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.\" $XFree86: xc/doc/man/Xext/Xmbuf.man,v 1.3 2001/02/07 22:35:21 tsi Exp $
.\" $XdotOrg$
.\"
.de ZN
.ie t \fB\^\\$1\^\fR\\$2
.el \fI\^\\$1\^\fP\\$2
..
.TH XMBUF __libmansuffix__ __xorgversion__ "X FUNCTIONS"
.SH NAME
XmbufQueryExtension, XmbufGetVersion, XmbufCreateBuffers, XmbufDestroyBuffers, XmbufDisplayBuffers, XmbufGetWindowAttributes, XmbufChangeWindowAttributes, XmbufGetBufferAttributes, XmbufChangeBufferAttributes, XmbufGetScreenInfo, XmbufCreateStereoWindow - X multibuffering functions
.SH SYNTAX
.nf
.LP
\&#include <X11/extensions/multibuf.h>
.LP
Bool XmbufQueryExtension(
    Display *dpy,
    Display *dpy,
    int *event_base_return,
    int *error_base_return);
.LP
Status XmbufGetVersion(
    Display *dpy,
    int *major_version_return,
    int *minor_version_return);
.LP
int XmbufCreateBuffers(
    Display *dpy,
    Window window,
    int count,
    int update_action,
    int update_hint,
    Multibuffer *buffers_update);
.LP
void XmbufDestroyBuffers(
    Display *dpy,
    Window window);
.LP
void XmbufDisplayBuffers(
    Display *dpy,
    int count,
    Multibuffer *buffers,
    int min_delay,
    int max_delay);
.LP
Status XmbufGetWindowAttributes(
    Display *dpy,
    Window window,
    XmbufWindowAttributes *attributes);
.LP
void XmbufChangeWindowAttributes(
    Display *dpy,
    Window window,
    unsigned long valuemask,
    XmbufSetWindowAttributes *attributes);
.LP
Status XmbufGetBufferAttributes(
    Display *dpy,
    Multibuffer buffer,
    XmbufBufferAttributes *attributes);
.LP
void XmbufChangeBufferAttributes(
    Display *dpy,
    Multibuffer buffer,
    unsigned long valuemask,
    XmbufSetBufferAttributes *attributes);
.LP
Status XmbufGetScreenInfo(
    Display *dpy,
    Drawable drawable,
    int *nmono_return,
    XmbufBufferInfo **mono_info_return,
    int *nstereo_return,
    XmbufBufferInfo **stereo_info_return);
.LP
Window XmbufCreateStereoWindow(
    Display *dpy,
    Window parent,
    int x,
    int y,
    unsigned int width,
    unsigned int height,
    unsigned int border_width,
    int depth,
    unsigned int class,                 /\(** InputOutput, InputOnly*/
    Visual *visual,
    unsigned long valuemask,
    XSetWindowAttributes *attributes,
    Multibuffer *left_return,
    Multibuffer *right_return);
.fi
.SH STRUCTURES
.nf
.ta 3i
\fIEvents:\fP
typedef struct {
    int type;	/\(** of event */
    unsigned long serial;	/\(** # of last request processed by server */
    int send_event;	/\(** true if this came frome a SendEvent request */
    Display *display;	/\(** Display the event was read from */
    Multibuffer buffer;	/\(** buffer of event */
    int state;	/\(** see Clobbered constants above */
} XmbufClobberNotifyEvent;
.LP
typedef struct {
    int type;	/\(** of event */
    unsigned long serial;	/\(** # of last request processed by server */
    int send_event;	/\(** true if this came frome a SendEvent request */
    Display *display;	/\(** Display the event was read from */
    Multibuffer buffer;	/\(** buffer of event */
} XmbufUpdateNotifyEvent;
.LP
\fIPer-window attributes that can be got:\fP
typedef struct {
    int displayed_index;	/\(** which buffer is being displayed */
    int update_action;	/\(** Undefined, Background, Untouched, Copied */
    int update_hint;	/\(** Frequent, Intermittent, Static */
    int window_mode;	/\(** Mono, Stereo */
    int nbuffers;	/\(** Number of buffers */
    Multibuffer *buffers;	/\(** Buffers */
} XmbufWindowAttributes;
.LP
\fIPer-window attributes that can be set:\fP
typedef struct {
    int update_hint;	/\(** Frequent, Intermittent, Static */
} XmbufSetWindowAttributes;
.LP
\fIPer-buffer attributes that can be got:\fP
typedef struct {
    Window window;	/\(** which window this belongs to */
    unsigned long event_mask;	/\(** events that have been selected */
    int buffer_index;	/\(** which buffer is this */
    int side;	/\(** Mono, Left, Right */
} XmbufBufferAttributes;
.LP
\fIPer-buffer attributes that can be set:\fP
typedef struct {
    unsigned long event_mask;	/\(** events that have been selected */
} XmbufSetBufferAttributes;
.LP
\fIPer-screen buffer info (there will be lists of them):\fP
typedef struct {
    VisualID visualid;	/\(** visual usuable at this depth */
    int max_buffers;	/\(** most buffers for this visual */
    int depth;	/\(** depth of buffers to be created */
} XmbufBufferInfo;
.fi
.SH DESCRIPTION
The application programming library for the
\fIX11 Double-Buffering, Multi-Buffering, and Stereo Extension\fP
contains the interfaces described below.
