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XLib Surfaces

XLib Surfaces — X Window System rendering using XLib

Synopsis

#define             CAIRO_HAS_XLIB_SURFACE
cairo_surface_t *   cairo_xlib_surface_create           (Display *dpy,
                                                         Drawable drawable,
                                                         Visual *visual,
                                                         int width,
                                                         int height);
cairo_surface_t *   cairo_xlib_surface_create_for_bitmap
                                                        (Display *dpy,
                                                         Pixmap bitmap,
                                                         Screen *screen,
                                                         int width,
                                                         int height);
void                cairo_xlib_surface_set_size         (cairo_surface_t *surface,
                                                         int width,
                                                         int height);
Display *           cairo_xlib_surface_get_display      (cairo_surface_t *surface);
Screen *            cairo_xlib_surface_get_screen       (cairo_surface_t *surface);
void                cairo_xlib_surface_set_drawable     (cairo_surface_t *surface,
                                                         Drawable drawable,
                                                         int width,
                                                         int height);
Drawable            cairo_xlib_surface_get_drawable     (cairo_surface_t *surface);
Visual *            cairo_xlib_surface_get_visual       (cairo_surface_t *surface);
int                 cairo_xlib_surface_get_width        (cairo_surface_t *surface);
int                 cairo_xlib_surface_get_height       (cairo_surface_t *surface);
int                 cairo_xlib_surface_get_depth        (cairo_surface_t *surface);

Description

The XLib surface is used to render cairo graphics to X Window System windows and pixmaps using the XLib library.

Note that the XLib surface automatically takes advantage of X render extension if it is available.

Details

CAIRO_HAS_XLIB_SURFACE

#define CAIRO_HAS_XLIB_SURFACE 1

Defined if the Xlib surface backend is available. This macro can be used to conditionally compile backend-specific code.

cairo_xlib_surface_create ()

cairo_surface_t *   cairo_xlib_surface_create           (Display *dpy,
                                                         Drawable drawable,
                                                         Visual *visual,
                                                         int width,
                                                         int height);

Creates an Xlib surface that draws to the given drawable. The way that colors are represented in the drawable is specified by the provided visual.

Note: If drawable is a Window, then the function cairo_xlib_surface_set_size() must be called whenever the size of the window changes.

When drawable is a Window containing child windows then drawing to the created surface will be clipped by those child windows. When the created surface is used as a source, the contents of the children will be included.

dpy :

 an X Display

drawable :

 an X Drawable, (a Pixmap or a Window)

visual :

 the visual to use for drawing to drawable. The depth of the visual must match the depth of the drawable. Currently, only TrueColor visuals are fully supported.

width :

 the current width of drawable.

height :

 the current height of drawable.

Returns :

 the newly created surface

cairo_xlib_surface_create_for_bitmap ()

cairo_surface_t *   cairo_xlib_surface_create_for_bitmap
                                                        (Display *dpy,
                                                         Pixmap bitmap,
                                                         Screen *screen,
                                                         int width,
                                                         int height);

Creates an Xlib surface that draws to the given bitmap. This will be drawn to as a CAIRO_FORMAT_A1 object.

dpy :

 an X Display

bitmap :

 an X Drawable, (a depth-1 Pixmap)

screen :

 the X Screen associated with bitmap

width :

 the current width of bitmap.

height :

 the current height of bitmap.

Returns :

 the newly created surface

cairo_xlib_surface_set_size ()

void                cairo_xlib_surface_set_size         (cairo_surface_t *surface,
                                                         int width,
                                                         int height);

Informs cairo of the new size of the X Drawable underlying the surface. For a surface created for a Window (rather than a Pixmap), this function must be called each time the size of the window changes. (For a subwindow, you are normally resizing the window yourself, but for a toplevel window, it is necessary to listen for ConfigureNotify events.)

A Pixmap can never change size, so it is never necessary to call this function on a surface created for a Pixmap.

surface :

 a cairo_surface_t for the XLib backend

width :

 the new width of the surface

height :

 the new height of the surface

cairo_xlib_surface_get_display ()

Display *           cairo_xlib_surface_get_display      (cairo_surface_t *surface);

Get the X Display for the underlying X Drawable.

surface :

 a cairo_xlib_surface_t

Returns :

 the display.

Since 1.2

cairo_xlib_surface_get_screen ()

Screen *            cairo_xlib_surface_get_screen       (cairo_surface_t *surface);

Get the X Screen for the underlying X Drawable.

surface :

 a cairo_xlib_surface_t

Returns :

 the screen.

Since 1.2

cairo_xlib_surface_set_drawable ()

void                cairo_xlib_surface_set_drawable     (cairo_surface_t *surface,
                                                         Drawable drawable,
                                                         int width,
                                                         int height);

Informs cairo of a new X Drawable underlying the surface. The drawable must match the display, screen and format of the existing drawable or the application will get X protocol errors and will probably terminate. No checks are done by this function to ensure this compatibility.

surface :

 a cairo_surface_t for the XLib backend

drawable :

 the new drawable for the surface

width :

 the width of the new drawable

height :

 the height of the new drawable

cairo_xlib_surface_get_drawable ()

Drawable            cairo_xlib_surface_get_drawable     (cairo_surface_t *surface);

Get the underlying X Drawable used for the surface.

surface :

 a cairo_xlib_surface_t

Returns :

 the drawable.

Since 1.2

cairo_xlib_surface_get_visual ()

Visual *            cairo_xlib_surface_get_visual       (cairo_surface_t *surface);

Gets the X Visual associated with surface, suitable for use with the underlying X Drawable. If surface was created by cairo_xlib_surface_create(), the return value is the Visual passed to that constructor.

surface :

 a cairo_xlib_surface_t

Returns :

 the Visual or NULL if there is no appropriate Visual for surface.

Since 1.2

cairo_xlib_surface_get_width ()

int                 cairo_xlib_surface_get_width        (cairo_surface_t *surface);

Get the width of the X Drawable underlying the surface in pixels.

surface :

 a cairo_xlib_surface_t

Returns :

 the width of the surface in pixels.

Since 1.2

cairo_xlib_surface_get_height ()

int                 cairo_xlib_surface_get_height       (cairo_surface_t *surface);

Get the height of the X Drawable underlying the surface in pixels.

surface :

 a cairo_xlib_surface_t

Returns :

 the height of the surface in pixels.

Since 1.2

cairo_xlib_surface_get_depth ()

int                 cairo_xlib_surface_get_depth        (cairo_surface_t *surface);

Get the number of bits used to represent each pixel value.

surface :

 a cairo_xlib_surface_t

Returns :

 the depth of the surface in bits.

Since 1.2

See Also

cairo_surface_t