XLib Surfaces: Cairo: A Vector Graphics Library

## XLib Surfaces XLib Surfaces — X Window System rendering using XLib |

## Functions

cairo_surface_t * | cairo_xlib_surface_create ()
cairo_surface_t * | cairo_xlib_surface_create_for_bitmap ()
void | cairo_xlib_surface_set_size ()
Display * | cairo_xlib_surface_get_display ()
Screen * | cairo_xlib_surface_get_screen ()
void | cairo_xlib_surface_set_drawable ()
Drawable | cairo_xlib_surface_get_drawable ()
Visual * | cairo_xlib_surface_get_visual ()
int | cairo_xlib_surface_get_width ()
int | cairo_xlib_surface_get_height ()
int | cairo_xlib_surface_get_depth ()
void | cairo_xlib_device_debug_cap_xrender_version ()
int | cairo_xlib_device_debug_get_precision ()
void | cairo_xlib_device_debug_set_precision ()

## 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

## See Also

cairo_surface_t