private void Draw(TEdge edge, D2dBrush brush, D2dGraphics g)
{
Vec2F startPoint = new Vec2F();
Vec2F endPoint = new Vec2F();
CircleF c = new CircleF();
bool moreThan180 = false;
Vec2F endTangent;
Vec2F textPoint;
int route = edge.FromRoute.Index;
if (GetEdgeGeometry(edge, route, ref startPoint, ref endPoint, ref c, ref moreThan180))
{
g.DrawLine(new PointF(startPoint.X, startPoint.Y),
new PointF(endPoint.X, endPoint.Y),
brush,
m_theme.StrokeWidth);
endTangent = endPoint - startPoint;
textPoint = (endPoint + startPoint) * 0.5f;
}
else
{
// prepare to draw arc
RectangleF rect = new RectangleF(c.Center.X - c.Radius, c.Center.Y - c.Radius, 2 * c.Radius, 2 * c.Radius);
double angle1 = Math.Atan2(startPoint.Y - c.Center.Y, startPoint.X - c.Center.X);
double angle2 = Math.Atan2(endPoint.Y - c.Center.Y, endPoint.X - c.Center.X);
const double twoPi = 2 * Math.PI;
// swap so we always go clockwise
if (angle1 > angle2)
{
double temp = angle1;
angle1 = angle2;
angle2 = temp;
}
double startAngle = angle1;
double sweepAngle = angle2 - angle1;
if (moreThan180)
{
if (sweepAngle < Math.PI)
{
sweepAngle = -(twoPi - sweepAngle);
}
}
else
{
if (sweepAngle > Math.PI)
{
sweepAngle = -(twoPi - sweepAngle);
}
}
const double RadiansToDegrees = 360 / twoPi;
startAngle *= RadiansToDegrees;
sweepAngle *= RadiansToDegrees;
g.DrawArc((D2dEllipse)rect,
brush,
(float)startAngle,
(float)sweepAngle,
m_theme.StrokeWidth);
endTangent = endPoint - c.Center; endTangent = endTangent.Perp;
textPoint = (endPoint + startPoint) * 0.5f;
CircleF.Project(textPoint, c, ref textPoint);
if (moreThan180)
{
textPoint -= 2 * (textPoint - c.Center);
}
}
DrawArrow(endPoint, endTangent, brush, g);
string label = edge.Label;
if (!string.IsNullOrEmpty(label))
{
RectangleF textBox = new RectangleF(textPoint.X - 512, textPoint.Y, 1024, m_theme.TextFormat.FontHeight);
g.DrawText(label, m_theme.TextFormat, textBox, m_theme.TextBrush);
}
}
