A CodeLab BitmapEffect that draws a pixel art target in Paint.NET

BitmapEffect_ProceduralTarget.cs

// Name: Procedural Target
// Submenu: AAAAAAAA
// Author: Diogo Marques
// Title: Procedural Target
// Version: 0.01
// Desc: Draws a pixel art target, procedurally. Recommended image size: 17x17
// Keywords:
// URL: https://gist.github.com/diogotito/0149dc2dc120c4b06ff5a2628993a004
// Help:

// For help writing a Bitmap plugin: https://boltbait.com/pdn/CodeLab/help/tutorial/bitmap/

static readonly ColorBgra32[] TARGET_COLORS = [
    ColorBgra.GreenYellow,
    ColorBgra.OrangeRed,
    ColorBgra.DeepSkyBlue,
    //ColorBgra.DeepSkyBlue,
    ColorBgra.Black,
    ColorBgra.Black,
    ColorBgra.White,
    ColorBgra.White,
];

ColorBgra32 ComputePixel(double x, double y)
{
    double distance = Math.Sqrt(x * x + y * y);
    int iDist = (int) Math.Round(distance);
    if (iDist >= TARGET_COLORS.Length) return ColorBgra.Transparent;
    return TARGET_COLORS[iDist];
}

#region UICode

#endregion

protected override void OnRender(IBitmapEffectOutput output)
{
    using IEffectInputBitmap<ColorBgra32> sourceBitmap = Environment.GetSourceBitmapBgra32();
    using IBitmapLock<ColorBgra32> sourceLock = sourceBitmap.Lock(new RectInt32(0, 0, sourceBitmap.Size));
    RegionPtr<ColorBgra32> sourceRegion = sourceLock.AsRegionPtr();

    RectInt32 outputBounds = output.Bounds;
    using IBitmapLock<ColorBgra32> outputLock = output.LockBgra32();
    RegionPtr<ColorBgra32> outputSubRegion = outputLock.AsRegionPtr();
    var outputRegion = outputSubRegion.OffsetView(-outputBounds.Location);

    // Delete any of these lines you don't need
    int canvasCenterX = Environment.Document.Size.Width / 2;
    int canvasCenterY = Environment.Document.Size.Height / 2;

    // Loop through the output canvas tile
    for (int y = outputBounds.Top; y < outputBounds.Bottom; ++y)
    {
        if (IsCancelRequested) return;

        for (int x = outputBounds.Left; x < outputBounds.Right; ++x)
        {
            double px = 0.5 + (double) x;
            double py = 0.5 + (double) y;
            double cx = 0.5 + (double) canvasCenterX;
            double cy = 0.5 + (double) canvasCenterY;

            // Save your pixel to the output canvas
            outputRegion[x,y] = ComputePixel(cx - px, cy - py);
        }
    }
}