This value is specified in the CreateAC request as the identifier to be used when referring to a particular AccessContext resource within the server. These resources are used by the server to store client-specified authorization information. This information may be used by the server to determine whether or not the client should be granted access to particular font data.

In order to preserve the integrity of font licensing being performed by the font server, care must be taken by a client to properly represent the identity of the true user of the font. Some font clients will in fact be servers (for example, X servers) requesting fonts for their own clients. Other font clients may be doing work on behalf of a number of different users over time (for example, print spoolers).

AccessContexts must be created (with CreateAC ) and switched among (with SetAuthorization ) to represent all of these "font users" properly.

This structure specifies the NAME, encoded in ISO 8859-1 according to Section 3, of another font server that may be useful as a substitute for this font server. The SUBSET field indicates whether or not the alternate server is likely to only contain a subset of the fonts available from this font server. This information is returned during the initial connection setup and may be used by the client to find a backup server in case of failure.

This structure specifies the name of an authorization protocol and initial data for that protocol. It is used in the authorization negotiation in the initial connection setup and in the CreateAC request.

This structure specifies how glyph images are transmitted in response to QueryXBitmaps8 and QueryXBitmaps16 requests.

If the BYTE-ORDER-MSB bit (1 << 0) is set, the Most Significant Byte of each scanline unit is returned first. Otherwise, the Least Significant Byte is returned first.

If the BIT-ORDER-MSB bit (1 << 1) is set, the left-most bit in each glyph scanline unit is stored in the Most Significant Bit of each transmitted scanline unit. Otherwise, the left-most bit is stored in the Least Significant Bit.

The IMAGE-RECT field specifies a rectangle of pixels within the glyph image. It contains one of the following alternate values:

     ImageRectMin          (0 << 2)
     ImageRectMaxWidth     (1 << 2)
     ImageRectMax          (2 << 2)

For a glyph with extents XCHARINFO in a font with header information XFONTINFO, the IMAGE-RECT values have the following meanings:

ImageRectMin - This refers to the minimal bounding rectangle surrounding the inked pixels in the glyph. This is the most compact representation. The edges of the rectangle are:

         left:     XCHARINFO.LBEARING
         right:    XCHARINFO.RBEARING
         top:      XCHARINFO.ASCENT
         bottom:   XCHARINFO.DESCENT

ImageRectMaxWidth - This refers to the scanlines between the glyph's ascent and descent, padded on the left to the minimum left-bearing (or 0, whichever is less) and on the right to the maximum right-bearing (or logical-width, whichever is greater). All glyph images share a common horizontal origin. This is a combination of ImageRectMax in the horizontal direction and ImageRectMin in the vertical direction. The edges of the rectangle are:

left:         min (XFONTINFO.MIN-BOUNDS.LBEARING, 0)
right:        max (XFONTINFO.MAX-BOUNDS.RBEARING,
                   XFONTINFO.MAX-BOUNDS.WIDTH)
top:               XCHARINFO.ASCENT
bottom:            XCHARINFO.DESCENT

ImageRectMax - This refers to all scanlines, from the maximum ascent (or the font ascent, whichever is greater) to the maximum descent (or the font descent, whichever is greater), padded to the same horizontal extents as MaxWidth. All glyph images have the same sized bitmap and share a common origin. This is the least compact representation, but may be the easiest or most efficient (particularly for character cell fonts) for some clients to use. The edges of the rectangle are:

left:         min (XFONTINFO.MIN-BOUNDS.LBEARING, 0)
right:        max (XFONTINFO.MAX-BOUNDS.RBEARING,
                   XFONTINFO.MAX-BOUNDS.WIDTH)
top:          max (XFONTINFO.FONT-ASCENT,
                   XFONTINFO.MAX-BOUNDS.ASCENT)
bottom:       max (XFONTINFO.FONT-DESCENT,
                   XFONTINFO.MAX-BOUNDS.DESCENT)

The SCANLINE-PAD field specifies the number of bits (8, 16, 32, or 64) to which each glyph scanline is padded before transmitting. It contains one of the following alternate values:

     ScanlinePad8          (0 << 8)
     ScanlinePad16         (1 << 8)
     ScanlinePad32         (2 << 8)
     ScanlinePad64         (3 << 8)

The SCANLINE-UNIT field specifies the number of bits (8, 16, 32, or 64) that should be treated as a unit for swapping. This value must be less than or equal to the number of bits specified by the SCANLINE-PAD. It contains one of the following alternate values:

     ScanlineUnit8          (0 << 12)
     ScanlineUnit16         (1 << 12)
     ScanlineUnit32         (2 << 12)
     ScanlineUnit64         (3 << 12)

BITMAPFORMATs are byte-swapped as CARD32s. All unspecified bits must be zero.

