From 5e410b4a68d11a06c331139905171952ef535cf8 Mon Sep 17 00:00:00 2001
From: bsalomon <bsalomon@google.com>
Date: Thu, 28 Apr 2016 09:30:46 -0700
Subject: [PATCH] Detect empty (r)rects in GrShape. GOLD_TRYBOT_URL=
 https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1929643002

Review-Url: https://codereview.chromium.org/1929643002
---
 src/gpu/GrShape.h     | 42 ++++++++++++++++++++++++++++++++++--------
 tests/GrShapeTest.cpp | 15 ++++++++++++++-
 2 files changed, 48 insertions(+), 9 deletions(-)

diff --git a/src/gpu/GrShape.h b/src/gpu/GrShape.h
index 57b1d8a..0e863e2 100644
--- a/src/gpu/GrShape.h
+++ b/src/gpu/GrShape.h
@@ -33,16 +33,25 @@
  */
 class GrShape {
 public:
-    GrShape(const SkPath& path)
+    GrShape() : fType(Type::kEmpty) {}
+
+    explicit GrShape(const SkPath& path)
             : fType(Type::kPath)
             , fPath(&path) {
         this->attemptToReduceFromPath();
     }
 
-    GrShape() : fType(Type::kEmpty) {}
+    explicit GrShape(const SkRRect& rrect)
+        : fType(Type::kRRect)
+        , fRRect(rrect) {
+        this->attemptToReduceFromRRect();
+    }
 
-    explicit GrShape(const SkRRect& rrect) : fType(Type::kRRect), fRRect(rrect) {}
-    explicit GrShape(const SkRect& rect) : fType(Type::kRRect), fRRect(SkRRect::MakeRect(rect)) {}
+    explicit GrShape(const SkRect& rect)
+        : fType(Type::kRRect)
+        , fRRect(SkRRect::MakeRect(rect)) {
+        this->attemptToReduceFromRRect();
+    }
 
     GrShape(const SkPath& path, const GrStyle& style)
         : fType(Type::kPath)
@@ -54,12 +63,16 @@ public:
     GrShape(const SkRRect& rrect, const GrStyle& style)
         : fType(Type::kRRect)
         , fRRect(rrect)
-        , fStyle(style) {}
+        , fStyle(style) {
+        this->attemptToReduceFromRRect();
+    }
 
     GrShape(const SkRect& rect, const GrStyle& style)
         : fType(Type::kRRect)
         , fRRect(SkRRect::MakeRect(rect))
-        , fStyle(style) {}
+        , fStyle(style) {
+        this->attemptToReduceFromRRect();
+    }
 
     GrShape(const SkPath& path, const SkPaint& paint)
         : fType(Type::kPath)
@@ -71,12 +84,16 @@ public:
     GrShape(const SkRRect& rrect, const SkPaint& paint)
         : fType(Type::kRRect)
         , fRRect(rrect)
-        , fStyle(paint) {}
+        , fStyle(paint) {
+        this->attemptToReduceFromRRect();
+    }
 
     GrShape(const SkRect& rect, const SkPaint& paint)
         : fType(Type::kRRect)
         , fRRect(SkRRect::MakeRect(rect))
-        , fStyle(paint) {}
+        , fStyle(paint) {
+        this->attemptToReduceFromRRect();
+    }
 
     GrShape(const GrShape&);
     GrShape& operator=(const GrShape& that);
@@ -182,12 +199,21 @@ private:
         }
     }
 
+    void attemptToReduceFromRRect() {
+        SkASSERT(Type::kRRect == fType);
+        SkASSERT(!fInheritedKey.count());
+        if (fRRect.isEmpty()) {
+            fType = Type::kEmpty;
+        }
+    }
+
     static Type AttemptToReduceFromPathImpl(const SkPath& path, SkRRect* rrect,
                                             const SkPathEffect* pe, const SkStrokeRec& strokeRec) {
         if (path.isEmpty()) {
             return Type::kEmpty;
         }
         if (path.isRRect(rrect)) {
+            SkASSERT(!rrect->isEmpty());
             return Type::kRRect;
         }
         SkRect rect;
diff --git a/tests/GrShapeTest.cpp b/tests/GrShapeTest.cpp
index de08457..715afcb 100644
--- a/tests/GrShapeTest.cpp
+++ b/tests/GrShapeTest.cpp
@@ -550,9 +550,22 @@ void test_empty_shape(skiatest::Reporter* reporter) {
     dashAndStroke.setPathEffect(make_dash());
     dashAndStroke.setStrokeWidth(2.f);
     dashAndStroke.setStyle(SkPaint::kStroke_Style);
-    TestCase dashAndStrokeEmptyCase(emptyPath3, stroke);
+    TestCase dashAndStrokeEmptyCase(emptyPath3, dashAndStroke);
     dashAndStrokeEmptyCase.compare(reporter, fillEmptyCase,
                                    TestCase::kAllSame_ComparisonExpecation);
+
+    // A shape made from an empty rrect should behave the same as an empty path.
+    SkRRect emptyRRect = SkRRect::MakeRect(SkRect::MakeEmpty());
+    REPORTER_ASSERT(reporter, emptyRRect.getType() == SkRRect::kEmpty_Type);
+    TestCase dashAndStrokeEmptyRRectCase(emptyRRect, dashAndStroke);
+    dashAndStrokeEmptyRRectCase.compare(reporter, fillEmptyCase,
+                                        TestCase::kAllSame_ComparisonExpecation);
+
+    // Same for a rect.
+    SkRect emptyRect = SkRect::MakeEmpty();
+    TestCase dashAndStrokeEmptyRectCase(emptyRect, dashAndStroke);
+    dashAndStrokeEmptyRectCase.compare(reporter, fillEmptyCase,
+                                       TestCase::kAllSame_ComparisonExpecation);
 }
 
 DEF_TEST(GrShape, reporter) {
-- 
2.7.4