Remove the call overhead when the API layer cannot load configuration. Improve setup process and instructions.

Author: mbucchia

Install-Layer.ps1

@@ -0,0 +1,2 @@
+$JsonPath = Join-Path "$PSScriptRoot" "XR_APILAYER_NOVENDOR_fov_modifier.json"
+Start-Process -FilePath reg.exe -Verb RunAs -Wait -ArgumentList "ADD HKLM\Software\Khronos\OpenXR\1\ApiLayers\Implicit /v `"$JsonPath`" /f /t REG_DWORD /d 0"

Install-XR_APILAYER_NOVENDOR_fov_multiplier.ps1

@@ -2,23 +2,23 @@
 
 ## Download
 
-A ZIP file containing the necessary files to install and use the layer can be found on the release page: https://github.com/mbucchia/XR_APILAYER_NOVENDOR_fov_modifier/releases.
+A ZIP file containing the necessary files to install and use the layer can be found on the release page: https://github.com/mbucchia/XR_APILAYER_NOVENDOR_fov_modifier/releases. Check under *Assets*.
 
 ## Setup
 
 1. Create a folder in `%ProgramFiles%`. It's important to make it in `%ProgramFiles%` so that UWP applications can access it! For example: `C:\Program Files\OpenXR-API-Layers`.
 
-2. Place `XR_APILAYER_NOVENDOR_fov_modifier.json`, `XR_APILAYER_NOVENDOR_fov_modifier.dll`, `Install-Layer.ps1` and `Uninstall-Layer.ps1` in the folder created above.
+2. Place `XR_APILAYER_NOVENDOR_fov_modifier.json`, `XR_APILAYER_NOVENDOR_fov_modifier.dll`, `Install-XR_APILAYER_NOVENDOR_fov_modifier.ps1` and `Uninstall-XR_APILAYER_NOVENDOR_fov_modifier.ps1` in the folder created above.
 
-3. Run the script `Install-Layer.ps1` **as Administrator**.
+3. Run the script `Install-XR_APILAYER_NOVENDOR_fov_modifier.ps1`. You will be prompted for elevation (running as Administrator).
 
 4. Start the OpenXR Developer Tools for Windows Mixed Reality, under the *System Status* tab, scroll down to *API Layers*. A layer named `XR_APILAYER_NOVENDOR_fov_modifier` should be listed.
 
 ## Removal
 
 1. Go to the folder where the API layer is installed. For example: `C:\Program Files\OpenXR-API-Layers`.
 
-2. Run the script `Uninstall-Layer.ps1` **as Administrator**.
+2. Run the script `Uninstall-XR_APILAYER_NOVENDOR_fov_modifier.ps1` You will be prompted for elevation (running as Administrator).
 
 3. Start the OpenXR Developer Tools for Windows Mixed Reality, under the *System Status* tab, scroll down to *API Layers*. There should be no layer named `XR_APILAYER_NOVENDOR_fov_modifier`.
 
