moved include/ to rfb/

1 files changed, 944 insertions, 0 deletions

diff --git a/rfb/rfbproto.h b/rfb/rfbproto.h
new file mode 100644
index 0000000..9a64484
--- /dev/null
+++ b/rfb/rfbproto.h
@@ -0,0 +1,944 @@
+#ifndef RFBPROTO_H
+#define RFBPROTO_H
+
+/*
+ *  Copyright (C) 2000-2002 Constantin Kaplinsky.  All Rights Reserved.
+ *  Copyright (C) 2000 Tridia Corporation.  All Rights Reserved.
+ *  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
+ *
+ *  This is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This software is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this software; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ *  USA.
+ */
+
+/*
+ * rfbproto.h - header file for the RFB protocol version 3.3
+ *
+ * Uses types CARD<n> for an n-bit unsigned integer, INT<n> for an n-bit signed
+ * integer (for n = 8, 16 and 32).
+ *
+ * All multiple byte integers are in big endian (network) order (most
+ * significant byte first).  Unless noted otherwise there is no special
+ * alignment of protocol structures.
+ *
+ *
+ * Once the initial handshaking is done, all messages start with a type byte,
+ * (usually) followed by message-specific data.  The order of definitions in
+ * this file is as follows:
+ *
+ *  (1) Structures used in several types of message.
+ *  (2) Structures used in the initial handshaking.
+ *  (3) Message types.
+ *  (4) Encoding types.
+ *  (5) For each message type, the form of the data following the type byte.
+ *      Sometimes this is defined by a single structure but the more complex
+ *      messages have to be explained by comments.
+ */
+
+
+/*****************************************************************************
+ *
+ * Structures used in several messages
+ *
+ *****************************************************************************/
+
+/*-----------------------------------------------------------------------------
+ * Structure used to specify a rectangle.  This structure is a multiple of 4
+ * bytes so that it can be interspersed with 32-bit pixel data without
+ * affecting alignment.
+ */
+
+typedef struct {
+    uint16_t x;
+    uint16_t y;
+    uint16_t w;
+    uint16_t h;
+} rfbRectangle;
+
+#define sz_rfbRectangle 8
+
+
+/*-----------------------------------------------------------------------------
+ * Structure used to specify pixel format.
+ */
+
+typedef struct {
+
+    uint8_t bitsPerPixel;		/* 8,16,32 only */
+
+    uint8_t depth;		/* 8 to 32 */
+
+    uint8_t bigEndian;		/* True if multi-byte pixels are interpreted
+				   as big endian, or if single-bit-per-pixel
+				   has most significant bit of the byte
+				   corresponding to first (leftmost) pixel. Of
+				   course this is meaningless for 8 bits/pix */
+
+    uint8_t trueColour;		/* If false then we need a "colour map" to
+				   convert pixels to RGB.  If true, xxxMax and
+				   xxxShift specify bits used for red, green
+				   and blue */
+
+    /* the following fields are only meaningful if trueColour is true */
+
+    uint16_t redMax;		/* maximum red value (= 2^n - 1 where n is the
+				   number of bits used for red). Note this
+				   value is always in big endian order. */
+
+    uint16_t greenMax;		/* similar for green */
+
+    uint16_t blueMax;		/* and blue */
+
+    uint8_t redShift;		/* number of shifts needed to get the red
+				   value in a pixel to the least significant
+				   bit. To find the red value from a given
+				   pixel, do the following:
+				   1) Swap pixel value according to bigEndian
+				      (e.g. if bigEndian is false and host byte
+				      order is big endian, then swap).
+				   2) Shift right by redShift.
+				   3) AND with redMax (in host byte order).
+				   4) You now have the red value between 0 and
+				      redMax. */
+
+    uint8_t greenShift;		/* similar for green */
+
+    uint8_t blueShift;		/* and blue */
+
+    uint8_t pad1;
+    uint16_t pad2;
+
+} rfbPixelFormat;
+
+#define sz_rfbPixelFormat 16
+
+
+
+/*****************************************************************************
+ *
+ * Initial handshaking messages
+ *
+ *****************************************************************************/
+
+/*-----------------------------------------------------------------------------
+ * Protocol Version
+ *
+ * The server always sends 12 bytes to start which identifies the latest RFB
+ * protocol version number which it supports.  These bytes are interpreted
+ * as a string of 12 ASCII characters in the format "RFB xxx.yyy\n" where
+ * xxx and yyy are the major and minor version numbers (for version 3.3
+ * this is "RFB 003.003\n").
