/// <summary>
/// Get the Geometry of the Stroke
/// </summary>
/// <param name="drawingAttributes"></param>
/// <returns></returns>
public Geometry GetGeometry(DrawingAttributes drawingAttributes)
{
if (drawingAttributes == null)
{
throw new ArgumentNullException("drawingAttributes");
}
bool geometricallyEqual = DrawingAttributes.GeometricallyEqual(drawingAttributes, this.DrawingAttributes);
// need to recalculate the PathGemetry if the DA passed in is "geometrically" different from
// this DA, or if the cached PathGeometry is dirty.
if (false == geometricallyEqual || (true == geometricallyEqual && null == _cachedGeometry))
{
//Recalculate _pathGeometry;
StrokeNodeIterator iterator = StrokeNodeIterator.GetIterator(this, drawingAttributes);
Geometry geometry;
Rect bounds;
StrokeRenderer.CalcGeometryAndBounds(iterator,
drawingAttributes,
#if DEBUG_RENDERING_FEEDBACK
null, 0d, false,
#endif
true, //calc bounds
out geometry,
out bounds);
// return the calculated value directly. We cannot cache the result since the DA passed in
// is "geometrically" different from this.DrawingAttributes.
if (false == geometricallyEqual)
{
return(geometry);
}
// Cache the value and set _isPathGeometryDirty to false;
SetGeometry(geometry);
SetBounds(bounds);
return(geometry);
}
// return a ref to our _cachedGeometry
System.Diagnostics.Debug.Assert(_cachedGeometry != null && _cachedGeometry.IsFrozen);
return(_cachedGeometry);
}
/// <summary>
/// The core functionality to draw a stroke. The function can be called from the following code paths.
/// i) From StrokeVisual.OnRender
/// a. Highlighter strokes have been grouped and the correct opacity has been set on the container visual.
/// b. For a highlighter stroke with color.A != 255, the DA passed in is a copy with color.A set to 255.
/// c. _drawAsHollow can be true, i.e., Selected stroke is drawn as hollow
/// ii) From StrokeCollection.Draw.
/// a. Highlighter strokes have been grouped and the correct opacity has been pushed.
/// b. For a highlighter stroke with color.A != 255, the DA passed in is a copy with color.A set to 255.
/// c. _drawAsHollow is always false, i.e., Selected stroke is not drawn as hollow
/// iii) From Stroke.Draw
/// a. The correct opacity has been pushed for a highlighter stroke
/// b. For a highlighter stroke with color.A != 255, the DA passed in is a copy with color.A set to 255.
/// c. _drawAsHollow is always false, i.e., Selected stroke is not drawn as hollow
/// We need to document the following:
/// 1) our default implementation so developers can see what we've done here -
/// including how we handle IsHollow
/// 2) the fact that opacity has already been set up correctly for the call.
/// 3) that developers should not call base.DrawCore if they override this
/// </summary>
/// <param name="drawingContext">DrawingContext to draw on</param>
/// <param name="drawingAttributes">DrawingAttributes to draw with</param>
protected virtual void DrawCore(DrawingContext drawingContext, DrawingAttributes drawingAttributes)
{
if (null == drawingContext)
{
throw new System.ArgumentNullException("drawingContext");
}
if (null == drawingAttributes)
{
throw new System.ArgumentNullException("drawingAttributes");
}
if (_drawAsHollow == true)
{
// Draw as hollow. Our profiler result shows that the two-pass-rendering approach is about 5 times
// faster that using GetOutlinePathGeometry.
// also, the minimum display size for selected ink is our default width / height
Matrix innerTransform, outerTransform;
DrawingAttributes selectedDA = drawingAttributes.Clone();
selectedDA.Height = Math.Max(selectedDA.Height, DrawingAttributes.DefaultHeight);
selectedDA.Width = Math.Max(selectedDA.Width, DrawingAttributes.DefaultWidth);
CalcHollowTransforms(selectedDA, out innerTransform, out outerTransform);
// First pass drawing. Use drawingAttributes.Color to create a solid color brush. The stroke will be drawn as
// 1 avalon-unit higher and wider (HollowLineSize = 1.0f)
selectedDA.StylusTipTransform = outerTransform;
SolidColorBrush brush = new SolidColorBrush(drawingAttributes.Color);
brush.Freeze();
drawingContext.DrawGeometry(brush, null, GetGeometry(selectedDA));
//Second pass drawing with a white color brush. The stroke will be drawn as
// 1 avalon-unit shorter and narrower (HollowLineSize = 1.0f) if the actual-width/height (considering StylusTipTransform)
// is larger than HollowLineSize. Otherwise the same size stroke is drawn.
selectedDA.StylusTipTransform = innerTransform;
drawingContext.DrawGeometry(Brushes.White, null, GetGeometry(selectedDA));
}
else
{
#if DEBUG_RENDERING_FEEDBACK
//render debug feedback?
Guid guid = new Guid("52053C24-CBDD-4547-AAA1-DEFEBF7FD1E1");
if (this.ContainsPropertyData(guid))
{
double thickness = (double)this.GetPropertyData(guid);
//first, draw the outline of the stroke
drawingContext.DrawGeometry(null,
new Pen(Brushes.Black, thickness),
GetGeometry());
Geometry g2;
Rect b2;
//next, overlay the connecting quad points
StrokeRenderer.CalcGeometryAndBounds(StrokeNodeIterator.GetIterator(this, drawingAttributes),
drawingAttributes,
drawingContext, thickness, true,
true, //calc bounds
out g2,
out b2);
}
else
{
#endif
SolidColorBrush brush = new SolidColorBrush(drawingAttributes.Color);
brush.Freeze();
drawingContext.DrawGeometry(brush, null, GetGeometry(drawingAttributes));
#if DEBUG_RENDERING_FEEDBACK
}
#endif
}
}
