This patch implements generalized DAG connectivity for SkImageFilter. SkImageFilter maintains a list of inputs, which can be constructed either from a SkImageFilter** or zero or more SkImageFilter* arguments (varargs).

Existing filters which maintained their own filter connectivity were refactored to use the new constructors and flattening/unflattening code.  Modifying the remaining filters which are not yet DAG-friendly is left for future work; they are considered to have zero inputs for now.

Review URL: https://codereview.appspot.com/6443119

git-svn-id: http://skia.googlecode.com/svn/trunk@5891 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 29 insertions, 21 deletions

diff --git a/include/core/SkImageFilter.h b/include/core/SkImageFilter.h
index 92a5a58d28..f035bf9d37 100644
--- a/include/core/SkImageFilter.h
+++ b/include/core/SkImageFilter.h
@@ -109,8 +109,18 @@ public:
     virtual GrTexture* onFilterImageGPU(Proxy*, GrTexture* texture, const SkRect& rect);
 
 protected:
-    SkImageFilter() {}
-    explicit SkImageFilter(SkFlattenableReadBuffer& rb) : INHERITED(rb) {}
+    SkImageFilter(int numInputs, SkImageFilter** inputs);
+
+    // The ... represents numInputs SkImageFilter pointers, upon which this
+    // constructor will call SkSafeRef().  This is the same behaviour as
+    // the SkImageFilter(int, SkImageFilter**) constructor above.
+    explicit SkImageFilter(int numInputs, ...);
+
+    virtual ~SkImageFilter();
+
+    explicit SkImageFilter(SkFlattenableReadBuffer& rb);
+
+    virtual void flatten(SkFlattenableWriteBuffer& wb) const SK_OVERRIDE;
 
     // Default impl returns false
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
@@ -118,8 +128,17 @@ protected:
     // Default impl copies src into dst and returns true
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*);
 
+    int numInputs() const { return fNumInputs; }
+    SkImageFilter* getInput(int i) const { SkASSERT(i < fNumInputs); return fInputs[i]; }
+    // Return the result of processing the given input, or the source bitmap
+    // if we have no connected input at that index.
+    SkBitmap getInputResult(int index, Proxy*, const SkBitmap& src, const SkMatrix&,
+                            SkIPoint*);
+
 private:
     typedef SkFlattenable INHERITED;
+    int fNumInputs;
+    SkImageFilter** fInputs;
 };
 
 #endif
diff --git a/include/effects/SkBlendImageFilter.h b/include/effects/SkBlendImageFilter.h
index be1be68054..ff528ad2ad 100644
--- a/include/effects/SkBlendImageFilter.h
+++ b/include/effects/SkBlendImageFilter.h
@@ -43,9 +43,9 @@ protected:
 
 private:
     Mode fMode;
-    SkImageFilter* fBackground;
-    SkImageFilter* fForeground;
     typedef SkImageFilter INHERITED;
+    SkImageFilter* getBackgroundInput() { return getInput(0); }
+    SkImageFilter* getForegroundInput() { return getInput(1); }
 };
 
 #endif
diff --git a/include/effects/SkSingleInputImageFilter.h b/include/effects/SkSingleInputImageFilter.h
index b29eca039d..e7819c4f2f 100644
--- a/include/effects/SkSingleInputImageFilter.h
+++ b/include/effects/SkSingleInputImageFilter.h
@@ -35,10 +35,9 @@ protected:
     GrTexture* getInputResultAsTexture(Proxy* proxy, GrTexture* src, const SkRect& rect);
 #endif
 
-    SkImageFilter* input() const { return fInput; }
+    SkImageFilter* input() const { return getInput(0); }
 private:
     typedef SkImageFilter INHERITED;
-    SkImageFilter* fInput;
 };
 
 #endif
diff --git a/include/effects/SkTestImageFilters.h b/include/effects/SkTestImageFilters.h
index 4c96776a00..c31a439ddb 100755
--- a/include/effects/SkTestImageFilters.h
+++ b/include/effects/SkTestImageFilters.h
@@ -7,7 +7,7 @@
 
 class SkOffsetImageFilter : public SkImageFilter {
 public:
-    SkOffsetImageFilter(SkScalar dx, SkScalar dy) {
+    SkOffsetImageFilter(SkScalar dx, SkScalar dy) : INHERITED(0) {
         fOffset.set(dx, dy);
     }
 
@@ -29,28 +29,19 @@ private:
 
 class SkComposeImageFilter : public SkImageFilter {
 public:
-    SkComposeImageFilter(SkImageFilter* outer, SkImageFilter* inner) {
-        fOuter = outer;
-        fInner = inner;
-        SkSafeRef(outer);
-        SkSafeRef(inner);
-    }
+    SkComposeImageFilter(SkImageFilter* outer, SkImageFilter* inner) : INHERITED(2, outer, inner) {}
     virtual ~SkComposeImageFilter();
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkComposeImageFilter)
 
 protected:
     SkComposeImageFilter(SkFlattenableReadBuffer& buffer);
-    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
 
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* loc) SK_OVERRIDE;
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) SK_OVERRIDE;
 
 private:
-    SkImageFilter*  fOuter;
-    SkImageFilter*  fInner;
-
     typedef SkImageFilter INHERITED;
 };
 
@@ -75,7 +66,6 @@ protected:
     virtual bool onFilterBounds(const SkIRect&, const SkMatrix&, SkIRect*) SK_OVERRIDE;
 
 private:
-    SkImageFilter**     fFilters;
     uint8_t*            fModes; // SkXfermode::Mode
     int                 fCount;
 
@@ -83,8 +73,8 @@ private:
     // of the filters and modes (unless fCount is so large we can't fit).
     intptr_t    fStorage[16];
 
-    void initAlloc(int count, bool hasModes);
-    void init(SkImageFilter* const [], int count, const SkXfermode::Mode []);
+    void initAllocModes();
+    void initModes(const SkXfermode::Mode []);
 
     typedef SkImageFilter INHERITED;
 };
@@ -94,7 +84,7 @@ private:
 // Fun mode that scales down (only) and then scales back up to look pixelated
 class SkDownSampleImageFilter : public SkImageFilter {
 public:
-    SkDownSampleImageFilter(SkScalar scale) : fScale(scale) {}
+    SkDownSampleImageFilter(SkScalar scale) : INHERITED(0), fScale(scale) {}
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDownSampleImageFilter)