revised strokerect gm

include/core/SkScalar.h

 /*
  * 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.
  */
 
 #ifndef SkScalar_DEFINED
 #define SkScalar_DEFINED
 
@@ skipping 150 matching lines @@
  *      SkASSERT(0 == ix);    // <--- fails
  *      ix = SkDScalarRoundToInt(x);
  *      SkASSERT(0 == ix);    // <--- succeeds
  */
 static inline int SkDScalarRoundToInt(SkScalar x) {
     double xx = x;
     xx += 0.5;
     return (int)floor(xx);
 }
 
+/**
+  * Variant of SkScalarRoundToInt, identical to SkDScalarRoundToInt except when the input fraction
+  * is 0.5. In this case only, round the value down. This is used to round the top and left
+  * of a rectangle, and corresponds to the way the scan converter treats the top and left edges.
+  */
+static inline int SkDScalarRoundDownToInt(SkScalar x) {
+    double xx = x;
+    xx += 0.5;
+    double floorXX = floor(xx);
+    return (int)floorXX - (xx == floorXX);
+}
+
 static inline SkScalar SkScalarClampMax(SkScalar x, SkScalar max) {
     x = SkTMin(x, max);
     x = SkTMax<SkScalar>(x, 0);
     return x;
 }
 
 static inline SkScalar SkScalarPin(SkScalar x, SkScalar min, SkScalar max) {
     return SkTPin(x, min, max);
 }
 
@@ skipping 79 matching lines @@
     SkASSERT(n >= 0);
     for (int i = 0; i < n; ++i) {
         if (a[i] != b[i]) {
             return false;
         }
     }
     return true;
 }
 
 #endif