The alignment a dynamic uniform-buffer offset must satisfy.
256 bytes is the WebGPU default minUniformBufferOffsetAlignment, and it is
also the specification's maximum permitted value for that limit — so a
fixed 256 is valid on every conforming device, while reading the limit and
using a smaller stride would only ever save memory on devices that permit it.
A fixed stride keeps the per-frame uniform packing arithmetic a constant
(§33: the frame's byte layout must not vary with the device), which is worth
more here than the bytes are (decision, WP-R1.1).
The alignment a dynamic uniform-buffer offset must satisfy.
256 bytes is the WebGPU default
minUniformBufferOffsetAlignment, and it is also the specification's maximum permitted value for that limit — so a fixed 256 is valid on every conforming device, while reading the limit and using a smaller stride would only ever save memory on devices that permit it. A fixed stride keeps the per-frame uniform packing arithmetic a constant (§33: the frame's byte layout must not vary with the device), which is worth more here than the bytes are (decision, WP-R1.1).