C# 円錐形グラデーション

円錐形のグラデーションの描画方法が分からなかったので、

書いてみた。

本当はもっと簡単な方法があるのかもしれない。

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1. //  
2. // ConicalGradient  円錐形グラデーションの描画クラス  
3. //  
4. using System;  
5. using System.Drawing;  
6. using System.Drawing.Imaging;  
7. using System.Runtime.InteropServices;  
8.   
9. using System.Threading.Tasks;  
10.   
11. namespace DrawTest  
12. {  
13.     class ConicalGradient  
14.     {  
15.           
16.         public static Bitmap GetBitmap(Color[] colorList, int width, int height)  
17.         {  
18.             return GetBitmap(colorList, 0, width, height, width / 2, height / 2);  
19.         }  
20.   
21.         public static Bitmap GetBitmap(Color[] colorList, double d, int width, int height)  
22.         {  
23.             return GetBitmap(colorList, d, width, height, width / 2, height / 2);  
24.         }  
25.   
26.         public static Bitmap GetBitmap(Color[] colorList, double d, int width, int height, int centerX, int centerY)  
27.         {  
28.             try  
29.             {  
30.                 //Color配列が空の時はHueの値でも入れとく  
31.                 if (colorList == null || colorList.Length == 0)  
32.                 {  
33.                     colorList = new Color[6];  
34.                     colorList[0] = Color.FromArgb(255, 0, 0);  
35.                     colorList[1] = Color.FromArgb(255, 255, 0);  
36.                     colorList[2] = Color.FromArgb(0, 255, 0);  
37.                     colorList[3] = Color.FromArgb(0, 255, 255);  
38.                     colorList[4] = Color.FromArgb(0, 0, 255);  
39.                     colorList[5] = Color.FromArgb(255, 0, 255);  
40.                 }  
41.   
42.                 Color[] colArry;  
43.                 int colLength;  
44.   
45.                 //色と色の間隔は最大でも256色なので×配列の要素数分の色を作っとく  
46.                 colArry = new Color[colorList.Length * 256];  
47.                 colLength = colArry.Length;  
48.                 Parallel.For(0, colLength, delegate(int i)  
49.                 {  
50.                 //for (int i = 0; i < colLength; i++)  
51.                 //{  
52.                     colArry[i] = GetColor(colorList, ((double)i / colLength) * 360.0);  
53.                 //}  
54.                 });  
55.   
56.   
57.                 Bitmap bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb);  
58.                 BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);  
59.                 int stride = bmpData.Stride;  
60.                 byte[] bmpByte = new byte[height * stride];  
61.   
62.                 const double rad = 180 / Math.PI;  
63.   
64.                 Parallel.For(0, width, delegate(int i)  
65.                 {  
66.                 //for (int i = 0; i < width; i++)   
67.                 //{  
68.                     for (int j = 0; j < height; j++)  
69.                     {  
70.                         double angle = (Math.Atan2(centerY - j, centerX - i) * rad) + 180 + d;  
71.                         angle = (angle + 360) % 360;//0～359.99…の中に収める  
72.   
73.                         Color col = colArry[(int)(angle * (colLength / 360.0))];  
74.   
75.                         bmpByte[(i * 4) + (j * stride) + 3] = col.A;  
76.                         bmpByte[(i * 4) + (j * stride) + 2] = col.R;  
77.                         bmpByte[(i * 4) + (j * stride) + 1] = col.G;  
78.                         bmpByte[(i * 4) + (j * stride) + 0] = col.B;  
79.                     }  
80.                 //}  
81.                 });  
82.   
83.                 Marshal.Copy(bmpByte, 0, bmpData.Scan0, bmpByte.Length);  
84.                 bmp.UnlockBits(bmpData);  
85.   
86.                 return bmp;  
87.             }  
88.             catch  
89.             {  
90.                 return null;  
91.             }  
92.         }  
93.   
94.         /// <summary>  
95.         /// 色の取得  
96.         /// </summary>  
97.         /// <param name="colors">/// <param name="angle">0.0～259.99...        /// <returns></returns>         private static Color GetColor(Color[] colors, double angle)         {             //色の初期化             int a, r, g, b,                 //色の数              length = colors.Length,               num = 0;              int d = (int)(angle / (360.0 / length));              double rest = (angle % (360.0 / length)) / (360.0 / length);               if (d + 1 < length) num = d + 1;              int startA = colors[d].A, endA = colors[num].A,                 startR = colors[d].R, endR = colors[num].R,                 startG = colors[d].G, endG = colors[num].G,                 startB = colors[d].B, endB = colors[num].B;              if (startA < endA)             {                 a = startA + (int)((endA - startA) * rest);             }             else             {                 a = startA - (int)((startA - endA) * rest);             }              if (startR < endR)             {                 r = startR + (int)((endR - startR) * rest);             }             else             {                 r = startR - (int)((startR - endR) * rest);             }              if (startG < endG)             {                 g = startG + (int)((endG - startG) * rest);             }             else             {                 g = startG - (int)((startG - endG) * rest);             }              if (startB < endB)             {                 b = startB + (int)((endB - startB) * rest);             }             else             {                 b = startB - (int)((startB - endB) * rest);             }              return Color.FromArgb(a, r, g, b);         }     } }    

