Readme.md - platform/packages/modules/ANGLE - Git at Google

 # ANGLE for Android Readme

 Additional ANGLE developer instructions for all platforms (Windows, Linux, MacOS, and Android) are
 available [here](https://chromium.googlesource.com/angle/angle/+/master/doc/DevSetup.md).

 # Download

 The full ANGLE for Android APK build uses the Chromium and Android build systems, so both the
 Chromium and Android repos must be cloned.   Note that these instructions are only focused on
 building with Linux, since the Android build process is only supported on Linux and MacOS.

 ## Chromium

 The following is a summary of the
 [Checking out and building Chromium for Android](https://chromium.googlesource.com/chromium/src/+/master/docs/android_build_instructions.md)
 page. Please refer to it for more details.

 ### Install depot_tools
 Clone the depot_tools repository:
 ```bash
 mkdir /path/to/depot_tools && cd /path/to/depot_tools
 git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
 ```

 Add depot_tools to the end of your PATH (you will probably want to put this in your `~/.bashrc` or
 `~/.zshrc`).
 ```bash
 export PATH="$PATH:/path/to/depot_tools"
 ```

 ### Get the Chromium Code
 Clone the Chromium repository:
 ```bash
 mkdir /path/to/chromium && cd /path/to/chromium
 fetch --nohooks android
 ```

 ## ANGLE
 To use the ToT from the ANGLE repository in the Chromium build, modify Chromium's `.gclient` file:
 ```bash
 vi /path/to/chromium/.gclient
 ```

 Update the `custom_deps` section:

 ```
 solutions = [
   {
     "url": "https://chromium.googlesource.com/chromium/src.git",
     "managed": False,
     "name": "src",
     "custom_deps":
     {
       "src/third_party/angle": None,
     },
     "custom_vars": {},
   },
 ]
 target_os=["android"]
 ```

 Bootstrap the ANGLE build so it's got the correct `.gclient`:

 ```
 timvp@timvp:~/code/chromium/src/third_party/angle$ python scripts/bootstrap.py
 ```

 Now update ANGLE to fetch the ToT.

 ## Android

 The following is a summary of the directions available from the
 [Downloading the Source](https://source.android.com/setup/build/downloading) page. Please refer to
 it for more details.

 ### Install Repo

 ```bash
 mkdir /path/to/bin/repo
 PATH=/path/to/bin/repo:$PATH
 curl https://storage.googleapis.com/git-repo-downloads/repo > /path/to/bin/repo
 chmod a+x /path/to/bin/repo
 ```

 ### Initialize Repo Client

 1. Create a working directory to hold the Android source code.

 ```bash
 mkdir /path/to/android && cd /path/to/android
 ```

 1. Configure git with your real name and email address. To use the Gerrit code-review tool, you will
 need an email address that is connected with a registered Google account. Make sure this is a live
 address at which you can receive messages. The name that you provide here will show up in
 attributions for your code submissions.

 ```bash
 git config --global user.name "Your Name"
 git config --global user.email "[email protected]"
 ```

 1. Run repo init to bring down the latest version of Repo with all its most recent bug fixes. You
 must specify a URL for the manifest, which specifies where the various repositories included in the
 Android source will be placed within your working directory.

 ```bash
 repo init -u https://android.googlesource.com/platform/manifest
 ```

 To check out a branch other than "master", specify it with -b. For a list of branches, see
 [Source Code Tags and Builds](https://source.android.com/setup/start/build-numbers.html#source-code-tags-and-builds).

 ```bash
 repo init -u https://android.googlesource.com/platform/manifest -b android-4.0.1_r1
 ```

 ### Downloading the Android source tree

 To pull down the Android source tree to your working directory from the repositories as specified in
 the default manifest, run

 ```bash
 repo sync
 ```

 The Android source files will be located in your working directory under their project names. The
 initial sync operation will take an hour or more to complete.

