Provided by: libxrandr-dev_1.3.2-2_amd64 bug

NAME

        Xrandr - X Resize, Rotate and Reflection extension.

SYNTAX

       #include <X11/extensions/Xrandr.h>

       Bool XRRQueryExtension (Display *dpy,
            int *event_base_return, int *error_base_return);

       Status XRRQueryVersion (Display *dpy,
            int *major_version_return,
            int *minor_version_return);

       XRRScreenConfiguration *XRRGetScreenInfo (Display *dpy,
            Drawable draw);

       void XRRFreeScreenConfigInfo (
            XRRScreenConfiguration *config);

       Status XRRSetScreenConfig (Display *dpy,
            XRRScreenConfiguration *config,
            Drawable draw,
            int size_index,
            Rotation rotation,
            Time timestamp);

       Status XRRSetScreenConfigAndRate (Display *dpy,
                             XRRScreenConfiguration *config,
                             Drawable draw,
                             int size_index,
                             Rotation rotation,
                             short rate,
                             Time timestamp);

       Rotation XRRConfigRotations(
            XRRScreenConfiguration *config,
            Rotation *current_rotation);

       Time XRRConfigTimes (
            XRRScreenConfiguration *config,
            Time *config_timestamp);

       XRRScreenSize *XRRConfigSizes(
            XRRScreenConfiguration *config,
            int *nsizes);

       short *XRRConfigRates (
            XRRScreenConfiguration *config,
            int size_index,
            int *nrates);

       SizeID XRRConfigCurrentConfiguration (
            XRRScreenConfiguration *config,
            Rotation *rotation);

       short XRRConfigCurrentRate (
            XRRScreenConfiguration *config);

       int XRRRootToScreen(
            Display *dpy,
            Window root);

       void XRRSelectInput(Display *dpy, Window window, int mask);

       /∗
        * intended to take RRScreenChangeNotify,  or
        * ConfigureNotify (on the root window)
        * returns 1 if it is an event type it understands, 0 if not
        */
       int XRRUpdateConfiguration(XEvent *event);

       /∗
        * the following are always safe to call, even if RandR is
        * not implemented on a screen
        */
       Rotation XRRRotations(
            Display *dpy, int screen,
            Rotation *current_rotation);

       XRRScreenSize *XRRSizes(Display *dpy,
            int screen, int *nsizes);

       short *XRRRates (Display *dpy, int screen,
            int size_index, int *nrates);

       Time XRRTimes (Display *dpy, int screen, Time *config_timestamp);

ARGUMENTS

       display   Specifies the connection to the X server.

       screen    Specifies which screen.

       draw      Specifies the screen.

       rotation  Specifies the possible rotations or reflections of the screen.

       current_rotation
                 Specifies the current rotations and reflection of the screen.

       timestamp Specifies the server timestamp.

       config_timestamp
                 Specifies the timestamp when the screen was last (re)configured.

       config    Specifies the screen configuration being used.

       sizes     Specifies the array of supported sizes.

       rate      Specifies the refresh rate in Hz.

DATATYPES

       Rotations/Reflections

       Can be any of:
       #define RR_Rotate_0             1
       #define RR_Rotate_90            2
       #define RR_Rotate_180           4
       #define RR_Rotate_270           8

       /∗ new in 1.0 protocol, to allow reflection of screen */
       /∗ reflection is applied after rotation */

       #define RR_Reflect_X            16
       #define RR_Reflect_Y            32

       typedef struct {
           int   width, height;
           int   mwidth, mheight;
       } XRRScreenSize;

       typedef struct {
           int type;                 /∗ event base */
           unsigned long serial;     /∗ # of last request processed by server */
           Bool send_event;          /∗ true if this came from a SendEvent request */
           Display *display;         /∗ Display the event was read from */
           Window window;            /∗ window which selected for this event */
           Window root;              /∗ Root window for changed screen */
           Time timestamp;           /∗ when the screen change occurred */
           Time config_timestamp;    /∗ when the last configuration change */
           SizeID size_index;
           SubpixelOrder subpixel_order;
           Rotation rotation;
           int width;
           int height;
           int mwidth;
           int mheight;
       } XRRScreenChangeNotifyEvent;

       The XRRScreenSize structure contains a possible root size in pixels and in millimeters.

       A  XRRScreenChangeNotifyEvent is sent to a client that has requested notification whenever
       the screen configuration is  changed.  A  client  can  perform  this  request  by  calling
       XRRSelectInput,  passing  the  display,  the root window, and the RRScreenChangeNotifyMask
       mask.

       XRRScreenConfiguration is an opaque data type containing the configuration information for
       a screen.

       Timestamps

       Time  stamps  are  included  and  must be used to ensure the client is playing with a full
       deck: the screen may change properties on the fly and this ensures its  knowledge  of  the
       configuration is up to date.  This is to help issues when screens may become hot-pluggable
       in the future.

DESCRIPTION

       Xrandr is a simple library designed to interface the X Resize and Rotate Extension.   This
       allows  clients to change the size and rotation of the root window of a screen, along with
       the ability to reflect the screen about either axis (if supported by the  implementation).
       Rotation  and  reflection  may  be  implemented  by  software  and  may  result  in slower
       performance if rotation and reflection  are  implemented  in  this  fashion  (as  are  all
       implementations as of October 2002).