//
// ConicalGradient  円錐形グラデーションの描画クラス
//
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;

using System.Threading.Tasks;

namespace DrawTest
{
    class ConicalGradient
    {
        
        public static Bitmap GetBitmap(Color[] colorList, int width, int height)
        {
            return GetBitmap(colorList, 0, width, height, width / 2, height / 2);
        }

        public static Bitmap GetBitmap(Color[] colorList, double d, int width, int height)
        {
            return GetBitmap(colorList, d, width, height, width / 2, height / 2);
        }

        public static Bitmap GetBitmap(Color[] colorList, double d, int width, int height, int centerX, int centerY)
        {
            try
            {
                //Color配列が空の時はHueの値でも入れとく
                if (colorList == null || colorList.Length == 0)
                {
                    colorList = new Color[6];
                    colorList[0] = Color.FromArgb(255, 0, 0);
                    colorList[1] = Color.FromArgb(255, 255, 0);
                    colorList[2] = Color.FromArgb(0, 255, 0);
                    colorList[3] = Color.FromArgb(0, 255, 255);
                    colorList[4] = Color.FromArgb(0, 0, 255);
                    colorList[5] = Color.FromArgb(255, 0, 255);
                }

                Color[] colArry;
                int colLength;

                //色と色の間隔は最大でも256色なので×配列の要素数分の色を作っとく
                colArry = new Color[colorList.Length * 256];
                colLength = colArry.Length;
                Parallel.For(0, colLength, delegate(int i)
                {
                //for (int i = 0; i < colLength; i++)
                //{
                    colArry[i] = GetColor(colorList, ((double)i / colLength) * 360.0);
                //}
                });


                Bitmap bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb);
                BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
                int stride = bmpData.Stride;
                byte[] bmpByte = new byte[height * stride];

                const double rad = 180 / Math.PI;

                Parallel.For(0, width, delegate(int i)
                {
                //for (int i = 0; i < width; i++) 
                //{
                    for (int j = 0; j < height; j++)
                    {
                        double angle = (Math.Atan2(centerY - j, centerX - i) * rad) + 180 + d;
                        angle = (angle + 360) % 360;//0～359.99…の中に収める

                        Color col = colArry[(int)(angle * (colLength / 360.0))];

                        bmpByte[(i * 4) + (j * stride) + 3] = col.A;
                        bmpByte[(i * 4) + (j * stride) + 2] = col.R;
                        bmpByte[(i * 4) + (j * stride) + 1] = col.G;
                        bmpByte[(i * 4) + (j * stride) + 0] = col.B;
                    }
                //}
                });

                Marshal.Copy(bmpByte, 0, bmpData.Scan0, bmpByte.Length);
                bmp.UnlockBits(bmpData);

                return bmp;
            }
            catch
            {
                return null;
            }
        }

        /// 

        /// 色の取得
        /// 
        /// /// 0.0～259.99...        ///          private static Color GetColor(Color[] colors, double angle)         {             //色の初期化             int a, r, g, b,                 //色の数              length = colors.Length,               num = 0;              int d = (int)(angle / (360.0 / length));              double rest = (angle % (360.0 / length)) / (360.0 / length);               if (d + 1 < length) num = d + 1;              int startA = colors[d].A, endA = colors[num].A,                 startR = colors[d].R, endR = colors[num].R,                 startG = colors[d].G, endG = colors[num].G,                 startB = colors[d].B, endB = colors[num].B;              if (startA < endA)             {                 a = startA + (int)((endA - startA) * rest);             }             else             {                 a = startA - (int)((startA - endA) * rest);             }              if (startR < endR)             {                 r = startR + (int)((endR - startR) * rest);             }             else             {                 r = startR - (int)((startR - endR) * rest);             }              if (startG < endG)             {                 g = startG + (int)((endG - startG) * rest);             }             else             {                 g = startG - (int)((startG - endG) * rest);             }              if (startB < endB)             {                 b = startB + (int)((endB - startB) * rest);             }             else             {                 b = startB - (int)((startB - endB) * rest);             }              return Color.FromArgb(a, r, g, b);         }     } }  

