public static void SetPixel(this BitmapData bitmapData, int x, int y, Color color)
{
if (x < 0 || x >= bitmapData.Width ||
y < 0 || y >= bitmapData.Height)
{
return;
}
unsafe
{
int bytesPerPixel = System.Drawing.Bitmap.GetPixelFormatSize(PixelFormat.Format32bppArgb) >> 3;
int widthInBytes = bitmapData.Width * bytesPerPixel;
y = bitmapData.Height - y - 1;
byte *ptrFirstPixel = (byte *)bitmapData.Scan0;
byte *row = ptrFirstPixel + (y * bitmapData.Stride);
int col = x * bytesPerPixel;
row[col + 2] = color.R;
row[col + 1] = color.G;
row[col] = color.B;
}
}
public Circle(int x_center, int y_center, int r, Color color)
{
X_Center = x_center;
Y_Center = y_center;
R = r;
Color = color;
}
/// <summary>
/// Draws anti-aliased circle using Fast Antialiased Line Generation — Xiaolin Wu.
/// </summary>
public override void AntiAliasingRender(BitmapData bitmapData)
{
byte lineColor = 0;
byte bgColor = 255;
int x_ceil = R;
int y = 0;
while (x_ceil > y)
{
double x_real = Math.Sqrt(R * R - y * y);
x_ceil = (int)Math.Ceiling(x_real);
double error = Error(x_ceil, x_real);
byte color_r = (byte)(lineColor * (1 - error) + bgColor * error);
byte color_l = (byte)(lineColor * error + bgColor * (1 - error));
var colorR = new Color()
{
R = color_r, G = color_r, B = color_r
};
var colorL = new Color()
{
R = color_l, G = color_l, B = color_l
};
bitmapData.SetPixel(x_ceil + X_Center, y + Y_Center, colorR);
bitmapData.SetPixel(x_ceil - 1 + X_Center, y + Y_Center, colorL);
bitmapData.SetPixel(y + X_Center, x_ceil + Y_Center, colorR);
bitmapData.SetPixel(y + X_Center, x_ceil + Y_Center - 1, colorL);
bitmapData.SetPixel(y + X_Center, -x_ceil + Y_Center, colorR);
bitmapData.SetPixel(y + X_Center, -x_ceil + Y_Center + 1, colorL);
bitmapData.SetPixel(x_ceil + X_Center, -y + Y_Center, colorR);
bitmapData.SetPixel(x_ceil - 1 + X_Center, -y + Y_Center, colorL);
bitmapData.SetPixel(-x_ceil + X_Center, -y + Y_Center, colorR);
bitmapData.SetPixel(-x_ceil + 1 + X_Center, -y + Y_Center, colorL);
bitmapData.SetPixel(-y + X_Center, -x_ceil + Y_Center, colorR);
bitmapData.SetPixel(-y + X_Center, -x_ceil + Y_Center + 1, colorL);
bitmapData.SetPixel(-y + X_Center, x_ceil + Y_Center, colorR);
bitmapData.SetPixel(-y + X_Center, x_ceil + Y_Center - 1, colorL);
bitmapData.SetPixel(-x_ceil + X_Center, y + Y_Center, colorR);
bitmapData.SetPixel(-x_ceil + 1 + X_Center, y + Y_Center, colorL);
y++;
}
}
public Line(double x0, double y0, double x1, double y1, Color color, int thickness = 5)
{
this.x0 = x0;
this.y0 = y0;
this.x1 = x1;
this.y1 = y1;
this.thickness = thickness;
Color = color;
}
