pango-glyph-storage.html

GTK+-2.0源码之pango-1.15.6.tar.gz

<td>
<span class="term"><em class="parameter"><code>dy</code></em>&#160;:</span></td>
<td> yn/out Y component of a distance vector
</td>
</tr>
</tbody>
</table></div>
<p>Since  1.16
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2772450"></a><h3>
<a name="pango-matrix-transform-rectangle"></a>pango_matrix_transform_rectangle ()</h3>
<a class="indexterm" name="id2772465"></a><pre class="programlisting">void        pango_matrix_transform_rectangle
                                            (const <a href="pango-Glyph-Storage.html#PangoMatrix">PangoMatrix</a> *matrix,
                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *rect);</pre>
<p>
First transforms <em class="parameter"><code>rect</code></em> using <em class="parameter"><code>matrix</code></em>, then calculates the bounding box
of the transformed rectangle.  The rectangle should be in Pango units.
</p>
<p>
This function is useful for example when you want to draw a rotated
<em class="parameter"><code>PangoLayout</code></em> to an image buffer, and want to know how large the image
should be and how much you should shift the layout when rendering.
</p>
<p>
If you have a rectangle in device units (pixels), use
<a href="pango-Glyph-Storage.html#pango-matrix-transform-pixel-rectangle"><code class="function">pango_matrix_transform_pixel_rectangle()</code></a>.
</p>
<p>
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 <a href="pango-Glyph-Storage.html#pango-extents-to-pixels"><code class="function">pango_extents_to_pixels()</code></a>,
as <em class="parameter"><code>ink_rect</code></em>.  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).</p>
<p>

</p>
<div class="variablelist"><table border="0">
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<tbody>
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<td>
<span class="term"><em class="parameter"><code>matrix</code></em>&#160;:</span></td>
<td> a <a href="pango-Glyph-Storage.html#PangoMatrix"><span class="type">PangoMatrix</span></a>, or <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>rect</code></em>&#160;:</span></td>
<td> in/out bounding box in Pango units, or <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>
</td>
</tr>
</tbody>
</table></div>
<p>Since  1.16
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2772640"></a><h3>
<a name="pango-matrix-transform-pixel-rectangle"></a>pango_matrix_transform_pixel_rectangle ()</h3>
<a class="indexterm" name="id2772656"></a><pre class="programlisting">void        pango_matrix_transform_pixel_rectangle
                                            (const <a href="pango-Glyph-Storage.html#PangoMatrix">PangoMatrix</a> *matrix,
                                             <a href="pango-Glyph-Storage.html#PangoRectangle">PangoRectangle</a> *rect);</pre>
<p>
First transforms the <em class="parameter"><code>rect</code></em> using <em class="parameter"><code>matrix</code></em>, then calculates the bounding box
of the transformed rectangle.  The rectangle should be in device units
(pixels).
</p>
<p>
This function is useful for example when you want to draw a rotated
<em class="parameter"><code>PangoLayout</code></em> to an image buffer, and want to know how large the image
should be and how much you should shift the layout when rendering.
</p>
<p>
For better accuracy, you should use <a href="pango-Glyph-Storage.html#pango-matrix-transform-rectangle"><code class="function">pango_matrix_transform_rectangle()</code></a> on
original rectangle in Pango units and convert to pixels afterward
using <a href="pango-Glyph-Storage.html#pango-extents-to-pixels"><code class="function">pango_extents_to_pixels()</code></a> as <em class="parameter"><code>ink_rect</code></em>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
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<td>
<span class="term"><em class="parameter"><code>matrix</code></em>&#160;:</span></td>
<td> a <a href="pango-Glyph-Storage.html#PangoMatrix"><span class="type">PangoMatrix</span></a>, or <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>
</td>
</tr>
<tr>
<td>
<span class="term"><em class="parameter"><code>rect</code></em>&#160;:</span></td>
<td> in/out bounding box in device units, or <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>
</td>
</tr>
</tbody>
</table></div>
<p>Since  1.16
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2772822"></a><h3>
<a name="pango-matrix-get-font-scale-factor"></a>pango_matrix_get_font_scale_factor ()</h3>
<a class="indexterm" name="id2772838"></a><pre class="programlisting">double      pango_matrix_get_font_scale_factor
                                            (const <a href="pango-Glyph-Storage.html#PangoMatrix">PangoMatrix</a> *matrix);</pre>
<p>
Returns the scale factor of a matrix on the height of the font.
That is, the scale factor in the direction perpendicular to the
vector that the X coordinate is mapped to.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><em class="parameter"><code>matrix</code></em>&#160;:</span></td>
<td> a <a href="pango-Glyph-Storage.html#PangoMatrix"><span class="type">PangoMatrix</span></a>, may be <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>
</td>
</tr>
<tr>
<td>
<span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></td>
<td> the scale factor of <em class="parameter"><code>matrix</code></em> on the height of the font,
or 1.0 if <em class="parameter"><code>matrix</code></em> is <a
href="../glib/glib-Standard-Macros.html#NULL:CAPS"
><code class="literal">NULL</code></a>.

