Adding a PictureResolution option to SkPictureImageFilter

include/effects/SkPictureImageFilter.h

Index: include/effects/SkPictureImageFilter.h
diff --git a/include/effects/SkPictureImageFilter.h b/include/effects/SkPictureImageFilter.h
index ed5c63c18a51007b476c1bc17b55d101d5930943..f9d33f0bf8a29323d03c45912b08685566e4ea58 100644
--- a/include/effects/SkPictureImageFilter.h
+++ b/include/effects/SkPictureImageFilter.h
@@ -24,15 +24,37 @@ public:
      *  Refs the passed-in picture. cropRect can be used to crop or expand the destination rect when
      *  the picture is drawn. (No scaling is implied by the dest rect; only the CTM is applied.)
      */
-    static SkPictureImageFilter* Create(const SkPicture* picture, const SkRect& cropRect, uint32_t uniqueID = 0) {
-        return SkNEW_ARGS(SkPictureImageFilter, (picture, cropRect, uniqueID));
+    static SkPictureImageFilter* Create(const SkPicture* picture, const SkRect& cropRect,
+                                        uint32_t uniqueID = 0) {
+        return SkNEW_ARGS(SkPictureImageFilter, (picture, cropRect, uniqueID,
+                                                 kDeviceSpace_PictureResolution));
+    }
+
+    /**
+     *  Refs the passed-in picture. The picture is rasterized at a resolution that matches the
+     *  local coordinate space. If the picture needs to be resampled for drawing it into the
+     *  destination canvas, bilinear filtering will be used. cropRect can be used to crop or
+     *  expand the destination rect when the picture is drawn. (No scaling is implied by the
+     *  dest rect; only the CTM is applied.)
+     */
+    static SkPictureImageFilter* CreateForLocalSpace(const SkPicture* picture,
+                                                     const SkRect& cropRect,
+                                                     uint32_t uniqueID = 0) {
+        return SkNEW_ARGS(SkPictureImageFilter, (picture, cropRect, uniqueID,
+                                                 kLocalSpace_PictureResolution));
     }
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureImageFilter)
 
 protected:
+    enum PictureResolution {
+        kDeviceSpace_PictureResolution,
+        kLocalSpace_PictureResolution

[Stephen White, 2014/12/01 16:02:12]

Is "local space" the usual Skia nomenclature for non-device space?

[Justin Novosad, 2014/12/02 16:33:36]

It is standard nomenclature in computer graphics.
Local space = the space that is current. In the scene graph metaphor, it is the
space of the current node during a traversal, as opposed to "World Space" which
is the space of the root node (post-transform). 

BTW, in the case of SkCanvas (and many other 2D APIs), there is no distinciton
between world transforms and projections (a.k.a camera tranforms). Therefore
there is no practical distinction between "world space" and "device space" in
skia, at least as far as the API is concerned. 

+    };
+
     explicit SkPictureImageFilter(const SkPicture* picture, uint32_t uniqueID);
-    SkPictureImageFilter(const SkPicture* picture, const SkRect& cropRect, uint32_t uniqueID);
+    SkPictureImageFilter(const SkPicture* picture, const SkRect& cropRect, uint32_t uniqueID,
+                         PictureResolution);
     virtual ~SkPictureImageFilter();
     /*  Constructs an SkPictureImageFilter object from an SkReadBuffer.
      *  Note: If the SkPictureImageFilter object construction requires bitmap
@@ -48,8 +70,16 @@ protected:
                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 
 private:
-    const SkPicture* fPicture;
-    SkRect           fCropRect;
+
+
+    void drawPictureAtNativeResolution(Proxy*, SkBaseDevice*, const SkIRect& deviceBounds,

[Stephen White, 2014/12/01 16:02:12]

We have native, device, local and original. Is there a better/simpler naming we
could use?

[Justin Novosad, 2014/12/02 16:33:36]

Acknowledged.

+                                       const Context&) const;
+    void drawPictureAtOriginalResolution(Proxy*, SkBaseDevice*, const SkIRect& deviceBounds,
+                                       const Context&) const;
+
+    const SkPicture*      fPicture;
+    SkRect                fCropRect;
+    PictureResolution     fPictureResolution;
     typedef SkImageFilter INHERITED;
 };