+ *
+ * The client then replies with a similar 12-byte message giving the version
+ * number of the protocol which should actually be used (which may be different
+ * to that quoted by the server).
+ *
+ * It is intended that both clients and servers may provide some level of
+ * backwards compatibility by this mechanism.  Servers in particular should
+ * attempt to provide backwards compatibility, and even forwards compatibility
+ * to some extent.  For example if a client demands version 3.1 of the
+ * protocol, a 3.0 server can probably assume that by ignoring requests for
+ * encoding types it doesn't understand, everything will still work OK.  This
+ * will probably not be the case for changes in the major version number.
+ *
+ * The format string below can be used in sprintf or sscanf to generate or
+ * decode the version string respectively.
+ */
+
+#define rfbProtocolVersionFormat "RFB %03d.%03d\n"
+#define rfbProtocolMajorVersion 3
+#define rfbProtocolMinorVersion 3
+
+typedef char rfbProtocolVersionMsg[13];	/* allow extra byte for null */
+
+#define sz_rfbProtocolVersionMsg 12
+
+
+/*-----------------------------------------------------------------------------
+ * Authentication
+ *
+ * Once the protocol version has been decided, the server then sends a 32-bit
+ * word indicating whether any authentication is needed on the connection.
+ * The value of this word determines the authentication scheme in use.  For
+ * version 3.0 of the protocol this may have one of the following values:
+ */
+
+#define rfbConnFailed 0
+#define rfbNoAuth 1
+#define rfbVncAuth 2
+
+/*
+ * rfbConnFailed:	For some reason the connection failed (e.g. the server
+ *			cannot support the desired protocol version).  This is
+ *			followed by a string describing the reason (where a
+ *			string is specified as a 32-bit length followed by that
+ *			many ASCII characters).
+ *
+ * rfbNoAuth:		No authentication is needed.
+ *
+ * rfbVncAuth:		The VNC authentication scheme is to be used.  A 16-byte
+ *			challenge follows, which the client encrypts as
+ *			appropriate using the password and sends the resulting
+ *			16-byte response.  If the response is correct, the
+ *			server sends the 32-bit word rfbVncAuthOK.  If a simple
+ *			failure happens, the server sends rfbVncAuthFailed and
+ *			closes the connection. If the server decides that too
+ *			many failures have occurred, it sends rfbVncAuthTooMany
+ *			and closes the connection.  In the latter case, the
+ *			server should not allow an immediate reconnection by
+ *			the client.
+ */
+
+#define rfbVncAuthOK 0
+#define rfbVncAuthFailed 1
+#define rfbVncAuthTooMany 2
+
+
+/*-----------------------------------------------------------------------------
+ * Client Initialisation Message
+ *
+ * Once the client and server are sure that they're happy to talk to one
+ * another, the client sends an initialisation message.  At present this
+ * message only consists of a boolean indicating whether the server should try
+ * to share the desktop by leaving other clients connected, or give exclusive
+ * access to this client by disconnecting all other clients.
+ */
+
+typedef struct {
+    uint8_t shared;
+} rfbClientInitMsg;
+
+#define sz_rfbClientInitMsg 1
+
+
+/*-----------------------------------------------------------------------------
+ * Server Initialisation Message
+ *
+ * After the client initialisation message, the server sends one of its own.
+ * This tells the client the width and height of the server's framebuffer,
+ * its pixel format and the name associated with the desktop.
+ */
+
+typedef struct {
+    uint16_t framebufferWidth;
+    uint16_t framebufferHeight;
+    rfbPixelFormat format;	/* the server's preferred pixel format */
+    uint32_t nameLength;
+    /* followed by char name[nameLength] */
+} rfbServerInitMsg;
+
+#define sz_rfbServerInitMsg (8 + sz_rfbPixelFormat)
+
+
+/*
+ * Following the server initialisation message it's up to the client to send
+ * whichever protocol messages it wants.  Typically it will send a
+ * SetPixelFormat message and a SetEncodings message, followed by a
+ * FramebufferUpdateRequest.  From then on the server will send
+ * FramebufferUpdate messages in response to the client's
+ * FramebufferUpdateRequest messages.  The client should send
+ * FramebufferUpdateRequest messages with incremental set to true when it has
+ * finished processing one FramebufferUpdate and is ready to process another.
