Optimized implementation of quickReject()

include/core/SkCanvas.h

 /*
  * Copyright 2006 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.
  */
 
 #ifndef SkCanvas_DEFINED
 #define SkCanvas_DEFINED
 
@@ skipping 1587 matching lines @@
      *  paint (or default if null) would overwrite the entire root device of the canvas
      *  (i.e. the canvas' surface if it had one).
      */
     bool wouldOverwriteEntireSurface(const SkRect*, const SkPaint*, ShaderOverrideOpacity) const;
 
     /**
      *  Returns true if the paint's imagefilter can be invoked directly, without needed a layer.
      */
     bool canDrawBitmapAsSprite(SkScalar x, SkScalar y, int w, int h, const SkPaint&);
 
-    /*  These maintain a cache of the clip bounds in local coordinates,
-        (converted to 2s-compliment if floats are slow).
+
+    /**
+     *  Keep track of the device clip bounds and if the matrix is scale-translate.  This allows
+     *  us to do a fast quick reject in the common case.
      */
-    mutable SkRect fCachedLocalClipBounds;
-    mutable bool   fCachedLocalClipBoundsDirty;
+    bool   fConservativeIsScaleTranslate;
+    SkRect fDeviceClipBounds;
+
     bool fAllowSoftClip;
     bool fAllowSimplifyClip;
     const bool fConservativeRasterClip;
 
-    const SkRect& getLocalClipBounds() const {
-        if (fCachedLocalClipBoundsDirty) {
-            if (!this->getClipBounds(&fCachedLocalClipBounds)) {
-                fCachedLocalClipBounds.setEmpty();
-            }
-            fCachedLocalClipBoundsDirty = false;
-        }
-        return fCachedLocalClipBounds;
-    }
-
     class AutoValidateClip : ::SkNoncopyable {
     public:
         explicit AutoValidateClip(SkCanvas* canvas) : fCanvas(canvas) {
             fCanvas->validateClip();
         }
         ~AutoValidateClip() { fCanvas->validateClip(); }
 
     private:
         const SkCanvas* fCanvas;
     };
@@ skipping 46 matching lines @@
 
 class SkCanvasClipVisitor {
 public:
     virtual ~SkCanvasClipVisitor();
     virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0;
     virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0;
 };
 
 #endif