Unify implementations of stroking radius calculations

src/core/SkPaint.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPaint.h"
 #include "SkAutoKern.h"
 #include "SkChecksum.h"
@@ skipping 2007 matching lines @@
         this->getLooper()->computeFastBounds(*this, *src, storage);
         return *storage;
     }
 
     SkRect tmpSrc;
     if (this->getPathEffect()) {
         this->getPathEffect()->computeFastBounds(&tmpSrc, origSrc);
         src = &tmpSrc;
     }
 
-    if (kFill_Style != style) {
-        // since we're stroked, outset the rect by the radius (and join type)
-        SkScalar radius = SkScalarHalf(this->getStrokeWidth());
-        if (0 == radius) {  // hairline
-            radius = SK_Scalar1;
-        } else if (this->getStrokeJoin() == SkPaint::kMiter_Join) {
-            SkScalar scale = this->getStrokeMiter();
-            if (scale > SK_Scalar1) {
-                radius = SkScalarMul(radius, scale);
-            }
-        }
-        storage->set(src->fLeft - radius, src->fTop - radius,
-                     src->fRight + radius, src->fBottom + radius);
-    } else {
-        *storage = *src;
-    }
+    SkScalar radius = SkStrokeRec::GetInflationRadius(*this, style);
+    *storage = src->makeOutset(radius, radius);
 
     if (this->getMaskFilter()) {
         this->getMaskFilter()->computeFastBounds(*storage, storage);
     }
 
     if (this->getImageFilter()) {
         *storage = this->getImageFilter()->computeFastBounds(*storage);
     }
 
     return *storage;
@@ skipping 317 matching lines @@
 }
 
 uint32_t SkPaint::getHash() const {
     // We're going to hash 10 pointers and 7 32-bit values, finishing up with fBitfields,
     // so fBitfields should be 10 pointers and 6 32-bit values from the start.
     static_assert(offsetof(SkPaint, fBitfields) == 9 * sizeof(void*) + 6 * sizeof(uint32_t),
                   "SkPaint_notPackedTightly");
     return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(this),
                                offsetof(SkPaint, fBitfields) + sizeof(fBitfields));
 }