Function GradientFill 

pub unsafe extern "system" fn GradientFill(
    hdc: *mut c_void,
    pvertex: *const TRIVERTEX,
    nvertex: u32,
    pmesh: *const c_void,
    nmesh: u32,
    ulmode: u32,
) -> i32

METAFILE#11 GradientFill

specifies filling rectangles or triangles with gradients of color

See also

• MS-EMF:v14 2.3.5.12 EMR_GRADIENTFILL Record