The GdkPixbuf Structure

Name

The GdkPixbuf Structure -- Information that describes an image.

Synopsis


#include <gdk-pixbuf/gdk-pixbuf.h>


enum        GdkPixbufError;
#define     GDK_PIXBUF_ERROR
enum        GdkColorspace;
enum        GdkPixbufAlphaMode;
struct      GdkPixbuf;
GdkColorspace gdk_pixbuf_get_colorspace     (const GdkPixbuf *pixbuf);
int         gdk_pixbuf_get_n_channels       (const GdkPixbuf *pixbuf);
gboolean    gdk_pixbuf_get_has_alpha        (const GdkPixbuf *pixbuf);
int         gdk_pixbuf_get_bits_per_sample  (const GdkPixbuf *pixbuf);
guchar*     gdk_pixbuf_get_pixels           (const GdkPixbuf *pixbuf);
int         gdk_pixbuf_get_width            (const GdkPixbuf *pixbuf);
int         gdk_pixbuf_get_height           (const GdkPixbuf *pixbuf);
int         gdk_pixbuf_get_rowstride        (const GdkPixbuf *pixbuf);
G_CONST_RETURN gchar* gdk_pixbuf_get_option (GdkPixbuf *pixbuf,
                                             const gchar *key);


Description

The GdkPixbuf structure contains information that describes an image in memory.

Details

enum GdkPixbufError

typedef enum {
        /* image data hosed */
        GDK_PIXBUF_ERROR_CORRUPT_IMAGE,
        /* no mem to load image */
        GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY,
        /* bad option passed to save routine */
        GDK_PIXBUF_ERROR_BAD_OPTION,
        /* unsupported image type (sort of an ENOSYS) */
        GDK_PIXBUF_ERROR_UNKNOWN_TYPE,
        /* unsupported operation (load, save) for image type */
        GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION,
        GDK_PIXBUF_ERROR_FAILED
} GdkPixbufError;

An error code in the GDK_PIXBUF_ERROR domain. Many gdk-pixbuf operations can cause errors in this domain, or in the G_FILE_ERROR domain.


GDK_PIXBUF_ERROR

#define GDK_PIXBUF_ERROR gdk_pixbuf_error_quark ()

Error domain used for pixbuf operations. Indicates that the error code will be in the GdkPixbufError enumeration. See GError for information on error domains and error codes.


enum GdkColorspace

typedef enum {
	GDK_COLORSPACE_RGB
} GdkColorspace;

This enumeration defines the color spaces that are supported by the gdk-pixbuf library. Currently only RGB is supported.


enum GdkPixbufAlphaMode

typedef enum
{
        GDK_PIXBUF_ALPHA_BILEVEL,
        GDK_PIXBUF_ALPHA_FULL
} GdkPixbufAlphaMode;

These values can be passed to gdk_pixbuf_render_to_drawable_alpha() to control how the alpha chanel of an image should be handled. This function can create a bilevel clipping mask (black and white) and use it while painting the image. In the future, when the X Window System gets an alpha channel extension, it will be possible to do full alpha compositing onto arbitrary drawables. For now both cases fall back to a bilevel clipping mask.


struct GdkPixbuf

struct GdkPixbuf;

This is the main structure in the gdk-pixbuf library. It is used to represent images. It contains information about the image's pixel data, its color space, bits per sample, width and height, and the rowstride or number of bytes between rows.


gdk_pixbuf_get_colorspace ()

GdkColorspace gdk_pixbuf_get_colorspace     (const GdkPixbuf *pixbuf);

Queries the color space of a pixbuf.


gdk_pixbuf_get_n_channels ()

int         gdk_pixbuf_get_n_channels       (const GdkPixbuf *pixbuf);

Queries the number of channels of a pixbuf.


gdk_pixbuf_get_has_alpha ()

gboolean    gdk_pixbuf_get_has_alpha        (const GdkPixbuf *pixbuf);

Queries whether a pixbuf has an alpha channel (opacity information).


gdk_pixbuf_get_bits_per_sample ()

int         gdk_pixbuf_get_bits_per_sample  (const GdkPixbuf *pixbuf);

Queries the number of bits per color sample in a pixbuf.


gdk_pixbuf_get_pixels ()

guchar*     gdk_pixbuf_get_pixels           (const GdkPixbuf *pixbuf);

Queries a pointer to the pixel data of a pixbuf.


gdk_pixbuf_get_width ()

int         gdk_pixbuf_get_width            (const GdkPixbuf *pixbuf);

Queries the width of a pixbuf.


gdk_pixbuf_get_height ()

int         gdk_pixbuf_get_height           (const GdkPixbuf *pixbuf);

Queries the height of a pixbuf.


gdk_pixbuf_get_rowstride ()

int         gdk_pixbuf_get_rowstride        (const GdkPixbuf *pixbuf);

Queries the rowstride of a pixbuf, which is the number of bytes between rows.


gdk_pixbuf_get_option ()

G_CONST_RETURN gchar* gdk_pixbuf_get_option (GdkPixbuf *pixbuf,
                                             const gchar *key);

Looks up key in the list of options that may have been attached to the pixbuf when it was loaded.