テストに作ってみたコントロール クリックで中心が移動してドラッグで回転する感じ。

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1. using System.Drawing;  
2. using System.Windows.Forms;  
3. using System;  
4. using System.Drawing.Drawing2D;  
5. using System.Diagnostics;  
6.   
7. namespace DrawTest  
8. {  
9.     class ConicalGradientView : Control  
10.     {  
11.         private Bitmap bmp;  
12.   
13.         private double angle = 0;  
14.   
15.         private Point center;  
16.         public Point Center  
17.         {  
18.             get { return center; }  
19.             set  
20.             {  
21.                 center = value;  
22.                 Refresh();  
23.             }  
24.         }  
25.   
26.         private Color[] colors = null;  
27.         public Color[] Colors  
28.         {  
29.             get { return colors; }  
30.             set  
31.             {  
32.                 colors = value;  
33.                 Refresh();  
34.             }  
35.         }  
36.   
37.         public ConicalGradientView()  
38.         {  
39.             SetStyle(ControlStyles.UserPaint, true);  
40.             SetStyle(ControlStyles.AllPaintingInWmPaint, true);  
41.             SetStyle(ControlStyles.OptimizedDoubleBuffer, true);  
42.   
43.             SetStyle(ControlStyles.SupportsTransparentBackColor, true);  
44.             SetStyle(ControlStyles.ResizeRedraw, true);  
45.         }  
46.   
47.         protected override void OnPaint(PaintEventArgs pe)  
48.         {  
49.             base.OnPaint(pe);  
50.             Stopwatch sw = new Stopwatch();  
51.             sw.Start();  
52.   
53.             bmp = ConicalGradient.GetBitmap(colors, angle, this.ClientSize.Width, this.ClientSize.Height, Center.X, Center.Y);  
54.   
55.             Console.WriteLine(sw.Elapsed);  
56.   
57.             if (bmp != null)  
58.             {  
59.                 pe.Graphics.SmoothingMode = SmoothingMode.AntiAlias;  
60.                 pe.Graphics.FillEllipse(new TextureBrush(bmp), 0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1);  
61.                 pe.Graphics.DrawEllipse(Pens.Black, 0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1);  
62.   
63.                 pe.Graphics.DrawEllipse(Pens.Black, Center.X - 5, Center.Y - 5, 10, 10);  
64.             }  
65.         }  
66.   
67.         protected override void OnMouseDown(MouseEventArgs e)  
68.         {  
69.             base.OnMouseDown(e);  
70.             Center = e.Location;  
71.         }  
72.   
73.         protected override void OnMouseMove(MouseEventArgs e)  
74.         {  
75.             base.OnMouseMove(e);  
76.             if (e.Button == MouseButtons.Left)  
77.             {  
78.                 angle = (Math.Atan2(Center.X - e.X, Center.Y - e.Y) * (180 / Math.PI));  
79.   
80.                 Refresh();  
81.             }  
82.         }  
83.     }  
84. }  

using System.Drawing;
using System.Windows.Forms;
using System;
using System.Drawing.Drawing2D;
using System.Diagnostics;

namespace DrawTest
{
    class ConicalGradientView : Control
    {
        private Bitmap bmp;

        private double angle = 0;

        private Point center;
        public Point Center
        {
            get { return center; }
            set
            {
                center = value;
                Refresh();
            }
        }

        private Color[] colors = null;
        public Color[] Colors
        {
            get { return colors; }
            set
            {
                colors = value;
                Refresh();
            }
        }

        public ConicalGradientView()
        {
            SetStyle(ControlStyles.UserPaint, true);
            SetStyle(ControlStyles.AllPaintingInWmPaint, true);
            SetStyle(ControlStyles.OptimizedDoubleBuffer, true);

            SetStyle(ControlStyles.SupportsTransparentBackColor, true);
            SetStyle(ControlStyles.ResizeRedraw, true);
        }

        protected override void OnPaint(PaintEventArgs pe)
        {
            base.OnPaint(pe);
            Stopwatch sw = new Stopwatch();
            sw.Start();

            bmp = ConicalGradient.GetBitmap(colors, angle, this.ClientSize.Width, this.ClientSize.Height, Center.X, Center.Y);

            Console.WriteLine(sw.Elapsed);

            if (bmp != null)
            {
                pe.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
                pe.Graphics.FillEllipse(new TextureBrush(bmp), 0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1);
                pe.Graphics.DrawEllipse(Pens.Black, 0, 0, this.ClientSize.Width - 1, this.ClientSize.Height - 1);

                pe.Graphics.DrawEllipse(Pens.Black, Center.X - 5, Center.Y - 5, 10, 10);
            }
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            Center = e.Location;
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);
            if (e.Button == MouseButtons.Left)
            {
                angle = (Math.Atan2(Center.X - e.X, Center.Y - e.Y) * (180 / Math.PI));

                Refresh();
            }
        }
    }
}

Conical Gradient