add isRect() check to AAClip, to detect if a soft-clip is really just an irect

src/core/SkAAClip.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkAAClip_DEFINED
 #define SkAAClip_DEFINED
@@ skipping 11 matching lines @@
     friend bool operator==(const SkAAClip&, const SkAAClip&);
     friend bool operator!=(const SkAAClip& a, const SkAAClip& b) {
         return !(a == b);
     }
 
     void swap(SkAAClip&);
 
     bool isEmpty() const { return NULL == fRunHead; }
     const SkIRect& getBounds() const { return fBounds; }
 
+    // Returns true iff the clip is not empty, and is just a hard-edged rect (no partial alpha).
+    // If true, getBounds() can be used in place of this clip.
+    bool isRect() const;
+
     bool setEmpty();
     bool setRect(const SkIRect&);
     bool setRect(const SkRect&, bool doAA = true);
     bool setPath(const SkPath&, const SkRegion* clip = NULL, bool doAA = true);
     bool setRegion(const SkRegion&);
     bool set(const SkAAClip&);
 
     bool op(const SkAAClip&, const SkAAClip&, SkRegion::Op);
 
     // Helpers for op()
@@ skipping 81 matching lines @@
     enum {
         kSize = 32 * 32
     };
     SkAutoSMalloc<kSize> fGrayMaskScratch;  // used for blitMask
     void* fScanlineScratch;  // enough for a mask at 32bit, or runs+aa
 
     void ensureRunsAndAA();
 };
 
 #endif