The advantage of a raster graphic CRT is that it provides fixed-rate refreshing and
does not differentiate one graphic image type from another. However, as illustrated
above, its graphic images can have jagged edges, and every pixel must be redrawn in
every refresh cycle. In spite of these relatively minor problems, raster graphics is the most
popular type of CRT used with PCs.Vector Graphics
Vector graphics, which are also called object-oriented graphics, are based on vectors,
mathematical information that defines how a graphic image is to be drawn on the display.
For example, a line created in vector graphics is defined in terms of its length, width, and
the direction it is drawn from a source point. In contrast to the bit-mapped diagonal line
in Figure 16-11, a vector graphic line is straight with smooth edges. The vector information
to create a circle on the screen would contain thexandypixel location of its center, its line
thickness, line structure (whether it is solid or dashed), and any texturing or coloring of
the line or fill.
The advantages of vector graphics, besides smooth lines and edges, are that they are
easily resized, repositioned, or stretched without degrading the original image, and they re-
quire less video memory than a raster graphic. However, they can use more memory if used
todisplayaphotograph,aparticularimagetypeforwhichavectorgraphicisnotwell-suited.(^388) PC Hardware: A Beginner’s Guide
Figure 16-11. A sloping line created using raster graphics