public static Shape createRoundTrianglePath( float x1, float y1, float x2, float y2,
		float x3, float y3, float arc )
	{
		double averageSideLength = (distance( x1,y1, x2,y2 ) + distance( x2,y2, x3,y3 ) + distance( x3,y3, x1,y1 )) / 3;
		double t1 = (1 / averageSideLength) * arc;
		double t2 = 1 - t1;

		return createPath(
			lerp( x3, x1, t2 ), lerp( y3, y1, t2 ),
			QUAD_TO, x1, y1, lerp( x1, x2, t1 ), lerp( y1, y2, t1 ),
			lerp( x1, x2, t2 ), lerp( y1, y2, t2 ),
			QUAD_TO, x2, y2, lerp( x2, x3, t1 ), lerp( y2, y3, t1 ),
			lerp( x2, x3, t2 ), lerp( y2, y3, t2 ),
			QUAD_TO, x3, y3, lerp( x3, x1, t1 ), lerp( y3, y1, t1 ) );
	}
Creates a rounded triangle shape for the given points and arc radius.

@since 3
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java