MetaFun - Pragma ADE

6 Page backgrounds
Especially in interactive documents, adding backgrounds to the page and text areas not only enhances readability,
but also makes it more convenient to identify header, footers and navigational areas. In this chapter
we will demonstrate that with METAPOST we can go beyond the TEX based features present in CONTEXT. One
section is dedicated to graphics and printing, especially bleeding.
6.1 The basic layout
In the CONTEXT manual you can find many details on the composition of the page. When TEX typesets
text, crossing the page boundary triggers TEX's output routine. This routine is responsible for
pasting the body text that goes onto a page in the correct area. A simple representation of such a
page is:
The red areas are the header and footer, while the yellow areas contains the text flow. We can turn
headers on and off and/or hide them. For this reason, the header, text and footer areas together
make up the height of the text.
A close look at the left picture will reveal that the two arrows point to the center of the lines. This is
achieved by the top and lft directives. If we would not have clipped the picture, the arrow would
have stuck half a line width outside the gray area that represents the page. When constructing
such pictures, one should really pay attention to such details, since it pays off in the overall look
and feel of the document.
The vertical arrow represents the top space, while the horizontal arrow denotes the distance to the
back of the cover (back space). By changing their values, you can shift the main body text on the
page. In a double sided layout scheme, the back space is automatically mirrored on even pages.
The basic layout Page backgrounds
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