Add refcnting to SkClipStack on SkCanvas

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 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.
  */
 
 #include "SkCanvas.h"
 #include "SkCanvasDrawable.h"
 #include "SkCanvasPriv.h"
@@ skipping 214 matching lines @@
     }
 };
 
 class SkDrawIter : public SkDraw {
 public:
     SkDrawIter(SkCanvas* canvas, bool skipEmptyClips = true) {
         canvas = canvas->canvasForDrawIter();
         fCanvas = canvas;
         canvas->updateDeviceCMCache();
 
-        fClipStack = &canvas->fClipStack;
+        fClipStack = canvas->fClipStack.get();
         fCurrLayer = canvas->fMCRec->fTopLayer;
         fSkipEmptyClips = skipEmptyClips;
     }
 
     bool next() {
         // skip over recs with empty clips
         if (fSkipEmptyClips) {
             while (fCurrLayer && fCurrLayer->fClip.isEmpty()) {
                 fCurrLayer = fCurrLayer->fNext;
             }
@@ skipping 189 matching lines @@
     fMetaData = NULL;
 
     fMCRec = (MCRec*)fMCStack.push_back();
     new (fMCRec) MCRec(fConservativeRasterClip);
 
     fMCRec->fLayer = SkNEW_ARGS(DeviceCM, (NULL, 0, 0, NULL, NULL, fConservativeRasterClip));
     fMCRec->fTopLayer = fMCRec->fLayer;
 
     fSurfaceBase = NULL;
 
+    fClipStack.reset(SkNEW(SkClipStack));
+
     if (device) {
         device->initForRootLayer(fProps.pixelGeometry());
         if (device->forceConservativeRasterClip()) {
             fConservativeRasterClip = true;
         }
         device->onAttachToCanvas(this);
         fMCRec->fLayer->fDevice = SkRef(device);
         fMCRec->fRasterClip.setRect(device->getGlobalBounds());
     }
     return device;
@@ skipping 326 matching lines @@
 
 //////////////////////////////////////////////////////////////////////////////
 
 void SkCanvas::updateDeviceCMCache() {
     if (fDeviceCMDirty) {
         const SkMatrix& totalMatrix = this->getTotalMatrix();
         const SkRasterClip& totalClip = fMCRec->fRasterClip;
         DeviceCM*       layer = fMCRec->fTopLayer;
 
         if (NULL == layer->fNext) {   // only one layer
-            layer->updateMC(totalMatrix, totalClip, fClipStack, NULL);
+            layer->updateMC(totalMatrix, totalClip, *fClipStack, NULL);
         } else {
             SkRasterClip clip(totalClip);
             do {
-                layer->updateMC(totalMatrix, clip, fClipStack, &clip);
+                layer->updateMC(totalMatrix, clip, *fClipStack, &clip);
             } while ((layer = layer->fNext) != NULL);
         }
         fDeviceCMDirty = false;
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkCanvas::checkForDeferredSave() {
     if (fMCRec->fDeferredSaveCount > 0) {
@@ skipping 56 matching lines @@
     for (int i = 0; i < n; ++i) {
         this->restore();
     }
 }
 
 void SkCanvas::internalSave() {
     MCRec* newTop = (MCRec*)fMCStack.push_back();
     new (newTop) MCRec(*fMCRec);    // balanced in restore()
     fMCRec = newTop;
 
-    fClipStack.save();
+    fClipStack->save();
 }
 
 static bool bounds_affects_clip(SkCanvas::SaveFlags flags) {
 #ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     return (flags & SkCanvas::kClipToLayer_SaveFlag) != 0;
 #else
     return true;
 #endif
 }
 
@@ skipping 21 matching lines @@
             if (bounds_affects_clip(flags)) {
                 fMCRec->fRasterClip.setEmpty();
             }
             return false;
         }
     } else {    // no user bounds, so just use the clip
         ir = clipBounds;
     }
 
     if (bounds_affects_clip(flags)) {
-        fClipStack.clipDevRect(ir, op);
+        fClipStack->clipDevRect(ir, op);
         // early exit if the clip is now empty
         if (!fMCRec->fRasterClip.op(ir, op)) {
             return false;
         }
     }
 
     if (intersection) {
         *intersection = ir;
     }
     return true;
@@ skipping 101 matching lines @@
         return this->saveLayer(bounds, &tmpPaint, flags);
     }
 }
 
 void SkCanvas::internalRestore() {
     SkASSERT(fMCStack.count() != 0);
 
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
 
-    fClipStack.restore();
+    fClipStack->restore();
 
     // reserve our layer (if any)
     DeviceCM* layer = fMCRec->fLayer;   // may be null
     // now detach it from fMCRec so we can pop(). Gets freed after its drawn
     fMCRec->fLayer = NULL;
 
