summaryrefslogtreecommitdiff
path: root/html/en/func/clipping.html
diff options
context:
space:
mode:
authorscuri <scuri>2008-10-17 06:10:33 +0000
committerscuri <scuri>2008-10-17 06:10:33 +0000
commit7b52cc13af4e85f1ca2deb6b6c77de9c95ea0dcf (patch)
treed0857278bde2eff784227c57dcaf930346ceb7ac /html/en/func/clipping.html
First commit - moving from LuaForge to SourceForge
Diffstat (limited to 'html/en/func/clipping.html')
-rw-r--r--html/en/func/clipping.html62
1 files changed, 62 insertions, 0 deletions
diff --git a/html/en/func/clipping.html b/html/en/func/clipping.html
new file mode 100644
index 0000000..b30db55
--- /dev/null
+++ b/html/en/func/clipping.html
@@ -0,0 +1,62 @@
+<!doctype HTML PUBLIC "-//IETF//DTD HTML//EN">
+<html>
+ <head>
+ <title>Clipping</title>
+ <meta http-equiv="Content-Language" content="en-us">
+ <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
+ <link rel="stylesheet" type="text/css" href="../../style.css">
+ </head>
+ <body>
+ <h2 align="center">Clipping</h2>
+ <p>The clipping area is an area that limits the available drawing area inside the
+ canvas. Any primitive is drawn only inside the clipping area. It affects all
+ primitives.</p>
+ <p>You can set the clipping area by using the function <b>cdClipArea</b>, and
+ retrieve it using <b>cdGetClipArea</b>. The clipping area is a rectangle by
+ default, but it can has other shapes. In some drivers a polygon area can be
+ defined, and in display based drivers a complex region can be defined. The
+ complex region can be a combination of boxes, polygons, sectors, chords and
+ texts.</p>
+ <p>The <b>cdClip</b> function activates and deactivaes the clipping.</p>
+ <hr>
+ <pre class="function"><span class="mainFunction">int&nbsp;cdCanvasClip(cdCanvas* canvas, int mode); [in C]</span>
+
+canvas:Clip(mode: number) -&gt; (old_mode: number) [in Lua]</pre>
+ <p>Activates or deactivates clipping. Returns the previous status. Values: <b>CD_CLIPAREA,
+ CD_CLIPPOLYGON, CD_CLIPREGION</b> or <b>CD_CLIPOFF</b>. The value <b>CD_QUERY</b>
+ simply returns the current status. Default value: <b>CD_CLIPOFF</b>.</p>
+ <p>The value <b>CD_CLIPAREA</b> activates a rectangular area as the clipping
+ region.
+ </p>
+ <p>The value <b>CD_CLIPPOLYGON</b> activates a polygon as a clipping region, but
+ works only in some drivers (please refer to the notes of each driver). The
+ clipping polygon must be defined before activating the polygon clipping; if it
+ is not defined, the current clipping state remains unchanged. See the
+ documentation of <a href="polygon.html">cdBegin/cdVertex/cdEnd</a> to create a
+ polygon.</p>
+ <p>The value <b>CD_CLIPREGION</b> activates a complex clipping region. See the
+ documentation of <a href="region.html">Regions</a>.</p>
+ <pre class="function"><span class="mainFunction">void cdCanvasClipArea(cdCanvas* canvas, int xmin, int xmax, int ymin, int ymax); [in C]</span>
+void cdfCanvasClipArea(cdCanvas* canvas, double xmin, double xmax, double ymin, double ymax); [in C]
+void wdCanvasClipArea(cdCanvas* canvas, double xmin, double xmax, double ymin, double ymax); (WC) [in C]
+
+canvas:ClipArea(xmin, xmax, ymin, ymax: number) [in Lua]
+canvas:wClipArea(xmin, xmax, ymin, ymax: number) (WC) [in Lua]</pre>
+ <p>Defines a rectangle for clipping. Only the points in the interval <i><b>xmin&lt;=
+ x &lt;= xmax</b></i> and<b> </b><i><b>ymin &lt;= y &lt;= ymax</b></i> will
+ be printed. Default region: (0, w-1, 0, h-1).
+ </p>
+ <pre class="function"><span class="mainFunction">int&nbsp;cdCanvasGetClipArea(cdCanvas* canvas, int *xmin, int *xmax, int *ymin, int *ymax); [in C]</span>
+int cdfCanvasGetClipArea(cdCanvas* canvas, double *xmin, double *xmax, double *ymin, double *ymax); [in C]
+int wdCanvasGetClipArea(cdCanvas* canvas, double *xmin, double *xmax, double *ymin, double *ymax); (WC) [in C]
+
+canvas:GetClipArea() -&gt; (xmin, xmax, ymin, ymax, status: number) [in Lua]
+canvas:wGetClipArea() -&gt; (xmin, xmax, ymin, ymax, status: number) (WC) [in Lua]</pre>
+ <p>Returns the rectangle and the clipping status. It is not necessary to provide
+ all return pointers, you can provide only the desired values and <i><b>NULL</b></i>
+ for the others.</p>
+ <h4><a name="Polygons">Polygons</a></h4>
+ <p>A polygon for clipping can be created using <font face="Courier"><strong>cdBegin(</strong>CD_CLIP<strong>)/cdVertex(x,y)/.../cdEnd()</strong></font>.</p>
+ <p>See the documentation of <a href="polygon.html">cdBegin/cdVertex/cdEnd</a>.</p>
+ </body>
+</html>