WGPU texture sharing via DMA-BUF to Glutin and Slint

Requirements

• Linux OS
• Wgpu and Slint configured using OpenGL backends
• EGL extensions:
  • EGL_MESA_image_dma_buf_export
  • EGL_EXT_image_dma_buf_import

Problem

I was not able to use Wgpu content in a Slint image on Linux.

Solution

Export an OpenGL texture to DMA-BUF using the WGPU hal api.
Should be possible as this C example works: https://gitlab.com/blaztinn/dma-buf-texture-sharing/-/blob/master/main.c

How It Works

• access the WGPU OpenGL texture via the hal api
• export it in a dma_buf_fd using eglExportDMABUFImageMESA
• I used two separate processes connected using Unix Datagram sockets
• read the texture back via glEGLImageTargetTexture2DOES
• use BorrowedOpenGLTextureBuilder to create the Slint Image or map it via a shader in Glutin

How to Run

Cross process:

• Run sender using env WGPU_BACKEND=gl
• Run one of:
  • receiver_glutin
  • receiver_slint using env SLINT_BACKEND=GL

Same process:

• Run slint_wgpu_same_process using both env variables as mentioned above

Note

I am not a Rust developer nor a graphics programmer, tips are always welcome!