     // now do the normal restore()
     fMCRec->~MCRec();       // balanced in save()
     fMCStack.pop_back();
     fMCRec = (MCRec*)fMCStack.back();
@@ skipping 284 matching lines @@
     }
 
     if (fMCRec->fMatrix.rectStaysRect()) {
         // for these simpler matrices, we can stay a rect even after applying
         // the matrix. This means we don't have to a) make a path, and b) tell
         // the region code to scan-convert the path, only to discover that it
         // is really just a rect.
         SkRect      r;
 
         fMCRec->fMatrix.mapRect(&r, rect);
-        fClipStack.clipDevRect(r, op, kSoft_ClipEdgeStyle == edgeStyle);
+        fClipStack->clipDevRect(r, op, kSoft_ClipEdgeStyle == edgeStyle);
         fMCRec->fRasterClip.op(r, this->getBaseLayerSize(), op, kSoft_ClipEdgeStyle == edgeStyle);
     } else {
         // since we're rotated or some such thing, we convert the rect to a path
         // and clip against that, since it can handle any matrix. However, to
         // avoid recursion in the case where we are subclassed (e.g. Pictures)
         // we explicitly call "our" version of clipPath.
         SkPath  path;
 
         path.addRect(rect);
         this->SkCanvas::onClipPath(path, op, edgeStyle);
@@ skipping 19 matching lines @@
     SkRRect transformedRRect;
     if (rrect.transform(fMCRec->fMatrix, &transformedRRect)) {
         AutoValidateClip avc(this);
 
         fDeviceCMDirty = true;
         fCachedLocalClipBoundsDirty = true;
         if (!fAllowSoftClip) {
             edgeStyle = kHard_ClipEdgeStyle;
         }
 
-        fClipStack.clipDevRRect(transformedRRect, op, kSoft_ClipEdgeStyle == edgeStyle);
+        fClipStack->clipDevRRect(transformedRRect, op, kSoft_ClipEdgeStyle == edgeStyle);
 
         SkPath devPath;
         devPath.addRRect(transformedRRect);
 
         rasterclip_path(&fMCRec->fRasterClip, this, devPath, op, kSoft_ClipEdgeStyle == edgeStyle);
         return;
     }
 
     SkPath path;
     path.addRRect(rrect);
@@ skipping 44 matching lines @@
     // made us empty. Note this can also happen if we contained NaN
     // values. computing the bounds detects this, and will set our
     // bounds to empty if that is the case. (see SkRect::set(pts, count))
     if (devPath.getBounds().isEmpty()) {
         // resetting the path will remove any NaN or other wanky values
         // that might upset our scan converter.
         devPath.reset();
     }
 
     // if we called path.swap() we could avoid a deep copy of this path
-    fClipStack.clipDevPath(devPath, op, kSoft_ClipEdgeStyle == edgeStyle);
+    fClipStack->clipDevPath(devPath, op, kSoft_ClipEdgeStyle == edgeStyle);
 
     if (fAllowSimplifyClip) {
         bool clipIsAA = getClipStack()->asPath(&devPath);
         if (clipIsAA) {
             edgeStyle = kSoft_ClipEdgeStyle;
         }
 
         op = SkRegion::kReplace_Op;
     }
 
     rasterclip_path(&fMCRec->fRasterClip, this, devPath, op, edgeStyle);
 }
 
 void SkCanvas::clipRegion(const SkRegion& rgn, SkRegion::Op op) {
     this->checkForDeferredSave();
     this->onClipRegion(rgn, op);
 }
 
 void SkCanvas::onClipRegion(const SkRegion& rgn, SkRegion::Op op) {
     AutoValidateClip avc(this);
 
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
 
     // todo: signal fClipStack that we have a region, and therefore (I guess)
     // we have to ignore it, and use the region directly?
-    fClipStack.clipDevRect(rgn.getBounds(), op);
+    fClipStack->clipDevRect(rgn.getBounds(), op);
 
     fMCRec->fRasterClip.op(rgn, op);
 }
 
 #ifdef SK_DEBUG
 void SkCanvas::validateClip() const {
     // construct clipRgn from the clipstack
     const SkBaseDevice* device = this->getDevice();
     if (!device) {
         SkASSERT(this->isClipEmpty());
         return;
     }
 
     SkIRect ir;
     ir.set(0, 0, device->width(), device->height());
     SkRasterClip tmpClip(ir, fConservativeRasterClip);
 
-    SkClipStack::B2TIter                iter(fClipStack);
+    SkClipStack::B2TIter                iter(*fClipStack);
     const SkClipStack::Element* element;
     while ((element = iter.next()) != NULL) {
         switch (element->getType()) {
             case SkClipStack::Element::kRect_Type:
                 element->getRect().round(&ir);
                 tmpClip.op(ir, element->getOp());
                 break;
             case SkClipStack::Element::kEmpty_Type:
                 tmpClip.setEmpty();
                 break;
             default: {
                 SkPath path;
                 element->asPath(&path);
                 rasterclip_path(&tmpClip, this, path, element->getOp(), element->isAA());
                 break;
             }
         }
     }
 }
 #endif
 
 void SkCanvas::replayClips(ClipVisitor* visitor) const {
-    SkClipStack::B2TIter                iter(fClipStack);
+    SkClipStack::B2TIter                iter(*fClipStack);
     const SkClipStack::Element*         element;
 
     while ((element = iter.next()) != NULL) {
         element->replay(visitor);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkCanvas::isClipEmpty() const {
@@ skipping 1032 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }