
void DrawFilledCircle(Mat img, Point center);//绘制圆
void DrawPolygon(Mat img);//绘制多边形
void DrawLine(Mat img, Point start, Point end);//绘制线段



//---------------------------------------【main( )函数】--------------------------------------
//		描述：控制台应用程序的入口函数，我们的程序从这里开始执行
//-----------------------------------------------------------------------------------------------
int main(void)
{

	// 创建空白的Mat图像
	Mat atomImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
	Mat rookImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);

	// ---------------------<1>绘制化学中的原子示例图------------------------

	//【1.1】先绘制出椭圆
	DrawEllipse(atomImage, 90);
	DrawEllipse(atomImage, 0);
	DrawEllipse(atomImage, 45);
	DrawEllipse(atomImage, -45);

	//【1.2】再绘制圆心
	DrawFilledCircle(atomImage, Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2));

	// ----------------------------<2>绘制组合图-----------------------------
	//【2.1】先绘制出椭圆
	DrawPolygon(rookImage);

	// 【2.2】绘制矩形
	rectangle(rookImage,
		Point(0, 7 * WINDOW_WIDTH / 8),
		Point(WINDOW_WIDTH, WINDOW_WIDTH),
		Scalar(0, 255, 255),
		-1,
		8);

	// 【2.3】绘制一些线段
	DrawLine(rookImage, Point(0, 15 * WINDOW_WIDTH / 16), Point(WINDOW_WIDTH, 15 * WINDOW_WIDTH / 16));
	DrawLine(rookImage, Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 4, WINDOW_WIDTH));
	DrawLine(rookImage, Point(WINDOW_WIDTH / 2, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 2, WINDOW_WIDTH));
	DrawLine(rookImage, Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH));

	// ---------------------------<3>显示绘制出的图像------------------------
	imshow(WINDOW_NAME1, atomImage);
	moveWindow(WINDOW_NAME1, 0, 200);
	imshow(WINDOW_NAME2, rookImage);
	moveWindow(WINDOW_NAME2, WINDOW_WIDTH, 200);

	waitKey(0);
	return(0);
}



//-------------------------------【DrawEllipse( )函数】--------------------------------
//		描述：自定义的绘制函数，实现了绘制不同角度、相同尺寸的椭圆
//-----------------------------------------------------------------------------------------
void DrawEllipse(Mat img, double angle)
{
	int thickness = 2;//线粗
	int lineType = 8;//线型

	ellipse(img,
		Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2),
		Size(WINDOW_WIDTH / 4, WINDOW_WIDTH / 16),
		angle,
		0,
		360,
		Scalar(255, 129, 0),
		thickness,
		lineType);
}


//-----------------------------------【DrawFilledCircle( )函数】---------------------------
//		描述：自定义的绘制函数，实现了实心圆的绘制
//-----------------------------------------------------------------------------------------
void DrawFilledCircle(Mat img, Point center)
{
	int thickness = -1;
	int lineType = 8;

	circle(img,
		center,
		WINDOW_WIDTH / 32,
		Scalar(0, 0, 255),//红色
		thickness,
		lineType);
}


//-----------------------------------【DrawPolygon( )函数】--------------------------
//		描述：自定义的绘制函数，实现了凹多边形的绘制
//--------------------------------------------------------------------------------------
void DrawPolygon(Mat img)
{
	int lineType = 8;

	//创建一些点
	Point rookPoints[1][20];
	rookPoints[0][0] = Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
	rookPoints[0][1] = Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
	rookPoints[0][2] = Point(3 * WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);
	rookPoints[0][3] = Point(11 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
	rookPoints[0][4] = Point(19 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
	rookPoints[0][5] = Point(3 * WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
	rookPoints[0][6] = Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
	rookPoints[0][7] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
	rookPoints[0][8] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
	rookPoints[0][9] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
	rookPoints[0][10] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
	rookPoints[0][11] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
	rookPoints[0][12] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
	rookPoints[0][13] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
	rookPoints[0][14] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
	rookPoints[0][15] = Point(WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
	rookPoints[0][16] = Point(WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
	rookPoints[0][17] = Point(13 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
	rookPoints[0][18] = Point(5 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
	rookPoints[0][19] = Point(WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);

	const Point* ppt[1] = { rookPoints[0] };
	int npt[] = { 20 };

	fillPoly(img,
		ppt,
		npt,
		1,
		Scalar(255, 255, 255),
		lineType);
}


//-----------------------------------【DrawLine( )函数】--------------------------
//		描述：自定义的绘制函数，实现了线的绘制
//---------------------------------------------------------------------------------
void DrawLine(Mat img, Point start, Point end)
{//用图像于在图像img上画一条从start开始到点end结束的直线段
	int thickness = 2;
	int lineType = 8;
	line(img,
		start,
		end,
		Scalar(0, 0, 0),//黑色
		thickness,
		lineType);
}

running result

Atom Diagram

Custom Polygon