Function glCompressedTextureSubImage1DEXT 

pub unsafe extern "C" fn glCompressedTextureSubImage1DEXT(
    texture: GLuint,
    target: GLenum,
    level: GLint,
    xoffset: GLint,
    width: GLsizei,
    format: GLenum,
    imageSize: GLsizei,
    bits: *const c_void,
)