 # Update Source Code
 ## Chromium
 In a shell separate from the Android shell:
 ```bash
 cd /path/to/chromium
 git rebase-update
 gclient sync
 ```

 ## ANGLE
 In a shell separate from the Android shell:
 ```bash
 cd /path/to/chromium/src/third_party/angle
 git rebase-update
 gclient sync
 ```

 ## Android
 In a shell separate from the Chromium shell:
 ```bash
 cd /path/to/android
 repo sync -c -j40
 repo rebase
 ```

 # Build
 ## Build ANGLE Libraries
 The first time you build the ANGLE for Android libraries on Linux:
 ```bash
 cd /path/to/chromium/src/
 ./build/install-build-deps.sh
 ```

 NOTE: If the `build/install-build-deps-android.sh` script fails, you may need to manually install
 some packages yourself, using `sudo apt install`.  Then, re-run the command to ensure it succeeds.

 The build arguments need to be configured first:

 ```bash
 cd /path/to/chromium/src
 gn args out/Default
 ```

 NOTE: The `gn args` command will open an editor to enter the desired ANGLE build arugments.
 The "Release" and "Debug" sections below contain values that can be used for either scenario.

 Then the ANGLE shared objects can be built:

 ```bash
 ninja -C out/Default third_party/angle:angle_apk
 ```

 These commands will create the following ANGLE shared object libraries:
 ```bash
 /path/to/chromium/src/out/Default/libEGL_angle.so
 /path/to/chromium/src/out/Default/libfeature_support_angle.so
 /path/to/chromium/src/out/Default/libGLESv1_CM_angle.so
 /path/to/chromium/src/out/Default/libGLESv2_angle.so
 ```

 ### Release

 ```
 target_os = "android"
 target_cpu = "arm64"
 is_debug = false
 android32_ndk_api_level = 26
 android64_ndk_api_level = 26
 build_angle_deqp_tests = false
 dcheck_always_on = true
 ffmpeg_branding = "Chrome"
 is_component_build = false
 proprietary_codecs = true
 symbol_level = 1
 angle_enable_vulkan = true
 angle_enable_vulkan_validation_layers = false
 angle_libs_suffix = "_angle"
 build_apk_secondary_abi = true
 angle_enable_null = false
 angle_force_thread_safety = true
 ```

 ### Debug

 ```
 target_os = "android"
 target_cpu = "arm64"
 is_debug = true
 android32_ndk_api_level = 26
 android64_ndk_api_level = 26
 build_angle_deqp_tests = true
 dcheck_always_on = true
 ffmpeg_branding = "Chrome"
 is_component_build = false
 proprietary_codecs = true
 symbol_level = 2
 angle_enable_vulkan = true
 angle_enable_vulkan_validation_layers = true
 angle_libs_suffix = "_angle"
 build_apk_secondary_abi = true
 angle_enable_null = false
 angle_force_thread_safety = true
 ```

 ## Build ANGLE APK

 Once the Chromium ANGLE build has completed, copy the generated 32b and 64b ANGLE shared object
 libraries into the Android source tree:

 ```bash
 cp /path/to/chromium/src/out/Default/android_clang_arm/lib*angle.so /path/to/android/vendor/unbundled_google/modules/ANGLEPrebuilt/lib/arm
 cp /path/to/chromium/src/out/Default/lib*angle.so /path/to/android/vendor/unbundled_google/modules/ANGLEPrebuilt/lib/arm64
 ```

 Build the ANGLE APK:

 ```bash
 cd /path/to/android
 source build/envsetup.sh
 tapas GoogleANGLE <arm|arm64|x86|x86_64>
 make -j
 ```

 # Install

 ```bash
 cd /path/to/android
 adb install out/target/product/generic_arm64/system/product/priv-app/GoogleANGLE/GoogleANGLE.apk
 ```

 # Using ANGLE

 ## Disable OpenGL ES Driver Preloading
 Android Q disables OpenGL ES driver preloading by default.

 If the device is running something other than Q:
 ```bash
 adb root
 adb shell setprop ro.zygote.disable_gl_preload 1
 adb shell stop && adb shell start
 ```

 ## Skia
 For best results, it's recommended to configure Skia to use the Vulkan back-end:
 ```bash
 adb shell setprop debug.hwui.renderer skiavk
 ```

 To revert back to the default Skia backend:
 ```bash
 adb shell setprop debug.hwui.renderer none
 ```

 ## Enable ANGLE

 ## Developer Options

 The ANGLE Developer Options allow for toggling various ANGLE settings:

 Settings > Developer Options > ANGLE Preferences > Show dialog box when ANGLE is loaded

 The "Select OpenGL Driver" section allows a user to specify which OpenGL ES driver is used for a
 particular package.   Selecting an installed Application will present a dialog box with the following
 options:
 * default
     * Use the rules file to determine if ANGLE should be enabled or not.
 * angle
     * Force enabling ANGLE.
 * native
     * Force enabling the native driver.