Use of an invalid BITMAPFORMAT causes a Format error to be returned.

This is a mask of bits representing the fields in a BITMAPFORMAT:

This is a boolean value containing one of the following alternate values:

     False              0
     True               1

This is an unsigned byte of data whose encoding is determined by the context in which it is used.

These are unsigned numbers. The latter two are byte-swapped when the server and client have different byte orders.

This structure specifies an individual character code within either a 2-dimensional matrix (using BYTE1 and BYTE2 as the row and column indices, respectively) or a vector (using BYTE1 and BYTE2 as most- and least-significant bytes, respectively). This data type is treated as a pair of 8-bit values and is never byte-swapped. Therefore, the client should always transmit BYTE1 first.

This is a mask of bits indicating which of an extension's (or the core's) maskable events the client would like to receive. Each bit indicates one or more events, and a bit value of one indicates interest in a corresponding set of events. The following bits are defined for event masks specified for the core protocol (i.e. an EXTENSION-OPCODE of zero in SetEventMask and GetEventMask requests):

     CatalogueListChangeMask          (1 << 0)
     FontListChangeMask               (1 << 1)

If CatalogueListChangeMask is set, client is interested in receiving CatalogueListNotify events. If FontListChangeMask is set, the client is interested in receiving FontListNotify events.

Extensions that provide additional events may define their own event masks. These event masks have their own scope and may use the same bit values as the core or other extensions. All unused bits must be set to zero. In SetEventMask requests, if any bits are set that are not defined for the extension (or core) for which this EVENTMASK is intended (according to the EXTENSION- OPCODE given in the SetEventMask request), an EventMask error is generated. This value is swapped as a CARD32.

This is specified by the client in the request OpenBitmapFont as the identifier to be used when referring to a particular open font.

This is a 32-bit value in which the top 3 bits must be clear, and at least 1 other bit must be set (yielding a range of 1 through 2^29-1). It is specified by the client to represent objects in the server. Identifiers are scoped according to their type are private to the client; thus, the same identifier may be used for both a FONTID and an ACCESSCONTEXT as well as by multiple clients.

An ID of zero is referred to as None.

These are signed numbers. The latter two are byte-swapped when the client and server have different byte orders.

This structure indicates a position and length within a block of data.

This structure describes the list of properties provided by a font. Strings for all of the properties names and values are stored within the data block and are located using a table of offsets and lengths.

This structure is padded to 32-bit alignment.

This structure specifies the position, length, and type of of data for a property.

The NAME field specifies the position and length (which must be greater than zero) of the property name relative to the beginning of the PROPINFO.DATA block for this font. The interpretation of the position and length of the VALUE field is determined by the TYPE field, which contains one of the following alternate values:

which have the following meanings:

This property contains a counted string of bytes. The data is stored in the PROPINFO.DATA block beginning at relative byte VALUE.POSITION (beginning with zero), extending for VALUE.LENGTH (at least zero) bytes.

This property contains a unsigned, 32-bit number stored as a CARD32 in VALUE.POSITION (VALUE.LENGTH is zero).

This property contains a signed, 32-bit number stored as an INT32 in VALUE.POSITION (VALUE.LENGTH is zero). This structure is zero-padded to 32-bit alignment.

This structure specifies a range of character codes. A single character is represented by MIN-CHAR equals MAX-CHAR. If the linear interpretation of MAX-CHAR is less than that of MIN-CHAR, or if MIN-CHAR is less than the font's XFONTINFO.CHAR-RANGE.MIN-CHAR, or if MAX-CHAR is greater than the font's XFONTINFO.CHAR-RANGE.MAX-CHAR, the range is invalid.

This structure specifies resolution and point size to be used in resolving partially-specified scaled font names. The X-RESOLUTION and Y-RESOLUTION are measured in pixels-per-inch and must be greater than zero. The DECIPOINT-SIZE is the preferred font size, measured in tenths of a point, and must be greater than zero.

This is a counted list of 1-byte character codes, typically encoded in ISO 8859-1. A character code "c" is equivalent to a CHAR2B structure whose BYTE1 is zero and whose BYTE2 is "c".

This is the number of milliseconds that have passed since a server- dependent origin. It is provided in errors and events and is permitted to wrap.

This structure specifies the ink extents and horizontal escapement (also known as the set- or logical width) of an individual character. The first five values represent directed distances in a coordinate system whose origin is aligned with the lower-left edge of the left-most pixel of the glyph baseline (i.e. the baseline falls between two pixels as shown in Figure 3-1 of the "Bitmap Distribution Format 2.1" Consortium standard [2]).

