Revert[2] of "quick-accept clipRect calls"

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 "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
@@ skipping 1490 matching lines @@
         if (this->quickReject(rect)) {
             fDeviceCMDirty = true;
             fCachedLocalClipBoundsDirty = true;
 
             fClipStack->clipEmpty();
             return fMCRec->fRasterClip.setEmpty();
         }
     }
 #endif
 
+    if (!fAllowSoftClip) {
+        edgeStyle = kHard_ClipEdgeStyle;
+    }
+
+    const bool rectStaysRect = fMCRec->fMatrix.rectStaysRect();
+    SkRect devR;
+    if (rectStaysRect) {
+        fMCRec->fMatrix.mapRect(&devR, rect);
+    }
+
+    // Check if we can quick-accept the clip call (and do nothing)
+    //
+    // TODO: investigate if a (conservative) version of this could be done in ::clipRect,
+    //       so that subclasses (like PictureRecording) didn't see unnecessary clips, which in turn
+    //       might allow lazy save/restores to eliminate entire save/restore blocks.
+    //
+    if (SkRegion::kIntersect_Op == op &&
+        kHard_ClipEdgeStyle == edgeStyle
+        && rectStaysRect)
+    {
+        if (devR.round().contains(fMCRec->fRasterClip.getBounds())) {
+#if 0
+            SkDebugf("------- ignored clipRect [%g %g %g %g]\n",
+                     rect.left(), rect.top(), rect.right(), rect.bottom());
+#endif
+            return;
+        }
+    }
+
     AutoValidateClip avc(this);
 
     fDeviceCMDirty = true;
     fCachedLocalClipBoundsDirty = true;
-    if (!fAllowSoftClip) {
-        edgeStyle = kHard_ClipEdgeStyle;
-    }
 
-    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);
-        fMCRec->fRasterClip.op(r, this->getBaseLayerSize(), op, kSoft_ClipEdgeStyle == edgeStyle);
+    if (rectStaysRect) {
+        const bool isAA = kSoft_ClipEdgeStyle == edgeStyle;
+        fClipStack->clipDevRect(devR, op, isAA);
+        fMCRec->fRasterClip.op(devR, this->getBaseLayerSize(), op, isAA);
     } 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 1392 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }