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<p align="center"><img src="./images/vulkan_configurator.png" width=400 /></p>

*Vulkan Configurator* allows overriding the [layers configuration](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md#layers) used by Vulkan applications at runtime.

A Vulkan application may configure layers when creating a Vulkan Instance. This layers configuration may be overridden using *Vulkan Configurator* globally or for a selected list of Vulkan applications.

Finally *Vulkan Configurator* allows using layers from user-defined directories.

* **[Change Log and Known Issues](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/CHANGELOG.md)**
* **Bug reports**: Please submit [GitHub issues](https://github.com/LunarG/VulkanTools/issues) if you encounter any issue.
* **Information for contributors**: [All contribution information](https://github.com/LunarG/VulkanTools/blob/master/CONTRIBUTING.md), [FAQ](#faq), [Roadmap](https://github.com/LunarG/VulkanTools/projects/2)
* **Build instruction**: It requires *[Qt 5](https://www.qt.io/download)* to be install and *Qt* `bin` directory to be added to the `PATH` environment variable. *Vulkan Configurator* is built as part of the [VulkanTools](https://github.com/LunarG/VulkanTools/blob/master/BUILD.md) using *CMake* build system or alternatively with `vkconfig.pro` using Qt Creator.

--------------
## Platform Support

| Windows                  | :heavy_check_mark:       |
| ------------------------ | ------------------------ |
| [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-icon-windows.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-windows.png) | [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-icon-windows.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-windows.png)

| Linux                    | :heavy_check_mark:       |
| ------------------------ | ------------------------ |
| [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-icon-linux.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-linux.png) | [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-icon-linux.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-linux.png)

| macOS                    | :heavy_check_mark:       |
| ------------------------ | ------------------------ |
| [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-icon-mac.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-main-mac.png) | [ ![Main Window](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-icon-mac.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vkconfig-layers-mac.png)

--------------
## Downloads

*Vulkan Configurator* is delivered with the [Vulkan SDK](https://vulkan.lunarg.com/sdk/home).

--------------
## Using the Vulkan Configurator

Vulkan Configurator is a graphical user interface (GUI) that may be launched from the console using `vkconfig`.

The tool is distributed differently, depending on the platform:
- Ubuntu packages: Upon installing the `lunarg-vkconfig` package, the tools will be available from the command line as `vkconfig`.
- Linux tarball: The vkconfig executable comes pre-built. Run vkconfig on the command line. 
- Windows: The tool will be present on the start menu, in the Vulkan SDK menu. User can also invoke from a command line.
- macOS: The tool is provided as an application bundle. Run it by double-clicking the bundle from a Finder window.

Vulkan Configurator may be used with command line arguments to averride layers. Use `vkconfig --help` in the console for more information.

--------------
## Terminology

***[Vulkan Layer](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md#layers)***: A layer is an optional library that can intercept Vulkan functions on their way from the Vulkan application down to the Vulkan drivers. Multiple layers can be chained together to use multiple layer functionalities simultaneously.

***Vulkan Layers Configuration***: A collection of Vulkan Layers executed in [a specific order](#vulkan-layers-execution-order-overview) with specific settings for each layer.

***[Vulkan Explicit Layers vs Implicit Layer](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md#implicit-vs-explicit-layers)***: An explicit layer has to be explicitly activated by the user from source in `vkCreateInstance`, using Vulkan Configurator or `VK_INSTANCE_LAYERS` environment variable. Implicit layers are enabled by their existence on the system by default.

***[Vulkan Meta-Layer](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md#meta-layers)***: Meta-layers are a special kind of layer which is only available through the desktop [Vulkan Loader](https://github.com/KhronosGroup/Vulkan-Loader). While usual layers are associated with one particular library, a meta-layer is actually a collection layer which contains an ordered list of other layers called *component layers*. 

***Vulkan Override Layer***: The Vulkan Override Layer is an implicit meta-layer found on the system with the name `VK_LAYER_LUNARG_override`. It is the mechanism used by *Vulkan Configurator* to override Vulkan applications layers. This layer contains:
- The ordered list of layers to activate
- The list of layers to exclude from execution
- The list of paths to executables that the layers override applies to. If this list is empty, the override is applied to every application upon startup.

