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<h2 align="center">Open, Closed and Filled Polygons,<br>
Bezier Lines and<br>
Regions Creation</h2>
<p>The functions <font><strong>cdBegin</strong></font>,
<font><strong>cdVertex</strong></font> and <font>
<strong>cdEnd</strong></font> are use for many situations.
<font><strong>cdBegin</strong></font> is called once,
<font><strong>cdVertex</strong></font> can be called many
times, and <font><strong>cdEnd</strong></font> is called once
to actually do something. If you call <font><strong>cdBegin</strong></font>
again before <font><strong>cdEnd</strong></font> the process is
restarted, except for <strong><font>cdBegin(</font></strong><b>CD_REGION</b><strong><font>)</font></strong>
that can contains one or more polygons inside. </p>
<hr>
<pre class="function"><span class="mainFunction">void <a name="cdBegin">cdCanvasBegin</a>(cdCanvas* canvas, int mode); [in C]</span>
canvas:Begin(mode: number) [in Lua]</pre>
<p>Starts defining a polygon to be drawn (or filled) according to the mode:
<b>CD_CLOSED_LINES</b>, <b>CD_OPEN_LINES</b>, <b>CD_FILL</b><strong><b>,
</b></strong><b>CD_CLIP, CD_REGION</b> or <strong><b>CD_BEZIER</b></strong>.
Do not create embedded polygons, that is, do not call function
<font><strong>cdBegin</strong></font> twice without a call to
<font><strong>cdEnd</strong></font> in between.</p>
<ul>
<li><strong>CD_OPEN_LINES</strong><b>:</b> connects all the points at cdEnd. Depends
on line width and line style attributes. </li>
<li><b><b>CD_CLOSED_LINES:</b> </b>connects all the points at cdEnd and
connects the last point to the first. Depends on line width and line
style attributes. </li>
<li><b>CD_FILL:</b> connects the last point to the first and fills
the resulting polygon according to the current interior style. When the
interior style <strong><b>CD_HOLLOW</b></strong> is defined the it behaves
as if the mode were <b>CD_CLOSED_LINES</b><strong>.</strong></li>
<li><b>CD_CLIP: i</b>nstead of creating a polygon to be drawn,
creates a polygon to define a polygonal clipping region. </li>
<li><strong><b>CD_BEZIER:</b></strong><b> </b>defines the points of a bezier
curve. There must be at least 4 points: <i>start</i>, <i>control</i>, <i>
control</i> and <i>end</i>. To specify a sequence of curves use 3 more points
for each curve: <i>control</i>, <i>control</i>, <i>end</i>, <i>control</i>, <i>
control</i>, <i>end</i>, ... The end point is used as start point for the next
curve.</li>
<li><strong><b>CD_REGION</b></strong>: starts the creation of a complex
region for clipping. All calls to <font><strong>cdBox</strong></font>,
<font><strong>cdSector</strong></font>, <font>
<strong>cdChord, Filled</strong></font> <font><strong>Polygons</strong></font>
and <font><strong>cdText</strong></font> will be composed in a
region for clipping. See <a href="region.html">Regions</a> documentation.</li>
</ul>
<p align="center"><font size="4">Open, Closed and Filled Polygons<br>
</font><img src="../../img/polygon.gif" border="2" width="249" height="116"></p>
<p align="center"><font size="4">Bezier Lines<br>
</font><img src="../../img/bezier.gif" border="2" width="241" height="220"></p>
<pre class="function"><span class="mainFunction">void <a name="cdVertex">cdCanvasVertex</a>(cdCanvas* canvas, int x, int y); [in C]</span>
void cdfCanvasVertex(cdCanvas* canvas, double x, double y); [in C]
void wdCanvasVertex(cdCanvas* canvas, double x, double y); (WC) [in C]
canvas:Vertex(x, y: number) [in Lua]
canvas:wVertex(x, y: number) (WC) [in Lua]</pre>
<p>Adds a vertex to the polygon definition.</p>
<pre class="function"><span class="mainFunction">void <a name="cdEnd">cdCanvasEnd</a>(cdCanvas* canvas); [in C]</span>
canvas:End() [in Lua]</pre>
<p>Ends the polygon's definition and draws it.</p>
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