rough clamped tracking in SkRasterPipeline

This should make srgb_color_filter draw correctly in software.
Previously the Rec2020 block would overflow.

Change-Id: Ied4516728039e54214886d55bba92662beee9a26
Reviewed-on: https://skia-review.googlesource.com/26562
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/core/SkRasterPipeline.h b/src/core/SkRasterPipeline.h
index 4e2feb3066..e9cb886e6f 100644
--- a/src/core/SkRasterPipeline.h
+++ b/src/core/SkRasterPipeline.h
@@ -138,6 +138,11 @@ 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;
@@ -152,6 +157,7 @@ private:
     StageList*    fStages;
     int           fNumStages;
     int           fSlotsNeeded;
+    bool          fClamped;
 };
 
 template <size_t bytes>