[C#/WINFORM] 사인(Sine)과 코사인(Cosine)을 사용해 원과 타원 그리기

TestProject.zip

다운로드

▶ MainForm.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace TestProject
{
    /// <summary>
    /// 메인 폼
    /// </summary>
    public partial class MainForm : Form
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Constructor
        ////////////////////////////////////////////////////////////////////////////////////////// Public

        #region 생성자 - MainForm()

        /// <summary>
        /// 생성자
        /// </summary>
        public MainForm()
        {
            InitializeComponent();

            Load  += Form_Load;
            Paint += Form_Paint;
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Private
        //////////////////////////////////////////////////////////////////////////////// Event

        #region 폼 로드시 처리하기 - Form_Load(sender, e)

        /// <summary>
        /// 폼 로드시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void Form_Load(object sender, EventArgs e)
        {
            ResizeRedraw = true;
        }

        #endregion
        #region 폼 페인트시 처리하기 - Form_Paint(sender, e)

        /// <summary>
        /// 폼 페인트시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        private void Form_Paint(object sender, PaintEventArgs e)
        {
            e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;

            float centerX = ClientRectangle.Width  / 2f;
            float centerY = ClientRectangle.Height / 2f;

            float radiusX = Math.Min(centerX, centerY) - 10;
            float radiusY = radiusX;

            DrawCircle
            (
                e.Graphics,
                Pens.Blue,
                Pens.Orange,
                centerX,
                centerY,
                radiusX,
                radiusY,
                100,
                12,
                0.1f
            );

            radiusX *= 0.8f;
            radiusY *= 0.6f;

            DrawCircle
            (
                e.Graphics,
                Pens.Red,
                Pens.Black,
                centerX,
                centerY,
                radiusX,
                radiusY,
                16,
                16,
                0.1f
            );
        }

        #endregion

        //////////////////////////////////////////////////////////////////////////////// Function

        #region 원 그리기 - DrawCircle(graphics, circlePen, tickPen, centerX, centerY, radiusX, radiusY, thetaCount, tickCount, tickFraction)

        /// <summary>
        /// 원 그리기
        /// </summary>
        /// <param name="graphics">그래픽스</param>
        /// <param name="circlePen">원 펜</param>
        /// <param name="tickPen">틱 펜</param>
        /// <param name="centerX">중심 X</param>
        /// <param name="centerY">중심 Y</param>
        /// <param name="radiusX">반경 X</param>
        /// <param name="radiusY">반경 Y</param>
        /// <param name="thetaCount">세타 카운트</param>
        /// <param name="tickCount">틱 카운트</param>
        /// <param name="tickFraction">틱 조각</param>
        private void DrawCircle
        (
            Graphics graphics,
            Pen      circlePen,
            Pen      tickPen,
            float    centerX,
            float    centerY,
            float    radiusX,
            float    radiusY,
            float    thetaCount,
            float    tickCount,
            float    tickFraction
        )
        {
            List<PointF> pointList = new List<PointF>();

            float deltaTheta = (float)(2 * Math.PI / thetaCount);

            float theta = 0;

            for(int i = 0; i < thetaCount; i++)
            {
                float x = (float)(centerX + radiusX * Math.Cos(theta));
                float y = (float)(centerY + radiusY * Math.Sin(theta));

                pointList.Add(new PointF(x, y));

                theta += deltaTheta;
            }

            graphics.DrawPolygon(circlePen, pointList.ToArray());

            deltaTheta = (float)(2 * Math.PI / tickCount);

            theta = 0;

            float temporaryX = radiusX * (1 - tickFraction);
            float temporaryT = radiusY * (1 - tickFraction);

            for(int i = 0; i < tickCount; i++)
            {
                float x1 = (float)(centerX + radiusX * Math.Cos(theta));
                float y1 = (float)(centerY + radiusY * Math.Sin(theta));

                float x2 = (float)(centerX + temporaryX * Math.Cos(theta));
                float y2 = (float)(centerY + temporaryT * Math.Sin(theta));

                graphics.DrawLine(tickPen, x1, y1, x2, y2);

                theta += deltaTheta;
            }
        }

        #endregion
    }
}