HP 5961-0509 manual Pattern Transparency for Rectangular Area Fill

Pattern Transparency for Rectangular Area Fill

Pattern transparency, described in Chapter 13, under “Pattern Transparency Mode Command,” affects how a pattern is applied to the rectangular fill area. Rectangular areas are special case images for transparency mode. The pattern and pattern type are selected by the Pattern ID command (EC*c#G) and the Fill Rectangular Area (EC*c#P) command (described earlier in this chapter).

Note	Source transparency has no effect on the rectangular fill area since
	the rectangular area is viewed as all 1’s (solid black) source image.

When applying a pattern (area fill) to the rectangular area, the usual transparency mode settings apply. The pattern transparency mode determines the effect white pixels of the pattern have on the destination for value fields 0 (black fill), 2 (shaded fill), 3 (cross-hatch fill), or 5 (current pattern fill) of the Fill Rectangular Area command.

The “0” bits of the area fill are either applied (opaque) or ignored (transparent) based on the transparency mode setting (see Figure

14-3). When a value field of 1 (white fill) is used, pattern transparency mode is always treated as if it were opaque.

The effect of transparency modes on rectangular areas is illustrated in Figure 14-3. In both examples, the source transparency mode is opaque regardless of the actual setting. In the first example, the pattern transparency mode is transparent; the white pixels in the pattern are not applied to the destination, so that the pattern is visible in only two quadrants of the destination. In the second example, the pattern transparency mode is opaque, and the pattern is visible in the entire rectangular area.

EN Pattern Transparency for Rectangular Area Fill 14-11