Update formatting on BUILD_LINUX.md.

BUILD_LINUX.md

@@ -1,75 +1,96 @@
 # Build Linux
 
-*Last Updated on December 1, 2020*
+*Last Updated on December 1, 2021*
 
 Please read the [general build guide](BUILD.md) for information on dependencies required for all platforms. Only Linux specific instructions are found in this file.
 
 You can use the [Vircadia Builder](https://github.com/vircadia/vircadia-builder) to build on Linux more easily. Alternatively, you can follow the manual steps below.
 
-## Ubuntu 16.04/18.04 specific build guide
+## Ubuntu 16.04/18.04
+
 ### Ubuntu 16.04 only
-Add the following line to *.bash_profile*  
+
-`export QT_QPA_FONTDIR=/usr/share/fonts/truetype/dejavu/`
+Add the following line to `.bash_profile`:
-### Ubuntu 18.04 server only
+
+```bash
+export QT_QPA_FONTDIR=/usr/share/fonts/truetype/dejavu/
+```
+
+### Ubuntu 18.04 Server only
 Add the universe repository:  
-_(This is not enabled by default on the server edition)_
+_(This is not enabled by default on the server edition.)_
 ```bash
 sudo add-apt-repository universe
 sudo apt-get update
 ```
+
 #### Install build tools:
 -  First update the repositories:  
 ```bash
 sudo apt-get update -y
 sudo apt-get upgrade -y
 ```
--  git
+
+-  Install git
 ```bash
 sudo apt-get install git -y
 ```
-Verify by git --version  
+Verify git was installed by running `git --version`.
--  g++
+
+-  Install g++
 ```bash
 sudo apt-get install g++ -y
 ```
-Verify by g++ --version  
+Verify g++ was installed by running `g++ --version`.
--  *Ubuntu 18.04* cmake
+
+-  **Ubuntu 18.04** CMake
 ```bash
 sudo apt-get install cmake -y
 ```
-Verify by cmake --version  
+Verify CMake was installed by running `cmake --version`.
-- *Ubuntu 16.04* cmake  
+
+- **Ubuntu 16.04** CMake  
 ```bash
 wget https://cmake.org/files/v3.14/cmake-3.14.2-Linux-x86_64.sh
 sudo sh cmake-3.14.2-Linux-x86_64.sh --prefix=/usr/local --exclude-subdir
 ```
+
 #### Install build dependencies:
 -  OpenSSL:
 ```bash
 sudo apt-get install libssl-dev
 ```
-Verify with `openssl version`  
+Verify OpenSSL was installed by running `openssl version`.
+
 - OpenGL:
 ```bash
 sudo apt-get install libgl1-mesa-dev -y
 sudo ln -s /usr/lib/x86_64-linux-gnu/libGL.so.346.35 /usr/lib/x86_64-linux-gnu/libGL.so.1.2.0
 ```
-- Verify OpenGL:
+Verify OpenGL:
-  - First install mesa-utils with the command `sudo apt install mesa-utils -y`
+  - First install mesa-utils with the command `sudo apt install mesa-utils -y`.
-  - Then run `glxinfo | grep "OpenGL version"`  
+  - Then run `glxinfo | grep "OpenGL version"`.
-#### To compile interface in a server you must install:
+
+
+#### Extra dependencies to compile an Interface on a server
+
+
+- Install the following:
 ```bash
 sudo apt-get -y install libpulse0 libnss3 libnspr4 libfontconfig1 libxcursor1 libxcomposite1 libxtst6 libxslt1.1
 ```
+
 -  Misc dependencies:
 ```bash
 sudo apt-get install libasound2 libxmu-dev libxi-dev freeglut3-dev libasound2-dev libjack0 libjack-dev libxrandr-dev libudev-dev libssl-dev zlib1g-dev
 ```
+
 -  Install Python 3 and required packages:
 ```bash
 sudo apt-get install python python3 python3-distro
 ```
--  Install node, required to build the jsdoc documentation:
+
+-  Install Node.js as it is required to build the jsdoc documentation:
 ```bash
 sudo apt-get install nodejs
 ```
@@ -81,16 +102,16 @@ Clone this repository:
 git clone https://github.com/vircadia/vircadia.git
 ```
 
-To compile a DEV version checkout the branch you need. To get a list of all tags:
+Then checkout the master branch with:
-```bash
-git fetch -a
-```
-
-Then checkout the main branch with:
 ```bash
 git checkout master
 ```
 
+If you need a different branch, you can get a list of all tags with:
+```bash
+git fetch -a
+```
+
 ### Using a custom Qt build
 
 Qt binaries are only provided for Ubuntu. In order to build on other distributions, a Qt5 install
@@ -104,6 +125,19 @@ The system's Qt can be used, if the development packages are installed, by setti
 also the last version available in the Qt 5 branch. It is expected that Linux distributions will have
 Qt 5.15.2 available for a long time.
 
+### Architecture support
+
+If the build is intended to be packaged for distribution, the `VIRCADIA_CPU_ARCHITECTURE`
+CMake variable needs to be set to an architecture specific value.
+
+By default, it is set to `-march=native -mtune=native`, which yields builds optimized for a particular
+machine, but these builds will not work on machines lacking same CPU instructions.
+
+For packaging, it is recommended to set it to a different value, for example `-msse3`. This will help ensure that the build will run on all reasonably modern CPUs.
+
+Setting `VIRCADIA_CPU_ARCHITECTURE` to an empty string will use the default compiler settings and yield
+maximum compatibility.
+
 ### Compiling
 
 Create the build directory:
@@ -118,33 +152,30 @@ Prepare makefiles:
 cmake ..
 ```
 
