Converting from PdnRegion to Direct2D geometry

[null54]

I am trying to convert my Content Aware Fill plugin to a BitmapEffect.

 

The effect creates a new PdnRegion representing the area outside of the selection that the plugin uses for sampling, this region is then converted to a mask bitmap.

 

private PdnRegion CreateSampleRegion()
{
    if (this.sampleSize < 0)
    {
        throw new ArgumentOutOfRangeException(nameof(this.sampleSize), "The sample size cannot be negative.");
    }

    Rectangle[] expandedScans = this.selection.GetRegionScansInt();

    for (int i = 0; i < expandedScans.Length; i++)
    {
        // Expand each scan rectangle by the specified number of pixels.
        expandedScans[i].Inflate(this.sampleSize, this.sampleSize);
    }

    PdnRegion sampleRegion;

    using (PdnGraphicsPath path = new())
    {
        path.FillMode = System.Drawing.Drawing2D.FillMode.Winding;
        path.AddRectangles(expandedScans);

        sampleRegion = new PdnRegion(path);
    }

    // Clip the expanded region to the surface bounds and exclude the original selection.
    // Excluding the original selection prevents sampling from the area that is to be replaced.
    sampleRegion.Intersect(this.sourceBounds);
    sampleRegion.Exclude(this.selection);

    return sampleRegion;
}

 

What would the equivalent IGeometry code be?

ID2D1GeometrySink does not have an AddRectangle method, so I assume that the rectangles would have to be converted to lines.

[Rick Brewster]

You're using this for a mask bitmap? If so then I would create an Alpha8 bitmap and draw into it using FillRectangle() calls. Geometry operations can be quite slow for a complicated selection, but deviceContext.DrawRectangle(RectInt32.Inflate(rect, this.sampleSize, this.sampleSize), brush) should be reasonably fast for this scenario.

 

IImagingFactory imagingFactory = this.GetService<IImagingFactory>();
IDirect2DFactory d2dFactory = this.GetService<IDirect2DFactory>();

IBitmap<ColorAlpha8> maskBitmap = imagingFactory.CreateBitmap<ColorAlpha8>(width, height);

using (IDeviceContext deviceContext = d2dFactory.CreateBitmapDeviceContext(maskBitmap))
{
    using ISolidColorBrush fillBrush = deviceContext.CreateSolidColorBrush(Colors.White);
    using (deviceContext.UseBeginDraw())
    {
        deviceContext.Clear(Colors.Black);
        foreach (RectInt32 rect in selectionRects)
        {
            deviceContext.FillRectangle(RectInt32.Inflate(rect, this.sampleSize, this.sampleSize), fillBrush);
        }
    }
}

 

[null54]

1 hour ago, Rick Brewster said:

You're using this for a mask bitmap?

 

Yes, but my mask bitmap is custom MaskSurface type a not a WIC Bitmap. This avoid having to lock and unlock the bitmap when using it.

 

One issue that I see with your proposed code is that the original selection rectangle is not excluded, but that could be solved with a second FillRectangle call.

Does FillRectangle already handle clipping the rectangle to the image bounds?

 

I also need the bounds of the expanded region, but I can get that from the scan rectangles.

[null54]

@Rick Brewster I got your FillRectange code sample working, but Direct2D ignores the second FilllRectangle call that I am trying to use to mask out the selection.

 

IBitmap<ColorAlpha8> sourceMask = this.imagingFactory.CreateBitmap<ColorAlpha8>(this.environment.Document.Size);
IDirect2DFactory d2dFactory = this.serviceProvider.GetService<IDirect2DFactory>();

RectInt32 maskBounds = RectInt32.Empty;

using (PaintDotNet.Direct2D1.IDeviceContext deviceContext = d2dFactory.CreateBitmapDeviceContext(this.sourceMask))
{
    using (ISolidColorBrush selectedRegionBrush = deviceContext.CreateSolidColorBrush(Colors.White))
    using (ISolidColorBrush unselectedRegionBrush = deviceContext.CreateSolidColorBrush(Colors.TransparentBlack))
    using (deviceContext.UseBeginDraw())
    {
        IReadOnlyList<RectInt32> selectionRects = this.environment.Selection.RenderScans;
        RectInt32 surfaceBounds = this.sourceMask.Bounds();

        deviceContext.Clear(Colors.TransparentBlack);
        foreach (RectInt32 rect in selectionRects)
        {
            RectInt32 expandedRect = RectInt32.Inflate(rect, this.sampleSize, this.sampleSize);
            RectInt32 selectedArea = RectInt32.Intersect(expandedRect, surfaceBounds);

            deviceContext.FillRectangle(selectedArea, selectedRegionBrush);
            // Exclude the pixels in the original selection.
            // Direct2D ignores this command.
            deviceContext.FillRectangle(rect, unselectedRegionBrush);

            maskBounds = RectInt32.Union(maskBounds, selectedArea);
        }
    }
}

 

The alternative approach I have been considering is drawing the mask outline using 4 rectangles, but I would like to avoid that if possible.

[Rick Brewster]

3 hours ago, null54 said:

@Rick Brewster I got your FillRectange code sample working, but Direct2D ignores the second FilllRectangle call that I am trying to use to mask out the selection.

That's because it's transparent and blending is enabled by default -- you need to set the PrimitiveBlend property to PrimitiveBlend.Copy.