Enable rect clips

include/gpu/GrClip.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrClip_DEFINED
 #define GrClip_DEFINED
 
 #include "SkClipStack.h"
 #include "GrSurface.h"
 
 struct SkIRect;
 
 /**
  * GrClip encapsulates the information required to construct the clip
  * masks. 'A GrClip is either wide open, just an IRect, just a Rect(TODO), or a full clipstack.
  * If the clip is a clipstack than the origin is used to translate the stack with
  * respect to device coordinates. This allows us to use a clip stack that is
  * specified for a root device with a layer device that is restricted to a subset
  * of the original canvas. For other clip types the origin will always be (0,0).
  *
  * NOTE: GrClip *must* point to a const clipstack
  */
 class GrClip : SkNoncopyable {
 public:
-    GrClip() : fClipType(kWideOpen_ClipType) {}
+    GrClip() : fClipType(kWideOpen_ClipType) {
+        fOrigin.setZero();
+    }
     GrClip(const SkIRect& rect) : fClipType(kIRect_ClipType) {
+        fOrigin.setZero();
         fClip.fIRect = rect;
     }
     ~GrClip() { this->reset(); }
 
     const GrClip& operator=(const GrClip& other) {
         this->reset();
         fClipType = other.fClipType;
         switch (other.fClipType) {
             default:
                 SkFAIL("Incomplete Switch\n");
             case kWideOpen_ClipType:
+                fOrigin.setZero();
                 break;
             case kClipStack_ClipType:
-                fClip.fClipStack.fStack = SkRef(other.clipStack());
-                fClip.fClipStack.fOrigin = other.origin();
+                fClip.fStack = SkRef(other.clipStack());
+                fOrigin = other.origin();
                 break;
             case kIRect_ClipType:
                 fClip.fIRect = other.irect();
+                fOrigin.setZero();
                 break;
         }
         return *this;
     }
 
     bool operator==(const GrClip& other) const {
         if (this->clipType() != other.clipType()) {
             return false;
         }
 
@@ skipping 19 matching lines @@
                 break;
         }
     }
 
     bool operator!=(const GrClip& other) const {
         return !(*this == other);
     }
 
     const SkClipStack* clipStack() const {
         SkASSERT(kClipStack_ClipType == fClipType);
-        return fClip.fClipStack.fStack;
+        return fClip.fStack;
     }
 
     void setClipStack(const SkClipStack* clipStack, const SkIPoint* origin = NULL) {
         if (clipStack->isWideOpen()) {
             fClipType = kWideOpen_ClipType;
+            fOrigin.setZero();
         } else {
             fClipType = kClipStack_ClipType;
-            fClip.fClipStack.fStack = SkRef(clipStack);
+            fClip.fStack = SkRef(clipStack);
             if (origin) {
-                fClip.fClipStack.fOrigin = *origin;
+                fOrigin = *origin;
             } else {
-                fClip.fClipStack.fOrigin.setZero();
+                fOrigin.setZero();
             }
         }
     }
 
     const SkIRect& irect() const {
         SkASSERT(kIRect_ClipType == fClipType);
         return fClip.fIRect;
     }
 
     void reset() {
         if (kClipStack_ClipType == fClipType) {
-            fClip.fClipStack.fStack->unref();
-            fClip.fClipStack.fStack = NULL;
+            fClip.fStack->unref();
+            fClip.fStack = NULL;
         }
         fClipType = kWideOpen_ClipType;
+        fOrigin.setZero();
     }
 
+    // We support this for all cliptypes to simplify the logic a bit in clip mask manager.
+    // non clipstack clip types MUST have a (0,0) origin
     const SkIPoint& origin() const {
-        SkASSERT(kClipStack_ClipType == fClipType);
-        return fClip.fClipStack.fOrigin;
+        SkASSERT(fClipType == kClipStack_ClipType || (fOrigin.fX == 0 && fOrigin.fY == 0));
+        return fOrigin;
     }
 
     bool isWideOpen(const SkRect& rect) const {
         return (kWideOpen_ClipType == fClipType) ||
                (kClipStack_ClipType == fClipType && this->clipStack()->isWideOpen()) ||
                (kIRect_ClipType == fClipType && this->irect().contains(rect));
     }
 
     bool isWideOpen(const SkIRect& rect) const {
         return (kWideOpen_ClipType == fClipType) ||
@@ skipping 22 matching lines @@
     enum ClipType {
         kClipStack_ClipType,
         kWideOpen_ClipType,
         kIRect_ClipType,
     };
 
     ClipType clipType() const { return fClipType; }
 
 private:
     union Clip {
-        struct ClipStack {
-            const SkClipStack* fStack;
-            SkIPoint fOrigin;
-        } fClipStack;
+        const SkClipStack* fStack;
         SkIRect fIRect;
     } fClip;
 
+    SkIPoint fOrigin;
     ClipType fClipType;
 };
 
 #endif