rdesktop: Connect to Windows 7 and Vista with ClearType font smoothing enabled

So Windows Vista finally allows to enable ClearType font smoothing for Remote Desktop / Terminal Services sessions. Update: Windows XP SP3 does too!
If you try to connect to a machine running Windows XP SP 3 or later using rdesktop, you won’t get smoothed font typing since at the time of this writing rdesktop does not officially offer an option to control this feature. However, here is a workaround:

rdesktop allows to specify the RDP5 experience via the -x experience switch.
One can either define one of three default experiences (modem, broadband, lan) or one can specify a raw hex value that is send to the server.

NOTE: You can skip over this rather technical part, if you’re not interested in the details. You’ll find the workaround below.

This hex value is actually a combination of defined bit flags. After some tinkering I found that the hex value 0×80 will enable font smoothing for the connection.
The file constants.h of the rdesktop sources contains these flags:

#define RDP5_DISABLE_NOTHING	0x00
#define RDP5_NO_WALLPAPER	0x01
#define RDP5_NO_FULLWINDOWDRAG	0x02
#define RDP5_NO_MENUANIMATIONS	0x04
#define RDP5_NO_THEMING		0x08
#define RDP5_NO_CURSOR_SHADOW	0x20
#define RDP5_NO_CURSORSETTINGS	0x40	/* disables cursor blinking */

So, naturally an additional flag constant can be defined like this:

#define RDP5_ENABLE_FONT_SMOOTHING 0x80

The file rdesktop.c would have to be extended preferably with an additional argument that controls the font smoothing.
If you want to use font smoothing with rdesktop now you have to combine the flags (bitwise OR, addition will do too) and specify the result via the -x switch.

Here is the workaround for the three defaults mentioned above:

rdesktop -x 0x8F mywinserver   # equals the modem default + font smoothing
rdesktop -x 0x81 mywinserver   # equals the broadband default + font smoothing
rdesktop -x 0x80 mywinserver   # equals the LAN default + font smoothing


9 Responses to “rdesktop: Connect to Windows 7 and Vista with ClearType font smoothing enabled”

  • Carl Carter-Schwendler Says:

    You can set the new experience options with the IMsRdpClientAdvancedSettings::put_PerformanceFlags, method. The flags for desktop composition and font smoothing are:

    TS_PERF_ENABLE_FONT_SMOOTHING 0×00000080

    and

    TS_PERF_ENABLE_DESKTOP_COMPOSITION 0×00000100

  • Keith Wedinger Says:

    Excellent! Specifying -x 0×80 in my rdesktop command line gives me ClearType fonts when connecting to my Vista system. Thanks!

  • Tim Acton Says:

    What can you tell me about using Remote Desktop , connecting a VISTA client to a SERVER 2003 system? I have downloaded a MS hotfix to the server , turned on “Font Smoothing) in the RDC Experience tab, turned OFF “font smooting” in the REC Experience tab with no luck. The basic Windows menu texts are not too bas, but desk in the 3rd party application is horrible.

    Turning on font smoothing for the XP clients via the RCD Experience tab works great.

    Thank You in Advance.

  • Jon Says:

    What can you tell me about using Remote Desktop , connecting a VISTA client to a SERVER 2003 system?

    rdesktop to a windows 2003 host, LAN settings font smoothing is:

    rdesktop -x 0×90 !

  • Andre Says:

    Tim, I’m not sure if Windows Server 2003 already supports Cleartype font smoothing. I know that Windows XP does support it in RDC sessions since SP3. So perhaps there is a hotfix or SP available to enable this feature in Windows Server 2003, too?

  • Ville Says:

    Thank you! This tip made my day!

  • Wiora Matthias Says:

    a dream! thx ! :D
    greetings from germany
    µatthias =)

  • humbled! Says:

    You rock dude!!!

    This makes life so much more pleasant for me.
    A big thank you from my colleagues and I!!

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