       The  Xrandr  library  does  some  minimal  caching  to avoid roundtrips to provide clients
       frequently used information.  See "The X Resize  and  Rotate  Extension"  for  a  detailed
       description;  also  note  that  depth  switching,  as  described  in  the  document is not
       implemented, and may (or may not) ever  be  implemented,  as  display  memory  is  growing
       rapidly,  and toolkits are already beginning to support migration, mitigating the need for
       depth switching.  If it is implemented in the future, we expect to do  so  via  an  upward
       compatible  extension to the current library/protocol; functionality described here should
       continue to work.

       Rotation and reflection and how they interact can be confusing.  In Randr, the  coordinate
       system  is  rotated  in  a counter-clockwise direction relative to the normal orientation.
       Reflection is along the window system coordinate system, not the physical screen X  and  Y
       axis,  so  that  rotation  and  reflection  do  not  interact.   The other way to consider
       reflection is to treat it as specified in the "normal" orientation, before rotation.

       The XRRScreenChangeNotify event is sent to clients that ask to be  informed  whenever  the
       root window configuration changes.  Configuration changes may include resolution, physical
       size, subpixel order (see XRender(3)), and rotation.  Note that changes to any or  all  of
       these  could  occur  due  to  external  events  (user control in the X server, a different
       monitor/flat  panel  display  being  hot-plugged)  and  is  not  only  the  result  of   a
       protocol/library request to the X server.

       Additionally,  to  eliminate  a  potential  race  condition,  this  event may be generated
       immediately upon selecting for notification if the screen has changed since the client  of
       Xrandr  connected  to  the  X server, to enable reliable screen resolution changing when a
       user may log in and change the configuration while one or many clients are starting up.

       Xlib notification

       Clients must call back into Xlib using XRRUpdateConfiguration  when  screen  configuration
       change  notify events are generated (or root window configuration changes occur, to update
       Xlib's view of the resolution, size, rotation, reflection or subpixel  order.   Generally,
       toolkits  will perform this operation on behalf of applications; we did not want to change
       display structure data behind the back of toolkits, as in multithreaded  clients,  various
       race  conditions  might  occur.   Toolkits  should  provide  clients  some  mechanism  for
       notification of screen change, of course.

FUNCTIONS

       There are two classes of interfaces: those which can be safely called even if RandR is not
       implemented  on  a  screen  (to  make  common  idioms  not  dependent on the server having
       support), and those which will return errors if the extension is not present.

       XRRRotations returns both the  possible  set  of  rotations/reflections  supported  (as  a
       bitmask)  as  the value of the function, along with the current rotation/reflection of the
       screen.

       XRRSizes returns the size and a pointer to the current sizes supported  by  the  specified
       screen.   The  first  size  specified  is  the default size of the server. If RandR is not
       supported, it returns 0 for the number of sizes.

       XRRRates returns a pointer to the rates supported by the specified size.  If RandR is  not
       supported, it returns 0 for the number of rates.

       XRRTimes  returns  the  time last reported by the server along with the timestamp the last
       configuration changed.  If the configuration has changed since the client last updated its
       view  of  the server time, requests to change the configuration will fail until the client
       has an up to date timestamp.

       XRRRootToScreen returns the screen number given  a  root  window  (for  example,  from  an
       XRRScreenChangeNotifyEvent).

       The  rest  of  the  functions  will  fail if applied to screens not implementing the RandR
       extension.  XRRSetScreenConfig sets the screen size and rotation  and  reflection  to  the
       desired  values  on the screen specified by draw, or returns a BadValue error.  size_index
       specifies which size configuration is to be used, rotation  specifies  which  rotation  or
       reflection  is to be used (or a BadValue error is returned).  The timestamp is used by the
       server to make sure the client  has  up  to  date  configuration  information.  Status  is
       returned  to  indicate  success  or  failure;  a  client  must  refresh  its configuration
       information if it fails and try the call again (by calling XRRGetScreenInfo).

       XRRSetScreenConfigAndRate is like XRRSetScreenConfig but also sets the  refresh  rate.  If
       specified rate is not supported a BadValue error is returned.

       XRRConfigRotations,    XRRConfigSizes,    XRRConfigCurrentConfiguration,   XRRConfigTimes,
       XRRConfigRates,  and  XRRConfigCurrentRate  are  used  to   get   specific   configuration
       information out of a screen configuration.

       XRRGetScreenInfo  returns a screen configuration for later use; the information is private
       to the library.  Call XRRFreeScreenConfigInfo  to  free  this  information  when  you  are
       finished with it.  It forces a round trip to the server.

       Other  functions  include: XRRQueryExtension which returns the event and error base codes,
       XRRQueryVersion , which returns the current version of the extension (this information  is
       cached by the library).

RESTRICTIONS

       Xrandr will remain upward compatible after the current 1.0 release.

AUTHOR

       Jim Gettys, and Keith Packard, HP.