Rework out-of-gamut handling in SkRasterPipeline

Instead of trying to carefully manage the in-gamut / out-of-gamut state
of the pipeline, let's do what a GPU would do, clamping to representable
range in any float -> integer conversion.

Most effects doing table lookups now clamp themselves internally, and
the store_foo() methods clamp when the destination is fixed point.  In
turn the from_srgb() conversions and all future transfer function stages
can care less about this stuff.

If I'm thinking right, the _lowp side of things need not change at all,
and that will soften the performance impact of this change.  Anything
that was fast to begin with was probably running a _lowp pipeline.

Bug: skia:7419

Change-Id: Id2e080ac240a97b900a1ac131c85d9e15f70af32
Reviewed-on: https://skia-review.googlesource.com/85740
Commit-Queue: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/src/core/SkRasterPipeline.h b/src/core/SkRasterPipeline.h
index 66dd5de648..005c3dd7ab 100644
--- a/src/core/SkRasterPipeline.h
+++ b/src/core/SkRasterPipeline.h
@@ -150,11 +150,6 @@ public:
 
     bool empty() const { return fStages == nullptr; }
 
-    // Used to track if we're handling values outside [0.0f, 1.0f],
-    // and to clamp back to [0.0f, 1.0f] if so.
-    void set_clamped(bool clamped) { fClamped = clamped; }
-    void clamp_if_unclamped(SkAlphaType);
-
 private:
     struct StageList {
         StageList* prev;
@@ -169,7 +164,6 @@ private:
     StageList*    fStages;
     int           fNumStages;
     int           fSlotsNeeded;
-    bool          fClamped;
 };
 
 template <size_t bytes>