1 files changed, 29 insertions, 0 deletions
diff --git a/src/codec/SkSampler.h b/src/codec/SkSampler.h
index 73e11c986e..af6f48598c 100644
--- a/src/codec/SkSampler.h
+++ b/src/codec/SkSampler.h
@@ -21,6 +21,30 @@ public:
     }
 
     /**
+     *  Update the sampler to sample every sampleY'th row.
+     */
+    void setSampleY(int sampleY) {
+        fSampleY = sampleY;
+    }
+
+    /**
+     *  Retrieve the value set for sampleY.
+     */
+    int sampleY() const {
+        return fSampleY;
+    }
+
+    /**
+     *  Based on fSampleY, return whether this row belongs in the output.
+     *
+     *  @param row Row of the image, starting with the first row used in the
+     *      output.
+     */
+    bool rowNeeded(int row) const {
+        return row % fSampleY == 0;
+    }
+
+    /**
      * Fill the remainder of the destination with a single color
      *
      * @param info
@@ -54,8 +78,13 @@ public:
     virtual void fill(const SkImageInfo& info, void* dst, size_t rowBytes,
             uint32_t colorOrIndex, SkCodec::ZeroInitialized zeroInit) {}
 
+    SkSampler()
+        : fSampleY(1)
+    {}
+
     virtual ~SkSampler() {}
 private:
+    int fSampleY;
 
     virtual int onSetSampleX(int) = 0;
 };