Make ClipStack honor save flags

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"
@@ skipping 702 matching lines @@
 
 int SkCanvas::internalSave(SaveFlags flags) {
     int saveCount = this->getSaveCount(); // record this before the actual save
 
     MCRec* newTop = (MCRec*)fMCStack.push_back();
     new (newTop) MCRec(fMCRec, flags);    // balanced in restore()
 
     newTop->fNext = fMCRec;
     fMCRec = newTop;
 
-    fClipStack.save();
-    SkASSERT(fClipStack.getSaveCount() == this->getSaveCount() - 1);
+    if (SkCanvas::kClip_SaveFlag & flags) {
+        fClipStack.save();
+    }
 
     return saveCount;
 }
 
 int SkCanvas::save(SaveFlags flags) {
     // call shared impl
     return this->internalSave(flags);
 }
 
 #define C32MASK (1 << SkBitmap::kARGB_8888_Config)
@@ skipping 154 matching lines @@
         this->internalRestore();
     }
 }
 
 void SkCanvas::internalRestore() {
     SkASSERT(fMCStack.count() != 0);
 
     fDeviceCMDirty = true;
     fLocalBoundsCompareTypeDirty = true;
 
-    fClipStack.restore();
+    SkRasterClip* oldRasterClip = fMCRec->fRasterClip;
+
     // 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();
 
+    if (NULL == fMCRec || fMCRec->fRasterClip != oldRasterClip) {

[bsalomon, 2013/08/14 15:49:13]

eek.. don't we want to stop computing raster clip for the GPU?

Is the problem than the MCRec doesn't remember the flags? Can it?

[robertphillips, 2013/08/14 16:16:58]

That is the problem.

[reed1, 2013/08/14 16:51:31]

If we pass the flags (or a subset of them) to clipstack.save(), would that make
the restore easier? (at least for the caller)

[robertphillips, 2013/08/14 17:00:16]

So a ClipStack frame would store the number of restores to ignore before really
restoring itself?

[bsalomon, 2013/08/14 18:23:28]

yeah I don't see why clip stack should see saves that don't affect it. It seems
legit to have the caller (SkCanvas) examine the flags to decide whether to
save/restore the clipstack.

+        fClipStack.restore();
+    }
+
     /*  Time to draw the layer's offscreen. We can't call the public drawSprite,
         since if we're being recorded, we don't want to record this (the
         recorder will have already recorded the restore).
     */
     if (NULL != layer) {
         if (layer->fNext) {
             const SkIPoint& origin = layer->fDevice->getOrigin();
             this->internalDrawDevice(layer->fDevice, origin.x(), origin.y(),
                                      layer->fPaint);
             // reset this, since internalDrawDevice will have set it to true
@@ skipping 1293 matching lines @@
     return *paint;
 }
 
 const SkRegion& SkCanvas::LayerIter::clip() const { return fImpl->getClip(); }
 int SkCanvas::LayerIter::x() const { return fImpl->getX(); }
 int SkCanvas::LayerIter::y() const { return fImpl->getY(); }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkCanvas::ClipVisitor::~ClipVisitor() { }