XLib Surfaces

XLib Surfaces — X Window System rendering using XLib

Functions

Types and Values

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.

Functions

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.

Parameters

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

Since: 1.0


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.

Parameters

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

Since: 1.0


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.

Parameters

surface

a cairo_surface_t for the XLib backend

 

width

the new width of the surface

 

height

the new height of the surface

 

Since: 1.0


cairo_xlib_surface_get_display ()

Display *
cairo_xlib_surface_get_display (cairo_surface_t *surface);

Get the X Display for the underlying X Drawable.

Parameters

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.

Parameters

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.

Parameters

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

 

Since: 1.0


cairo_xlib_surface_get_drawable ()

Drawable
cairo_xlib_surface_get_drawable (cairo_surface_t *surface);

Get the underlying X Drawable used for the surface.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

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.

Parameters

surface

a cairo_xlib_surface_t

 

Returns

the depth of the surface in bits.

Since: 1.2


cairo_xlib_device_debug_cap_xrender_version ()

void
cairo_xlib_device_debug_cap_xrender_version
                               (cairo_device_t *device,
                                int major_version,
                                int minor_version);

Restricts all future Xlib surfaces for this devices to the specified version of the RENDER extension. This function exists solely for debugging purpose. It lets you find out how cairo would behave with an older version of the RENDER extension.

Use the special values -1 and -1 for disabling the RENDER extension.

Parameters

device

a cairo_device_t for the Xlib backend

 

major_version

major version to restrict to

 

minor_version

minor version to restrict to

 

Since: 1.12


cairo_xlib_device_debug_get_precision ()

int
cairo_xlib_device_debug_get_precision (cairo_device_t *device);

Get the Xrender precision mode.

Parameters

device

a cairo_device_t for the Xlib backend

 

Returns

the render precision mode

Since: 1.12


cairo_xlib_device_debug_set_precision ()

void
cairo_xlib_device_debug_set_precision (cairo_device_t *device,
                                       int precision);

Render supports two modes of precision when rendering trapezoids. Set the precision to the desired mode.

Parameters

device

a cairo_device_t for the Xlib backend

 

precision

the precision to use

 

Since: 1.12

Types and Values

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.

Since: 1.0

See Also

cairo_surface_t