Function TexSubImage2D 

pub unsafe fn TexSubImage2D(
    target: u32,
    level: i32,
    xoffset: i32,
    yoffset: i32,
    width: i32,
    height: i32,
    format: u32,
    type_: u32,
    pixels: *const c_void,
)

Fallbacks: TexSubImage2DEXT