</td>
</tr>
</tbody>
</table></div>
<p>Since  1.12
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2772947"></a><h3>
<a name="PangoGlyph"></a>PangoGlyph</h3>
<a class="indexterm" name="id2772959"></a><pre class="programlisting">typedef guint32 PangoGlyph;
</pre>
<p>
A <a href="pango-Glyph-Storage.html#PangoGlyph"><span class="type">PangoGlyph</span></a> represents a single glyph in the output form of a string.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2772983"></a><h3>
<a name="PANGO-GLYPH-EMPTY:CAPS"></a>PANGO_GLYPH_EMPTY</h3>
<a class="indexterm" name="id2772996"></a><pre class="programlisting">#define PANGO_GLYPH_EMPTY           ((PangoGlyph)0x0FFFFFFF)
</pre>
<p>
The <a href="pango-Glyph-Storage.html#PANGO-GLYPH-EMPTY:CAPS"><code class="literal">PANGO_GLYPH_EMPTY</code></a> macro represents a <a href="pango-Glyph-Storage.html#PangoGlyph"><span class="type">PangoGlyph</span></a> value that has a
special meaning, which is a zero-width empty glyph.  This is useful for
example in shaper modules, to use as the glyph for various zero-width
Unicode characters (those passing <a href="pango-Miscellaneous-Utilities.html#pango-is-zero-width"><code class="function">pango_is_zero_width()</code></a>).
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2773046"></a><h3>
<a name="PANGO-GLYPH-UNKNOWN-FLAG:CAPS"></a>PANGO_GLYPH_UNKNOWN_FLAG</h3>
<a class="indexterm" name="id2773059"></a><pre class="programlisting">#define PANGO_GLYPH_UNKNOWN_FLAG    ((PangoGlyph)0x10000000)
</pre>
<p>
The <a href="pango-Glyph-Storage.html#PANGO-GLYPH-UNKNOWN-FLAG:CAPS"><code class="literal">PANGO_GLYPH_UNKNOWN_FLAG</code></a> macro is a flag value that can be added to
a <a
href="../glib/glib-Unicode-Manipulation.html#gunichar"
><span class="type">gunichar</span></a> value of a valid Unicode character, to produce a <a href="pango-Glyph-Storage.html#PangoGlyph"><span class="type">PangoGlyph</span></a>
value, representing an unknown-character glyph for the respective <a
href="../glib/glib-Unicode-Manipulation.html#gunichar"
><span class="type">gunichar</span></a>.
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2773113"></a><h3>
<a name="PANGO-GET-UNKNOWN-GLYPH:CAPS"></a>PANGO_GET_UNKNOWN_GLYPH()</h3>
<a class="indexterm" name="id2773126"></a><pre class="programlisting">#define PANGO_GET_UNKNOWN_GLYPH(wc) ((PangoGlyph)(wc)|PANGO_GLYPH_UNKNOWN_FLAG)
</pre>
<p>
Returns a <a href="pango-Glyph-Storage.html#PangoGlyph"><span class="type">PangoGlyph</span></a> value that means no glyph was found for <em class="parameter"><code>wc</code></em>.
The way this unknown glyphs are rendered is backend specific.  For example,
a box with the hexadecimal Unicode code-point of the character written in it
is what is done in the most common backends.
</p>
<div class="variablelist"><table border="0">
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<tbody><tr>
<td>
<span class="term"><em class="parameter"><code>wc</code></em>&#160;:</span></td>
<td>a Unicode character


