Fix bounds of checking if a radii are too long for a side.

BUG=skia:4692,skia:4413
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1617763003

Review URL: https://codereview.chromium.org/1617763003

1 files changed, 7 insertions, 6 deletions

diff --git a/src/core/SkScaleToSides.h b/src/core/SkScaleToSides.h
index 77637a3ac2..c3fa172f67 100644
--- a/src/core/SkScaleToSides.h
+++ b/src/core/SkScaleToSides.h
@@ -14,7 +14,7 @@
 
 class ScaleToSides {
 public:
-    // This code assumes that a and b fit in in a float, and therefore the resulting smaller value
+    // This code assumes that a and b fit in a float, and therefore the resulting smaller value
     // of a and b will fit in a float. The side of the rectangle may be larger than a float.
     // Scale must be less than or equal to the ratio limit / (*a + *b).
     // This code assumes that NaN and Inf are never passed in.
@@ -24,8 +24,7 @@ public:
         *a = (float)((double)*a * scale);
         *b = (float)((double)*b * scale);
 
-        // This check is conservative. (double)*a + (double)*b >= (double)(*a + *b)
-        if ((double)*a + (double)*b > limit) {
+        if (*a + *b > limit) {
             float* minRadius = a;
             float* maxRadius = b;
 
@@ -48,14 +47,16 @@ public:
             // reduced by one ULP to be less than limit - newMinRadius.
             // Note: nexttowardf is a c99 call and should be std::nexttoward, but this is not
             // implemented in the ARM compiler.
-            if ((double)newMaxRadius + (double)newMinRadius > limit) {
+            if (newMaxRadius + newMinRadius > limit) {
                 newMaxRadius = nexttowardf(newMaxRadius, 0.0);
             }
             *maxRadius = newMaxRadius;
         }
 
-        SkASSERTF(*a >= 0.0f && *b >= 0.0f, "a: %g, b: %g", *a, *b);
-        SkASSERTF((*a + *b) <= limit, "limit: %g, a: %g, b: %g", limit, *a, *b);
+        SkASSERTF(*a >= 0.0f && *b >= 0.0f, "a: %g, b: %g, limit: %g, scale: %g", *a, *b, limit,
+                  scale);
+        SkASSERTF(*a + *b <= limit, "\nlimit: %.10f, a: %.10f, b: %.10f, scale: %.20f",
+                  limit, *a, *b, scale);
     }
 };
 #endif // ScaleToSides_DEFINED