opencv circle

opencv circle

/** @brief Draws a circle.

The function circle draws a simple or filled circle with a given center and radius.
@param img Image where the circle is drawn.
@param center Center of the circle.
@param radius Radius of the circle.
@param color Circle color.
@param thickness Thickness of the circle outline, if positive. Negative thickness means that a
filled circle is to be drawn.
@param lineType Type of the circle boundary. See the line description.
@param shift Number of fractional bits in the coordinates of the center and in the radius value.
 */
CV_EXPORTS_W void circle(InputOutputArray img, Point center, int radius,
                       const Scalar& color, int thickness = 1,
                       int lineType = LINE_8, int shift = 0);

void circle( InputOutputArray _img, Point center, int radius,
             const Scalar& color, int thickness, int line_type, int shift )
{
    CV_INSTRUMENT_REGION();

    Mat img = _img.getMat();

    if( line_type == CV_AA && img.depth() != CV_8U )
        line_type = 8;

    CV_Assert( radius >= 0 && thickness <= MAX_THICKNESS &&
        0 <= shift && shift <= XY_SHIFT );

    double buf[4];
    scalarToRawData(color, buf, img.type(), 0);

    if( thickness > 1 || line_type != LINE_8 || shift > 0 )
    {
        Point2l _center(center);
        int64 _radius(radius);
        _center.x <<= XY_SHIFT - shift;
        _center.y <<= XY_SHIFT - shift;
        _radius <<= XY_SHIFT - shift;
        EllipseEx( img, _center, Size2l(_radius, _radius),
                   0, 0, 360, buf, thickness, line_type );
    }
    else
        Circle( img, center, radius, buf, thickness < 0 );
}

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