Merge pull request #1177 from paranoimia/winbuild-fix

Update BUILD_WIN.md with Qt Info

BUILD_WIN.md

@@ -53,11 +53,30 @@ Download the file named win64-x64 Installer from the [CMake Website](https://cma
 
 Install version 10.15.0 LTS (or greater) of [Node.JS and NPM](<https://nodejs.org/en/download/>).
 
-### Step 5. Create VCPKG environment variable
+### Step 5. (Optional) Install Qt
+
+If you would like to compile Qt instead of using the precompiled package provided during CMake, you can do so now. Install version 5.12.3 of [Qt](<https://www.qt.io/download-open-source>), as well as the following packages:
+* Qt 5.12.3
+* MSVC 2017 64-bit
+* Qt WebEngine
+* Qt Script (Deprecated)
+
+For convenience, you may also want the "Qt Debug Information" and "Sources" packages.
+
+You'll need to create the environment variable that CMake uses to find your system's Qt install.
+
+To create this variable:
+* Navigate to 'Edit the System Environment Variables' through the start menu.
+* Click on 'Environment Variables'
+* Select 'New'
+* Set "Variable name" to `QT_CMAKE_PREFIX_PATH`
+* Set "Variable value" to `%QT_INSTALL_DIR%\5.12.3\msvc2017_64\lib\cmake`, where `%QT_INSTALL_DIR%` is the directory you specified for Qt's installation. The default is `C:\Qt`.
+
+### Step 6. Create VCPKG environment variable
 In the next step, you will use CMake to build Vircadia. By default, the CMake process builds dependency files in Windows' `%TEMP%` directory, which is periodically cleared by the operating system. To prevent you from having to re-build the dependencies in the event that Windows clears that directory, we recommend that you create a `HIFI_VCPKG_BASE` environment variable linked to a directory somewhere on your machine. That directory will contain all dependency files until you manually remove them.
 
 To create this variable:
-* Naviagte to 'Edit the System Environment Variables' Through the start menu.
+* Navigate to 'Edit the System Environment Variables' Through the start menu.
 * Click on 'Environment Variables'
 * Select 'New'
 * Set "Variable name" to `HIFI_VCPKG_BASE`
@@ -66,13 +85,13 @@ To create this variable:
 Additionally, if you have Visual Studio 2019 installed and _only_ Visual Studio 2019 (i.e. you do not have Visual Studio 2017 installed) you must add an additional environment variable `HIFI_VCPKG_BOOTSTRAP` that will fix a bug in our `vcpkg` pre-build step.
 
 To create this variable:
-* Naviagte to 'Edit the System Environment Variables' Through the start menu.
+* Navigate to 'Edit the System Environment Variables' Through the start menu.
 * Click on 'Environment Variables'
 * Select 'New'
 * Set "Variable name" to `HIFI_VCPKG_BOOTSTRAP`
 * Set "Variable value" to `1`
 
-### Step 6. Running CMake to Generate Build Files
+### Step 7. Running CMake to Generate Build Files
 
 Run Command Prompt from Start and run the following commands:  
 `cd "%VIRCADIA_DIR%"`  
@@ -87,7 +106,7 @@ Run `cmake .. -G "Visual Studio 16 2019" -A x64`.
 
 Where `%VIRCADIA_DIR%` is the directory for the Vircadia repository.
 
-### Step 7. Making a Build
+### Step 8. Making a Build
 
 Open `%VIRCADIA_DIR%\build\vircadia.sln` using Visual Studio.
 
@@ -95,7 +114,7 @@ Change the Solution Configuration (menu ribbon under the menu bar, next to the g
 
 Run from the menu bar `Build > Build Solution`.
 
-### Step 8. Testing Interface
+### Step 9. Testing Interface
 
 Create another environment variable (see Step #3)
 * Set "Variable name": `_NO_DEBUG_HEAP`
@@ -103,7 +122,7 @@ Create another environment variable (see Step #3)
 
 Restart Visual Studio again.
 
-In Visual Studio, right+click "interface" under the Apps folder in Solution Explorer and select "Set as Startup Project". Run from the menu bar `Debug > Start Debugging`.
+In Visual Studio, right-click "interface" under the Apps folder in Solution Explorer and select "Set as Startup Project". Run from the menu bar `Debug > Start Debugging`.
 
 Now, you should have a full build of Vircadia and be able to run the Interface using Visual Studio.