The LBEARING field specifies the directed distance measured to the right from the origin to the left edge of the left-most inked pixel in the glyph.

The RBEARING field specifies the directed distance (measured to the right) from the origin to the right edge of the right-most inked pixel in the glyph.

The WIDTH field specifies the directed distance (measured to the right) from the origin to the position where the next character should appear (called the "escapement point"). This distance includes any whitespace used for intercharacter padding and is also referred to as the "logical width" or "horizontal escapement."

The ASCENT field specifies the directed distance (measured up) from the baseline to the top edge of the top-most inked pixel in the glyph.

The DESCENT field specifies the directed distance (measured down) from the baseline to the bottom edge of the bottom-most inked pixel.

The ATTRIBUTES field specifies glyph-specific information that is passed through the application. If this value is not being used, it should be zero.

The ink bounding box of a glyph is defined to be the smallest rectangle that encloses all of the inked pixels. This box has a width of RBEARING - LBEARING pixels and a height of ASCENT + DESCENT pixels.

This structure specifies attributes related to the font as a whole.

The FLAGS field is a bit mask containing zero or more of the following boolean values (unspecified bits must be zero):

     AllCharactersExist     (1 << 0)
     InkInside              (1 << 1)
     HorizontalOverlap      (1 << 2)

which have the following meanings:

AllCharactersExist

If this bit is set, all of the characters in the range given by CHAR-RANGE have glyphs encoded in the font. If this bit is clear, some of the characters may not have encoded glyphs.

InkInside

If this bit is set, the inked pixels of each glyph fall within the rectangle described by the font's ascent, descent, origin, and the glyph's escapement point. If this bit is clear, there may be glyphs whose ink extends outside this rectangle.

HorizontalOverlap

If this bit is set, the two ink bounding boxes (smallest rectangle enclosing the inked pixels) of some pairs of glyphs in the font may overlap when displayed side-by-side (i.e. the second character is imaged at the escapement point of the first) on a common baseline. If this bit is clear, there are no pairs of glyphs whose ink bounding boxes overlap.

The DRAWING-DIRECTION field contains a hint indicating whether most of the character metrics have a positive (or "LeftToRight") logical width or a negative ("RightToLeft") logical width. It contains the following alternate values:

         LeftToRight          0
         RightToLeft          1

The CHAR-RANGE.MIN-CHAR and CHAR-RANGE.MAX-CHAR fields specify the first and last character codes that have glyphs encoded in this font. All fonts must have at least one encoded glyph (in which case the MIN-CHAR and MAX-CHAR are equal), but are not required to have glyphs encoded at all positions between the first and last characters.

The DEFAULT-CHAR field specifies the character code of the glyph that the client should substitute for unencoded characters. Requests for extents or bitmaps for an unencoded character generate zero-filled metrics and a zero-length glyph bitmap, respectively.

The MIN-BOUNDS and MAX-BOUNDS fields contain the minimum and maximum values of each of the extents field of all encoded characters in the font (i.e. non-existent characters are ignored).

The FONT-ASCENT and FONT-DESCENT fields specify the font designer's logical height of the font, above and below the baseline, respectively. The sum of the two values is often used as the vertical line spacing of the font. Individual glyphs are permitted to have ascents and descents that are greater than these values.

The PROPERTIES field contains the property data associated with this font.

This structure is padded to 32-bit alignment.

The CLIENT-MAJOR-PROTOCOL-VERSION and CLIENT-MINOR-PROTOCOL-VERSION specify which version of the font service protocol the client would like to use. If the client can support multiple versions, the highest version should be given. This version of the protocol has a major version of 2 and a minor version of 0.

The AUTHORIZATION-PROTOCOLS contains a list of protocol names and optional initial data for which the client can provide information. The server may use this to determine which protocol to use or as part of the initial exchange of authorization data.

=>
status:                         { Success, Continue,
                                  Busy, Denied }
server-major-protocol-version:  CARD16
server-minor-protocol-version:  CARD16
alternate-servers-hint:         LISTofALTERNATESERVER
authorization-index:            CARD8
authorization-data:             LISTofBYTE

The SERVER-MAJOR-PROTOCOL-VERSION and SERVER-MINOR-PROTOCOL-VERSION specify the version of the font service protocol that the server expects from the client. If the server supports the version specified by the client, this version number should be returned. If the client has requested a higher version than is supported by the server, the server's highest version should be returned. Otherwise, if the client has requested a lower version than is supported by the server, the server's lowest version should be returned. It is the client's responsibility to decide whether or not it can match this version of the protocol.

