Trigonometric Bézier and Stancu polynomials over intervals and triangles

We introduce a family of trigonometric polynomials, denoted as Stancu polynomials, which contains the trigonometric Lagrange and Bernstein polynomials. This family depends only on one real parameter, denoted as design parameter. Our approach works for curves as well as for surfaces over triangles. The resulting Stancu curves respectively surfaces therefore establish a link between trigonometric interpolatory and Bernstein-Bézier curves respectively surfaces.