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2000-02-01 Federico Mena Quintero <federico@helixcode.com> * doc/tmpl/rendering.sgml: gnome_init() does not call gdk_rgb_init(), so don't mention that it does in the documentation. Thanks to Alexander Kruuse <kruuse@home.se> for pointing this out.
126 lines
2.8 KiB
Plaintext
126 lines
2.8 KiB
Plaintext
<!-- ##### SECTION Title ##### -->
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Rendering
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<!-- ##### SECTION Short_Description ##### -->
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Rendering a pixbuf to a GDK drawable.
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<!-- ##### SECTION Long_Description ##### -->
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<para>
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The GdkPixbuf library provides several convenience functions to
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render pixbufs to GDK drawables. It uses the GdkRGB to render the
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image data.
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</para>
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<para>
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At this point there is not a standard alpha channel extension for
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the X Window System, so it is not possible to use full opacity
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information when painting images to arbitrary drawables. The
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GdkPixbuf convenience functions will threshold the opacity
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information to create a bi-level clipping mask (black and white),
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and use that to draw the image onto a drawable.
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</para>
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<important>
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<para>
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Since these functions use GdkRGB for rendering, you must
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initialize GdkRGB before using any of them. You can do this by
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calling gdk_rgb_init() near the beginning of your program.
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</para>
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</important>
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<!-- ##### SECTION See_Also ##### -->
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<para>
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GdkRGB
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</para>
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<!-- ##### ENUM GdkPixbufAlphaMode ##### -->
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<para>
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These values can be passed to
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gdk_pixbuf_render_to_drawable_alpha() to control how the alpha
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chanel of an image should be handled. This function can create a
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bilevel clipping mask (black and white) and use it while painting
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the image. In the future, when the X Window System gets an alpha
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channel extension, it will be possible to do full alpha
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compositing onto arbitrary drawables. For now both cases fall
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back to a bilevel clipping mask.
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</para>
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@GDK_PIXBUF_ALPHA_BILEVEL: A bilevel clipping mask (black and white)
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will be created and used to draw the image. Pixels below 0.5 opacity
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will be considered fully transparent, and all others will be
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considered fully opaque.
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@GDK_PIXBUF_ALPHA_FULL: For now falls back to #GDK_PIXBUF_ALPHA_BILEVEL.
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In the future it will do full alpha compositing.
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<!-- ##### FUNCTION gdk_pixbuf_render_to_drawable_alpha ##### -->
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<para>
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</para>
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@pixbuf:
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@drawable:
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@src_x:
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@src_y:
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@dest_x:
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@dest_y:
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@width:
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@height:
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@alpha_mode:
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@alpha_threshold:
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@dither:
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@x_dither:
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@y_dither:
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<!-- ##### FUNCTION gdk_pixbuf_render_to_drawable ##### -->
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<para>
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</para>
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@pixbuf:
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@drawable:
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@gc:
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@src_x:
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@src_y:
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@dest_x:
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@dest_y:
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@width:
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@height:
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@dither:
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@x_dither:
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@y_dither:
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<!-- ##### FUNCTION gdk_pixbuf_render_threshold_alpha ##### -->
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<para>
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</para>
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@pixbuf:
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@bitmap:
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@src_x:
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@src_y:
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@dest_x:
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@dest_y:
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@width:
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@height:
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@alpha_threshold: <!--
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Local variables:
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mode: sgml
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sgml-parent-document: ("../gdk-pixbuf.sgml" "book" "refsect2" "")
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End:
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-->
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<!-- ##### FUNCTION gdk_pixbuf_render_pixmap_and_mask ##### -->
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<para>
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</para>
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@pixbuf:
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@pixmap_return:
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@mask_return:
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@alpha_threshold:
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