OpenCV学习（15）

基本图形绘制：DrawEllipse()函数的写法；DrawFilledCircle()函数的写法；DrawaPolygon()函数的写法；DrawLine()函数的写法；main函数写法

一，DrawEllipse()函数的写法

//----------—-——----------【 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;
	int lineType = 8;
	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);
}

此函数的写法解析如下。
函数DrawEllipse 调用了OpenCV中的ellipse函数，将椭圆画到图像img 上，椭圆中心为点(WINDOW_WIDTH/2.0,WINDOW_WIDTH/2.0 )，并且大小位于矩形 (WINDOw_WIDTH/4.0,WINDOw_WIDTH/16.0 )内。椭圆旋转角度为 angle，扩展的弧度从О度到360 度。图形颜色为Scalar(255,129,0)代表的蓝色，线宽(thickness)为2，线型(lineType)为8(8联通线型)。
二，DrawFilledCircle()函数的写法

//-—------------------- 【 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),
		thickness,
		lineType);
}

此函数的写法解析如下。
函数DrawFilledCircle()调用了OpenCV中的circle函数，将圆画到图像img上，圆心由点 center定义，圆的半径为 WINDOw_WIDTH/32，圆的颜色为Scalar(0,0,255)，按BGR的格式为红色，线粗定义为thickness = -1，因此绘制的圆是实心的。
三，DrawaPolygon()函数的写法

//-——------------------------------【 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);
}

此函数的写法解析如下。
函数DrawPolygon()调用了OpenCV中的 fillPoly函数，用于将多边形画到图像img 上，其中多边形的顶点集为ppt，要绘制的多边形顶点数目为npt，要绘制的多边形数量仅为1，多边形的颜色定义为白色Scalar(255,255,255)。
四，DrawLine()函数的写法

// ———---------------------------------【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)
{
	int thickness=2;
	int lineType=8;
	line(img,
		start,
		end,
		Scalar(0,0,0),
		thickness,
		lineType);
}

此函数的写法解析如下。
DrawLin()函数调用了OpenCV中的line函数，用于在图像 img 上画一条从点start到点end 的直线段，线的颜色为Scalar(0,0,0)代表的黑色，线的粗细thickness 为2，且此线为8联通( lineType = 8)。
五，main函数写法

int main()
{
	cv::utils::logging::setLogLevel(utils::logging::LOG_LEVEL_SILENT);//控制台不在输出日志文件
	//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);
	//-------------------绘制化学中的原子示例图----------------------------
	//绘制出椭圆
	DrawEllipse(atomImage,90); 
	DrawEllipse(atomImage,0); 
	DrawEllipse(atomImage,45); 
	DrawEllipse(atomImage,-45);
	//绘制圆心
	DrawFilledCircle(atomImage,Point(WINDOW_WIDTH/2,WINDOW_WIDTH/2));
	//--------------------------绘制组合图---------------------------------
	//绘制出椭圆
	DrawPolygon(rookImage);
	//绘制矩形
	rectangle(rookImage,Point(0,7*WINDOW_WIDTH / 8),Point(WINDOW_WIDTH, WINDOW_WIDTH),Scalar(0,255,255),-1,8);
	//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));
	/*----------------------------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;
}