The ALTERNATE-SERVERS-HINT is a list of other font servers that may have related sets of fonts (determined by means outside this protocol, typically by the system administrator). Clients may choose to contact these font servers if the connection is rejected or lost.

The STATUS field indicates whether the server accepted, rejected, or would like more information about the connection. It has one of the following alternate values:

          Success          0
          Continue         1
          Busy             2
          Denied           3

If STATUS is Denied, the server has rejected the client's authorization information. If STATUS is Busy, the server has simply decided that it cannot provide fonts to this client at this time (it may be able to at a later time). In both cases, AUTHORIZATION-INDEX is set to zero, no authorization-data is returned, and the server closes the connection after sending the data described so far.

Otherwise the AUTHORIZATION-INDEX is set to the index (beginning with 1) into the AUTHORIZATION-PROTOCOLS list of the protocol that the server will use for this connection. If the server does not want to use any of the given protocols, this value is set to zero. The AUTHORIZATION-DATA field is used to send back authorization protocol-dependent data to the client (such as a challenge, authentication of the server, etc.).

NoOp

Errors: Alloc

This request does nothing. It is typically used in response to a KeepAlive event.

names: LISTofSTRING8

Errors: Alloc

This request returns the names of the extension packages that are supported by the server. Extension names are case-sensitive and are encoded in ISO 8859-1.

name: STRING8

present: BOOL

major-version: CARD16

minor-version: CARD16

major-opcode: CARD8

first-event: CARD8

number-events: CARD8

first-error: CARD8

number-errors: CARD8

Errors: Alloc

This request determines whether or not the extension package specified by NAME (encoded in ISO 8859-1) is supported by the server and that there is sufficient number of major opcode, event, and error codes available. If so, then PRESENT is set to True, MAJOR-VERSION and MINOR-VERSION are set to the respective major and minor version numbers of the protocol that the server would prefer; MAJOR-OPCODE is set to the value to use in extension requests; FIRST-EVENT is set to the value of the first extension-specific event code or zero if the extension does not have any events; NUMBER-EVENTS is set to the number of new events that the event defines; FIRST-ERROR is set to the value of the first extension-specific error code or zero if the extension does not define any new errors; and NUMBER-ERRORS is set to the number of new errors the extension defines.

Otherwise, PRESENT is set to False and the remaining fields are set to zero.

The server is free to return different values to different clients. Therefore, clients must use this request before issuing any of the requests in the named extension package or using the SetEventMask request to express interest in any of this extension's events. Otherwise, a Request error is returned.

pattern: STRING8

max-names: CARD32

replies-following-hint: CARD32

names: LISTofSTRING8

Errors: Alloc

This request returns a list of at most MAX-NAMES names of collections (called catalogues) of fonts that match the specified PATTERN. In the pattern (which is encoded in ISO 8859-1), the `?' character (octal 77) matches any single character; the `*' character (octal 52) matches any series of zero or more characters; and alphabetic characters match either upper- or lowercase. The returned NAMES are encoded in ISO 8859-1 and may contain mixed character cases.

If PATTERN is of zero length or MAX-NAMES is equal to zero, one reply containing a zero-length list of names is returned. This may be used to synchronize the client with the server.

Servers are free to add or remove catalogues to the set returned by ListCatalogues between any two requests. This request is not cumulative; repeated uses are processed in isolation and do result in an iteration through the list.

To reduce the amount of buffering needed by the server, the list of names may be split across several reply packets, so long as the names arrive in the same order that they would have appeared had they been in a single packet. The REPLIES-FOLLOWING-HINT field in all but the last reply contains a positive value that specifies the number of replies that are likely, but not required, to follow. In the last reply, which may contain zero or more names, this field is set to zero.

names: LISTofSTRING8

Errors: Alloc , Name

This request sets the list of catalogues whose fonts should be visible to the client. The union of the fonts provided by each of the named catalogues forms the set of fonts whose names match patterns in ListFonts , ListFontsWithXInfo , and OpenBitmapFont requests. The catalogue names are case-insensitive and are encoded in ISO 8859-1. A zero-length list resets the client's catalogue list to the server-dependent default.

If any of the catalogue names are invalid, a Name error is returned and the request is ignored.

names: LISTofSTRING8

Errors: Alloc

This request returns the current list of catalogue names (encoded in ISO 8859-1) associated with the client. These catalogues determine the set of fonts that are visible to ListFonts, ListFontsWithXInfo, and OpenBitmapFont. A zero-length list indicates the server's default set of fonts. Catalogue names are case-insensitive and may be returned in mixed case.

extension-opcode: CARD8

event-mask: EVENTMASK

Errors: EventMask , Request

This request specifies the set of maskable events that the extension indicated by EXTENSION-OPCODE (or zero for the core) should generate for the client. Event masks are limited in scope to the extension (or core) for which they are defined, so expressing interest in events from one or more extensions requires multiple uses of this request.