 Each (currently non-system) package can have a different value selected, which will persist across
 reboots.

 ## `adb` Commands
 `adb` can be used to set the necessary Global.Settings values to force package(s) to use ANGLE or
 the native driver.

 ```bash
 adb shell settings put global angle_gl_driver_selection_pkgs <package name>
 adb shell settings put global angle_gl_driver_selection_values <driver>
 ```

 The possible values for the `<driver>` value are: `angle`, `native`, and `default`, which correspond
 to the Developer Options selections.

 For example, to enable ANGLE for the dEQP package:
 ```bash
 adb shell settings put global angle_gl_driver_selection_pkgs com.drawelements.deqp
 adb shell settings put global angle_gl_driver_selection_values angle
 ```

 Just like the Developer Options, this setting will persist across reboots.

 ### Enable ANGLE for All Packages
 ANGLE can be enabled for all packages with the following command:
 ```bash
 adb shell settings put global angle_gl_driver_all_angle 1
 ```

 This setting can be disabled by setting it back to `0`:
 ```bash
 adb shell settings put global angle_gl_driver_all_angle 0
 ```

 Note that this setting is disabled in the Developer Options, because it currently makes the device
 un-bootable.   The only way to enable/disable this setting is with `adb` to ensure that it's only
 toggled when the user has access to `adb` so the device can be recovered if it's accidentally left
 on across a reboot.

 ## Rules File method
 Part of the Android platform driver loading process is to analyze a JSON "rules file" within the
 ANGLE APK that specifies whether a particular package should use ANGLE or not based on certain
 criteria (device, GPU, Vulkan driver version, etc.).

 The current rules file can be found at:
 ```bash
 /path/to/chromium/third_party/angle/src/feature_support_util/a4a_rules.json
 ```

 Modifying this file will influence the choice made by the Android GLES loader, either to enable or
 disable ANGLE for a package.

 Additionally, a temporary rules file can be pushed to the device which will override the rules file
 within the ANGLE APK.   After creating/modifying a new `a4a_rules.json` file, it can be used by
 doing the following:

 ```bash
 adb push a4a_rules.json /data/local/tmp/a4a_rules.json
 adb shell setprop debug.angle.rules /data/local/tmp/a4a_rules.json
 ```

 This temporary file will be removed from the device and the property will be reset during the boot
 process, so these steps must be repeated after each boot completes.

 # Verify ANGLE is Being Used

 ## Toast Message
 A Toast message can be enabled with the "Show dialog box when ANGLE is loaded" setting in the ANGLE
 Developer Options.   If enabled, whenever an app with ANGLE enabled is launched, a Toast message
 containing the package name will be presented indicating ANGLE is enabled.

 ## Logcat
 To verify that the application is using ANGLE with logcat with verbose logging enabled (a debug
 Android build):
 ```bash
 adb logcat
 ```

 Verify the following text is output.   In this example, "com.drawelements.deqp" is opted into ANGLE.

 ```
 02-27 13:01:11.914 12134 12134 V GraphicsEnvironment: Package 'com.drawelements.deqp' should use ANGLE = 'true'
 [[[...]]]
 02-27 13:01:11.947 12134 12157 I ANGLE   : Vulkan 1.1.87(Adreno (TM) 540 (0x05040001))
 ```

 Note that the Vulkan driver vender/version will likely be different.

 # System Properties

 ## `ro.gfx.angle.supported`

 The system property `ro.gfx.angle.supported` indicates that ANGLE is in the currently running
 Android image. This will cause CTS to verify that ANGLE can be enabled and disabled with the
 Global.Settings and rules file.

 This system property must be set to `true` in all Android images for devices that are required to
 include ANGLE.

 | Value   | Description
 |---------|---------------------------------------------------------------
 | `true`  | ANGLE is supported in the currently running Android image.
 | `false` | ANGLE is NOT supported in the currently running Android image.

 ## `debug.angle.rules`

 The system property `debug.angle.rules` can be set to the path to a temporary rules file that
 overrides the default rules file present in the ANGLE APK. If the path is inaccessible, the default
 rules file in the ANGLE APK will be used.

