skip unpremul...premul with only linear ops between

Change-Id: I26ed83bb613a83a0fd73f2f8b868b775be1ce968
Reviewed-on: https://skia-review.googlesource.com/130121
Commit-Queue: Mike Klein <mtklein@chromium.org>
Auto-Submit: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/src/core/SkColorSpaceXformSteps.cpp b/src/core/SkColorSpaceXformSteps.cpp
index 08a59fc672..e4b465e6cf 100644
--- a/src/core/SkColorSpaceXformSteps.cpp
+++ b/src/core/SkColorSpaceXformSteps.cpp
@@ -102,4 +102,22 @@ SkColorSpaceXformSteps::SkColorSpaceXformSteps(SkColorSpace* src, SkAlphaType sr
         this->linearize_src = false;
         this->early_encode  = false;
     }
+
+    // Skip unpremul...premul if there are no non-linear operations between.
+    if ( this->early_unpremul &&
+        !this->linearize_src  &&
+        !this->early_encode   &&
+         this->premul)
+    {
+        this->early_unpremul = false;
+        this->premul         = false;
+    }
+
+    if ( this->late_unpremul &&
+        !this->early_encode  &&
+         this->premul)
+    {
+        this->late_unpremul = false;
+        this->premul        = false;
+    }
 }