gdk-gdkrgb.html

最新gtk中文资料集

int
main (int argc, char *argv[])
{
  GtkWidget *window, *darea;
  gint x, y;
  guchar *pos;

  gtk_init (&argc, &argv);

  window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
  darea = gtk_drawing_area_new ();
  gtk_widget_set_size_request (darea, IMAGE_WIDTH, IMAGE_HEIGHT);
  gtk_container_add (GTK_CONTAINER (window), darea);
  gtk_signal_connect (GTK_OBJECT (darea), "expose-event",
                      GTK_SIGNAL_FUNC (on_darea_expose), NULL);
  gtk_widget_show_all (window);

  /* Set up the RGB buffer. */
  pos = rgbbuf;
  for (y = 0; y < IMAGE_HEIGHT; y++)
    {
      for (x = 0; x < IMAGE_WIDTH; x++)
	{
	  *pos++ = x - x % 32;			/* Red. */
	  *pos++ = (x / 32) * 4 + y - y % 32;	/* Green. */
	  *pos++ = y - y % 32;			/* Blue. */
	}
    }

  gtk_main ();
  return 0;
}


gboolean
on_darea_expose (GtkWidget *widget,
		 GdkEventExpose *event,
		 gpointer user_data)
{
  gdk_draw_rgb_image (widget->window, widget->style->fg_gc[GTK_STATE_NORMAL],
		      0, 0, IMAGE_WIDTH, IMAGE_HEIGHT,
		      GDK_RGB_DITHER_MAX, rgbbuf, IMAGE_WIDTH * 3);