 This property will be cleared during a reboot of the device.

 | Value                     | Description
 |---------------------------|------------------------------------------------------
 | `/path/to/rulesFile.json` | The path to the location of the temporary rules file.

 # Global Settings

 ## `angle_gl_driver_all_angle`

 Force all Apps to use ANGLE. This overrides all other values that could disable ANGLE for a
 particular App.

 NOTE: This currently makes the device unbootable when enabled due to the Android boot process, how
 ANGLE is loaded, and the capabilities of ANGLE. Due to this, the setting can only be
 enabled/disabled with `adb` and not the Developer Options.

 | Value | Description
 |-------|------------------------------------
 | `0`   | Do not force all Apps to use ANGLE.
 | `1`   | Force all Apps to use ANGLE.

 ## `show_angle_in_use_dialog_box`

 Show a dialog box (Toast message) when the App is launched that indicates it is using ANGLE.

 | Value | Description
 |-------|----------------------------
 | `0`   | Do not show the dialog box.
 | `1`   | Show the dialog box.

 ## `angle_gl_driver_selection_pkgs`

 The list of Packages that have their OpenGL driver selection being forced to a particular value.
 This list of packages corresponds 1:1 to the list `angle_gl_driver_selection_values`.

 | Value            | Description
 |------------------|---------------------------------------------------------
 | `<package name>` | A package name or comma-separated list of package names.

 ## `angle_gl_driver_selection_values`

 The list of Packages that have their OpenGL driver selection being forced to a particular value.
 This list of packages corresponds 1:1 to the list `angle_gl_driver_selection_pkgs`.

 | Value     | Description
 |-----------|------------------------------------------------------
 | `angle`   | Force using ANGLE for the corresponding Package name.
 | `native`  | Force using the native driver for the corresponding Package name.
 | `default` | Use the default driver determined by the rules file for the corresponding Package name.

 ## `angle_whitelist`

 The list of package names present in the default rules file included in the ANGLE APK. This
 whitelist of package names is used to improve App startup time by only parsing the default rules
 file if the package name is present in the rules file.

 | Value            | Description
 |------------------|---------------------------------------------------------
 | `<package name>` | A package name or comma-separated list of package names.
	# ANGLE for Android Readme

	Additional ANGLE developer instructions for all platforms (Windows, Linux, MacOS, and Android) are
	available [here](https://chromium.googlesource.com/angle/angle/+/master/doc/DevSetup.md).

	# Download

	The full ANGLE for Android APK build uses the Chromium and Android build systems, so both the
	Chromium and Android repos must be cloned. Note that these instructions are only focused on
	building with Linux, since the Android build process is only supported on Linux and MacOS.

	## Chromium

	The following is a summary of the
	[Checking out and building Chromium for Android](https://chromium.googlesource.com/chromium/src/+/master/docs/android_build_instructions.md)
	page. Please refer to it for more details.

	### Install depot_tools
	Clone the depot_tools repository:
	```bash
	mkdir /path/to/depot_tools && cd /path/to/depot_tools
	git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
	```

	Add depot_tools to the end of your PATH (you will probably want to put this in your `~/.bashrc` or
	`~/.zshrc`).
	```bash
	export PATH="$PATH:/path/to/depot_tools"
	```

	### Get the Chromium Code
	Clone the Chromium repository:
	```bash
	mkdir /path/to/chromium && cd /path/to/chromium
	fetch --nohooks android
	```

	## ANGLE
	To use the ToT from the ANGLE repository in the Chromium build, modify Chromium's `.gclient` file:
	```bash
	vi /path/to/chromium/.gclient
	```

	Update the `custom_deps` section:

	```
	solutions = [
	{
	"url": "https://chromium.googlesource.com/chromium/src.git",
	"managed": False,
	"name": "src",
	"custom_deps":
	{
	"src/third_party/angle": None,
	},
	"custom_vars": {},
	},
	]
	target_os=["android"]
	```

	Bootstrap the ANGLE build so it's got the correct `.gclient`:

	```
	timvp@timvp:~/code/chromium/src/third_party/angle$ python scripts/bootstrap.py
	```

	Now update ANGLE to fetch the ToT.

