Account for square caps in SkStrokeRec::getInflationRadius

Bug: skia:
Change-Id: I85b359eaa89e804218af8b2442f6c3aefa9af99a
Reviewed-on: https://skia-review.googlesource.com/142271
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/src/core/SkStrokeRec.cpp b/src/core/SkStrokeRec.cpp
index 1b4007cd83..41a3c30e41 100644
--- a/src/core/SkStrokeRec.cpp
+++ b/src/core/SkStrokeRec.cpp
@@ -136,29 +136,36 @@ void SkStrokeRec::applyToPaint(SkPaint* paint) const {
 }
 
 static inline SkScalar get_inflation_bounds(SkPaint::Join join,
-                                            SkScalar strokeWidth,
-                                            SkScalar miterLimit) {
+                                            SkScalar miterLimit,
+                                            SkPaint::Cap cap,
+                                            SkScalar strokeWidth) {
     if (strokeWidth < 0) {  // fill
         return 0;
     } else if (0 == strokeWidth) {
+        // FIXME: We need a "matrixScale" parameter here in order to properly handle hairlines.
+        // Their with is determined in device space, unlike other strokes.
+        // http://skbug.com/8157
         return SK_Scalar1;
     }
-    // since we're stroked, outset the rect by the radius (and join type)
-    SkScalar radius = SkScalarHalf(strokeWidth);
+
+    // since we're stroked, outset the rect by the radius (and join type, caps)
+    SkScalar multiplier = SK_Scalar1;
     if (SkPaint::kMiter_Join == join) {
-        if (miterLimit > SK_Scalar1) {
-            radius *= miterLimit;
-        }
+        multiplier = SkTMax(multiplier, miterLimit);
+    }
+    if (SkPaint::kSquare_Cap == cap) {
+        multiplier = SkTMax(multiplier, SK_ScalarSqrt2);
     }
-    return radius;
+    return strokeWidth/2 * multiplier;
 }
 
 SkScalar SkStrokeRec::getInflationRadius() const {
-    return get_inflation_bounds((SkPaint::Join)fJoin, fWidth, fMiterLimit);
+    return get_inflation_bounds((SkPaint::Join)fJoin, fMiterLimit, (SkPaint::Cap)fCap, fWidth);
 }
 
 SkScalar SkStrokeRec::GetInflationRadius(const SkPaint& paint, SkPaint::Style style) {
     SkScalar width = SkPaint::kFill_Style == style ? -SK_Scalar1 : paint.getStrokeWidth();
-    return get_inflation_bounds(paint.getStrokeJoin(), width, paint.getStrokeMiter());
+    return get_inflation_bounds(paint.getStrokeJoin(), paint.getStrokeMiter(), paint.getStrokeCap(),
+                                width);
 
 }