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GTK+-2.0源码之pango-1.15.6.tar.gz

<refsect2>
<title><anchor id="pango-matrix-copy" role="function" condition="since:1.6"/>pango_matrix_copy ()</title>
<indexterm role="1.6"><primary>pango_matrix_copy</primary></indexterm><programlisting><link linkend="PangoMatrix">PangoMatrix</link>* pango_matrix_copy              (const <link linkend="PangoMatrix">PangoMatrix</link> *matrix);</programlisting>
<para>
Copies a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, can be <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
<varlistentry><term><emphasis>Returns</emphasis>&nbsp;:</term><listitem><simpara> the newly allocated <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, which should
              be freed with <link linkend="pango-matrix-free"><function>pango_matrix_free()</function></link>, or <link linkend="NULL:CAPS"><literal>NULL</literal></link> if
              <parameter>matrix</parameter> was <link linkend="NULL:CAPS"><literal>NULL</literal></link>.

</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-free" role="function" condition="since:1.6"/>pango_matrix_free ()</title>
<indexterm role="1.6"><primary>pango_matrix_free</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_free               (<link linkend="PangoMatrix">PangoMatrix</link> *matrix);</programlisting>
<para>
Free a <link linkend="PangoMatrix"><type>PangoMatrix</type></link> created with <link linkend="pango-matrix-copy"><function>pango_matrix_copy()</function></link>.
Does nothing if <parameter>matrix</parameter> is <link linkend="NULL:CAPS"><literal>NULL</literal></link>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, or <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-translate" role="function" condition="since:1.6"/>pango_matrix_translate ()</title>
<indexterm role="1.6"><primary>pango_matrix_translate</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_translate          (<link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="double">double</link> tx,
                                             <link linkend="double">double</link> ty);</programlisting>
<para>
Changes the transformation represented by <parameter>matrix</parameter> to be the
transformation given by first translating by (<parameter>tx</parameter>, <parameter>ty</parameter>)
then applying the original transformation.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>tx</parameter>&nbsp;:</term>
<listitem><simpara> amount to translate in the X direction
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>ty</parameter>&nbsp;:</term>
<listitem><simpara> amount to translate in the Y direction
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-scale" role="function" condition="since:1.6"/>pango_matrix_scale ()</title>
<indexterm role="1.6"><primary>pango_matrix_scale</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_scale              (<link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="double">double</link> scale_x,
                                             <link linkend="double">double</link> scale_y);</programlisting>
<para>
Changes the transformation represented by <parameter>matrix</parameter> to be the
transformation given by first scaling by <parameter>sx</parameter> in the X direction
and <parameter>sy</parameter> in the Y direction then applying the original
transformation.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>scale_x</parameter>&nbsp;:</term>
<listitem><simpara> amount to scale by in X direction
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>scale_y</parameter>&nbsp;:</term>
<listitem><simpara> amount to scale by in Y direction
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-rotate" role="function" condition="since:1.6"/>pango_matrix_rotate ()</title>
<indexterm role="1.6"><primary>pango_matrix_rotate</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_rotate             (<link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="double">double</link> degrees);</programlisting>
<para>
Changes the transformation represented by <parameter>matrix</parameter> to be the
transformation given by first rotating by <parameter>degrees</parameter> degrees
counter-clockwise then applying the original transformation.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>degrees</parameter>&nbsp;:</term>
<listitem><simpara> degrees to rotate counter-clockwise
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-concat" role="function" condition="since:1.6"/>pango_matrix_concat ()</title>
<indexterm role="1.6"><primary>pango_matrix_concat</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_concat             (<link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             const <link linkend="PangoMatrix">PangoMatrix</link> *new_matrix);</programlisting>
<para>
Changes the transformation represented by <parameter>matrix</parameter> to be the
transformation given by first applying transformation
given by <parameter>new_matrix</parameter> then applying the original transformation.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>new_matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.6
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-transform-point" role="function" condition="since:1.16"/>pango_matrix_transform_point ()</title>
<indexterm role="1.16"><primary>pango_matrix_transform_point</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_transform_point    (const <link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="double">double</link> *x,
                                             <link linkend="double">double</link> *y);</programlisting>
<para>
Transforms the point (<parameter>x</parameter>, <parameter>y</parameter>) by <parameter>matrix</parameter>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, or <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>x</parameter>&nbsp;:</term>
<listitem><simpara> in/out X position
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>y</parameter>&nbsp;:</term>
<listitem><simpara> in/out Y position
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.16
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-transform-distance" role="function" condition="since:1.16"/>pango_matrix_transform_distance ()</title>
<indexterm role="1.16"><primary>pango_matrix_transform_distance</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_transform_distance (const <link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="double">double</link> *dx,
                                             <link linkend="double">double</link> *dy);</programlisting>
<para>
Transforms the distance vector (<parameter>dx</parameter>,<parameter>dy</parameter>) by <parameter>matrix</parameter>. This is
similar to <link linkend="pango-matrix-transform-point"><function>pango_matrix_transform_point()</function></link> except that the translation
components of the transformation are ignored. The calculation of
the returned vector is as follows:
</para>
<para>
<programlisting>
dx2 = dx1 * xx + dy1 * xy;
dy2 = dx1 * yx + dy1 * yy;
</programlisting>
</para>
<para>
Affine transformations are position invariant, so the same vector
always transforms to the same vector. If (<parameter>x1</parameter>,<parameter>y1</parameter>) transforms
to (<parameter>x2</parameter>,<parameter>y2</parameter>) then (<parameter>x1</parameter>+<parameter>dx1</parameter>,<parameter>y1</parameter>+<parameter>dy1</parameter>) will transform to
(<parameter>x1</parameter>+<parameter>dx2</parameter>,<parameter>y1</parameter>+<parameter>dy2</parameter>) for all values of <parameter>x1</parameter> and <parameter>x2</parameter>.</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, or <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>dx</parameter>&nbsp;:</term>
<listitem><simpara> in/out X component of a distance vector
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>dy</parameter>&nbsp;:</term>
<listitem><simpara> yn/out Y component of a distance vector
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.16
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-transform-rectangle" role="function" condition="since:1.16"/>pango_matrix_transform_rectangle ()</title>
<indexterm role="1.16"><primary>pango_matrix_transform_rectangle</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_transform_rectangle
                                            (const <link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="PangoRectangle">PangoRectangle</link> *rect);</programlisting>
<para>
First transforms <parameter>rect</parameter> using <parameter>matrix</parameter>, then calculates the bounding box
of the transformed rectangle.  The rectangle should be in Pango units.
</para>
<para>
This function is useful for example when you want to draw a rotated
<parameter>PangoLayout</parameter> to an image buffer, and want to know how large the image
should be and how much you should shift the layout when rendering.
</para>
<para>
If you have a rectangle in device units (pixels), use
<link linkend="pango-matrix-transform-pixel-rectangle"><function>pango_matrix_transform_pixel_rectangle()</function></link>.
</para>
<para>
If you have the rectangle in Pango units and want to convert to
transformed pixel bounding box, it is more accurate to transform it first
(using this function) and pass the result to <link linkend="pango-extents-to-pixels"><function>pango_extents_to_pixels()</function></link>,
as <parameter>ink_rect</parameter>.  However, there is a reason that you may want to convert
to pixels first and then transform, and that is when the transformed
coordinates may overflow in Pango units (large matrix translation for
example).</para>
<para>

