Add f16 to the Reflect Trait

[klownie]

What problem does this solve or what need does it fill?

better packing for uniforms.

Especially useful when dealing with big storage buffers where its size will determine the performance of a shader

What solution would you like?

Let Reflect use f16 types.

[hukasu]

f16 is still nightly only

[klownie]

cant half lib just be used temporarly