/// <summary>
/// Renders a bond to the display
/// </summary>
public override void Render()
{
//set up the shared variables first
Point startPoint, endPoint;
startPoint = ParentBond.StartAtom.Position;
endPoint = ParentBond.EndAtom.Position;
var bondLength = ParentBond.Model.XamlBondLength;
var cv1 = ChemicalVisuals.ContainsKey(ParentBond.StartAtom);
var cv2 = ChemicalVisuals.ContainsKey(ParentBond.EndAtom);
//bale out in case we have a null start or end
if (!cv1 || !cv2)
{
// Abort if either ChemicalVisual is missing !
return;
}
//now get the geometry of start and end atoms
var startVisual = (AtomVisual)ChemicalVisuals[ParentBond.StartAtom];
var endVisual = (AtomVisual)ChemicalVisuals[ParentBond.EndAtom];
//first grab the main descriptor
BondDescriptor = GetBondDescriptor(ParentBond, startVisual, endVisual, bondLength);
_enclosingPoly = BondDescriptor.Boundary;
//set up the default pens for rendering
_mainBondPen = new Pen(Brushes.Black, BondThickness)
{
StartLineCap = PenLineCap.Round,
EndLineCap = PenLineCap.Round,
LineJoin = PenLineJoin.Miter
};
_subsidiaryBondPen = _mainBondPen.Clone();
switch (ParentBond.Order)
{
case Globals.OrderZero:
case Globals.OrderOther:
case "unknown":
// Handle Zero Bond
_mainBondPen.DashStyle = DashStyles.Dot;
using (DrawingContext dc = RenderOpen())
{
dc.DrawGeometry(Brushes.Black, _mainBondPen, BondDescriptor.DefiningGeometry);
//we need to draw another transparent rectangle to expand the bounding box
DrawHitTestOverlay(dc);
dc.Close();
}
DoubleBondLayout dbd = new DoubleBondLayout
{
Start = startPoint,
End = endPoint,
Placement = ParentBond.Placement
};
BondGeometry.GetDoubleBondPoints(dbd, bondLength);
_enclosingPoly = dbd.Boundary;
break;
case Globals.OrderPartial01:
_mainBondPen.DashStyle = DashStyles.Dash;
using (DrawingContext dc = RenderOpen())
{
dc.DrawGeometry(Brushes.Black, _mainBondPen, BondDescriptor.DefiningGeometry);
//we need to draw another transparent thicker line on top of the existing one
DrawHitTestOverlay(dc);
dc.Close();
}
//grab the enclosing polygon as for a double ParentBond - this overcomes a hit testing bug
DoubleBondLayout dbd2 = new DoubleBondLayout
{
Start = startPoint,
End = endPoint,
Placement = ParentBond.Placement
};
BondGeometry.GetDoubleBondPoints(dbd2, bondLength);
_enclosingPoly = dbd2.Boundary;
break;
case "1":
case Globals.OrderSingle:
// Handle Single bond
switch (ParentBond.Stereo)
{
case Globals.BondStereo.Indeterminate:
case Globals.BondStereo.None:
case Globals.BondStereo.Wedge:
using (DrawingContext dc = RenderOpen())
{
dc.DrawGeometry(Brushes.Black, _mainBondPen, BondDescriptor.DefiningGeometry);
//we need to draw another transparent rectangle to expand the bounding box
DrawHitTestOverlay(dc);
dc.Close();
}
break;
case Globals.BondStereo.Hatch:
using (DrawingContext dc = RenderOpen())
{
dc.DrawGeometry(GetHatchBrush(ParentBond.Angle), _mainBondPen, BondDescriptor.DefiningGeometry);
//we need to draw another transparent rectangle to expand the bounding box
DrawHitTestOverlay(dc);
dc.Close();
}
break;
}
break;
case Globals.OrderPartial12:
case Globals.OrderAromatic:
case "2":
case Globals.OrderDouble:
DoubleBondLayout dbd3 = (DoubleBondLayout)BondDescriptor;
Point? centroid = ParentBond.Centroid;
dbd3.PrimaryCentroid = centroid;
if (ParentBond.Order == Globals.OrderPartial12 || ParentBond.Order == Globals.OrderAromatic) // Handle 1.5 bond
{
_subsidiaryBondPen.DashStyle = DashStyles.Dash;
}
_enclosingPoly = dbd3.Boundary;
if (ParentBond.Stereo != Globals.BondStereo.Indeterminate)
{
using (DrawingContext dc = RenderOpen())
{
dc.DrawLine(_mainBondPen, BondDescriptor.Start, BondDescriptor.End);
dc.DrawLine(_subsidiaryBondPen,
dbd3.SecondaryStart,
dbd3.SecondaryEnd);
dc.Close();
}
}
else
{
using (DrawingContext dc = RenderOpen())
{
dc.DrawGeometry(_mainBondPen.Brush, _mainBondPen, BondDescriptor.DefiningGeometry);
dc.Close();
}
}
break;
case Globals.OrderPartial23:
case "3":
case Globals.OrderTriple:
if (ParentBond.Order == Globals.OrderPartial23) // Handle 2.5 bond
{
_subsidiaryBondPen.DashStyle = DashStyles.Dash;
}
var tbd = (BondDescriptor as TripleBondLayout);
using (DrawingContext dc = RenderOpen())
{
if (ParentBond.Placement == Globals.BondDirection.Clockwise)
{
dc.DrawLine(_mainBondPen, tbd.SecondaryStart, tbd.SecondaryEnd);
dc.DrawLine(_mainBondPen, tbd.Start, tbd.End);
dc.DrawLine(_subsidiaryBondPen, tbd.TertiaryStart, tbd.TertiaryEnd);
}
else
{
dc.DrawLine(_subsidiaryBondPen, tbd.SecondaryStart, tbd.SecondaryEnd);
dc.DrawLine(_mainBondPen, tbd.Start, tbd.End);
dc.DrawLine(_mainBondPen, tbd.TertiaryStart, tbd.TertiaryEnd);
}
dc.Close();
}
break;
}
void DrawHitTestOverlay(DrawingContext dc)
{
SolidColorBrush outliner = new SolidColorBrush(Colors.Salmon);
#if SHOWBOUNDS
outliner.Opacity = 0.2d;
#else
outliner.Opacity = 0d;
#endif
Pen outlinePen = new Pen(outliner, BondThickness * 5);
dc.DrawGeometry(outliner, outlinePen, BondDescriptor.DefiningGeometry);
}
}
