Constant COPY_BYTES_PER_ROW_ALIGNMENT 

pub const COPY_BYTES_PER_ROW_ALIGNMENT: u32 = 256; // 256u32

Available on crate feature unstable-wgpu-26 only.

Buffer-to-texture copies must have bytes_per_row aligned to this number.

This doesn’t apply to Queue::write_texture, only to copy_buffer_to_texture().