Optimized implementation of quickReject()

include/core/SkCanvas.h

Index: include/core/SkCanvas.h
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index c3f8599db4d31be8c0b708c97bfce64efe24e334..59c5a5622851acd05948afab0b3cb057e9502dd0 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -566,29 +566,7 @@ public:
         @return true if the horizontal band is completely clipped out (i.e. does
                      not intersect the current clip)
     */
-    bool quickRejectY(SkScalar top, SkScalar bottom) const {
-        SkASSERT(top <= bottom);
-
-#ifndef SK_WILL_NEVER_DRAW_PERSPECTIVE_TEXT
-        // TODO: add a hasPerspective method similar to getLocalClipBounds. This
-        // would cache the SkMatrix::hasPerspective result. Alternatively, have
-        // the MC stack just set a hasPerspective boolean as it is updated.
-        if (this->getTotalMatrix().hasPerspective()) {
-            // TODO: consider implementing some half-plane test between the
-            // two Y planes and the device-bounds (i.e., project the top and
-            // bottom Y planes and then determine if the clip bounds is completely
-            // outside either one).
-            return false;
-        }
-#endif
-
-        const SkRect& clipR = this->getLocalClipBounds();
-        // In the case where the clip is empty and we are provided with a
-        // negative top and positive bottom parameter then this test will return
-        // false even though it will be clipped. We have chosen to exclude that
-        // check as it is rare and would result double the comparisons.
-        return top >= clipR.fBottom || bottom <= clipR.fTop;
-    }
+    bool quickRejectY(SkScalar top, SkScalar bottom) const;
 
     /** Return the bounds of the current clip (in local coordinates) in the
         bounds parameter, and return true if it is non-empty. This can be useful
@@ -1639,25 +1617,18 @@ private:
      */
     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   fIsScaleTranslate;
+    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) {