***Vulkan Layer settings***: Per-layer settings loaded by each layer library and stored in the `vk_layer_settings.txt` file. This file is located either next to the Vulkan application executable or set globally and applied to all Vulkan applications thanks to *Vulkan Configurator*. These settings are described [here for VK_LAYER_KHRONOS_validation](https://github.com/KhronosGroup/Vulkan-ValidationLayers/blob/master/layers/vk_layer_settings.txt) and [here for other layers created by LunarG](https://github.com/LunarG/VulkanTools/blob/master/layersvt/vk_layer_settings.txt).

--------------
## Vulkan Layers execution order overview

[ ![Vulkan Loader](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vulkan_layers_order_small.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vulkan_layers_order.png)

--------------
## Vulkan Loader and Layers implementation overview

[ ![Vulkan Loader](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vulkan_loader_640px.png) ](https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/vulkan_loader.png)

For detailed information, read the [Architecture of the Vulkan Loader Interfaces](https://github.com/KhronosGroup/Vulkan-Loader/blob/master/loader/LoaderAndLayerInterface.md) document.

--------------
## OS user-specific modifications

The *Vulkan Configurator* does not make any system-wide changes to a system, but it does make user-specific changes.
These changes are documented below:

### Linux and macOS

Unix systems store files in the following paths:

- `$HOME/.local/share/vulkan/implicit_layer.d/VkLayer_override.json` tells a Vulkan application which layers to use
- `$HOME/.local/share/vulkan/settings.d/vk_layer_settings.txt` tells Vulkan layers which settings to use
- `$HOME/.config/LunarG/vkconfig.conf` stores the application settings for `vkconfig`

### Windows

Windows systems store files in the following paths:

- `%HOME%\AppData\Local\LunarG\vkconfig\override\VkLayerOverride.json` tells a Vulkan application which layers to use
- `%HOME%\AppData\Local\LunarG\vkconfig\override\vk_layer_settings.txt` tells Vulkan layers which settings to use

In addition, Windows system create registry entries in the following locations:

- `HKEY_CURRENT_USER\Software\Khronos\Vulkan\ImplicitLayers` will have an entry that points to the JSON file above
- `HKEY_CURRENT_USER\Software\Khronos\Vulkan\Settings` will have an entry that points to the text file above
- `HKEY_CURRENT_USER\Software\LunarG\vkconfig` stores the application settings for `vkconfig`

--------------
## Tests

### Unit Tests

On Windows, from the build directory:
```
ctest -C Debug --output-on-failure --parallel 16
ctest -C Release  --output-on-failure --parallel 16
```

On Linux and macOS, from the build directory:
```
ctest --output-on-failure --parallel 16
```

### Manual Tests

With each release of the Vulkan SDK some [manual tests](https://docs.google.com/document/d/1z0WqfMp2IBko1fvDICkjDE_3JKnf8SrU5APQTqKRR-U/edit) based on use cases are done.

--------------
## FAQ

### 1/ How do I use Vulkan Configurator to override only the Vulkan layers of a selected list of applications?

This is typically done by enabling the "Apply only to the selected list of Vulkan applications" check box.
<p align="center"><img src="https://github.com/LunarG/VulkanTools/blob/master/vkconfig/images/only_list.png" /></p>

If this is not working, it's likely that the *Vulkan Loader* on the system is too old. Version 1.2.141 or newer of the *Vulkan Loader* is required. Update the *Vulkan Loader* by installing the latest *[Vulkan Runtime](https://vulkan.lunarg.com/sdk/home)* to enable this feature.

### 2/ How does my application vk_layer_settings.txt file interacts with Vulkan Configurator?

When *Vulkan Configurator is used to override layers, the local `vk_layer_settings.txt` file is ignored.

### 3/ How do environment variables settings interact with Vulkan Configurator?

The short answer is that environment variables and *Vulkan Configurator* layers settings are mutually exclusive and the interaction between both is undefined.

This is because the interaction between environment variables and *Vulkan* Configuration layers settings are handled by the layers directly so the responsability of the layers developers.

We are working on defining layers development conventions to resolve this issue properly but in the meantime we highly recommend to use exclusively either environment variables or Vulkan Configurator.

## Known issues:

- On *macOS*, *vkcube* and *vkcubepp* need to be run at least once to get past the security checks before they can be used from *Vulkan Configurator*.
- The screenshot layer can crash if you do not specify a working directory that is writable by the current user.
