Unlike other texture functions in GLSL, textureGather() and
textureGatherOffset() do not expect the refZ value to be appended to
the texture coordinates. It is passed as a regular argument. So append
refZ to coordinates by default, and pass as a regular parameter only
for the gather functions.
Bug: tint:1459
Change-Id: Iad1255be3de5915aeff4adb9054479b9e92c45cb
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/82340
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Stephen White <senorblanco@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Stephen White
Ryan Harrison