+ * With a fast client, the rate at which FramebufferUpdateRequests are sent
+ * should be regulated to avoid hogging the network.
+ */
+
+
+
+/*****************************************************************************
+ *
+ * Message types
+ *
+ *****************************************************************************/
+
+/* server -> client */
+
+#define rfbFramebufferUpdate 0
+#define rfbSetColourMapEntries 1
+#define rfbBell 2
+#define rfbServerCutText 3
+#ifdef BACKCHANNEL
+#define rfbBackChannel 15
+#endif
+
+/* client -> server */
+
+#define rfbSetPixelFormat 0
+#define rfbFixColourMapEntries 1	/* not currently supported */
+#define rfbSetEncodings 2
+#define rfbFramebufferUpdateRequest 3
+#define rfbKeyEvent 4
+#define rfbPointerEvent 5
+#define rfbClientCutText 6
+
+
+
+
+/*****************************************************************************
+ *
+ * Encoding types
+ *
+ *****************************************************************************/
+
+#define rfbEncodingRaw 0
+#define rfbEncodingCopyRect 1
+#define rfbEncodingRRE 2
+#define rfbEncodingCoRRE 4
+#define rfbEncodingHextile 5
+#ifdef HAVE_LIBZ
+#define rfbEncodingZlib 6
+#define rfbEncodingTight 7
+#define rfbEncodingZlibHex 8
+#endif
+#ifdef BACKCHANNEL
+#define rfbEncodingBackChannel 15
+#endif
+#ifdef HAVE_ZRLE
+#define rfbEncodingZRLE 16
+#endif
+
+/*
+ * Special encoding numbers:
+ *   0xFFFFFF00 .. 0xFFFFFF0F -- encoding-specific compression levels;
+ *   0xFFFFFF10 .. 0xFFFFFF1F -- mouse cursor shape data;
+ *   0xFFFFFF20 .. 0xFFFFFF2F -- various protocol extensions;
+ *   0xFFFFFF30 .. 0xFFFFFFDF -- not allocated yet;
+ *   0xFFFFFFE0 .. 0xFFFFFFEF -- quality level for JPEG compressor;
+ *   0xFFFFFFF0 .. 0xFFFFFFFF -- cross-encoding compression levels.
+ */
+
+#define rfbEncodingCompressLevel0  0xFFFFFF00
+#define rfbEncodingCompressLevel1  0xFFFFFF01
+#define rfbEncodingCompressLevel2  0xFFFFFF02
+#define rfbEncodingCompressLevel3  0xFFFFFF03
+#define rfbEncodingCompressLevel4  0xFFFFFF04
+#define rfbEncodingCompressLevel5  0xFFFFFF05
+#define rfbEncodingCompressLevel6  0xFFFFFF06
+#define rfbEncodingCompressLevel7  0xFFFFFF07
+#define rfbEncodingCompressLevel8  0xFFFFFF08
+#define rfbEncodingCompressLevel9  0xFFFFFF09
+
+#define rfbEncodingXCursor         0xFFFFFF10
+#define rfbEncodingRichCursor      0xFFFFFF11
+#define rfbEncodingPointerPos      0xFFFFFF18
+
+#define rfbEncodingLastRect        0xFFFFFF20
+#define rfbEncodingNewFBSize       0xFFFFFF21
+
+#define rfbEncodingQualityLevel0   0xFFFFFFE0
+#define rfbEncodingQualityLevel1   0xFFFFFFE1
+#define rfbEncodingQualityLevel2   0xFFFFFFE2
+#define rfbEncodingQualityLevel3   0xFFFFFFE3
+#define rfbEncodingQualityLevel4   0xFFFFFFE4
+#define rfbEncodingQualityLevel5   0xFFFFFFE5
+#define rfbEncodingQualityLevel6   0xFFFFFFE6
+#define rfbEncodingQualityLevel7   0xFFFFFFE7
+#define rfbEncodingQualityLevel8   0xFFFFFFE8
+#define rfbEncodingQualityLevel9   0xFFFFFFE9
+
+
+/*****************************************************************************
+ *
+ * Server -> client message definitions
+ *
+ *****************************************************************************/
+
+
+/*-----------------------------------------------------------------------------
+ * FramebufferUpdate - a block of rectangles to be copied to the framebuffer.
