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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 cdCanvasClip(cdCanvas* canvas, int mode); [in C]</span> + +canvas:Clip(mode: number) -> (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<= + x <= xmax</b></i> and<b> </b><i><b>ymin <= y <= ymax</b></i> will + be printed. Default region: (0, w-1, 0, h-1). + </p> + <pre class="function"><span class="mainFunction">int 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() -> (xmin, xmax, ymin, ymax, status: number) [in Lua] +canvas:wGetClipArea() -> (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> |