<!-- Creator : groff version 1.21 --> <!-- CreationDate: Wed Feb 9 07:50:05 2011 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta name="generator" content="groff -Thtml, see www.gnu.org"> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <meta name="Content-Style" content="text/css"> <style type="text/css"> p { margin-top: 0; margin-bottom: 0; vertical-align: top } pre { margin-top: 0; margin-bottom: 0; vertical-align: top } table { margin-top: 0; margin-bottom: 0; vertical-align: top } h1 { text-align: center } </style> <title>pic-5.html</title> </head> <hr> <a href="http://validator.w3.org/check?uri=referer"><img src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a> [ <a href="pic-4.html">prev</a> | <a href="pic-6.html">next</a> | <a href="pic.html">top</a> ] <hr> <h2>5. Generalized Lines and Splines <a name="5. Generalized Lines and Splines"></a> </h2> <h3>5.1. Diagonal Lines <a name="5.1. Diagonal Lines"></a> </h3> <p style="margin-top: 1em">It is possible to specify diagonal lines or arrows by adding multiple <b>up</b>, <b>down</b>, <b>left</b>, and <b>right</b> modifiers to the line object. Any of these can have a multiplier. To understand the effects, think of the drawing area as being gridded with standard-sized boxes.</p> <p align="center" style="margin-top: 1em"><img src="img/pic14.png" alt="Image img/pic14.png"></p> <p align="center" style="margin-top: 1em">Figure 5-1: Diagonal arrows (dotted boxes show the implied 0.5-inch grid)</p> <h3>5.2. Multi-Segment Line Objects <a name="5.2. Multi-Segment Line Objects"></a> </h3> <p style="margin-top: 1em">A “line” or “arrow” object may actually be a path consisting of any number of segments of varying lengths and directions. To describe a path, connect several line or arrow commands with the keyword <b>then</b>.</p> <p align="center" style="margin-top: 1em"><img src="img/pic15.png" alt="Image img/pic15.png"></p> <p align="center" style="margin-top: 1em">Figure 5-2: <b>line right 1 then down .5 left 1 then right 1</b></p> <p style="margin-top: 1em">If a path starts with <b>then</b>, the first segment is assumed to be into the current direction, using the default length.</p> <h3>5.3. Spline Objects <a name="5.3. Spline Objects"></a> </h3> <p style="margin-top: 1em">If you start a path with the <b>spline</b> keyword, the path vertices are treated as control points for a spline curve fit.</p> <p align="center" style="margin-top: 1em"><img src="img/pic16.png" alt="Image img/pic16.png"></p> <p align="center" style="margin-top: 1em">Figure 5-3: <b>spline right 1 then down .5 left 1 then right 1</b></p> <p style="margin-top: 1em">You can describe many natural-looking but irregular curves this way. For example:</p> <p align="center" style="margin-top: 1em"><img src="img/pic17.png" alt="Image img/pic17.png"></p> <p align="center">Figure 5-4: Two more spline examples</p> <p style="margin-top: 1em">Note the arrow decorations. Arrowheads can be applied naturally to any path-based object, line or spline. We’ll see how in the next section.</p> <hr> <a href="http://validator.w3.org/check?uri=referer"><img src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01 Transitional" height="31" width="88"></a> [ <a href="pic-4.html">prev</a> | <a href="pic-6.html">next</a> | <a href="pic.html">top</a> ] <hr>