Adding a PictureResolution option to SkPictureImageFilter

include/effects/SkPictureImageFilter.h

 /*
  * Copyright 2013 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 SkPictureImageFilter_DEFINED
 #define SkPictureImageFilter_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkPicture.h"
 
 class SK_API SkPictureImageFilter : public SkImageFilter {
 public:
     /**
      *  Refs the passed-in picture.
      */
     static SkPictureImageFilter* Create(const SkPicture* picture, int32_t uniqueID = 0) {
         return SkNEW_ARGS(SkPictureImageFilter, (picture, uniqueID));
     }
 
     /**
      *  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
      *  decoding, the decoder must be set on the SkReadBuffer parameter by calling
      *  SkReadBuffer::setBitmapDecoder() before calling this constructor.
      *  @param SkReadBuffer Serialized picture data.
      */
 #ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
     explicit SkPictureImageFilter(SkReadBuffer&);
 #endif
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const Context&,
                                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;
 };
 
 #endif