The default event mask if SetEventMask has not been called is zero, indicating no interest in any maskable events. Some events are not maskable and cannot be blocked.

If EXTENSION-OPCODE is not a valid extension opcode previously returned by QueryExtension or zero, a Request error is returned. If EVENT-MASK contains any bits that do not correspond to valid events for the specified extension (or core), an EventMask error is returned and the request is ignored.

extension-opcode: CARD8

event-mask: EVENTMASK

Errors: Request

This request returns the set of maskable core events the extension indicated by EXTENSION-OPCODE (or the core if zero) should generate for the client. Non-maskable events are always sent to the client.

If EXTENSION-OPCODE is not a valid extension opcode previously returned by QueryExtension or zero, a Request error is returned.

ac: ACCESSCONTEXT

authorization-protocols: LISTofAUTH

status: { Success, Continue, Denied }

authorization-index: CARD8

authorization-data: LISTofBYTE

Errors: IDChoice

This request creates a new AccessContext object within the server containing the specified authorization data. When this AccessContext is selected by the client using the SetAuthorization request, the data may be used by the server to determine whether or not the client should be granted access to particular font information.

If STATUS is Denied, the server rejects the client's authorization information and does not associate AC with any valid AccessContext . In this case, AUTHORIZATION-INDEX is set to zero, and zero bytes of AUTHORIZATION-DATA is returned.

Otherwise, AUTHORIZATION-INDEX is set to the index (beginning with 1) into the AUTHORIZATION-PROTOCOLS list of the protocol that the server will use for this connection. If the server does not want to use any of the given protocols, this value is set to zero. The AUTHORIZATION-DATA field is used to send back authorization protocol-dependent data to the client (such as a challenge, authentication of the server, etc.).

If STATUS is Continue, the client is expected to continue the request by sending the following protocol and receiving the indicated response from the server. This continues until STATUS is set to either Success or Denied.

     ->
     more-authorization-data:          STRING8
     =>
     status:                           { Success, Continue, Denied }
     more-authorization-data:          LISTofBYTE

Once the connection has been accepted and STATUS is Success, the request is complete.

If AC is not in the range [1..2^29-1] or is already associated with an access context, an IDChoice error is returned.

ac: ACCESSCONTEXT

Errors: AccessContext , Alloc

This request indicates that the specified AC should no longer be associated with a valid access context. If AC is also the current AccessContext (as set by the SetAuthorization request), an implicit SetAuthorization of None is done to restore the AccessContext established for the initial connection setup. Operations on fonts that were opened under AC are not affected. The client may reuse the value of AC in a subsequent CreateAC request.

If AC isn't associated with any valid authorization previously created by CreateAC , an AccessContext error is returned.

ac: ACCESSCONTEXT

Errors: AccessContext

This request sets the AccessContext to be used for subsequent requests (except for QueryXInfo, QueryXExtents8, QueryXExtents16, QueryXBitmaps8, QueryXBitmaps16 and CloseFont which are done under the AccessContext of the corresponding OpenBitmapFont ")." An AC of None restores the AccessContext established for the initial connection setup.

If AC is neither None nor a value associated with a valid AccessContext previously created by CreateAC, an AccessContext error is returned.

resolutions: LISTofRESOLUTION

Errors: Resolution, Alloc

This request provides a hint as to the resolution and preferred point size of the drawing surfaces for which the client will be requesting fonts. The server may use this information to set the RESOLUTION_X and RESOLUTION_Y fields of scalable XLFD font names, to order sets of names based on their resolutions, and to choose the server-dependent instance that is used when a partially-specified scalable fontname is opened.

If a zero-length list of RESOLUTIONS is given, the server-dependent default value is restored. Otherwise, if elements of all of the specified RESOLUTIONS are non-zero, the default resolutions for this client are changed.

If a RESOLUTION entry contains a zero, a Resolution error is returned and the default resolutions are not changed.

resolutions: LISTofRESOLUTION

Errors: Alloc

This request returns the current list of default resolutions. If a client has not performed a SetResolution, a server-dependent default value is returned.

pattern: STRING8

max-names: CARD32

replies-following-hint: CARD32

names: LISTofSTRING8

Errors: Alloc

This request returns a list of at most MAX-NAMES font names that match the specified PATTERN, according to matching rules of the X Logical Font Description Conventions [3]. In the pattern (which is encoded in ISO 8859-1) the `?' character (octal 77) matches any single character; the `*' character (octal 52) matches any series of zero or more characters; and alphabetic characters match either upper- or lowercase. The returned NAMES are encoded in ISO 8859-1 and may contain mixed character cases. Font names are not required to be in XLFD format.

