diffing dir...
Sat Feb 20 13:13:59 EST 2010 ar...@rp...
* Add pixbufRenderThresholdAlpha
Ignore-this: f7c25ecfc1aba9f8437d7b49bda903be
{
hunk ./gtk/Graphics/UI/Gtk/Gdk/Pixbuf.chs 113
- pixbufGetFromDrawable
+ pixbufGetFromDrawable,
+
+ pixbufRenderThresholdAlpha,
+ pixbufRenderPixmapAndMaskForColormap
hunk ./gtk/Graphics/UI/Gtk/Gdk/Pixbuf.chs 130
+import Graphics.UI.Gtk.Gdk.Pixmap (Bitmap, Pixmap)
hunk ./gtk/Graphics/UI/Gtk/Gdk/Pixbuf.chs 717
+
+
+
+-- | Takes the opacity values in a rectangular portion of a pixbuf and
+-- thresholds them to produce a bi-level alpha mask that can be used
+-- as a clipping mask for a drawable.
+pixbufRenderThresholdAlpha ::
+ Pixbuf -- ^ A pixbuf.
+ -> Bitmap -- ^ Bitmap where the bilevel mask will be painted to.
+ -> Int -- ^ Source X coordinate.
+ -> Int -- ^ source Y coordinate.
+ -> Int -- ^ Destination X coordinate.
+ -> Int -- ^ Destination Y coordinate.
+ -> Int -- ^ Width of region to threshold, or -1 to use pixbuf width
+ -> Int -- ^ Height of region to threshold, or -1 to use pixbuf height
+ -> Int -- ^ Opacity values below this will be painted as zero; all other values will be painted as one.
+ -> IO ()
+pixbufRenderThresholdAlpha src dest srcX srcY destX destY w h at =
+ withForeignPtr (unPixmap dest) $ \destPtr ->
+ {#call unsafe pixbuf_render_threshold_alpha#} src
+ (castPtr destPtr)
+ (fromIntegral srcX)
+ (fromIntegral srcY)
+ (fromIntegral destX)
+ (fromIntegral destY)
+ (fromIntegral w)
+ (fromIntegral h)
+ (fromIntegral at)
+
+
+
+
+
+-- | Creates a pixmap and a mask bitmap which are returned and renders
+-- a pixbuf and its corresponding thresholded alpha mask to them. This
+-- is merely a convenience function; applications that need to render
+-- pixbufs with dither offsets or to given drawables should use
+-- 'Graphics.UI.Gtk.Gdk.Drawable.drawPixbuf', and
+-- 'pixbufRenderThresholdAlpha'.
+--
+-- The pixmap that is created uses the 'Colormap' specified by
+-- colormap. This colormap must match the colormap of the window where
+-- the pixmap will eventually be used or an error will result.
+--
+-- If the pixbuf does not have an alpha channel, then the returned
+-- mask will be @Nothing@.
+--
+pixbufRenderPixmapAndMaskForColormap ::
+ Pixbuf -- ^ A pixbuf.
+ -> Colormap -- ^ A Colormap
+ -> Int -- ^ Threshold value for opacity values
+ -> IO (Pixmap, Maybe Bitmap) -- ^ (Created pixmap, created mask)
+pixbufRenderPixmapAndMaskForColormap pixbuf colormap threshold =
+ alloca $ \pmRetPtr ->
+ alloca $ \bmRetPtr -> do
+ {#call unsafe pixbuf_render_pixmap_and_mask_for_colormap#} pixbuf
+ colormap
+ (castPtr pmRetPtr) -- seems to reject Pixmap**, so cast
+ (castPtr bmRetPtr)
+ (fromIntegral threshold)
+ pm <- constructNewGObject mkPixmap (peek pmRetPtr :: IO (Ptr Pixmap))
+ bm <- maybeNull (constructNewGObject mkPixmap) (peek bmRetPtr :: IO (Ptr Bitmap))
+ return (pm, bm)
+
+
}
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