Factory methods for heap-allocated SkImageFilter objects.

include/effects/SkDisplacementMapEffect.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkDisplacementMapEffect_DEFINED
 #define SkDisplacementMapEffect_DEFINED
 
 #include "SkImageFilter.h"
 #include "SkBitmap.h"
 
 class SK_API SkDisplacementMapEffect : public SkImageFilter {
 public:
     enum ChannelSelectorType {
         kUnknown_ChannelSelectorType,
         kR_ChannelSelectorType,
         kG_ChannelSelectorType,
         kB_ChannelSelectorType,
         kA_ChannelSelectorType,
         kKeyBits = 3 // Max value is 4, so 3 bits are required at most

[reed1, 2014/03/04 16:56:42]

I know its not part of this CL, but why is this enum value here, since it is a
dup of kB_ChannelSelectorType?
Does it have to be public?

[Stephen White, 2014/03/04 18:18:00]

It's not a dupe of that value; it's the number of bits required to represent the
enum. I agree that it shouldn't be public; should probably just be in the .cpp.

[Dominik Grewe, 2014/03/07 16:43:38]

I've replaced it with a #define inside the .cpp file.

     };
 
-    SkDisplacementMapEffect(ChannelSelectorType xChannelSelector,
-                            ChannelSelectorType yChannelSelector,
-                            SkScalar scale, SkImageFilter* displacement,
-                            SkImageFilter* color = NULL,
-                            const CropRect* cropRect = NULL);
+    ~SkDisplacementMapEffect();
 
-    ~SkDisplacementMapEffect();
+    static SkDisplacementMapEffect* Create(ChannelSelectorType xChannelSelector,
+                                           ChannelSelectorType yChannelSelector,
+                                           SkScalar scale, SkImageFilter* displacement,
+                                           SkImageFilter* color = NULL,
+                                           const CropRect* cropRect = NULL) {
+        return SkNEW_ARGS(SkDisplacementMapEffect, (xChannelSelector, yChannelSelector, scale,
+                                                    displacement, color, cropRect));
+    }
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDisplacementMapEffect)
 
     virtual bool onFilterImage(Proxy* proxy,
                                const SkBitmap& src,
                                const SkMatrix& ctm,
                                SkBitmap* dst,
                                SkIPoint* offset) const SK_OVERRIDE;
     virtual void computeFastBounds(const SkRect& src, SkRect* dst) const SK_OVERRIDE;
 
     virtual bool onFilterBounds(const SkIRect& src, const SkMatrix&,
                                 SkIRect* dst) const SK_OVERRIDE;
 
 #if SK_SUPPORT_GPU
     virtual bool canFilterImageGPU() const SK_OVERRIDE { return true; }
     virtual bool filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
                                 SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 #endif
 
 protected:
     explicit SkDisplacementMapEffect(SkReadBuffer& buffer);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
 
+#ifdef SK_SUPPORT_LEGACY_PUBLICEFFECTCONSTRUCTORS
+public:
+#endif
+    SkDisplacementMapEffect(ChannelSelectorType xChannelSelector,
+                            ChannelSelectorType yChannelSelector,
+                            SkScalar scale, SkImageFilter* displacement,
+                            SkImageFilter* color = NULL,
+                            const CropRect* cropRect = NULL);
+
 private:
     ChannelSelectorType fXChannelSelector;
     ChannelSelectorType fYChannelSelector;
     SkScalar fScale;
     typedef SkImageFilter INHERITED;
     const SkImageFilter* getDisplacementInput() const { return getInput(0); }
     const SkImageFilter* getColorInput() const { return getInput(1); }
 };
 
 #endif