If PATTERN is of zero length or MAX-NAMES is equal to zero, one reply containing a zero-length list of names is returned. This may be used to synchronize the client with the server.

Servers are free to add or remove fonts to the set returned by ListFonts between any two requests. This request is not cumulative; repeated uses are processed in isolation and do result in an iteration through the list.

To reduce the amount of buffering needed by the server, the list of names may be split across several reply packets, so long as the names arrive in the same order that they would have appeared had they been in a single packet. The REPLIES-FOLLOWING-HINT field in all but the last reply contains a positive value that specifies the number of replies that are likely, but not required, to follow. In the last reply, which may contain zero or more names, this field is set to zero.

pattern: STRING8

pattern: STRING8

pattern: STRING8

max-names: CARD32

replies-following-hint: CARD32

info: XFONTINFO

name: STRING8

Errors: Alloc

This request is similar to ListFonts except that a separate reply containing the name, header, and property data is generated for each matching font name. Following these replies, if any, a final reply containing a zero-length NAME and no INFO is sent.

The REPLIES-FOLLOWING-HINT field in all but the last reply contains a positive value that specifies the number of replies that are likely, but not required, to follow. In the last reply, this field is set to zero.

If PATTERN is of zero length or if MAX-NAMES is equal to zero, only the final reply containing a zero-length NAME and no INFO is returned. This may be used to synchronize the client with the server.

fontid: FONTID

pattern: STRING8

format-mask: BITMAPFORMATMASK

format-hint: BITMAPFORMAT

otherid: FONTID or None

otherid-valid: BOOL

cachable: BOOL

Errors: IDChoice, Name, Format, AccessContext, Alloc

This request looks for a server-dependent choice of the font names that match the specified PATTERN according to the rules described for ListFonts . If no matches are found, a Name error is returned. Otherwise, the server attempts to open the font associated with the chosen name.

Permission to access the font is determined by the server according the licensing policy used for this font. The server may use the client's current AccessContext (as set by the most recent SetAuthorization request or the original connection setup) to determine any client-specific sets of permissions. After the font has been opened, the client is allowed to specify a new AccessContext with SetAuthorization or release the AccessContext using FreeAC . Subsequent QueryXInfo, QueryXExtents8, QueryXExtents16, QueryXBitmaps8, QueryXBitmaps16 and CloseFont requests on this FONTID are performed according to permissions granted at the time of the OpenBitmapFont request.

If the server is willing and able to detect that the client has already opened the font successfully (possibly under a different name), the OTHERID field may be set to one of the identifiers previously used to open the font. The OTHERID-VALID field indicates whether or not OTHERID is still associated with an open font: if it is True, the client may use OTHERID as an alternative to FONTID. Otherwise, if OTHERID-VALID is False, OTHERID is no longer open but has not been reused by a subsequent OpenBitmapFont request.

If OTHERID is set to None, then OTHERID-VALID should be set to False.

The FORMAT-MASK indicates which fields in FORMAT-HINT the client is likely to use in subsequent GetXBitmaps8 and GetXBitmaps16 requests. Servers may wish to use this information to precompute certain values.

If CACHABLE is set to True, the client may cache the font (so that redundant opens of the same font may be avoided) and use it with all AccessContexts during the life of the client without violating the font's licensing policy. This flag is typically set whenever a font is unlicensed or is licensed on a per-display basis. If CACHABLE is False, the client should reopen the font for each AccessContext .

The server is permitted to add to or remove from the set of fonts returned by ListFonts between any two requests, though mechanisms outside the protocol. Therefore, it is possible for this request (which is atomic) to return a different font than would result from separate a ListFonts followed by an OpenBitmapFont with a non-wildcarded font name.

If FONTID is not in the range [1..2^29-1] or if it is already associated with an open font, an IDChoice error is returned. If no font is available that matches the specified PATTERN, a Name error is returned. If the font is present but the client is not permitted access, an AccessContext error is returned. If FORMAT-MASK has any unspecified bits set or if any of the fields in FORMAT-HINT indicated by FORMAT-MASK are invalid, a Format error is returned.

fontid: FONTID

info: XFONTINFO

Errors: Font, Alloc

This request returns the font header and property information for the open font associated with FONTID.

If FONTID is not associated with any open fonts, a Font error is returned.

fontid: FONTID

range: BOOL

chars: STRING8

extents: LISTofXCHARINFO

Errors: Font, Range, Alloc

This request is equivalent to QueryXExtents16 except that it uses 1-byte character codes.

fontid: FONTID

range: BOOL

chars: LISTofCHAR2B

extents: LISTofXCHARINFO

Errors: Font, Range, Alloc

This request returns a list of glyph extents from the open font associated with FONTID for the series of characters specified by RANGE and CHARS.

