gdk-gdkrgb.html

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<a name="id3128873"></a><h3>
<a name="gdk-rgb-find-color"></a>gdk_rgb_find_color ()</h3>
<a class="indexterm" name="id3128886"></a><pre class="programlisting">void                gdk_rgb_find_color                  (<a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap">GdkColormap</a> *colormap,
                                                         <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColor">GdkColor</a> *color);</pre>
<p>
<em class="parameter"><code>colormap</code></em> should be the colormap for the graphics context and
drawable you're using to draw. If you're drawing to a <a
href="/usr/share/gtk-doc/html/gtk/GtkWidget.html"
><span class="type">GtkWidget</span></a>,
call <a
href="/usr/share/gtk-doc/html/gtk/GtkWidget.html#gtk-widget-get-colormap"
><code class="function">gtk_widget_get_colormap()</code></a>.
</p>
<p>
<em class="parameter"><code>color</code></em> should have its <code class="literal">red</code>, <code class="literal">green</code>, and <code class="literal">blue</code> fields initialized;
<a class="link" href="gdk-GdkRGB.html#gdk-rgb-find-color"><code class="function">gdk_rgb_find_color()</code></a> will fill in the <code class="literal">pixel</code> field with the best
matching pixel from a color cube. The color is then ready to be
used for drawing, e.g. you can call <a class="link" href="gdk-Graphics-Contexts.html#gdk-gc-set-foreground"><code class="function">gdk_gc_set_foreground()</code></a> which
expects <code class="literal">pixel</code> to be initialized.
</p>
<p>
In many cases, you can avoid this whole issue by calling
<a class="link" href="gdk-Graphics-Contexts.html#gdk-gc-set-rgb-fg-color"><code class="function">gdk_gc_set_rgb_fg_color()</code></a> or <a class="link" href="gdk-Graphics-Contexts.html#gdk-gc-set-rgb-bg-color"><code class="function">gdk_gc_set_rgb_bg_color()</code></a>, which
do not expect <code class="literal">pixel</code> to be initialized in advance. If you use those
functions, there's no need for <a class="link" href="gdk-GdkRGB.html#gdk-rgb-find-color"><code class="function">gdk_rgb_find_color()</code></a>.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>colormap</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap"><span class="type">GdkColormap</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>color</code></em>&#160;:</span></p></td>
<td> a <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColor"><span class="type">GdkColor</span></a>
</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129139"></a><h3>
<a name="gdk-rgb-set-install"></a>gdk_rgb_set_install ()</h3>
<a class="indexterm" name="id3129152"></a><pre class="programlisting">void                gdk_rgb_set_install                 (<a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a> install);</pre>
<p>
If <em class="parameter"><code>install</code></em> is <a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"
><code class="literal">TRUE</code></a>, directs GdkRGB to always install a new "private"
colormap rather than trying to find a best fit with the colors already
allocated. Ordinarily, GdkRGB will install a colormap only if a
sufficient cube cannot be allocated.
</p>
<p>
A private colormap has more colors, leading to better quality display,
but also leads to the dreaded "colormap flashing" effect.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>install</code></em>&#160;:</span></p></td>
<td>
<a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"
><code class="literal">TRUE</code></a> to set install mode.


</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129233"></a><h3>
<a name="gdk-rgb-set-min-colors"></a>gdk_rgb_set_min_colors ()</h3>
<a class="indexterm" name="id3129246"></a><pre class="programlisting">void                gdk_rgb_set_min_colors              (<a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> min_colors);</pre>
<p>
Sets the minimum number of colors for the color cube. Generally,
GdkRGB tries to allocate the largest color cube it can. If it can't
allocate a color cube at least as large as <em class="parameter"><code>min_colors</code></em>, it installs a
private colormap.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>min_colors</code></em>&#160;:</span></p></td>
<td>The minimum number of colors accepted.


</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129303"></a><h3>
<a name="gdk-rgb-get-visual"></a>gdk_rgb_get_visual ()</h3>
<a class="indexterm" name="id3129316"></a><pre class="programlisting"><a class="link" href="gdk-Visuals.html#GdkVisual">GdkVisual</a>*          gdk_rgb_get_visual                  (void);</pre>
<p>
Gets a "preferred visual" chosen by GdkRGB for rendering image data
on the default screen. In previous versions of GDK, this was the
only visual GdkRGB could use for rendering. In current versions,
it's simply the visual GdkRGB would have chosen as the optimal one
in those previous versions. GdkRGB can now render to drawables with
any visual.</p>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> The <a class="link" href="gdk-Visuals.html#GdkVisual"><span class="type">GdkVisual</span></a> chosen by GdkRGB.
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3124990"></a><h3>
<a name="gdk-rgb-get-colormap"></a>gdk_rgb_get_colormap ()</h3>
<a class="indexterm" name="id3125003"></a><pre class="programlisting"><a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap">GdkColormap</a>*        gdk_rgb_get_colormap                (void);</pre>
<p>
Get the preferred colormap for rendering image data.  Not a
very useful function; historically, GDK could only render RGB image
data to one colormap and visual, but in the current version it can
render to any colormap and visual. So there's no need to call this
function.</p>
<p>