+ *
+ * This message consists of a header giving the number of rectangles of pixel
+ * data followed by the rectangles themselves.  The header is padded so that
+ * together with the type byte it is an exact multiple of 4 bytes (to help
+ * with alignment of 32-bit pixels):
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbFramebufferUpdate */
+    uint8_t pad;
+    uint16_t nRects;
+    /* followed by nRects rectangles */
+} rfbFramebufferUpdateMsg;
+
+#define sz_rfbFramebufferUpdateMsg 4
+
+/*
+ * Each rectangle of pixel data consists of a header describing the position
+ * and size of the rectangle and a type word describing the encoding of the
+ * pixel data, followed finally by the pixel data.  Note that if the client has
+ * not sent a SetEncodings message then it will only receive raw pixel data.
+ * Also note again that this structure is a multiple of 4 bytes.
+ */
+
+typedef struct {
+    rfbRectangle r;
+    uint32_t encoding;	/* one of the encoding types rfbEncoding... */
+} rfbFramebufferUpdateRectHeader;
+
+#define sz_rfbFramebufferUpdateRectHeader (sz_rfbRectangle + 4)
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Raw Encoding.  Pixels are sent in top-to-bottom scanline order,
+ * left-to-right within a scanline with no padding in between.
+ */
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * CopyRect Encoding.  The pixels are specified simply by the x and y position
+ * of the source rectangle.
+ */
+
+typedef struct {
+    uint16_t srcX;
+    uint16_t srcY;
+} rfbCopyRect;
+
+#define sz_rfbCopyRect 4
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * RRE - Rise-and-Run-length Encoding.  We have an rfbRREHeader structure
+ * giving the number of subrectangles following.  Finally the data follows in
+ * the form [<bgpixel><subrect><subrect>...] where each <subrect> is
+ * [<pixel><rfbRectangle>].
+ */
+
+typedef struct {
+    uint32_t nSubrects;
+} rfbRREHeader;
+
+#define sz_rfbRREHeader 4
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * CoRRE - Compact RRE Encoding.  We have an rfbRREHeader structure giving
+ * the number of subrectangles following.  Finally the data follows in the form
+ * [<bgpixel><subrect><subrect>...] where each <subrect> is
+ * [<pixel><rfbCoRRERectangle>].  This means that
+ * the whole rectangle must be at most 255x255 pixels.
+ */
+
+typedef struct {
+    uint8_t x;
+    uint8_t y;
+    uint8_t w;
+    uint8_t h;
+} rfbCoRRERectangle;
+
+#define sz_rfbCoRRERectangle 4
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Hextile Encoding.  The rectangle is divided up into "tiles" of 16x16 pixels,
+ * starting at the top left going in left-to-right, top-to-bottom order.  If
+ * the width of the rectangle is not an exact multiple of 16 then the width of
+ * the last tile in each row will be correspondingly smaller.  Similarly if the
+ * height is not an exact multiple of 16 then the height of each tile in the
+ * final row will also be smaller.  Each tile begins with a "subencoding" type
+ * byte, which is a mask made up of a number of bits.  If the Raw bit is set
+ * then the other bits are irrelevant; w*h pixel values follow (where w and h
+ * are the width and height of the tile).  Otherwise the tile is encoded in a
+ * similar way to RRE, except that the position and size of each subrectangle
+ * can be specified in just two bytes.  The other bits in the mask are as
+ * follows:
+ *
+ * BackgroundSpecified - if set, a pixel value follows which specifies
+ *    the background colour for this tile.  The first non-raw tile in a
+ *    rectangle must have this bit set.  If this bit isn't set then the
+ *    background is the same as the last tile.
+ *
+ * ForegroundSpecified - if set, a pixel value follows which specifies
+ *    the foreground colour to be used for all subrectangles in this tile.
+ *    If this bit is set then the SubrectsColoured bit must be zero.
+ *
+ * AnySubrects - if set, a single byte follows giving the number of
+ *    subrectangles following.  If not set, there are no subrectangles (i.e.
+ *    the whole tile is just solid background colour).
+ *
+ * SubrectsColoured - if set then each subrectangle is preceded by a pixel
+ *    value giving the colour of that subrectangle.  If not set, all
+ *    subrectangles are the same colour, the foreground colour;  if the
+ *    ForegroundSpecified bit wasn't set then the foreground is the same as
+ *    the last tile.