If RANGE is True, each succeeding pair of elements in CHARS is treated as a range of characters for which extents should be returned. If CHARS contains an odd number of elements, the font's XFONTINFO.CHAR-RANGE.MAX-CHAR is implicitly appended to the list. If CHARS contains no elements, the list is implicitly replaced with the font's XFONTINFO.CHAR-RANGE. If any of the resulting character ranges are invalid, a Range error is returned. Otherwise, the character ranges are concatenated in the order given by CHARS to produce a set of character codes for which extents are returned.

If RANGE is False, then CHARS specifies the set of character codes for which extents are returned. If CHARS is of zero length, then a zero-length list of extents is returned.

The extents for each character code in the resulting set (which may contain duplicates) are returned in the order in which the character codes appear in the set. At least one metric for each character shall be non-zero unless the character is not encoded in the font, in which case all-zero metrics are returned. A blank, zero-width character can be encoded with non-zero but equal left and right bearings.

If FONTID is not associated with any open fonts, a Font error is returned. If RANGE is True and CHARS contains any invalid ranges, a Range error is returned.

fontid: FONTID

range: BOOL

chars: STRING8

format: BITMAPFORMAT

replies-following-hint: CARD32

offsets: LISTofOFFSET32

bitmaps: LISTofBYTE

Errors: Font, Range, Format, Alloc

This request is equivalent to QueryXBitmaps16 except that it uses 1-byte character codes.

fontid: FONTID

range: BOOL

chars: LISTofCHAR2B

format: BITMAPFORMAT

replies-following-hint: CARD32

offsets: LISTofOFFSET32

bitmaps: LISTofBYTE

Errors: Font, Range, Format, Alloc

This request returns a list of glyph bitmaps from the open font associated with FONTID for the series of characters specified by RANGE and CHARS.

If RANGE is True, each succeeding pair of elements in CHARS is treated as a range of characters for which bitmaps should be returned. If CHARS contains an odd number of elements, the font's XFONTINFO.CHAR-RANGE.MAX-CHAR is implicitly appended to the list. If CHARS contains no elements, the list is implicitly replaced with the font's XFONTINFO.CHAR-RANGE. If any of the resulting character ranges are invalid, a Range error is returned. Otherwise, the character ranges are concatenated in the order given by CHARS to produce a set of character codes for which bitmaps are returned.

If RANGE is False, then CHARS specifies the set of character codes for which bitmaps are returned. If CHARS is of zero length, then a single reply containing a zero-length list of offsets and bitmaps is returned.

If any of the resulting character ranges are invalid, a Range error is returned. Otherwise, the resulting character ranges are concatenated in the order given by CHARS to produce a set of character codes for which bitmaps are returned.

The server is free to return the glyph bitmaps in multiple replies to reduce the amount of buffering that is necessary. In this situation, the set of characters obtained above is partitioned into an implementation-dependent number of ordered, non-overlapping subsets containing runs of one or more consecutive characters. The global ordering of characters must be maintained such that concatenating the subsets in order that they were produced yields the original set. A reply is generated for each subset, in the order that it was produced.

For each character in a subset, an image of that character's glyph is described by a rectangle of bits corresponding to the pixels specified by FORMAT.IMAGE-RECT. Within the image, set and clear bits represent inked and non-inked pixels, respectively.

Each scanline of a glyph image, from top to bottom, is zero-padded on the right to a multiple of the number of bits specified by FORMAT.SCANLINE-PAD. The scanline is then divided from left to right into a sequence of FORMAT.SCANLINE-UNIT bits. The bits of each unit are then arranged such that the left-most pixel is stored in the most- or least-significant bit, according to FORMAT.BIT-ORDER-MSB. The bytes of each unit are then arranged such that the most- or least-significant byte, according to FORMAT.BYTE-ORDER-MSB, is transmitted first. Finally, the units are arranged such that the left-most is transmitted first and the right-most is transmitted last.

The individual images within a subset are then concatenated in a server-dependent order to form the BITMAPS data of the reply. If a glyph image is duplicated within a reply, the server is free to return fewer (but at least one) copies of the image. If a character is not encoded within the font, a zero-length bitmap is substituted for this character. Each glyph image must begin at a bit position that is a multiple of the FORMAT.SCANLINE-UNIT.

The OFFSETS array in a reply contains one entry for each character in the subset being returned, in the order that the characters appear in the subset. Each entry specifies the starting location in bytes and size in bytes of the corresponding glyph image in the BITMAPS data of that reply (i.e. an offset may not refer to data in another reply).