With the exception of
.ZN XmbufQueryExtension ,
if any of these routines are
called with a display that does not support the extension, the
ExtensionErrorHandler (which can be set with
.ZN XSetExtensionErrorHandler
and functions the same way as
.ZN XSetErrorHandler )
will be called and the function will then return.
.PP
.ZN XmbufQueryExtension
returns 
.ZN True
if the multibuffering/stereo 
extension is available on the
given display.  If the extension exists, the value of the first event
code (which should be added to the event type constants
.ZN MultibufferClobberNotify
and 
.ZN MultibufferUpdateNotify
to get the actual
values) is stored into event_base_return and the value of the first
error code (which should be added to the error type constant
.ZN MultibufferBadBuffer
to get the actual value) is stored into error_base_return.
.PP
.ZN XmbufGetVersion
gets the major and minor version numbers of the extension.  
The return
value is zero if an error occurs or non-zero if no error happens.
.PP
.ZN XmbufCreateBuffers
requests that "count" buffers be 
created with the given update_action
and update_hint and be associated with the indicated window.  The
number of buffers created is returned (zero if an error occurred)
and buffers_update is filled in with that many Multibuffer identifiers.
.PP
.ZN XmbufDestroyBuffers
destroys the buffers associated 
with the given window.
.PP
.ZN XmbufDisplayBuffers
displays the indicated buffers their
appropriate windows within
max_delay milliseconds after min_delay milliseconds have passed.
No two buffers may be associated with the same window or else a Matc
error is generated.
.PP
.ZN XmbufGetWindowAttributes
gets the multibuffering attributes that apply 
to all buffers associated
with the given window.
The list of buffers returns may be freed with 
.ZN XFree .
Returns non-zero on success and zero if an error occurs.
.PP
.ZN XmbufChangeWindowAttributes
sets the multibuffering attributes 
that apply to all buffers associated
with the given window.  This is currently limited to the update_hint.
.PP
.ZN XmbufGetBufferAttributes
gets the attributes for the indicated buffer.
Returns non-zero on
success and zero if an error occurs.
.PP
.ZN XmbufChangeBufferAttributes
sets the attributes for the indicated buffer.
This is currently limited to the event_mask.
.PP
.ZN XmbufGetScreenInfo
gets the parameters controlling how
mono and stereo windows may be
created on the screen of the given drawable.  The numbers of sets of
visual and depths are returned in nmono_return and nstereo_return.  If
nmono_return is greater than zero, then mono_info_return is set to the
address of an array of 
.ZN XmbufBufferInfo
structures describing the
various visuals and depths that may be used.  Otherwise,
mono_info_return is set to NULL.  Similarly, stereo_info_return is set
according to nstereo_return.  The storage returned in mono_info_return
and stereo_info_return may be released by 
.ZN XFree .
If no errors are
encounted, non-zero will be returned.
.PP
.ZN XmbufCreateStereoWindow
creates a stereo window in the same way that 
.ZN XCreateWindow
creates a mono window.  The buffer ids for the left and right buffers are
returned in left_return and right_return, respectively.  If an
extension error handler that returns is installed, 
.ZN None
will be returned if the extension is not available on this display.
.SH PREDEFINED VALUES
.sp
Update_action field:
.in +.5i
.nf
.ZN MultibufferUpdateActionUndefined	
.ZN MultibufferUpdateActionBackground
.ZN MultibufferUpdateActionUntouched
.ZN MultibufferUpdateActionCopied
.in -.5i
.fi
.sp
Update_hint field:
.in +.5i
.nf
.ZN MultibufferUpdateHintFrequent		
.ZN MultibufferUpdateHintIntermittent
.ZN MultibufferUpdateHintStatic	
.in -.5i
.sp
.fi
Valuemask fields:
.in +.5i
.nf
.ZN MultibufferWindowUpdateHint
.ZN MultibufferBufferEventMask
.in -.5i
.fi
.sp
Mono vs. stereo and left vs. right:
.in +.5i
.nf
.ZN MultibufferModeMono	
.ZN MultibufferModeStereo
.ZN MultibufferSideMono
.ZN MultibufferSideLeft
.ZN MultibufferSideRight		
.in -.5i
.fi
.sp
Clobber state:
.in +.5i
.nf
.ZN MultibufferUnclobbered	
.ZN MultibufferPartiallyClobbered
.ZN MultibufferFullyClobbered	
.in -.5i
.fi
.sp
Event stuff:
.in +.5i
.nf
.ZN MultibufferClobberNotifyMask
.ZN MultibufferUpdateNotifyMask
.ZN MultibufferClobberNotify
.ZN MultibufferUpdateNotify
.ZN MultibufferNumberEvents
.ZN MultibufferBadBuffer
.ZN MultibufferNumberErrors
.in -.5i
.fi
.SH BUGS
This manual page needs more work.
.SH SEE ALSO
\fIExtending X for Double Buffering, Multi-Buffering, and Stereo\fP