Function fltk::draw::draw_rectf_with_rgb

pub fn draw_rectf_with_rgb(
    x: i32, 
    y: i32, 
    width: i32, 
    height: i32, 
    color_r: u8, 
    color_g: u8, 
    color_b: u8
)

Draws a filled rectangle with specified RGB color