@@ -35,7 +35,6 @@ dllHome is "C:\Program Files\OpenXR-API-Layers"
 XR_APILAYER_NOVENDOR_fov_modifier layer is active
 Could not load config for "FS2020"
 Could not load config for "Zouna"
-Using FOV for left 1.000 1.000 1.000 1.000 and right 1.000 1.000 1.000 
 ```
 
 4. In the same folder where `XR_APILAYER_NOVENDOR_fov_modifier.json` was copied during setup, create a file named after the application, and with the extension `.cfg`. For example `C:\Program Files\OpenXR-API-Layers\FS2020.cfg`.

README.md

@@ -0,0 +1,2 @@
+$JsonPath = Join-Path "$PSScriptRoot" "XR_APILAYER_NOVENDOR_fov_modifier.json"
+Start-Process -FilePath reg.exe -Verb RunAs -Wait -ArgumentList "DELETE HKLM\Software\Khronos\OpenXR\1\ApiLayers\Implicit /v `"$JsonPath`" /f"

Uninstall-Layer.ps1

@@ -100,10 +100,10 @@
   </ItemGroup>
   <ItemGroup>
     <None Include=".gitignore" />
-    <None Include="Install-Layer.ps1" />
+    <None Include="Install-XR_APILAYER_NOVENDOR_fov_multiplier.ps1" />
     <None Include="packages.config" />
     <None Include="README.md" />
-    <None Include="Uninstall-Layer.ps1" />
+    <None Include="Uninstall-XR_APILAYER_NOVENDOR_fov_multiplier.ps1" />
     <None Include="XR_APILAYER_NOVENDOR_fov_modifier.json" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />

Uninstall-XR_APILAYER_NOVENDOR_fov_multiplier.ps1

@@ -28,7 +28,7 @@
     <None Include="XR_APILAYER_NOVENDOR_fov_modifier.json" />
     <None Include=".gitignore" />
     <None Include="README.md" />
-    <None Include="Install-Layer.ps1" />
-    <None Include="Uninstall-Layer.ps1" />
+    <None Include="Install-XR_APILAYER_NOVENDOR_fov_multiplier.ps1" />
+    <None Include="Uninstall-XR_APILAYER_NOVENDOR_fov_multiplier.ps1" />
   </ItemGroup>
 </Project>

XR_APILAYER_NOVENDOR_fov_modifier.vcxproj

@@ -32,6 +32,8 @@ namespace {
     void Log(const char* fmt, ...);
 
     struct {
+        bool loaded;
+
         float leftAngleUp;
         float leftAngleDown;
         float leftAngleLeft;
@@ -43,13 +45,17 @@ namespace {
 
         void Dump()
         {
-            Log("Using FOV for left %.3f %.3f %.3f %.3f and right %.3f %.3f %.3f %.3f\n",
-                leftAngleUp, leftAngleDown, leftAngleLeft, leftAngleRight,
-                rightAngleUp, rightAngleDown, rightAngleLeft, rightAngleRight);
+            if (loaded)
+            {
+                Log("Using FOV for left %.3f %.3f %.3f %.3f and right %.3f %.3f %.3f %.3f\n",
+                    leftAngleUp, leftAngleDown, leftAngleLeft, leftAngleRight,
+                    rightAngleUp, rightAngleDown, rightAngleLeft, rightAngleRight);
+            }
         }
 
         void Reset()
         {
+            loaded = false;
             leftAngleUp = 1.0f;
             leftAngleDown = 1.0f;
             leftAngleLeft = 1.0f;
@@ -162,6 +168,8 @@ namespace {
             }
             configFile.close();
 
+            config.loaded = true;
+
             return true;
         }
 
@@ -214,7 +222,7 @@ namespace {
 
         // Call the chain to resolve the next function pointer.
         const XrResult result = nextXrGetInstanceProcAddr(instance, name, function);
-        if (result == XR_SUCCESS)
+        if (config.loaded && result == XR_SUCCESS)
         {
             const std::string apiName(name);
 
@@ -256,13 +264,13 @@ namespace {
             return XR_ERROR_INITIALIZATION_FAILED;
         }
 
+        // Store the next xrGetInstanceProcAddr to resolve the functions no handled by our layer.
+        nextXrGetInstanceProcAddr = apiLayerInfo->nextInfo->nextGetInstanceProcAddr;
+
         // Call the chain to create the instance.
         const XrResult result = apiLayerInfo->nextInfo->nextCreateApiLayerInstance(instanceCreateInfo, apiLayerInfo, instance);
         if (result == XR_SUCCESS)
         {
-            // Store the next xrGetInstanceProcAddr to resolve the functions no handled by our layer.
-            nextXrGetInstanceProcAddr = apiLayerInfo->nextInfo->nextGetInstanceProcAddr;
-
             // Identify the application and load our configuration. Try by application first, then fallback to engines otherwise.
             config.Reset();
             if (!LoadConfiguration(instanceCreateInfo->applicationInfo.applicationName)) {