+ *
+ * The position and size of each subrectangle is specified in two bytes.  The
+ * Pack macros below can be used to generate the two bytes from x, y, w, h,
+ * and the Extract macros can be used to extract the x, y, w, h values from
+ * the two bytes.
+ */
+
+#define rfbHextileRaw			(1 << 0)
+#define rfbHextileBackgroundSpecified	(1 << 1)
+#define rfbHextileForegroundSpecified	(1 << 2)
+#define rfbHextileAnySubrects		(1 << 3)
+#define rfbHextileSubrectsColoured	(1 << 4)
+
+#define rfbHextilePackXY(x,y) (((x) << 4) | (y))
+#define rfbHextilePackWH(w,h) ((((w)-1) << 4) | ((h)-1))
+#define rfbHextileExtractX(byte) ((byte) >> 4)
+#define rfbHextileExtractY(byte) ((byte) & 0xf)
+#define rfbHextileExtractW(byte) (((byte) >> 4) + 1)
+#define rfbHextileExtractH(byte) (((byte) & 0xf) + 1)
+
+#ifdef HAVE_LIBZ
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * zlib - zlib compressed Encoding.  We have an rfbZlibHeader structure
+ * giving the number of bytes following.  Finally the data follows is
+ * zlib compressed version of the raw pixel data as negotiated.
+ */
+
+typedef struct {
+    uint32_t nBytes;
+} rfbZlibHeader;
+
+#define sz_rfbZlibHeader 4
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * Tight Encoding.
+ *
+ *-- The first byte of each Tight-encoded rectangle is a "compression control
+ *   byte". Its format is as follows (bit 0 is the least significant one):
+ *
+ *   bit 0:    if 1, then compression stream 0 should be reset;
+ *   bit 1:    if 1, then compression stream 1 should be reset;
+ *   bit 2:    if 1, then compression stream 2 should be reset;
+ *   bit 3:    if 1, then compression stream 3 should be reset;
+ *   bits 7-4: if 1000 (0x08), then the compression type is "fill",
+ *             if 1001 (0x09), then the compression type is "jpeg",
+ *             if 0xxx, then the compression type is "basic",
+ *             values greater than 1001 are not valid.
+ *
+ * If the compression type is "basic", then bits 6..4 of the
+ * compression control byte (those xxx in 0xxx) specify the following:
+ *
+ *   bits 5-4:  decimal representation is the index of a particular zlib
+ *              stream which should be used for decompressing the data;
+ *   bit 6:     if 1, then a "filter id" byte is following this byte.
+ *
+ *-- The data that follows after the compression control byte described
+ * above depends on the compression type ("fill", "jpeg" or "basic").
+ *
+ *-- If the compression type is "fill", then the only pixel value follows, in
+ * client pixel format (see NOTE 1). This value applies to all pixels of the
+ * rectangle.
+ *
+ *-- If the compression type is "jpeg", the following data stream looks like
+ * this:
+ *
+ *   1..3 bytes:  data size (N) in compact representation;
+ *   N bytes:     JPEG image.
+ *
+ * Data size is compactly represented in one, two or three bytes, according
+ * to the following scheme:
+ *
+ *  0xxxxxxx                    (for values 0..127)
+ *  1xxxxxxx 0yyyyyyy           (for values 128..16383)
+ *  1xxxxxxx 1yyyyyyy zzzzzzzz  (for values 16384..4194303)
+ *
+ * Here each character denotes one bit, xxxxxxx are the least significant 7
+ * bits of the value (bits 0-6), yyyyyyy are bits 7-13, and zzzzzzzz are the
+ * most significant 8 bits (bits 14-21). For example, decimal value 10000
+ * should be represented as two bytes: binary 10010000 01001110, or
+ * hexadecimal 90 4E.
+ *
+ *-- If the compression type is "basic" and bit 6 of the compression control
+ * byte was set to 1, then the next (second) byte specifies "filter id" which
+ * tells the decoder what filter type was used by the encoder to pre-process
+ * pixel data before the compression. The "filter id" byte can be one of the
+ * following:
+ *
+ *   0:  no filter ("copy" filter);
+ *   1:  "palette" filter;
+ *   2:  "gradient" filter.
+ *
+ *-- If bit 6 of the compression control byte is set to 0 (no "filter id"
+ * byte), or if the filter id is 0, then raw pixel values in the client
+ * format (see NOTE 1) will be compressed. See below details on the
+ * compression.
