xrgears

xrgears is an OpenXR VR demo using Vulkan for rendering.

It is the next iteration of the old xrgears-legacy code, which included the compositor and used OpenHMD directly.

The Vulkan renderer is based on Sascha Willems' Vulkan Examples and the KTX (Khronos Texture) loader is a stripped down version of Khronos' KTX reference implementation libktx.

Dependencies

• OpenXR headers and loader
• Vulkan headers and loader

Build

• glslang
• glm
• xxd

License

xrgears is released under the MIT License.

The KTX loader code is licensed Apache 2.

The spherical photography Rooftop Night is licensed CC0.

Build

$ meson build

This will take a while since the texture is compiled into the binary.

$ ninja -C build

Run

$ ./build/src/xrgears

Run in Monado's XCB windowed mode, with Vulkan validation.

$ XRT_COMPOSITOR_FORCE_XCB=TRUE ./build/src/xrgears -v

Commands

Options:
  -g, --gpu GPU            GPU to use (default: 0)
  -v, --validation         Run Vulkan validation
  -h, --help               Show this help

Asset pipeline

• Tone map equirectangular Radiance HDR with Darktable or Luminance HDR
• Export PNG
• Convert to GL_COMPRESSED_RGBA_S3TC_DXT5_EXT KTX with ktxutils.

any2ktx rooftop_night_4k_tonemapped.png \
        rooftop_night_4k_tonemapped.png.ktx \
        -i GL_COMPRESSED_RGBA_S3TC_DXT5_EXT

TODO

• Controller support.
• Loading skydomes via command line.
• Skydome tone mapping.