glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
glPixelStorei(GL_UNPACK_SKIP_ROWS, skiprows);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, skippixels);
glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);