	## Android

	The following is a summary of the directions available from the
	[Downloading the Source](https://source.android.com/setup/build/downloading) page. Please refer to
	it for more details.

	### Install Repo

	```bash
	mkdir /path/to/bin/repo
	PATH=/path/to/bin/repo:$PATH
	curl https://storage.googleapis.com/git-repo-downloads/repo > /path/to/bin/repo
	chmod a+x /path/to/bin/repo
	```

	### Initialize Repo Client

	1. Create a working directory to hold the Android source code.

	```bash
	mkdir /path/to/android && cd /path/to/android
	```

	1. Configure git with your real name and email address. To use the Gerrit code-review tool, you will
	need an email address that is connected with a registered Google account. Make sure this is a live
	address at which you can receive messages. The name that you provide here will show up in
	attributions for your code submissions.

	```bash
	git config --global user.name "Your Name"
	git config --global user.email "[email protected]"
	```

	1. Run repo init to bring down the latest version of Repo with all its most recent bug fixes. You
	must specify a URL for the manifest, which specifies where the various repositories included in the
	Android source will be placed within your working directory.

	```bash
	repo init -u https://android.googlesource.com/platform/manifest
	```

	To check out a branch other than "master", specify it with -b. For a list of branches, see
	[Source Code Tags and Builds](https://source.android.com/setup/start/build-numbers.html#source-code-tags-and-builds).

	```bash
	repo init -u https://android.googlesource.com/platform/manifest -b android-4.0.1_r1
	```

	### Downloading the Android source tree

	To pull down the Android source tree to your working directory from the repositories as specified in
	the default manifest, run

	```bash
	repo sync
	```

	The Android source files will be located in your working directory under their project names. The
	initial sync operation will take an hour or more to complete.

	# Update Source Code
	## Chromium
	In a shell separate from the Android shell:
	```bash
	cd /path/to/chromium
	git rebase-update
	gclient sync
	```

	## ANGLE
	In a shell separate from the Android shell:
	```bash
	cd /path/to/chromium/src/third_party/angle
	git rebase-update
	gclient sync
	```

	## Android
	In a shell separate from the Chromium shell:
	```bash
	cd /path/to/android
	repo sync -c -j40
	repo rebase
	```

	# Build
	## Build ANGLE Libraries
	The first time you build the ANGLE for Android libraries on Linux:
	```bash
	cd /path/to/chromium/src/
	./build/install-build-deps.sh
	```

	NOTE: If the `build/install-build-deps-android.sh` script fails, you may need to manually install
	some packages yourself, using `sudo apt install`. Then, re-run the command to ensure it succeeds.

	The build arguments need to be configured first:

	```bash
	cd /path/to/chromium/src
	gn args out/Default
	```

	NOTE: The `gn args` command will open an editor to enter the desired ANGLE build arugments.
	The "Release" and "Debug" sections below contain values that can be used for either scenario.

	Then the ANGLE shared objects can be built:

	```bash
	ninja -C out/Default third_party/angle:angle_apk
	```

	These commands will create the following ANGLE shared object libraries:
	```bash
	/path/to/chromium/src/out/Default/libEGL_angle.so
	/path/to/chromium/src/out/Default/libfeature_support_angle.so
	/path/to/chromium/src/out/Default/libGLESv1_CM_angle.so
	/path/to/chromium/src/out/Default/libGLESv2_angle.so
	```

	### Release

	```
	target_os = "android"
	target_cpu = "arm64"
	is_debug = false
	android32_ndk_api_level = 26
	android64_ndk_api_level = 26
	build_angle_deqp_tests = false
	dcheck_always_on = true
	ffmpeg_branding = "Chrome"
	is_component_build = false
	proprietary_codecs = true
	symbol_level = 1
	angle_enable_vulkan = true
	angle_enable_vulkan_validation_layers = false
	angle_libs_suffix = "_angle"
	build_apk_secondary_abi = true
	angle_enable_null = false
	angle_force_thread_safety = true
	```

	### Debug

	```
	target_os = "android"
	target_cpu = "arm64"
	is_debug = true
	android32_ndk_api_level = 26
	android64_ndk_api_level = 26
	build_angle_deqp_tests = true
	dcheck_always_on = true
	ffmpeg_branding = "Chrome"
	is_component_build = false
	proprietary_codecs = true
	symbol_level = 2
	angle_enable_vulkan = true
	angle_enable_vulkan_validation_layers = true
	angle_libs_suffix = "_angle"
	build_apk_secondary_abi = true
	angle_enable_null = false
	angle_force_thread_safety = true
	```

