Update build docs

BUILD.md

@@ -13,7 +13,7 @@
 
 ### CMake External Project Dependencies
 
-These dependencies need not be installed manually. They are automatically downloaded on the platforms where they are required.  
+These dependencies need not be installed manually. They are automatically downloaded on the platforms where they are required.
 - [Bullet Physics Engine](https://github.com/bulletphysics/bullet3/releases):  2.83
 - [glm](https://glm.g-truc.net/0.9.8/index.html):  0.9.8
 - [Oculus SDK](https://developer.oculus.com/downloads/):   1.11 (Win32) / 0.5 (Mac)
@@ -22,7 +22,7 @@ These dependencies need not be installed manually. They are automatically downlo
 - [QuaZip](https://sourceforge.net/projects/quazip/files/quazip/):   0.7.3
 - [SDL2](https://www.libsdl.org/download-2.0.php):   2.0.3
 - [Intel Threading Building Blocks](https://www.threadingbuildingblocks.org/):   4.3
-- [vcpkg](https://github.com/highfidelity/vcpkg): 
+- [vcpkg](https://github.com/highfidelity/vcpkg):
 - [VHACD](https://github.com/virneo/v-hacd)
 - [zlib](http://www.zlib.net/):   1.28 (Win32 only)
 - [nvtt](https://github.com/highfidelity/nvidia-texture-tools):   2.1.1 (customized)
@@ -48,6 +48,18 @@ The path it needs to be set to will depend on where and how Qt5 was installed. e
     export QT_CMAKE_PREFIX_PATH=/usr/local/Cellar/qt5/5.10.1/lib/cmake
     export QT_CMAKE_PREFIX_PATH=/usr/local/opt/qt5/lib/cmake
 
+#### Vcpkg
+
+Hifi uses vcpkg to download and build dependencies.
+You do not need to install vcpkg.
+
+Building the dependencies can be lengthy and the resulting files will be stored in your OS temp directory.
+However, those files can potentially get cleaned up by the OS, so in order to avoid this and having to redo the lengthy build step, you can set the following environment variable:
+
+export HIFI_VCPKG_BASE=/path/to/directory
+
+Where /path/to/directory is the path to a directory where you wish the build files to get stored.
+
 #### Generating build files
 
 Create a build directory in the root of your checkout and then run the CMake build from there. This will keep the rest of the directory clean.
@@ -80,7 +92,7 @@ In the examples below the variable $NAME would be replaced by the name of the de
 
 ### Optional Components
 
-#### Build Options 
+#### Build Options
 
 The following build options can be used when running CMake
 
@@ -89,7 +101,7 @@ The following build options can be used when running CMake
 * BUILD_TESTS
 * BUILD_TOOLS
 
-#### Developer Build Options 
+#### Developer Build Options
 
 * USE_GLES
 * DISABLE_UI

BUILD_WIN.md

@@ -19,7 +19,7 @@ If you do not wish to use the Python installation bundled with Visual Studio, yo
 
 ### Step 2. Installing CMake
 
-Download and install the latest version of CMake 3.9. 
+Download and install the latest version of CMake 3.9.
 
 Download the file named win64-x64 Installer from the [CMake Website](https://cmake.org/download/). You can access the installer on this [3.9 Version page](https://cmake.org/files/v3.9/). During installation, make sure to check "Add CMake to system PATH for all users" when prompted.
 
@@ -35,20 +35,7 @@ Go to `Control Panel > System > Advanced System Settings > Environment Variables
 * Set "Variable name": `QT_CMAKE_PREFIX_PATH`
 * Set "Variable value": `C:\Qt\5.10.1\msvc2017_64\lib\cmake`
 
-### Step 5. Installing [vcpkg](https://github.com/Microsoft/vcpkg)
-
- * Clone the VCPKG [repository](https://github.com/Microsoft/vcpkg)
- * Follow the instructions in the [readme](https://github.com/Microsoft/vcpkg/blob/master/README.md) to bootstrap vcpkg
-   * Note, you may need to do these in a _Developer Command Prompt_
- * Set an environment variable VCPKG_ROOT to the location of the cloned repository
-   * Close and re-open any command prompts after setting the environment variable so that they will pick up the change
-
-### Step 6. Installing OpenSSL via vcpkg
-
- * In the vcpkg directory, install the 64 bit OpenSSL package with the command `.\vcpkg install openssl:x64-windows`
- * Once the build completes you should have a file `ssl.h` in `${VCPKG_ROOT}/installed/x64-windows/include/openssl`
-
-### Step 7. Running CMake to Generate Build Files
+### Step 5. Running CMake to Generate Build Files
 
 Run Command Prompt from Start and run the following commands:
 ```
@@ -58,9 +45,9 @@ cd build
 cmake .. -G "Visual Studio 15 Win64"
 ```
 
-Where `%HIFI_DIR%` is the directory for the highfidelity repository.     
+Where `%HIFI_DIR%` is the directory for the highfidelity repository.
 
-### Step 8. Making a Build
+### Step 6. Making a Build
 
 Open `%HIFI_DIR%\build\hifi.sln` using Visual Studio.
 
@@ -68,7 +55,7 @@ Change the Solution Configuration (menu ribbon under the menu bar, next to the g
 
 Run from the menu bar `Build > Build Solution`.
 
-### Step 9. Testing Interface
+### Step 7. Testing Interface
 
 Create another environment variable (see Step #4)
 * Set "Variable name": `_NO_DEBUG_HEAP`