Previous Next

                                        202
CHAPTER 4                                                                Graphics



tent stream may modify user space to be more suitable to its needs by applying
the coordinate transformation operator, cm (see Section 4.3.3, “Graphics State Op-
erators”). Thus, what may appear to be absolute coordinates in a content stream
are not absolute with respect to the current page because they are expressed in a
coordinate system that may slide around and shrink or expand. Coordinate sys-
tem transformation not only enhances device-independence but is a useful tool
in its own right. For example, a content stream originally composed to occupy an
entire page can be incorporated without change as an element of another page by
shrinking the coordinate system in which it is drawn.




                                                  Device space for
                                                   72-dpi screen

                                        CTM




                       User space




                                                 Device space for
                                                  300-dpi printer




                                FIGURE 4.3 User space

Previous Next