X Power Tools

Chapter 10. Core Fonts: Fonts the Old Way

Old Fonts Versus New Fonts

Once of the main differences between Old X and New X (Section 1.3) is the way that fonts are handled. The old font system is often called Core Fonts, because it manages fonts using requests defined in the X core protocols (as opposed to extensions; see Section 1.15). Fonts are managed by the server, and clients instruct the server when and where to draw each glyph(character image). The actual font information can come from files accessible to the server or from a font server, and they may be in any of several different formats.

The problem with core fonts is that they are monochrome only, meaning they are one color. This produces a staircase effect on diagonal lines called aliasing . The effect is very visible in the enlarged font sample shown in Figure 10-1, despite the fact that this font has been designed to minimize diagonal lines (note the use of vertical lines in the lowercase y character). The effect is particularly pronounced on small fonts or low-resolution displays.

Figure 10-1. Enlargement of a monochrome font showing aliasing; note the staircase effect on diagonal lines.

The solution to aliasing is to use intermediate colors—grays if rendering the font black-on-white—to smooth out the staircase effect, as shown in Figure 10-2.

The new font system, discussed in Chapter 11, enables the display of antialiased ...