Revert "Revert "implement SkScalar versions in terms of float versions""

This reverts commit 0e6db75eebab430e7f6665c8cfa1e7dcd2fef123.

Bug: skia:
Change-Id: I015d01efc58dfe03dae6bcc57c4b1102276e7566
Reviewed-on: https://skia-review.googlesource.com/127967
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 4 insertions, 16 deletions

diff --git a/include/core/SkScalar.h b/include/core/SkScalar.h
index 9c015e5ea4..938f698e05 100644
--- a/include/core/SkScalar.h
+++ b/include/core/SkScalar.h
@@ -60,7 +60,7 @@ typedef float SkScalar;
 #define SkScalarToFloat(x)      static_cast<float>(x)
 #define SkFloatToScalar(x)      static_cast<SkScalar>(x)
 #define SkScalarToDouble(x)     static_cast<double>(x)
-#define SkDoubleToScalar(x)     static_cast<SkScalar>(x)
+#define SkDoubleToScalar(x)     sk_double_to_float(x)
 
 #define SK_ScalarMin            (-SK_ScalarMax)
 
@@ -68,22 +68,10 @@ static inline bool SkScalarIsNaN(SkScalar x) { return x != x; }
 
 /** Returns true if x is not NaN and not infinite
  */
-static inline bool SkScalarIsFinite(SkScalar x) {
-    // We rely on the following behavior of infinities and nans
-    // 0 * finite --> 0
-    // 0 * infinity --> NaN
-    // 0 * NaN --> NaN
-    SkScalar prod = x * 0;
-    // At this point, prod will either be NaN or 0
-    return !SkScalarIsNaN(prod);
-}
+static inline bool SkScalarIsFinite(SkScalar x) { return sk_float_isfinite(x); }
 
 static inline bool SkScalarsAreFinite(SkScalar a, SkScalar b) {
-    SkScalar prod = 0;
-    prod *= a;
-    prod *= b;
-    // At this point, prod will either be NaN or 0
-    return !SkScalarIsNaN(prod);
+    return sk_float_isfinite(a) && sk_float_isfinite(b);
 }
 
 static inline bool SkScalarsAreFinite(const SkScalar array[], int count) {
@@ -92,7 +80,7 @@ static inline bool SkScalarsAreFinite(const SkScalar array[], int count) {
         prod *= array[i];
     }
     // At this point, prod will either be NaN or 0
-    return !SkScalarIsNaN(prod);
+    return prod == 0;   // if prod is NaN, this check will return false
 }
 
 /**