Function gl::BlitFramebuffer

pub unsafe fn BlitFramebuffer(srcX0: GLint,
                              srcY0: GLint,
                              srcX1: GLint,
                              srcY1: GLint,
                              dstX0: GLint,
                              dstY0: GLint,
                              dstX1: GLint,
                              dstY1: GLint,
                              mask: GLbitfield,
                              filter: GLenum)

Fallbacks: BlitFramebufferEXT, BlitFramebufferNV