xf86-video-vnc - VNC virtual framebuffer driver for the Xorg X server

The master development code repository can be found at:

        https://github.com/RealVNC/xf86-video-vnc

This code is based on the X.Org dummy video driver, which can be found at:

        https://gitlab.freedesktop.org/xorg/driver/xf86-video-dummy

And also incorporates changes from Nicholas Boichat, which can be found at:

        https://github.com/drinkcat/xf86-video-dummy/


## Automatic build instructions

The buildAndInstall script is intended to simplify building and installing this
driver on most common Linux systems. This should be invoked via sudo:

        $ sudo ./buildAndInstall


## Manual build instructions 

If you encounter problems using the supplied buildAndInstall script, the 
following manual instructions can be used to build and install the driver:

Ensure the required dependencies are installed on the system:
* C compiler
* GNU autoconf, automake and libtool
* pkg-config
* X server development packages:
  * on RHEL-based systems: xorg-x11-server-devel, xorg-x11-proto-devel
  * on Debian-based systems: xserver-xorg-dev, xutils-dev, x11proto-randr-dev, x11proto-render-dev

Configure and build the driver as follows:

        $ ./autogen.sh --disable-static
        $ make

Assuming the build is successful, the driver will be output to 
src/.libs/vnc_drv.so

Locate your Xorg driver directory, which is typically:
* /lib64/xorg/modules/drivers/ on 64 bit RHEL-based systems or 
* /usr/lib/xorg/modules/drivers/ on Debian-based systems

Then install the driver to this directory with:

        $ sudo install -vbs src/.libs/vnc_drv.so <XORG_DRIVER_DIR>


## Configuration

We recommend ensuring you have the latest version of VNC Connect installed,
which is available to download from:
https://www.realvnc.com/en/connect/download/vnc/
Note: If not using the latest version, the very minimum version required is 
6.2.0, which is the first version to support SystemXorg virtual mode.

Make sure SystemXorg virtual mode is enabled with

        $ vncinitconfig -enable-system-xorg

Running this command as root will enable it for all users on the machine, or
run without root privileges to enable just for the current user.

Copy the updated vncserver-virtual.conf from this repository to /etc/X11/


## Usage

Start a virtual mode session as normal, either via the vncserver-virtual 
command or by connecting via the virtual mode daemon (vncserver-virtuald).

The server will start with a single display mode (1024x768). New modes can be
made available via the xrandr command. first using "cvt" to output the 
modelines for the required modes, creating the mode and adding it to the 
output (vnc-0). For example, the following defines the mode 1920x1080:

        $ cvt 1920 1080
        # 1920x1080 59.96 Hz (CVT 2.07M9) hsync: 67.16 kHz; pclk: 173.00 MHz
        Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

        $ xrandr --newmode "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
        $ xrandr --addmode vnc-0 1920x1080_60.00

Swtiching to this new mode can then be done using your desktop environment's
display settings app, or by xrandr directly as follows:

        $ xrandr --output vnc-0 --mode 1920x1080_60.00