php-doc-en/reference/ps/functions/ps-rotate.xml

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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<!-- splitted from ./en/functions/ps.xml, last change in rev 1.12 -->
<refentry xml:id="function.ps-rotate" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>ps_rotate</refname>
<refpurpose>Sets rotation factor</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>bool</type><methodname>ps_rotate</methodname>
<methodparam><type>resource</type><parameter>psdoc</parameter></methodparam>
<methodparam><type>float</type><parameter>rot</parameter></methodparam>
</methodsynopsis>
<para>
Sets the rotation of the coordinate system.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>psdoc</parameter></term>
<listitem>
<para>
Resource identifier of the postscript file
as returned by <function>ps_new</function>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>rot</parameter></term>
<listitem>
<para>
Angle of rotation in degree.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
&return.success;
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Rotation of the coordinate system</title>
<programlisting role="php">
<![CDATA[
<?php
function rectangle($ps) {
ps_moveto($ps, 0, 0);
ps_lineto($ps, 0, 50);
ps_lineto($ps, 50, 50);
ps_lineto($ps, 50, 0);
ps_lineto($ps, 0, 0);
ps_stroke($ps);
}
$ps = ps_new();
if (!ps_open_file($ps, "rotation.ps")) {
print "Cannot open PostScript file\n";
exit;
}
ps_set_info($ps, "Creator", "rotation.php");
ps_set_info($ps, "Author", "Uwe Steinmann");
ps_set_info($ps, "Title", "Rotation example");
ps_set_info($ps, "BoundingBox", "0 0 596 842");
$psfont = ps_findfont($ps, "Helvetica", "", 0);
ps_begin_page($ps, 596, 842);
ps_set_text_pos($ps, 100, 100);
ps_save($ps);
ps_translate($ps, 100, 100);
ps_rotate($ps, 45);
rectangle($ps);
ps_restore($ps);
ps_setfont($ps, $psfont, 8.0);
ps_show($ps, "Text without rotation");
ps_end_page($ps);
ps_delete($ps);
?>
]]>
</programlisting>
<para>
The above example illustrates a very common way of rotating a
graphic (in this case just a rectangle) by simply rotating the
coordinate system. Since the graphic's coordinate system assumes
(0,0) to be the origin, the page coordinate system is also translated
to place the graphics not on the edge of the page. Pay attention
to the order of <function>ps_translate</function> and
<function>ps_rotate</function>. In the above case the rectancle is
rotated around the point (100, 100) in the untranslated coordinate
system. Switching the two statements has a completely
different result.
</para>
<para>
In order to output the following text at the original position, all
modifications of the coordinate system are encapsulated in
<function>ps_save</function> and <function>ps_restore</function>.
</para>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>ps_scale</function></member>
<member><function>ps_translate</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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