+ *
+ *-- The "gradient" filter pre-processes pixel data with a simple algorithm
+ * which converts each color component to a difference between a "predicted"
+ * intensity and the actual intensity. Such a technique does not affect
+ * uncompressed data size, but helps to compress photo-like images better. 
+ * Pseudo-code for converting intensities to differences is the following:
+ *
+ *   P[i,j] := V[i-1,j] + V[i,j-1] - V[i-1,j-1];
+ *   if (P[i,j] < 0) then P[i,j] := 0;
+ *   if (P[i,j] > MAX) then P[i,j] := MAX;
+ *   D[i,j] := V[i,j] - P[i,j];
+ *
+ * Here V[i,j] is the intensity of a color component for a pixel at
+ * coordinates (i,j). MAX is the maximum value of intensity for a color
+ * component.
+ *
+ *-- The "palette" filter converts true-color pixel data to indexed colors
+ * and a palette which can consist of 2..256 colors. If the number of colors
+ * is 2, then each pixel is encoded in 1 bit, otherwise 8 bits is used to
+ * encode one pixel. 1-bit encoding is performed such way that the most
+ * significant bits correspond to the leftmost pixels, and each raw of pixels
+ * is aligned to the byte boundary. When "palette" filter is used, the
+ * palette is sent before the pixel data. The palette begins with an unsigned
+ * byte which value is the number of colors in the palette minus 1 (i.e. 1
+ * means 2 colors, 255 means 256 colors in the palette). Then follows the
+ * palette itself which consist of pixel values in client pixel format (see
+ * NOTE 1).
+ *
+ *-- The pixel data is compressed using the zlib library. But if the data
+ * size after applying the filter but before the compression is less then 12,
+ * then the data is sent as is, uncompressed. Four separate zlib streams
+ * (0..3) can be used and the decoder should read the actual stream id from
+ * the compression control byte (see NOTE 2).
+ *
+ * If the compression is not used, then the pixel data is sent as is,
+ * otherwise the data stream looks like this:
+ *
+ *   1..3 bytes:  data size (N) in compact representation;
+ *   N bytes:     zlib-compressed data.
+ *
+ * Data size is compactly represented in one, two or three bytes, just like
+ * in the "jpeg" compression method (see above).
+ *
+ *-- NOTE 1. If the color depth is 24, and all three color components are
+ * 8-bit wide, then one pixel in Tight encoding is always represented by
+ * three bytes, where the first byte is red component, the second byte is
+ * green component, and the third byte is blue component of the pixel color
+ * value. This applies to colors in palettes as well.
+ *
+ *-- NOTE 2. The decoder must reset compression streams' states before
+ * decoding the rectangle, if some of bits 0,1,2,3 in the compression control
+ * byte are set to 1. Note that the decoder must reset zlib streams even if
+ * the compression type is "fill" or "jpeg".
+ *
+ *-- NOTE 3. The "gradient" filter and "jpeg" compression may be used only
+ * when bits-per-pixel value is either 16 or 32, not 8.
+ *
+ *-- NOTE 4. The width of any Tight-encoded rectangle cannot exceed 2048
+ * pixels. If a rectangle is wider, it must be split into several rectangles
+ * and each one should be encoded separately.
+ *
+ */
+
+#define rfbTightExplicitFilter         0x04
+#define rfbTightFill                   0x08
+#define rfbTightJpeg                   0x09
+#define rfbTightMaxSubencoding         0x09
+
+/* Filters to improve compression efficiency */
+#define rfbTightFilterCopy             0x00
+#define rfbTightFilterPalette          0x01
+#define rfbTightFilterGradient         0x02
+
+#endif
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * XCursor encoding. This is a special encoding used to transmit X-style
+ * cursor shapes from server to clients. Note that for this encoding,
+ * coordinates in rfbFramebufferUpdateRectHeader structure hold hotspot
+ * position (r.x, r.y) and cursor size (r.w, r.h). If (w * h != 0), two RGB
+ * samples are sent after header in the rfbXCursorColors structure. They
+ * denote foreground and background colors of the cursor. If a client
+ * supports only black-and-white cursors, it should ignore these colors and
+ * assume that foreground is black and background is white. Next, two bitmaps
+ * (1 bits per pixel) follow: first one with actual data (value 0 denotes
+ * background color, value 1 denotes foreground color), second one with
+ * transparency data (bits with zero value mean that these pixels are
+ * transparent). Both bitmaps represent cursor data in a byte stream, from
+ * left to right, from top to bottom, and each row is byte-aligned. Most
+ * significant bits correspond to leftmost pixels. The number of bytes in
+ * each row can be calculated as ((w + 7) / 8). If (w * h == 0), cursor
+ * should be hidden (or default local cursor should be set by the client).
