Commit 28aa9066 authored by Matthias Clasen's avatar Matthias Clasen
Browse files

GDK docs: Improve gdk_pixbuf_get_from_window docs

parent 32d1defc
......@@ -35,20 +35,21 @@
/**
* gdk_pixbuf_get_from_window:
* @dest: (allow-none): Destination pixbuf, or %NULL if a new pixbuf should be created.
* @src: Source drawable.
* @src_x: Source X coordinate within drawable.
* @src_y: Source Y coordinate within drawable.
* @dest_x: Destination X coordinate in pixbuf, or 0 if @dest is NULL.
* @dest_y: Destination Y coordinate in pixbuf, or 0 if @dest is NULL.
* @width: Width in pixels of region to get.
* @height: Height in pixels of region to get.
* @dest: (allow-none): Destination pixbuf, or %NULL if a new pixbuf
* should be created
* @window: Source window
* @src_x: Source X coordinate within @window
* @src_y: Source Y coordinate within @window
* @dest_x: Destination X coordinate in @dest, or 0 if @dest is NULL
* @dest_y: Destination Y coordinate in @dest, or 0 if @dest is NULL
* @width: Width in pixels of region to get
* @height: Height in pixels of region to get
*
* Transfers image data from a #GdkDrawable and converts it to an RGB(A)
* Transfers image data from a #GdkWindow and converts it to an RGB(A)
* representation inside a #GdkPixbuf. In other words, copies
* image data from a server-side drawable to a client-side RGB(A) buffer.
* This allows you to efficiently read individual pixels on the client side.
*
*
* If the specified destination pixbuf @dest is %NULL, then this
* function will create an RGB pixbuf with 8 bits per channel and no
* alpha, with the same size specified by the @width and @height
......@@ -57,18 +58,17 @@
* and it contains alpha information, then the filled pixels will be
* set to full opacity (alpha = 255).
*
* If the specified drawable is a window, and the window is off the
* screen, then there is no image data in the obscured/offscreen
* regions to be placed in the pixbuf. The contents of portions of the
* pixbuf corresponding to the offscreen region are undefined.
* If the window is off the screen, then there is no image data in the
* obscured/offscreen regions to be placed in the pixbuf. The contents
* of portions of the pixbuf corresponding to the offscreen region are
* undefined.
*
* If the window you're obtaining data from is partially obscured by
* other windows, then the contents of the pixbuf areas corresponding
* to the obscured regions are undefined.
*
* If the target drawable is not mapped (typically because it's
* iconified/minimized or not on the current workspace), then %NULL
* will be returned.
*
* If the window is not mapped (typically because it's iconified/minimized
* or not on the current workspace), then %NULL will be returned.
*
* If memory can't be allocated for the return value, %NULL will be returned
* instead.
......@@ -76,8 +76,9 @@
* (In short, there are several ways this function can fail, and if it fails
* it returns %NULL; so check the return value.)
*
* Return value: The same pixbuf as @dest if it was non-%NULL, or a newly-created
* pixbuf with a reference count of 1 if no destination pixbuf was specified, or %NULL on error
* Return value: The same pixbuf as @dest if it was non-%NULL, or a
* newly-created pixbuf with a reference count of 1 if no destinatio
* pixbuf was specified, or %NULL on error
**/
GdkPixbuf *
gdk_pixbuf_get_from_window (GdkPixbuf *dest,
......@@ -231,42 +232,29 @@ convert_no_alpha (guchar *dest_data,
/**
* gdk_pixbuf_get_from_surface:
* @dest: (allow-none): Destination pixbuf, or %NULL if a new pixbuf should be created.
* @dest: (allow-none): Destination pixbuf, or %NULL if a new pixbuf
* should be created
* @surface: surface to copy from
* @src_x: Source X coordinate within drawable.
* @src_y: Source Y coordinate within drawable.
* @dest_x: Destination X coordinate in pixbuf, or 0 if @dest is NULL.
* @dest_y: Destination Y coordinate in pixbuf, or 0 if @dest is NULL.
* @width: Width in pixels of region to get.
* @height: Height in pixels of region to get.
* @src_x: Source X coordinate within @surface
* @src_y: Source Y coordinate within @surface
* @dest_x: Destination X coordinate in @dest, or 0 if @dest is NULL
* @dest_y: Destination Y coordinate in @dest, or 0 if @dest is NULL
* @width: Width in pixels of region to get
* @height: Height in pixels of region to get
*
* Transfers image data from a #cairo_surface_t and converts it to an RGB(A)
* representation inside a #GdkPixbuf. This allows you to efficiently read individual
* pixels from Cairo surfaces. For #GdkWindows, use gdk_pixbuf_get_from_drawable()
* instead.
*
* If the specified destination pixbuf @dest is %NULL, then this
* function will create an RGB pixbuf with 8 bits per channel. The pixbuf will
* contain an alpha channel if the @surface contains one. In this case, the @dest_x
* and @dest_y arguments must be specified as 0.
*
* If the specified drawable is a window, and the window is off the
* screen, then there is no image data in the obscured/offscreen
* regions to be placed in the pixbuf. The contents of portions of the
* pixbuf corresponding to the offscreen region are undefined.
*
* If the window you're obtaining data from is partially obscured by
* other windows, then the contents of the pixbuf areas corresponding
* to the obscured regions are undefined.
*
* If memory can't be allocated for the return value, %NULL will be returned
* instead.
* representation inside a #GdkPixbuf. This allows you to efficiently read
* individual pixels from cairo surfaces. For #GdkWindows, use
* gdk_pixbuf_get_from_surface() instead.
*
* (In short, there are several ways this function can fail, and if it fails
* it returns %NULL; so check the return value.)
* If the specified destination pixbuf @dest is %NULL, then this function
* will create an RGB pixbuf with 8 bits per channel. The pixbuf will contain
* an alpha channel if the @surface contains one. In this case, the @dest_x
* and @dest_y arguments must be specified as 0.
*
* Return value: The same pixbuf as @dest if it was non-%NULL, or a newly-created
* pixbuf with a reference count of 1 if no destination pixbuf was specified, or %NULL on error
* Return value: The same pixbuf as @dest if it was non-%NULL, or a
* newly-created pixbuf with a reference count of 1 if no destination
* pixbuf was specified, or %NULL on error
**/
GdkPixbuf *
gdk_pixbuf_get_from_surface (GdkPixbuf *dest,
......@@ -288,9 +276,9 @@ gdk_pixbuf_get_from_surface (GdkPixbuf *dest,
if (!dest)
{
g_return_val_if_fail (dest_x == 0 && dest_y == 0, NULL);
content = cairo_surface_get_content (surface) | CAIRO_CONTENT_COLOR;
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
!!(content & CAIRO_CONTENT_ALPHA),
8,
width, height);
......
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