private void CompileBlendOp()
{
bool isDefaultOp = (properties.blendOp.GetType() == UserBlendOps.GetDefaultBlendOp());
if (this.Opacity == 255)
{
this.compiledBlendOp = properties.blendOp;
}
else
{
this.compiledBlendOp = properties.blendOp.CreateWithOpacity(this.Opacity);
}
}
public void Render(RenderArgs args, Rectangle[] roi, int startIndex, int length, bool clearBackground)
{
int startLayerIndex;
if (clearBackground)
{
BitmapLayer layer0;
layer0 = this.layers[0] as BitmapLayer;
// Special case: if the first layer is a visible BitmapLayer with full opacity using
// the default blend op, we can just copy the pixels straight over
if (layer0 != null &&
layer0.Visible &&
layer0.Opacity == 255 &&
layer0.BlendOp.GetType() == UserBlendOps.GetDefaultBlendOp())
{
args.Surface.CopySurface(layer0.Surface, roi, startIndex, length);
startLayerIndex = 1;
}
else
{
ClearBackground(args.Surface, roi, startIndex, length);
startLayerIndex = 0;
}
}
else
{
startLayerIndex = 0;
}
for (int i = startLayerIndex; i < this.layers.Count; ++i)
{
Layer layer = (Layer)this.layers[i];
if (layer.Visible)
{
layer.RenderUnchecked(args, roi, startIndex, length);
}
}
}