+ */
+
+typedef struct {
+    uint8_t foreRed;
+    uint8_t foreGreen;
+    uint8_t foreBlue;
+    uint8_t backRed;
+    uint8_t backGreen;
+    uint8_t backBlue;
+} rfbXCursorColors;
+
+#define sz_rfbXCursorColors 6
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * RichCursor encoding. This is a special encoding used to transmit cursor
+ * shapes from server to clients. It is similar to the XCursor encoding but
+ * uses client pixel format instead of two RGB colors to represent cursor
+ * image. For this encoding, coordinates in rfbFramebufferUpdateRectHeader
+ * structure hold hotspot position (r.x, r.y) and cursor size (r.w, r.h).
+ * After header, two pixmaps follow: first one with cursor image in current
+ * client pixel format (like in raw encoding), second with transparency data
+ * (1 bit per pixel, exactly the same format as used for transparency bitmap
+ * in the XCursor encoding). If (w * h == 0), cursor should be hidden (or
+ * default local cursor should be set by the client).
+ */
+
+
+/*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+ * ZRLE - encoding combining Zlib compression, tiling, palettisation and
+ * run-length encoding.
+ */
+
+typedef struct {
+    uint32_t length;
+} rfbZRLEHeader;
+
+#define sz_rfbZRLEHeader 4
+
+#define rfbZRLETileWidth 64
+#define rfbZRLETileHeight 64
+
+
+/*-----------------------------------------------------------------------------
+ * SetColourMapEntries - these messages are only sent if the pixel
+ * format uses a "colour map" (i.e. trueColour false) and the client has not
+ * fixed the entire colour map using FixColourMapEntries.  In addition they
+ * will only start being sent after the client has sent its first
+ * FramebufferUpdateRequest.  So if the client always tells the server to use
+ * trueColour then it never needs to process this type of message.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbSetColourMapEntries */
+    uint8_t pad;
+    uint16_t firstColour;
+    uint16_t nColours;
+
+    /* Followed by nColours * 3 * uint16_t
+       r1, g1, b1, r2, g2, b2, r3, g3, b3, ..., rn, bn, gn */
+
+} rfbSetColourMapEntriesMsg;
+
+#define sz_rfbSetColourMapEntriesMsg 6
+
+
+
+/*-----------------------------------------------------------------------------
+ * Bell - ring a bell on the client if it has one.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbBell */
+} rfbBellMsg;
+
+#define sz_rfbBellMsg 1
+
+
+
+/*-----------------------------------------------------------------------------
+ * ServerCutText - the server has new text in its cut buffer.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbServerCutText */
+    uint8_t pad1;
+    uint16_t pad2;
+    uint32_t length;
+    /* followed by char text[length] */
+} rfbServerCutTextMsg;
+
+#define sz_rfbServerCutTextMsg 8
+
+#ifdef BACKCHANNEL
+typedef rfbServerCutTextMsg rfbBackChannelMsg;
+#define sz_rfbBackChannelMsg 8
+#endif
+
+
+/*-----------------------------------------------------------------------------
+ * Union of all server->client messages.
+ */
+
+typedef union {
+    uint8_t type;
+    rfbFramebufferUpdateMsg fu;
+    rfbSetColourMapEntriesMsg scme;
+    rfbBellMsg b;
+    rfbServerCutTextMsg sct;
+} rfbServerToClientMsg;
+
+
+
+/*****************************************************************************
+ *
+ * Message definitions (client -> server)
+ *
+ *****************************************************************************/
+
+
+/*-----------------------------------------------------------------------------
+ * SetPixelFormat - tell the RFB server the format in which the client wants
+ * pixels sent.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbSetPixelFormat */
+    uint8_t pad1;
+    uint16_t pad2;
+    rfbPixelFormat format;
+} rfbSetPixelFormatMsg;
+
+#define sz_rfbSetPixelFormatMsg (sz_rfbPixelFormat + 4)
+
+
+/*-----------------------------------------------------------------------------
+ * FixColourMapEntries - when the pixel format uses a "colour map", fix
+ * read-only colour map entries.