</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td> the preferred colormap
</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3125048"></a><h3>
<a name="gdk-rgb-get-cmap"></a>gdk_rgb_get_cmap</h3>
<a class="indexterm" name="id3125062"></a><pre class="programlisting">#define gdk_rgb_get_cmap               gdk_rgb_get_colormap
</pre>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p><code class="literal">gdk_rgb_get_cmap</code> is deprecated and should not be used in newly-written code.</p>
</div>
<p>
Gets the colormap set by GdkRGB. This colormap and the corresponding
visual should be used when creating windows that will be drawn in by GdkRGB.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>The <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap"><span class="type">GdkColormap</span></a> set by GdkRGB.


</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129631"></a><h3>
<a name="gdk-rgb-ditherable"></a>gdk_rgb_ditherable ()</h3>
<a class="indexterm" name="id3129644"></a><pre class="programlisting"><a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a>            gdk_rgb_ditherable                  (void);</pre>
<p>
Determines whether the preferred visual is ditherable. This function may be
useful for presenting a user interface choice to the user about which
dither mode is desired; if the display is not ditherable, it may make
sense to gray out or hide the corresponding UI widget.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>
<a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"
><code class="literal">TRUE</code></a> if the preferred visual is ditherable.


</td>
</tr></tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129694"></a><h3>
<a name="gdk-rgb-colormap-ditherable"></a>gdk_rgb_colormap_ditherable ()</h3>
<a class="indexterm" name="id3129708"></a><pre class="programlisting"><a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a>            gdk_rgb_colormap_ditherable         (<a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap">GdkColormap</a> *cmap);</pre>
<p>
Determines whether the visual associated with <em class="parameter"><code>cmap</code></em> is ditherable. This 
function may be useful for presenting a user interface choice to the user 
about which dither mode is desired; if the display is not ditherable, it may 
make sense to gray out or hide the corresponding UI widget.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>cmap</code></em>&#160;:</span></p></td>
<td>a <a class="link" href="gdk-Colormaps-and-Colors.html#GdkColormap"><span class="type">GdkColormap</span></a>
</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span>&#160;:</span></p></td>
<td>
<a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"
><code class="literal">TRUE</code></a> if the visual associated with <em class="parameter"><code>cmap</code></em> is ditherable.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3129798"></a><h3>
<a name="gdk-rgb-set-verbose"></a>gdk_rgb_set_verbose ()</h3>
<a class="indexterm" name="id3129812"></a><pre class="programlisting">void                gdk_rgb_set_verbose                 (<a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gboolean"
>gboolean</a> verbose);</pre>
<p>
Sets the "verbose" flag. This is generally only useful for debugging.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody><tr>
<td><p><span class="term"><em class="parameter"><code>verbose</code></em>&#160;:</span></p></td>
<td>
<a
href="/usr/share/gtk-doc/html/glib/glib-Standard-Macros.html#TRUE:CAPS"
><code class="literal">TRUE</code></a> if verbose messages are desired.


</td>
</tr></tbody>
</table></div>
</div>
</div>
<div class="refsect1" lang="en">
<a name="id3129870"></a><h2>See Also</h2>
<p>
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><a class="link" href="gdk-Colormaps-and-Colors.html#GdkColor"><span class="type">GdkColor</span></a></span></p></td>
<td><p>The underlying GDK mechanism for allocating
colors.</p></td>
</tr>
<tr>
<td><p><span class="term"><a
href="/usr/share/gtk-doc/html/gdk-pixbuf/gdk-pixbuf-gdk-pixbuf.html#GdkPixbuf"
><span class="type">GdkPixbuf</span></a> and <a class="link" href="gdk-Drawing-Primitives.html#gdk-draw-pixbuf"><code class="function">gdk_draw_pixbuf()</code></a></span></p></td>
<td><p>Higher-level image handling.</p></td>
</tr>
</tbody>
</table></div>
<p>

</p>
</div>
<div class="refsect1" lang="en">
<a name="id3129927"></a><div class="refsect2" lang="en"><a name="id3129928"></a></div>
<hr>
<div class="refsect2" lang="en"><a name="id3129930"></a></div>
</div>
</div>
</body>
</html>