	## Build ANGLE APK

	Once the Chromium ANGLE build has completed, copy the generated 32b and 64b ANGLE shared object
	libraries into the Android source tree:

	```bash
	cp /path/to/chromium/src/out/Default/android_clang_arm/lib*angle.so /path/to/android/vendor/unbundled_google/modules/ANGLEPrebuilt/lib/arm
	cp /path/to/chromium/src/out/Default/lib*angle.so /path/to/android/vendor/unbundled_google/modules/ANGLEPrebuilt/lib/arm64
	```

	Build the ANGLE APK:

	```bash
	cd /path/to/android
	source build/envsetup.sh
	tapas GoogleANGLE <arm\|arm64\|x86\|x86_64>
	make -j
	```

	# Install

	```bash
	cd /path/to/android
	adb install out/target/product/generic_arm64/system/product/priv-app/GoogleANGLE/GoogleANGLE.apk
	```

	# Using ANGLE

	## Disable OpenGL ES Driver Preloading
	Android Q disables OpenGL ES driver preloading by default.

	If the device is running something other than Q:
	```bash
	adb root
	adb shell setprop ro.zygote.disable_gl_preload 1
	adb shell stop && adb shell start
	```

	## Skia
	For best results, it's recommended to configure Skia to use the Vulkan back-end:
	```bash
	adb shell setprop debug.hwui.renderer skiavk
	```

	To revert back to the default Skia backend:
	```bash
	adb shell setprop debug.hwui.renderer none
	```

	## Enable ANGLE

	## Developer Options

	The ANGLE Developer Options allow for toggling various ANGLE settings:

	Settings > Developer Options > ANGLE Preferences > Show dialog box when ANGLE is loaded

	The "Select OpenGL Driver" section allows a user to specify which OpenGL ES driver is used for a
	particular package. Selecting an installed Application will present a dialog box with the following
	options:
	* default
	* Use the rules file to determine if ANGLE should be enabled or not.
	* angle
	* Force enabling ANGLE.
	* native
	* Force enabling the native driver.

	Each (currently non-system) package can have a different value selected, which will persist across
	reboots.

	## `adb` Commands
	`adb` can be used to set the necessary Global.Settings values to force package(s) to use ANGLE or
	the native driver.

	```bash
	adb shell settings put global angle_gl_driver_selection_pkgs <package name>
	adb shell settings put global angle_gl_driver_selection_values <driver>
	```

	The possible values for the `<driver>` value are: `angle`, `native`, and `default`, which correspond
	to the Developer Options selections.

	For example, to enable ANGLE for the dEQP package:
	```bash
	adb shell settings put global angle_gl_driver_selection_pkgs com.drawelements.deqp
	adb shell settings put global angle_gl_driver_selection_values angle
	```

	Just like the Developer Options, this setting will persist across reboots.

	### Enable ANGLE for All Packages
	ANGLE can be enabled for all packages with the following command:
	```bash
	adb shell settings put global angle_gl_driver_all_angle 1
	```

	This setting can be disabled by setting it back to `0`:
	```bash
	adb shell settings put global angle_gl_driver_all_angle 0
	```

	Note that this setting is disabled in the Developer Options, because it currently makes the device
	un-bootable. The only way to enable/disable this setting is with `adb` to ensure that it's only
	toggled when the user has access to `adb` so the device can be recovered if it's accidentally left
	on across a reboot.

	## Rules File method
	Part of the Android platform driver loading process is to analyze a JSON "rules file" within the
	ANGLE APK that specifies whether a particular package should use ANGLE or not based on certain
	criteria (device, GPU, Vulkan driver version, etc.).

	The current rules file can be found at:
	```bash
	/path/to/chromium/third_party/angle/src/feature_support_util/a4a_rules.json
	```

	Modifying this file will influence the choice made by the Android GLES loader, either to enable or
	disable ANGLE for a package.

