XVK_DROID: Add X11 window surface support for Android Vulkan driver in Termux.

Project stage

Proved viable (Successfully tested on simple programs).
Current implementation first copies VkImage inside the swapchain to a VkBuffer, then uses xcb PutImage request to copies the image data inside the VkBuffer to the window surface.

Tests

Programs

✅: Works fine.
🛠️: Tested, but not functioning well.
❌: Tested, but not working or barely working.
⏹️: Untested.

• ✅ xcb hello triangle
• ✅ GLFW hello triangle
• ✅ vkcube (Currently only support BGRA_SRGB surface format, not prefered by vkcube)
• ✅ vkmark (~900 FPS on SD8Gen3)
• 🛠️ gears (Only shows the red gear's first face)
• 🛠️ glmark2 (Can't finish the benchmark, crash in the middle of it, error: ralloc_header *get_header(const void *): assertion "info->canary == CANARY" failed. ~350-400 FPS on SD8Gen3)
• ❌ firefox (Only 4 FPS in WebGL Samples Aquarium)
• ❌ chromium (When enabling vulkan flag: in chome://gpu, vulkan info shows it is using xvk_droid, but dawn is using the original vulkan loader)
• ❌ programs inside proot-distro (When compiling using glibc, the program can't load android dynamic library, we need to compile bionic libdl to work)
• ❌ glibc packages (Same reason as proot-distro programs)
• ⏹️ box64 wine dxvk (need to fix glibc packages first)
• ⏹️ Minecraft (Require compiling OpenJFX for termux)
• ⏹️ wgpu programs (winit is assuming termux an android environment and not using x11 surface)

TODO

• Support test programs listed above.
• Support loading android libvulkan.so when compiled using glibc, so that it can be used for glibc-repo programs and proot\chroot gnu linux programs.
• Provide prebuilt binaries and make it a deb package.
• Publish to Termux repo.
• Make it an ICD driver to support coexisting with other vulkan drivers.
• Reduce overhead to improve performance.

How to use the program

Using pre-built binary

You can get it at the release page.

Build the program

Requirement: rust

Run in the repository:

cargo build -r -p xvk_droid

The resulting library will be target/release/libxvk_droid.so

Use the program to replace the default libvulkan

Run in the repository:

make create_link

if you have make installed, or run

ln -s target/release/libxvk_droid.so libvulkan.so
ln -s target/release/libxvk_droid.so libvulkan.so.1

if you don't.

This will create symbolic links to the library in the root of the repository, the reason to do this is

1. for convenience
2. GLFW load libvulkan.so.1 rather than libvulkan.so. We need to create an additional libvulkan.so.1 for programs using GLFW to work.

To run program using the xvk_droid. Run

LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH program_name

in the root of the repository.
For example:

LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH vkcube

vkcube can be installed using

pkg i vulkan-tools

Or you can export envirenment variables to use xvk_droid to run all the program in the this shell.

export LD_LIBRARY_PATH=$PWD:$LD_LIBRARY_PATH

Or using

. set_env.sh

for convenience. Afterwards the programs ran in the same shell will use xvk_droid as the vulkan implementation. For example:

. set_env.sh
vkmark

vkmark is in the tur-repo, to install it, run:

pkg i tur-repo
pkg i vkmark