Image Data in Memory

The gdk-pixbuf Library
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Description

The most basic way to create a pixbuf is to wrap an existing pixel buffer with a GdkPixbuf structure. You can use the gdk_pixbuf_new_from_data() function to do this You need to specify the destroy notification function that will be called when the data buffer needs to be freed; this will happen when a GdkPixbuf is finalized by the reference counting functions If you have a chunk of static data compiled into your application, you can pass in NULL as the destroy notification function so that the data will not be freed.

The gdk_pixbuf_new() function can be used as a convenience to create a pixbuf with an empty buffer. This is equivalent to allocating a data buffer using malloc() and then wrapping it with gdk_pixbuf_new_from_data(). The gdk_pixbuf_new() function will compute an optimal rowstride so that rendering can be performed with an efficient algorithm.

As a special case, you can use the gdk_pixbuf_new_from_xpm_data() function to create a pixbuf from inline XPM image data.

You can also copy an existing pixbuf with the gdk_pixbuf_copy() function. This is not the same as just doing a gdk_pixbuf_ref() on the old pixbuf; the copy function will actually duplicate the pixel data in memory and create a new GdkPixbuf structure for it.

Details

gdk_pixbuf_new ()

GdkPixbuf*  gdk_pixbuf_new                  (GdkColorspace colorspace,
                                             gboolean has_alpha,
                                             int bits_per_sample,
                                             int width,
                                             int height);

Creates a new GdkPixbuf structure and allocates a buffer for it. The buffer has an optimal rowstride. Note that the buffer is not cleared; you will have to fill it completely yourself.

`colorspace` :	Color space for image.
`has_alpha` :	Whether the image should have transparency information.
`bits_per_sample` :	Number of bits per color sample.
`width` :	Width of image in pixels.
`height` :	Height of image in pixels.
Returns :	A newly-created GdkPixbuf with a reference count of 1, or `NULL` if not enough memory could be allocated for the image buffer.

gdk_pixbuf_new_from_data ()

GdkPixbuf*  gdk_pixbuf_new_from_data        (const guchar *data,
                                             GdkColorspace colorspace,
                                             gboolean has_alpha,
                                             int bits_per_sample,
                                             int width,
                                             int height,
                                             int rowstride,
                                             GdkPixbufDestroyNotify destroy_fn,
                                             gpointer destroy_fn_data);

Creates a new GdkPixbuf out of in-memory image data. Currently only RGB images with 8 bits per sample are supported.

`data` :	Image data in 8-bit/sample packed format.
`colorspace` :	Colorspace for the image data.
`has_alpha` :	Whether the data has an opacity channel.
`bits_per_sample` :	Number of bits per sample.
`width` :	Width of the image in pixels.
`height` :	Height of the image in pixels.
`rowstride` :	Distance in bytes between rows.
`destroy_fn` :	Function used to free the data when the pixbuf's reference count drops to zero, or `NULL` if the data should not be freed.
`destroy_fn_data` :	Closure data to pass to the destroy notification function.
Returns :	A newly-created GdkPixbuf structure with a reference count of 1.

gdk_pixbuf_new_from_xpm_data ()

GdkPixbuf*  gdk_pixbuf_new_from_xpm_data    (const char **data);

Creates a new pixbuf by parsing XPM data in memory. This data is commonly the result of including an XPM file into a program's C source.

`data` :	Pointer to inline XPM data.
Returns :	A newly-created pixbuf with a reference count of 1.

gdk_pixbuf_copy ()

GdkPixbuf*  gdk_pixbuf_copy                 (const GdkPixbuf *pixbuf);

Creates a new GdkPixbuf with a copy of the information in the specified pixbuf.

`pixbuf` :	A pixbuf.
Returns :	A newly-created pixbuf with a reference count of 1, or `NULL` if not enough memory could be allocated.