-- If cmake fails with a vcpkg error - delete /tmp/hifi/vcpkg.  
+If cmake fails with a vcpkg error, then delete `/tmp/vircadia/vcpkg`.  
 
-Start compilation of the server and get a cup of coffee:
+Start compilation of the server and grab a cup of coffee:
 ```bash
 make domain-server assignment-client
 ```
 
-To compile interface:
+To compile the Interface:
 ```bash
 make interface
 ```
 
-The commands above will compile with a single thread. If you have enough memory,
+The commands above will compile with a single thread. If you have enough memory, you can decrease your build time using the `-j` flag. Since most x64 CPUs support two threads per core, this works out to CPU_COUNT*2. As an example, if you have a 2 core machine, you could use:
-you can decrease your build time using the `-j` flag. Since most x64 CPUs
-support two threads per core, this works out to CPU_COUNT*2. As an example, if
-you have a 2 core machine, you could use:
 ```
 make -j4 interface
 ```
 
-In a server, it does not make sense to compile interface.
+*Note: In a server, it is not necessary to compile the Interface.*
 
 ### Running the software
 
 #### Domain server
 
-Running domain server:
+Running Domain server:
 ```bash
 ./domain-server/domain-server
 ```
@@ -163,19 +194,11 @@ Running interface:
 ./interface/interface
 ```
 
-Go to localhost in the running interface.
+Go to localhost in the running Interface to visit your newly launched world.
 
 #### Notes
 
-If your goal is to set up a development environment, it is desirable to set the
+If your goal is to set up a development environment, it is desirable to set the directory that vcpkg builds into with the `HIFI_VCPKG_BASE` environment variable.
-directory that vcpkg builds into with the `HIFI_VCPKG_BASE` environment variable.
 For example, you might set `HIFI_VCPKG_BASE` to `/home/$USER/vcpkg`.
-By default, vcpkg will build in the system `/tmp` directory.
 
-If build is intended for packaging or creation of AppImage, `VIRCADIA_CPU_ARCHITECTURE`
+By default, vcpkg will build in the system `/tmp` directory.
-CMake variable needs to be set to architecture specific value.
-It defaults to `-march=native -mtune=native`, which yields builds optimized for particular
-machine, but builds will not work on machines lacking same CPU instructions.
-For packaging and AppImage it is recommended to set it to different value, for example `-msse3`.
-Setting `VIRCADIA_CPU_ARCHITECTURE` to empty string will use default compiler settings and yield
-maximum compatibility.