The maximum number of textures available for this graphic card's fragment shader.

def max_texture_limit(self):
        """The maximum number of textures available for this graphic card's fragment shader."""
        max_unit_array = (gl.GLint * 1)()
        gl.glGetIntegerv(gl.GL_MAX_TEXTURE_IMAGE_UNITS, max_unit_array)
        return max_unit_array[0]