The REPLIES-FOLLOWING-HINT field in all but the last reply contains a positive value that specifies the number of replies that are likely, but not required, to follow. In the last reply, which may contain data for zero or more characters, this field is set to zero.

If FONTID is not associated with any open fonts, a Font error is returned. If RANGE is True and CHARS contains any invalid ranges, a Range error is returned. If FORMAT is invalid, a Format error is returned.

fontid: FONTID

Errors: Font, Alloc

This request indicates that the specified FONTID should no longer be associated with an open font. The server is free to release any client-specific storage or licenses allocated for the font. The client may reuse the value of FONTID in a subsequent OpenBitmapFont request.

If FONTID is not associated with any open fonts, a Font error is returned.

When a connection is closed, a CloseFont is done on all fonts that are open on the connection. In addition, the server is free to release any storage or licenses allocated on behalf of the client that made the connection.

type: CARD8 value of 1

error-code: CARD8

sequence-number: CARD16

length: CARD32

timestamp: TIMESTAMP

major-opcode: CARD8

minor-opcode: CARD8

data-or-unused: CARD16

data-or-unused: CARD16 unused

This error is generated by any request that has an unknown combination of major and minor request numbers, or by any extension request that is issued before a QueryExtension of that extension.

data-or-unused: CARD16 unused

format: BITMAPFORMAT bad format value

This error is generated by the use of an invalid BITMAPFORMAT in the OpenBitmapFont, QueryXBitmaps8, and QueryXBitmaps16 requests. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

fontid: FONTID bad font identifier

This error is generated by an invalid FONTID in the QueryXInfo, QueryXExtents8, QueryXExtents16, QueryXBitmaps8, QueryXBitmaps16 and CloseFont requests. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

range: RANGE bad range

This error is generated by an invalid RANGE in the QueryXExtents8, QueryXExtents16, QueryXBitmaps8 and QueryXBitmaps16 requests. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

event-mask: EVENTMASK bad event mask

This error is generated by an invalid EVENTMASK in the SetEventMask request. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

ac: ACCESSCONTEXT unaccepted AccessContext

This error is generated by an invalid ACCESSCONTEXT in the FreeAC or SetAuthorization request or by an OpenBitmapFont request performed without sufficient authorization. In the first two cases, the ACCESSCONTEXT of the errant request is returned as extra data. In the third case, the current ACCESSCONTEXT is returned as extra data.

data-or-unused: CARD16 unused

id: ID bad identifier

This error is generated by an invalid or already associated ACCESSCONTEXT identifier in a CreateAC request or FONTID identifier in an OpenBitmapFont request. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

This error is generated by a font name pattern that matches no fonts in an OpenBitmapFont request or no catalogue names in a SetCatalogues request.

data-or-unused: CARD16 X value of errant resolution

y-resolution: CARD16 Y value of errant resolution

point-size: CARD16 point size of errant resolution

This error is generated in response to an invalid RESOLUTION structure in a SetResolution request. The value that caused the error is included in the DATA-OR-UNUSED field and as extra data.

data-or-unused: CARD16 unused

This error is generated by any request for which the server lacks sufficient resources (especially memory).

data-or-unused: CARD16 unused

length: CARD32 bad length value

This error is generated by any request that has a length field greater than (MAXIMUM-REQUEST-LENGTH * 4) bytes. The value that caused the error is included as extra data.

data-or-unused: CARD16 unused

This error may be generated in response to any request that the server is unable to process because it is deficient. Use of this error is highly discouraged and indicates lack of conformance to the protocol. Additional errors may be defined by extensions.

type: CARD8 value of 2

event-code: CARD8

sequence-number: CARD16

length: CARD32

timestamp: TIMESTAMP

This unsolicited, nonmaskable event may be sent by the server to verify that the connection has not been broken (for transports that do not provide this information). Clients should acknowledge receipt of this request by sending any request (such as NoOp ")."

added: BOOL

deleted: BOOL

This event is sent to clients that have included CatalogueListChangeMask in their core event mask whenever the list of catalogues that are available has changed. The ADDED field is True if new catalogues have been added to the server, otherwise it is False. The DELETED field is True if any existing catalogues have been removed from the server, otherwise it is False.

added: BOOL

deleted: BOOL

This event is sent to clients that have included FontListChangeMask in their event mask whenever the list of fonts that are provided by the currently selected catalogues has changed. The ADDED field is True if new fonts have been added to any of the catalogues currently used by the client, otherwise it is False. The DELETED field is True if any existing fonts have been removed from any of catalogues used by the client, otherwise it is False.

Additional events may be defined by extensions.