opencv::绘制-基本几何

画线   cv::line（LINE_4\LINE_8\LINE_AA）
画椭圆 cv::ellipse
画矩形 cv::rectangle
画圆   cv::circle
画填充 cv::fillPoly

    putText(bgImage, "Hello OpenCV 你好 ", Point(, ), CV_FONT_HERSHEY_COMPLEX, 1.0, Scalar(, , ), , );

void MyLines() {
    Point p1 = Point(, );
    Point p2;
    p2.x = ;
    p2.y = ;
    Scalar color = Scalar(, , );
    line(bgImage, p1, p2, color, , LINE_AA);
}

void MyRectangle() {
    Rect rect = Rect(, , , );
    Scalar color = Scalar(, , );
    rectangle(bgImage, rect, color, , LINE_8);
}

void MyEllipse() {
    Scalar color = Scalar(, , );
    ellipse(bgImage, Point(bgImage.cols / , bgImage.rows / ), Size(bgImage.cols / , bgImage.rows / ), , , , color, , LINE_8);
}

void MyCircle() {
    Scalar color = Scalar(, , );
    Point center = Point(bgImage.cols / , bgImage.rows / );
    circle(bgImage, center, , color, , );
}

void MyPolygon() {
    Point pts[][];
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );
    pts[][] = Point(, );

    const Point* ppts[] = { pts[] };
    int npt[] = {  };
    Scalar color = Scalar(, , );

    fillPoly(bgImage, ppts, npt, , color, );
}

void RandomLineDemo() {
    RNG rng();
    Point pt1;
    Point pt2;
    Mat bg = Mat::zeros(bgImage.size(), bgImage.type());
    namedWindow("random line demo", CV_WINDOW_AUTOSIZE);
    for (int i = ; i < ; i++) {
        pt1.x = rng.uniform(, bgImage.cols);
        pt2.x = rng.uniform(, bgImage.cols);
        pt1.y = rng.uniform(, bgImage.rows);
        pt2.y = rng.uniform(, bgImage.rows);
        Scalar color = Scalar(rng.uniform(, ), rng.uniform(, ), rng.uniform(, ));
        if (waitKey() > ) {
            break;
        }
        line(bg, pt1, pt2, color, , );
        imshow("random line demo", bg);
    }
}

int drawRandomLines(Mat image) {
    RNG rng(0xffffff);
    Point pt1, pt2;
    for (int i = ; i < ; i++) {
        pt1.x = rng.uniform(, image.cols);
        pt2.x = rng.uniform(, image.cols);
        pt1.y = rng.uniform(, image.rows);
        pt2.y = rng.uniform(, image.rows);
        int r = rng.uniform(, );
        int g = rng.uniform(, );
        int b = rng.uniform(, );
        line(image, pt1, pt2, Scalar(b, g, r), , LINE_8);
        putText(image, "Open CV Core Tutorial", Point(image.cols /  - , image.rows / ),
            CV_FONT_HERSHEY_PLAIN, 2.0, Scalar(, , ), , LINE_8);

        imshow(WINTITLE, image);
        if (waitKey() >= )
        {
            return -;
        }
    }
    return ;
}