  return TRUE;
}
</pre></div>
</div>
<br class="example-break">
</div>
<div class="refsect1" lang="en">
<a name="id3126172"></a><h2>Details</h2>
<div class="refsect2" lang="en">
<a name="id3126182"></a><h3>
<a name="gdk-rgb-init"></a>gdk_rgb_init ()</h3>
<a class="indexterm" name="id3126196"></a><pre class="programlisting">void                gdk_rgb_init                        (void);</pre>
<div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Warning</h3>
<p><code class="literal">gdk_rgb_init</code> is deprecated and should not be used in newly-written code.</p>
</div>
<p>
This function no longer does anything at all. It's completely useless
(and harmless).
</p>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3126232"></a><h3>
<a name="gdk-draw-rgb-image"></a>gdk_draw_rgb_image ()</h3>
<a class="indexterm" name="id3126245"></a><pre class="programlisting">void                gdk_draw_rgb_image                  (<a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable">GdkDrawable</a> *drawable,
                                                         <a class="link" href="gdk-Graphics-Contexts.html#GdkGC">GdkGC</a> *gc,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> x,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> y,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> width,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> height,
                                                         <a class="link" href="gdk-GdkRGB.html#GdkRgbDither">GdkRgbDither</a> dith,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guchar"
>guchar</a> *rgb_buf,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> rowstride);</pre>
<p>
Draws an RGB image in the drawable. This is the core GdkRGB
function, and likely the only one you will need to use.
</p>
<p>
The <em class="parameter"><code>rowstride</code></em> parameter allows for lines to be aligned more flexibly.
For example, lines may be allocated to begin on 32-bit boundaries,
even if the width of the rectangle is odd. Rowstride is also useful
when drawing a subrectangle of a larger image in memory. Finally, to
replicate the same line a number of times, the trick of setting
<em class="parameter"><code>rowstride</code></em> to 0 is allowed.
</p>
<p>
In general, for 0 &lt;= i &lt; <em class="parameter"><code>width</code></em> and 0 &lt;= j &lt; height,
the pixel (x + i, y + j) is colored with red value <em class="parameter"><code>rgb_buf</code></em>[<em class="parameter"><code>j</code></em> *
<em class="parameter"><code>rowstride</code></em> + <em class="parameter"><code>i</code></em> * 3], green value <em class="parameter"><code>rgb_buf</code></em>[<em class="parameter"><code>j</code></em> * <em class="parameter"><code>rowstride</code></em> + <em class="parameter"><code>i</code></em> * 3 +
1], and blue value <em class="parameter"><code>rgb_buf</code></em>[<em class="parameter"><code>j</code></em> * <em class="parameter"><code>rowstride</code></em> + <em class="parameter"><code>i</code></em> * 3 + 2].
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>drawable</code></em>&#160;:</span></p></td>
<td>The <a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable"><span class="type">GdkDrawable</span></a> to draw in (usually a <a class="link" href="gdk-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>).
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>gc</code></em>&#160;:</span></p></td>
<td>The graphics context (all GDK drawing operations require one; its
contents are ignored).
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em>&#160;:</span></p></td>
<td>The x coordinate of the top-left corner in the drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em>&#160;:</span></p></td>
<td>The y coordinate of the top-left corner in the drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td>The width of the rectangle to be drawn.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td>The height of the rectangle to be drawn.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dith</code></em>&#160;:</span></p></td>
<td>A <a class="link" href="gdk-GdkRGB.html#GdkRgbDither"><span class="type">GdkRgbDither</span></a> value, selecting the desired dither mode.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rgb_buf</code></em>&#160;:</span></p></td>
<td>The pixel data, represented as packed 24-bit data.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rowstride</code></em>&#160;:</span></p></td>
<td>The number of bytes from the start of one row in <em class="parameter"><code>rgb_buf</code></em> to the
start of the next.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3126605"></a><h3>
<a name="gdk-draw-rgb-image-dithalign"></a>gdk_draw_rgb_image_dithalign ()</h3>
<a class="indexterm" name="id3126619"></a><pre class="programlisting">void                gdk_draw_rgb_image_dithalign        (<a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable">GdkDrawable</a> *drawable,
                                                         <a class="link" href="gdk-Graphics-Contexts.html#GdkGC">GdkGC</a> *gc,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> x,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> y,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> width,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> height,
                                                         <a class="link" href="gdk-GdkRGB.html#GdkRgbDither">GdkRgbDither</a> dith,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#guchar"
>guchar</a> *rgb_buf,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> rowstride,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> xdith,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> ydith);</pre>
<p>
Draws an RGB image in the drawable, with an adjustment for dither alignment.
</p>
<p>
This function is useful when drawing dithered images into a window
that may be scrolled. Pixel (x, y) will be drawn dithered as if its
actual location is (x + <em class="parameter"><code>xdith</code></em>, y + <em class="parameter"><code>ydith</code></em>). Thus, if you draw an
image into a window using zero dither alignment, then scroll up one
pixel, subsequent draws to the window should have <em class="parameter"><code>ydith</code></em> = 1.
</p>
<p>
Setting the dither alignment correctly allows updating of small parts
of the screen while avoiding visible "seams" between the different
dither textures.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>drawable</code></em>&#160;:</span></p></td>
<td>The <a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable"><span class="type">GdkDrawable</span></a> to draw in (usually a <a class="link" href="gdk-Windows.html#GdkWindow"><span class="type">GdkWindow</span></a>).
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>gc</code></em>&#160;:</span></p></td>
<td>The graphics context.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>x</code></em>&#160;:</span></p></td>
<td>The x coordinate of the top-left corner in the drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>y</code></em>&#160;:</span></p></td>
<td>The y coordinate of the top-left corner in the drawable.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>width</code></em>&#160;:</span></p></td>
<td>The width of the rectangle to be drawn.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>height</code></em>&#160;:</span></p></td>
<td>The height of the rectangle to be drawn.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>dith</code></em>&#160;:</span></p></td>
<td>A <a class="link" href="gdk-GdkRGB.html#GdkRgbDither"><span class="type">GdkRgbDither</span></a> value, selecting the desired dither mode.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rgb_buf</code></em>&#160;:</span></p></td>
<td>The pixel data, represented as packed 24-bit data.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>rowstride</code></em>&#160;:</span></p></td>
<td>The number of bytes from the start of one row in <em class="parameter"><code>rgb_buf</code></em> to the
start of the next.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>xdith</code></em>&#160;:</span></p></td>
<td>An x offset for dither alignment.
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>ydith</code></em>&#160;:</span></p></td>
<td>A y offset for dither alignment.


</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2" lang="en">
<a name="id3126951"></a><h3>
<a name="gdk-draw-indexed-image"></a>gdk_draw_indexed_image ()</h3>
<a class="indexterm" name="id3126964"></a><pre class="programlisting">void                gdk_draw_indexed_image              (<a class="link" href="gdk-Drawing-Primitives.html#GdkDrawable">GdkDrawable</a> *drawable,
                                                         <a class="link" href="gdk-Graphics-Contexts.html#GdkGC">GdkGC</a> *gc,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> x,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> y,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> width,
                                                         <a
href="/usr/share/gtk-doc/html/glib/glib-Basic-Types.html#gint"
>gint</a> height,