public static void AddRoundedRectangle(this GraphicsPath graphicsPath, RectangleF rect, float radius, float penWidth = 1)
{
if (radius <= 0f)
{
graphicsPath.AddRectangleProper(rect);
}
else
{
if (penWidth == 1)
{
rect = new RectangleF(rect.X, rect.Y, rect.Width - 1, rect.Height - 1);
}
// If the corner radius is greater than or equal to
// half the width, or height (whichever is shorter)
// then return a capsule instead of a lozenge
if (radius >= (Math.Min(rect.Width, rect.Height) / 2.0f))
{
graphicsPath.AddCapsule(rect);
}
else
{
// Create the arc for the rectangle sides and declare
// a graphics path object for the drawing
float diameter = radius * 2.0f;
SizeF size = new SizeF(diameter, diameter);
RectangleF arc = new RectangleF(rect.Location, size);
// Top left arc
graphicsPath.AddArc(arc, 180, 90);
// Top right arc
arc.X = rect.Right - diameter;
graphicsPath.AddArc(arc, 270, 90);
// Bottom right arc
arc.Y = rect.Bottom - diameter;
graphicsPath.AddArc(arc, 0, 90);
// Bottom left arc
arc.X = rect.Left;
graphicsPath.AddArc(arc, 90, 90);
graphicsPath.CloseFigure();
}
}
}
