Our optimizer ignores index expressions, but has a few simplifications
that it can perform on swizzles. (Added extra code to SwizzleByIndex
which demonstrates this.)
Change-Id: If3c85a0456d98749008d796e422944b602ee6933
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341460
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
We will need to emit a helper function to work around this case, as
GLSL supports swizzled out params, but Metal does not. In this CL, we
do not yet synthesize the helper function, but we annotate the code with
a comment indicating affected calls. (Of course, this will be replaced
with a helper function in a followup CL)
Even detecting a swizzle is actually an interesting problem, because
index expressions are sometimes actually swizzles, depending on the type
of the base expression. Also, the index or swizzle might be nested in
several other valid assignable expressions.
Change-Id: I8c74f9a7daec08eff1f32387f8b6b96851c1bd6e
Bug: skia:10855
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/341057
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
