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<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>
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