</para><variablelist role="params">
<varlistentry><term><parameter>matrix</parameter>&nbsp;:</term>
<listitem><simpara> a <link linkend="PangoMatrix"><type>PangoMatrix</type></link>, or <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
<varlistentry><term><parameter>rect</parameter>&nbsp;:</term>
<listitem><simpara> in/out bounding box in Pango units, or <link linkend="NULL:CAPS"><literal>NULL</literal></link>
</simpara></listitem></varlistentry>
</variablelist><para>Since  1.16
</para></refsect2>
<refsect2>
<title><anchor id="pango-matrix-transform-pixel-rectangle" role="function" condition="since:1.16"/>pango_matrix_transform_pixel_rectangle ()</title>
<indexterm role="1.16"><primary>pango_matrix_transform_pixel_rectangle</primary></indexterm><programlisting><link linkend="void">void</link>        pango_matrix_transform_pixel_rectangle
                                            (const <link linkend="PangoMatrix">PangoMatrix</link> *matrix,
                                             <link linkend="PangoRectangle">PangoRectangle</link> *rect);</programlisting>
<para>
First transforms the <parameter>rect</parameter> using <parameter>matrix</parameter>, then calculates the bounding box
of the transformed rectangle.  The rectangle should be in device units
(pixels).
</para>
<para>
This function is useful for example when you want to draw a rotated
<parameter>PangoLayout</parameter> to an image buffer, and want to know how large the image
should be and how much you should shift the layout when rendering.