This subdirectory contains Android's Vulkan loader, as well as some Vulkan-related tools useful to platform developers.

The former contents of doc/implementors_guide/ are now at https://source.android.com/devices/graphics/implement-vulkan.

We follow the Chromium coding style for naming and formatting, except with four-space indentation instead of two spaces. In general, any C++ features supported by the prebuilt platform toolchain are allowed.

Use "clang-format -style=file" to format all C/C++ code, except code imported verbatim from elsewhere. Setting up git-clang-format in your environment is recommended.

We generate several parts of the loader and tools directly from the Vulkan Registry (external/vulkan-headers/registry/vk.xml). Code generation must be done manually because the generator is not part of the platform toolchain (yet?). Files named foo_gen.* are generated by the code generator.

Install Python3 (if not already installed) and execute below: $ ./scripts/code_generator.py

This script parses the Vulkan XML registry (vk.xml) and generates vk.py, which contains Python representations of Vulkan structures and mappings. Key functions include:

• Parsing vk.xml to extract Vulkan API constants, enums, handles, structs, and extensions.
• Generating Python dataclasses for Vulkan structs and handles.
• Creating mappings for features, extensions, and core versions to their corresponding structs.
• Handling C to Python type conversions and aliases.
• The main function is gen_vk().

This script generates the C++ code for serializing Vulkan device capabilities into a JSON format. It uses vk.py as its source of truth for Vulkan API information.

• gen_h(): Generates vkjson.h, which defines the C++ structs (VkJsonInstance, VkJsonDevice, etc.) for storing Vulkan properties.
• gen_cc(): Generates vkjson.cc, providing the JSON serialization and deserialization logic for the C++ structs.
• gen_instance_cc(): Generates vkjson_instance.cc, which implements functions to query a physical device and populate the C++ structs with its capabilities.

This script serves as the primary entry point for regenerating all Vulkan JSON-related files. It performs the code generation process by calling the necessary functions from vk_parser.py and vkjson_generator.py in the correct order. Running this single script ensures that vk.py, vkjson.h, vkjson.cc, and vkjson_instance.cc are all updated based on the Vulkan XML registry.

This guide outlines the three main parts for updating the Vulkan EDI pipeline.

• Location: Android repository : $ANDROID_BUILD_TOP/frameworks/native/vulkan
• Command: python3 scripts/vkjson_codegen.py

• Location: Android repository: $ANDROID_BUILD_TOP/cts
• Command: python3 common/device-side/device-info/src/com/android/compatibility/common/deviceinfo/scripts/code_generator.py

• Location: Android repository root: $ANDROID_BUILD_TOP
• Commands:

      # Build the necessary CTS modules
      mmma cts/tools/cts-device-info/ cts/common/device-side/device-info
  
      # Install the collector APK. Note: The path depends on your lunch target.
      adb install -r -g out/target/product/<target_name>/testcases/CtsDeviceInfo/arm64/CtsDeviceInfo.apk
  
      # Run the instrumented test to generate the file on the device
      adb shell am instrument --no-isolated-storage -w \
      -e class com.android.compatibility.common.deviceinfo.VulkanDeviceInfo \
      com.android.compatibility.common.deviceinfo/androidx.test.runner.AndroidJUnitRunner
  
      # Pull the generated JSON from the device
      adb pull /sdcard/device-info-files/VulkanDeviceInfo.deviceinfo.json
  

Next, move to your google3 workspace to update the source files and run the final proto generator script.

1. Update vk.py: Copy the vk.py from $ANDROID_BUILD_TOP/frameworks/native/vulkan/scripts file to wireless/android/partner/adl/proto/scripts/.

   • In the copied vk.py file, add a comment in the file to disable lint errors - # pylint: disable=all

2. Update VulkanDeviceInfo.deviceinfo.json: Copy the JSON file generated in the previous step (A) to javatests/com/google/wireless/android/partner/adl/pipeline/extendeddeviceinfo/.

3. Run Generator: Execute the following command to update the .proto files, apfe.sdl, and the ExtendedDeviceInfoTest.java test file.

   • Location: google3
   • Command: python3 wireless/android/partner/adl/proto/scripts/vulkan_proto_gen.py