	Additionally, a temporary rules file can be pushed to the device which will override the rules file
	within the ANGLE APK. After creating/modifying a new `a4a_rules.json` file, it can be used by
	doing the following:

	```bash
	adb push a4a_rules.json /data/local/tmp/a4a_rules.json
	adb shell setprop debug.angle.rules /data/local/tmp/a4a_rules.json
	```

	This temporary file will be removed from the device and the property will be reset during the boot
	process, so these steps must be repeated after each boot completes.

	# Verify ANGLE is Being Used

	## Toast Message
	A Toast message can be enabled with the "Show dialog box when ANGLE is loaded" setting in the ANGLE
	Developer Options. If enabled, whenever an app with ANGLE enabled is launched, a Toast message
	containing the package name will be presented indicating ANGLE is enabled.

	## Logcat
	To verify that the application is using ANGLE with logcat with verbose logging enabled (a debug
	Android build):
	```bash
	adb logcat
	```

	Verify the following text is output. In this example, "com.drawelements.deqp" is opted into ANGLE.

	```
	02-27 13:01:11.914 12134 12134 V GraphicsEnvironment: Package 'com.drawelements.deqp' should use ANGLE = 'true'
	[[[...]]]
	02-27 13:01:11.947 12134 12157 I ANGLE : Vulkan 1.1.87(Adreno (TM) 540 (0x05040001))
	```

	Note that the Vulkan driver vender/version will likely be different.

	# System Properties

	## `ro.gfx.angle.supported`

	The system property `ro.gfx.angle.supported` indicates that ANGLE is in the currently running
	Android image. This will cause CTS to verify that ANGLE can be enabled and disabled with the
	Global.Settings and rules file.

	This system property must be set to `true` in all Android images for devices that are required to
	include ANGLE.

	\| Value \| Description
	\|---------\|---------------------------------------------------------------
	\| `true` \| ANGLE is supported in the currently running Android image.
	\| `false` \| ANGLE is NOT supported in the currently running Android image.

	## `debug.angle.rules`

	The system property `debug.angle.rules` can be set to the path to a temporary rules file that
	overrides the default rules file present in the ANGLE APK. If the path is inaccessible, the default
	rules file in the ANGLE APK will be used.

	This property will be cleared during a reboot of the device.

	\| Value \| Description
	\|---------------------------\|------------------------------------------------------
	\| `/path/to/rulesFile.json` \| The path to the location of the temporary rules file.

	# Global Settings

	## `angle_gl_driver_all_angle`

	Force all Apps to use ANGLE. This overrides all other values that could disable ANGLE for a
	particular App.

	NOTE: This currently makes the device unbootable when enabled due to the Android boot process, how
	ANGLE is loaded, and the capabilities of ANGLE. Due to this, the setting can only be
	enabled/disabled with `adb` and not the Developer Options.

	\| Value \| Description
	\|-------\|------------------------------------
	\| `0` \| Do not force all Apps to use ANGLE.
	\| `1` \| Force all Apps to use ANGLE.

	## `show_angle_in_use_dialog_box`

	Show a dialog box (Toast message) when the App is launched that indicates it is using ANGLE.

	\| Value \| Description
	\|-------\|----------------------------
	\| `0` \| Do not show the dialog box.
	\| `1` \| Show the dialog box.

	## `angle_gl_driver_selection_pkgs`

	The list of Packages that have their OpenGL driver selection being forced to a particular value.
	This list of packages corresponds 1:1 to the list `angle_gl_driver_selection_values`.

	\| Value \| Description
	\|------------------\|---------------------------------------------------------
	\| `<package name>` \| A package name or comma-separated list of package names.

	## `angle_gl_driver_selection_values`

	The list of Packages that have their OpenGL driver selection being forced to a particular value.
	This list of packages corresponds 1:1 to the list `angle_gl_driver_selection_pkgs`.

	\| Value \| Description
	\|-----------\|------------------------------------------------------
	\| `angle` \| Force using ANGLE for the corresponding Package name.
	\| `native` \| Force using the native driver for the corresponding Package name.
	\| `default` \| Use the default driver determined by the rules file for the corresponding Package name.

	## `angle_whitelist`

	The list of package names present in the default rules file included in the ANGLE APK. This
	whitelist of package names is used to improve App startup time by only parsing the default rules
	file if the package name is present in the rules file.

	\| Value \| Description
	\|------------------\|---------------------------------------------------------
	\| `<package name>` \| A package name or comma-separated list of package names.