+ *
+ *    ***************** NOT CURRENTLY SUPPORTED *****************
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbFixColourMapEntries */
+    uint8_t pad;
+    uint16_t firstColour;
+    uint16_t nColours;
+
+    /* Followed by nColours * 3 * uint16_t
+       r1, g1, b1, r2, g2, b2, r3, g3, b3, ..., rn, bn, gn */
+
+} rfbFixColourMapEntriesMsg;
+
+#define sz_rfbFixColourMapEntriesMsg 6
+
+
+/*-----------------------------------------------------------------------------
+ * SetEncodings - tell the RFB server which encoding types we accept.  Put them
+ * in order of preference, if we have any.  We may always receive raw
+ * encoding, even if we don't specify it here.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbSetEncodings */
+    uint8_t pad;
+    uint16_t nEncodings;
+    /* followed by nEncodings * uint32_t encoding types */
+} rfbSetEncodingsMsg;
+
+#define sz_rfbSetEncodingsMsg 4
+
+
+/*-----------------------------------------------------------------------------
+ * FramebufferUpdateRequest - request for a framebuffer update.  If incremental
+ * is true then the client just wants the changes since the last update.  If
+ * false then it wants the whole of the specified rectangle.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbFramebufferUpdateRequest */
+    uint8_t incremental;
+    uint16_t x;
+    uint16_t y;
+    uint16_t w;
+    uint16_t h;
+} rfbFramebufferUpdateRequestMsg;
+
+#define sz_rfbFramebufferUpdateRequestMsg 10
+
+
+/*-----------------------------------------------------------------------------
+ * KeyEvent - key press or release
+ *
+ * Keys are specified using the "keysym" values defined by the X Window System.
+ * For most ordinary keys, the keysym is the same as the corresponding ASCII
+ * value.  Other common keys are:
+ *
+ * BackSpace		0xff08
+ * Tab			0xff09
+ * Return or Enter	0xff0d
+ * Escape		0xff1b
+ * Insert		0xff63
+ * Delete		0xffff
+ * Home			0xff50
+ * End			0xff57
+ * Page Up		0xff55
+ * Page Down		0xff56
+ * Left			0xff51
+ * Up			0xff52
+ * Right		0xff53
+ * Down			0xff54
+ * F1			0xffbe
+ * F2			0xffbf
+ * ...			...
+ * F12			0xffc9
+ * Shift		0xffe1
+ * Control		0xffe3
+ * Meta			0xffe7
+ * Alt			0xffe9
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbKeyEvent */
+    uint8_t down;			/* true if down (press), false if up */
+    uint16_t pad;
+    uint32_t key;			/* key is specified as an X keysym */
+} rfbKeyEventMsg;
+
+#define sz_rfbKeyEventMsg 8
+
+
+/*-----------------------------------------------------------------------------
+ * PointerEvent - mouse/pen move and/or button press.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbPointerEvent */
+    uint8_t buttonMask;		/* bits 0-7 are buttons 1-8, 0=up, 1=down */
+    uint16_t x;
+    uint16_t y;
+} rfbPointerEventMsg;
+
+#define rfbButton1Mask 1
+#define rfbButton2Mask 2
+#define rfbButton3Mask 4
+
+#define sz_rfbPointerEventMsg 6
+
+
+
+/*-----------------------------------------------------------------------------
+ * ClientCutText - the client has new text in its cut buffer.
+ */
+
+typedef struct {
+    uint8_t type;			/* always rfbClientCutText */
+    uint8_t pad1;
+    uint16_t pad2;
+    uint32_t length;
+    /* followed by char text[length] */
+} rfbClientCutTextMsg;
+
+#define sz_rfbClientCutTextMsg 8
+
+
+
+/*-----------------------------------------------------------------------------
+ * Union of all client->server messages.
+ */
+
+typedef union {
+    uint8_t type;
+    rfbSetPixelFormatMsg spf;
+    rfbFixColourMapEntriesMsg fcme;
+    rfbSetEncodingsMsg se;
+    rfbFramebufferUpdateRequestMsg fur;
+    rfbKeyEventMsg ke;
+    rfbPointerEventMsg pe;
+    rfbClientCutTextMsg cct;
+} rfbClientToServerMsg;
+
+#endif