Would Backend using nanoVG and MetalNanoVG?

[zoujiaqing]

NanoGUI builds on GLFW for cross-platform context creation and event handling, GLAD to access OpenGL functionality on Windows, and NanoVG/MetalNanoVG to draw 2D primitives.

• https://github.com/mitsuba-renderer/nanogui
• https://github.com/memononen/nanovg
• https://github.com/ollix/MetalNanoVG

[drug007]

Nanogui uses nanovg like original. I personally have no plans to add support for Metal because I have no interest in mac related things. It is a nice feature but I have no both time and hardware.