gtk2/docs/reference/gdk-pixbuf/tmpl/gdk-pixbuf-unused.sgml

<!-- ##### USER_FUNCTION GdkPixbufLastUnref ##### -->
  <para>
    A function of this type can be used to override the default
    operation when a pixbuf loses its last reference, i.e. when
    gdk_pixbuf_unref() is called on a #GdkPixbuf structure that has a
    reference count of 1.  This function should determine whether to
    finalize the pixbuf by calling gdk_pixbuf_finalize(), or whether
    to just resume normal execution.  The last unref handler for a
    #GdkPixbuf can be set using the
    gdk_pixbuf_set_last_unref_handler() function.  By default, pixbufs
    will be finalized automatically if no last unref handler has been
    defined.
  </para>

@pixbuf: The pixbuf that is losing its last reference.
@data: User closure data.

<!-- ##### SECTION ./tmpl/from-drawables.sgml:Title ##### -->
Drawables to Pixbufs


<!-- ##### ARG GnomeCanvasPixbuf:height_pixels ##### -->
<para>

</para>


<!-- ##### SECTION ./tmpl/rendering.sgml:See_Also ##### -->
  <para>
    GdkRGB
  </para>


<!-- ##### FUNCTION gdk_pixbuf_render_pixmap_and_mask ##### -->
<para>

</para>

@pixbuf: 
@pixmap_return: 
@mask_return: 
@alpha_threshold: <!--
Local variables:
mode: sgml
sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
End:
-->

<!-- ##### FUNCTION gdk_pixbuf_render_to_drawable ##### -->
<para>

</para>

@pixbuf: 
@drawable: 
@gc: 
@src_x: 
@src_y: 
@dest_x: 
@dest_y: 
@width: 
@height: 
@dither: 
@x_dither: 
@y_dither: 

<!-- ##### FUNCTION gdk_pixbuf_get_from_drawable ##### -->
<para>

</para>

@dest: 
@src: 
@cmap: 
@src_x: 
@src_y: 
@dest_x: 
@dest_y: 
@width: 
@height: 
@Returns: <!--
Local variables:
mode: sgml
sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
End:
-->

<!-- ##### FUNCTION gdk_pixbuf_new_from_art_pixbuf ##### -->
<para>

</para>

@art_pixbuf: 
@Returns: 

<!-- ##### ARG GnomeCanvasPixbuf:y_pixels ##### -->
<para>

</para>


<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Short_Description ##### -->



<!-- ##### SECTION ./tmpl/from-drawables.sgml:Long_Description ##### -->
  <para>
    The functions in this section allow you to take the image data
    from a GDK drawable and dump it into a #GdkPixbuf.  This can be
    used for screenshots and other special effects.  Note that these
    operations can be expensive, since the image data has to be
    transferred from the X server to the client program and converted.
  </para>


<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:See_Also ##### -->
<para>

</para>


<!-- ##### FUNCTION gdk_pixbuf_finalize ##### -->
<para>

</para>

@pixbuf: <!--
Local variables:
mode: sgml
sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
End:
-->

<!-- ##### SECTION ./tmpl/rendering.sgml:Short_Description ##### -->
Rendering a pixbuf to a GDK drawable.


<!-- ##### FUNCTION gdk_pixbuf_set_last_unref_handler ##### -->
<para>

</para>

@pixbuf: 
@last_unref_fn: 
@last_unref_fn_data: 

<!-- ##### ARG GnomeCanvasPixbuf:x_set ##### -->
  <para>
    Determines whether the <link
    linkend="GnomeCanvasPixbuf--x">x</link> argument is used to
    translate the pixbuf from its logical origin in item-relative
    coordinates.
  </para>


<!-- ##### FUNCTION gdk_pixbuf_get_format ##### -->
<para>

</para>

@pixbuf: 
@Returns: 

<!-- ##### FUNCTION gdk_pixbuf_render_to_drawable_alpha ##### -->
<para>

</para>

@pixbuf: 
@drawable: 
@src_x: 
@src_y: 
@dest_x: 
@dest_y: 
@width: 
@height: 
@alpha_mode: 
@alpha_threshold: 
@dither: 
@x_dither: 
@y_dither: 

<!-- ##### ARG GnomeCanvasPixbuf:x_pixels ##### -->
<para>

</para>


<!-- ##### SECTION ./tmpl/from-drawables.sgml:See_Also ##### -->
  <para>
    gdk_image_get().
  </para>


<!-- ##### SECTION ./tmpl/rendering.sgml:Title ##### -->
Rendering


<!-- ##### MACRO GDK_PIXBUF_LOADER ##### -->
  <para>
    Casts a #GtkObject to a #GdkPixbufLoader.
  </para>

@obj: A GTK+ object.

<!-- ##### ARG GnomeCanvasPixbuf:y_set ##### -->
  <para>
    Determines whether the <link
    linkend="GnomeCanvasPixbuf--y">y</link> argument is used to
    translate the pixbuf from its logical origin in item-relative
    coordinates.  Works in the same way as the <link
    linkend="GnomeCanvasPixbuf--x-set">x_set</link> argument.  The
    default is %FALSE.
  </para>


<!-- ##### SECTION ./tmpl/rendering.sgml:Long_Description ##### -->
  <para>
    The <application>gdk-pixbuf</application> library provides several
    convenience functions to render pixbufs to GDK drawables.  It uses
    the GdkRGB to render the image data.
  </para>

  <para>
    At this point there is not a standard alpha channel extension for
    the X Window System, so it is not possible to use full opacity
    information when painting images to arbitrary drawables.  The
    <application>gdk-pixbuf</application> convenience functions will
    threshold the opacity information to create a bi-level clipping
    mask (black and white), and use that to draw the image onto a
    drawable.
  </para>

  <important>
    <para>
      Since these functions use GdkRGB for rendering, you must
      initialize GdkRGB before using any of them.  You can do this by
      calling gdk_rgb_init() near the beginning of your program.
    </para>
  </important>


<!-- ##### SECTION ./tmpl/from-drawables.sgml:Short_Description ##### -->
Getting parts of a drawable's image data into a pixbuf.


<!-- ##### FUNCTION gdk_pixbuf_render_threshold_alpha ##### -->
<para>

</para>

@pixbuf: 
@bitmap: 
@src_x: 
@src_y: 
@dest_x: 
@dest_y: 
@width: 
@height: 
@alpha_threshold: 

<!-- ##### ARG GnomeCanvasPixbuf:width_pixels ##### -->
<para>

</para>


<!-- ##### ENUM GdkPixbufAlphaMode ##### -->
  <para>
    These values can be passed to
    gdk_pixbuf_render_to_drawable_alpha() to control how the alpha
    chanel of an image should be handled.  This function can create a
    bilevel clipping mask (black and white) and use it while painting
    the image.  In the future, when the X Window System gets an alpha
    channel extension, it will be possible to do full alpha
    compositing onto arbitrary drawables.  For now both cases fall
    back to a bilevel clipping mask.
  </para>

@GDK_PIXBUF_ALPHA_BILEVEL: A bilevel clipping mask (black and white)
will be created and used to draw the image.  Pixels below 0.5 opacity
will be considered fully transparent, and all others will be
considered fully opaque.
@GDK_PIXBUF_ALPHA_FULL: For now falls back to #GDK_PIXBUF_ALPHA_BILEVEL.
In the future it will do full alpha compositing.

<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Long_Description ##### -->
<para>

</para>


<!-- ##### SECTION ./tmpl/gdk-pixbuf-io.sgml:Title ##### -->
gdk-pixbuf-io