public static FastBitmap BlendLayers(FastBitmap output, IEnumerable<Layer> layers)
{
DrawingVisual dv = new DrawingVisual();
RenderTargetBitmap rtb = RenderTargetBitmapUtility.CreateRenderTargetBitmap(output.Width, output.Height);
// Draw background.
var dc2 = dv.RenderOpen();
dc2.DrawImage(output.InnerBitmap, new System.Windows.Rect(0, 0, output.Width, output.Height));
dc2.Close();
rtb.Render(dv);
var layersList = layers.ToList();
// As an optimisation, if BlendMode=Normal for all layers, don't use LayerBlenderEffect.
// Just draw images directly using DrawImage.
if (layersList.All(x => x.BlendMode == BlendMode.Normal))
{
foreach (var layer in layersList)
DrawImage(dv, layer, rtb);
}
else
{
ImageSource imageSource = output.InnerBitmap;
foreach (var layer in layersList)
{
using (var effect = new LayerBlenderEffect(layer.BlendMode, output.Width, output.Height)
{
Background = new ImageBrush(imageSource)
{
TileMode = TileMode.None,
Stretch = Stretch.None,
ViewportUnits = BrushMappingMode.RelativeToBoundingBox,
Viewport = new System.Windows.Rect(0, 0, 1, 1)
}
})
{
dv.Effect = effect;
DrawImage(dv, layer, rtb);
}
imageSource = rtb;
}
}
return new FastBitmap(rtb);
}
public static FastBitmap BlendLayers(FastBitmap output, IEnumerable<Layer> layers)
{
DrawingVisual dv = new DrawingVisual();
RenderTargetBitmap rtb = RenderTargetBitmapUtility.CreateRenderTargetBitmap(output.Width, output.Height);
// Draw background.
DrawingContext dc2 = dv.RenderOpen();
dc2.DrawImage(output.InnerBitmap, new System.Windows.Rect(0, 0, output.Width, output.Height));
dc2.Close();
rtb.Render(dv);
ImageSource imageSource = output.InnerBitmap;
foreach (Layer layer in layers)
{
using (var effect = new LayerBlenderEffect(layer.BlendMode, output.Width, output.Height)
{
Background = new ImageBrush(imageSource)
{
TileMode = TileMode.None,
Stretch = Stretch.None,
ViewportUnits = BrushMappingMode.RelativeToBoundingBox,
Viewport = new System.Windows.Rect(0, 0, 1, 1)
}
})
{
dv.Effect = effect;
DrawingContext dc = dv.RenderOpen();
dc.PushTransform(new TranslateTransform(layer.X + layer.Padding.Left, layer.Y + layer.Padding.Top));
dc.DrawImage(layer.Bitmap.InnerBitmap, new System.Windows.Rect(0, 0, layer.Bitmap.Width, layer.Bitmap.Height));
dc.Pop();
dc.Close();
rtb.Render(dv);
}
imageSource = rtb;
}
return new FastBitmap(rtb);
}
