Add bundletool script samples

Change-Id: I3625feb040f9a1aa36846e62c93e43e184039d74

Author: agiuglia

PlayAssetDelivery/BundletoolScriptSample/README.md

@@ -0,0 +1,157 @@
+# Asset Pack packaging scripts
+
+## Setup
+
+1.  Set up virtualenv (Optional, recommended)
+
+    ```
+    $ virtualenv -p python3 venv
+    $ . ./venv/bin/activate
+    ```
+
+2.  Install required packages
+
+    ```
+    (venv) $ pip install -r requirements.txt
+    ```
+
+## Usage
+
+### Generating Asset Packs
+
+```
+$ generate_asset_pack.py \
+   --packagename APP_PACKAGE_NAME \
+   --deliverymode [install-time, fast-follow, on-demand] \
+   --assetsdir ASSETS_DIR \
+   --outdir OUTPUT_DIR \
+   --assetpackname MY_PACK
+```
+
+### Adding Asset Packs into an App Bundle
+
+```
+$ add_packs.py \
+   --androidsdk ANDROID_SDK_PATH \
+   --sdkver SDK_VERSION \
+   --buildtoolsver BUILD_TOOLS_VERSION \
+   --bundletool BUNDLETOOL_JAR \
+   --inputbundle APP.AAB \
+   --packdir PACK_DIR \
+   --packnames MY_PACK_1.ZIP,MY_PACK_2.ZIP \
+   --output OUTPUT_APP.AAB \
+   [--overwrite] \
+   [--striptcfsuffixes] \
+   [--prelollipop] \
+   [--compressinstalltimeassets] \
+```
+
+Please note that the last flag (compressinstalltimeassets) is an EAP feature, and
+availability is restricted to allowed titles only.
+
+#### Making texture targeted asset packs
+
+Generate your asset files in multiple formats (ASTC, ETC2, ETC1, etc...), and
+put them in directories suffixed by `#tcf_xxx` (see values for `xxx` below). For
+example:
+
+```
+my_asset_pack
+├── some_common_file
+├── some_common_directory
+│   └── ....
+├── textures
+│   └── some_file
+├── textures#tcf_astc
+│   └── some_file
+├── textures#tcf_dxt1
+│   └── some_file
+├── textures#tcf_etc2
+│   └── some_file
+└── textures#tcf_pvrtc
+    └── some_file
+```
+
+Generate your asset packs as usual (with `generate_asset_pack.py`) and,
+optionally, generate your AAB with the `--striptcfsuffixes` option. The Android
+App Bundle that will be built when using this asset pack will have **a variant
+of the asset pack for each texture format**.
+
+If you specified `--striptcfsuffixes`, the `#tcf_xxx` suffixes will be removed
+from the folder names in each variant of the asset packs. This means that a
+folder named `my_asset_pack/textures#tcf_etc2` will be renamed to
+`my_asset_pack/textures` in the ETC2 asset pack.
+
+You can build the apks with bundletool and inspect the content to verify this:
+
+```bash
+bundletool build-apks --bundle=out/appbundle_with_tcf_asset_packs.aab --output=out/appbundle_with_tcf_asset_packs.apks
+zipinfo out/appbundle_with_tcf_asset_packs.apks
+# Note the variants for my_asset_pack:
+# -rw----     1.0 fat     6469 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-other_tcf.apk
+# -rw----     1.0 fat     6448 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-astc.apk
+# -rw----     1.0 fat     6461 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-etc2.apk
+# -rw----     1.0 fat     6467 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-dxt1.apk
+# -rw----     1.0 fat     6619 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-master.apk
+# -rw----     1.0 fat     6473 bx stor 70-Jan-01 01:00 asset-slices/my_asset_pack-pvrtc.apk
+# ...
+```
+
+Each asset pack variant contains only the common directories, and the
+directories for one texture format.
+
+The targeting is done as such:
+
+-   All supported formats are: `astc, pvrtc, s3tc, dxt1, latc, atc, 3dc, etc2,
+    etc1, paletted`.
+
+    -   Google Play delivers the first format, in this order, that is supported
+        by the device.
+
+-   If a folder has no suffix and has sibling(s) with the same base name but
+    suffixed (like `textures` in this example), it will be considered as a
+    "fallback". In this directory, place the default format of your texture
+    assets.
+
+    -   If none of the texture formats in the App Bundle are supported by the
+        device, Google Play delivers the "fallback" asset pack.
+
+### Example
+
+```
+$ generate_asset_pack.py \
+  --packagename com.karahan.ibrahim.dynamic.assetpacksapp \
+  --assetpackname myassets \
+  --deliverymode on-demand \
+  --assetsdir ~/assets/myassets/ \
+  --outdir ~/assets/asset_packs
+```
+
+```
+$ add_packs.py \
+  --androidsdk ~/Android/Sdk \
+  --sdkver 28 \
+  --buildtoolsver 28.0.3 \
+  --bundletool ~/bundletool-all-0.10.3.jar \
+  --inputbundle ~/src/app/release/app.aab \
+  --packdir ~/assets/asset_packs \
+  --packnames=myassets.zip \
+  --output ~/aug.aab
+```
+
+## Misc
+
+### Python Source File for App Bundle Config Proto
+
+The file `config_pb2.py` is generated from `config.proto` in
+[Bundletool source](https://github.com/google/bundletool/blob/master/src/main/proto/config.proto)
+using protobuf compiler (`protoc`). The compiler is installed together with the
+protobuf C++ runtime which is available on
+[GitHub](https://github.com/protocolbuffers/protobuf).
+
+It can be installed on Debian-like systems with: `$ sudo apt install
+protobuf-compiler` and on macOS with [Macports](https://www.macports.org/) with:
+`$ sudo /opt/local/bin/port install protobuf3-cpp`
+
+Use the following command to regenerate `config_pb2.py` if required: `$ protoc
+--python_out . config.proto`