Images

GDK Reference Manual
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struct GdkImage

struct GdkImage
{
  GdkImageType	type;
  GdkVisual    *visual;	    /* visual used to create the image */
  GdkByteOrder	byte_order;
  guint16	width;
  guint16	height;
  guint16	depth;
  guint16	bpp;	    /* bytes per pixel */
  guint16	bpl;	    /* bytes per line */
  gpointer	mem;
};

The GdkImage struct contains information on the image and the pixel data.

GdkImageType `type`	the type of the image.
GdkVisual *`visual`	the visual.
GdkByteOrder `byte_order`	the byte order.
guint16 `width`	the width of the image in pixels.
guint16 `height`	the height of the image in pixels.
guint16 `depth`	the depth of the image, i.e. the number of bits per pixel.
guint16 `bpp`	the number of bytes per pixel.
guint16 `bpl`	the number of bytes per line of the image.
gpointer `mem`	the pixel data.

gdk_image_new ()

GdkImage*   gdk_image_new                   (GdkImageType type,
                                             GdkVisual *visual,
                                             gint width,
                                             gint height);

Creates a new GdkImage.

`type` :	the type of the GdkImage, one of `GDK_IMAGE_NORMAL`, `GDK_IMAGE_SHARED` and `GDK_IMAGE_FASTEST`. `GDK_IMAGE_FASTEST` is probably the best choice, since it will try creating a `GDK_IMAGE_SHARED` image first and if that fails it will then use `GDK_IMAGE_NORMAL`.
`visual` :	the GdkVisual to use for the image.
`width` :	the width of the image in pixels.
`height` :	the height of the image in pixels.
Returns :	a new GdkImage, or NULL if the image could not be created.

enum GdkImageType

typedef enum
{
  GDK_IMAGE_NORMAL,
  GDK_IMAGE_SHARED,
  GDK_IMAGE_FASTEST
} GdkImageType;

Specifies the type of a GdkImage.

`GDK_IMAGE_NORMAL`	The original X image type, which is quite slow since the image has to be transferred from the client to the server to display it.
`GDK_IMAGE_SHARED`	A faster image type, which uses shared memory to transfer the image data between client and server. However this will only be available if client and server are on the same machine and the shared memory extension is supported by the server.
`GDK_IMAGE_FASTEST`	Specifies that `GDK_IMAGE_SHARED` should be tried first, and if that fails then `GDK_IMAGE_NORMAL` will be used.

gdk_image_new_bitmap ()

GdkImage*   gdk_image_new_bitmap            (GdkVisual *visual,
                                             gpointer data,
                                             gint width,
                                             gint height);

Creates a new GdkImage with a depth of 1 from the given data.

`visual` :	the GdkVisual to use for the image.
`data` :	the pixel data.
`width` :	the width of the image in pixels.
`height` :	the height of the image in pixels.
Returns :	a new GdkImage.

gdk_image_get ()

GdkImage*   gdk_image_get                   (GdkWindow *window,
                                             gint x,
                                             gint y,
                                             gint width,
                                             gint height);

Gets part of a GdkWindow and stores it in a new GdkImage.

`window` :	the GdkWindow to copy from.
`x` :	the left edge of the rectangle to copy from `window`.
`y` :	the top edge of the rectangle to copy from `window`.
`width` :	the width of the area to copy, in pixels.
`height` :	the height of the area to copy, in pixels.
Returns :	a new GdkImage with a copy of the given area of `window`.

gdk_image_destroy ()

void        gdk_image_destroy               (GdkImage *image);

Destroys a GdkImage, freeing any resources allocated for it.

image : a GdkImage.

gdk_image_put_pixel ()

void        gdk_image_put_pixel             (GdkImage *image,
                                             gint x,
                                             gint y,
                                             guint32 pixel);

Sets a pixel in a GdkImage to a given pixel value.

`image` :	a GdkImage.
`x` :	the x coordinate of the pixel to set.
`y` :	the y coordinate of the pixel to set.
`pixel` :	the pixel value to set.

gdk_image_get_pixel ()

guint32     gdk_image_get_pixel             (GdkImage *image,
                                             gint x,
                                             gint y);

Gets a pixel value at a specified position in a GdkImage.

`image` :	a GdkImage.
`x` :	the x coordinate of the pixel to get.
`y` :	the y coordinate of the pixel to get.
Returns :	the pixel value at the given position.