Change ScalarTo256 to more efficient implementation.

The previous implementation was likely more efficient when SkScalar was SkFixed.

BUG=skia:4632
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1693683002

Review URL: https://codereview.chromium.org/1693683002

1 files changed, 1 insertions, 8 deletions

diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index e205ee45c0..d07bcb8fcf 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1761,14 +1761,7 @@ bool SkTriColorShader::TriColorShaderContext::setup(const SkPoint pts[], const S
 #include "SkComposeShader.h"
 
 static int ScalarTo256(SkScalar v) {
-    int scale = SkScalarToFixed(v) >> 8;
-    if (scale < 0) {
-        scale = 0;
-    }
-    if (scale > 255) {
-        scale = 255;
-    }
-    return SkAlpha255To256(scale);
+    return static_cast<int>(SkScalarPin(v, 0, 1) * 256);
 }