</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2773178"></a><h3>
<a name="PangoGlyphInfo"></a>PangoGlyphInfo</h3>
<a class="indexterm" name="id2773190"></a><pre class="programlisting">typedef struct {
  PangoGlyph    glyph;
  PangoGlyphGeometry geometry;
  PangoGlyphVisAttr  attr;
} PangoGlyphInfo;
</pre>
<p>
The <a href="pango-Glyph-Storage.html#PangoGlyphInfo"><span class="type">PangoGlyphInfo</span></a> structure represents a single glyph together with
positioning information and visual attributes.
It contains the following fields.
</p>
<div class="variablelist"><table border="0">
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<tbody>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyph">PangoGlyph</a>&#160;<em class="structfield"><code>glyph</code></em>;</span></td>
<td>the glyph itself.
</td>
</tr>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyphGeometry">PangoGlyphGeometry</a>&#160;<em class="structfield"><code>geometry</code></em>;</span></td>
<td>the positional information about the glyph.
</td>
</tr>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyphVisAttr">PangoGlyphVisAttr</a>&#160;<em class="structfield"><code>attr</code></em>;</span></td>
<td>the visual attributes of the glyph.

</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2773285"></a><h3>
<a name="PangoGlyphGeometry"></a>PangoGlyphGeometry</h3>
<a class="indexterm" name="id2773298"></a><pre class="programlisting">typedef struct {
  PangoGlyphUnit width;
  PangoGlyphUnit x_offset;
  PangoGlyphUnit y_offset;
} PangoGlyphGeometry;
</pre>
<p>
The <a href="pango-Glyph-Storage.html#PangoGlyphGeometry"><span class="type">PangoGlyphGeometry</span></a> structure contains width and positioning
information for a single glyph. 
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyphUnit">PangoGlyphUnit</a>&#160;<em class="structfield"><code>width</code></em>;</span></td>
<td>the logical width to use for the the character.
</td>
</tr>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyphUnit">PangoGlyphUnit</a>&#160;<em class="structfield"><code>x_offset</code></em>;</span></td>
<td>horizontal offset from nominal character position.
</td>
</tr>
<tr>
<td>
<span class="term"><a href="pango-Glyph-Storage.html#PangoGlyphUnit">PangoGlyphUnit</a>&#160;<em class="structfield"><code>y_offset</code></em>;</span></td>
<td>vertical offset from nominal character position.

</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id2773393"></a><h3>
<a name="PangoGlyphUnit"></a>PangoGlyphUnit</h3>
<a class="indexterm" name="id2773406"></a><pre class="programlisting">typedef gint32 PangoGlyphUnit;
</pre>
<p>
The <a href="pango-Glyph-Storage.html#PangoGlyphUnit"><span class="type">PangoGlyphUnit</span></a> type is used to store dimensions within
Pango. Dimensions are stored in 1/<a href="pango-Glyph-Storage.html#PANGO-SCALE:CAPS"><code class="literal">PANGO_SCALE</code></a> of a device unit.
(A device unit might be a pixel for screen display, or
a point on a printer.) <a href="pango-Glyph-Storage.html#PANGO-SCALE:CAPS"><code class="literal">PANGO_SCALE</code></a> is currently 1024, and
may change in the future (unlikely though), but you should not
depend on its exact value. The <a href="pango-Glyph-Storage.html#PANGO-PIXELS:CAPS"><code class="function">PANGO_PIXELS()</code></a> macro can be used