1 files changed, 89 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/codec/SkSampler.h b/gfx/skia/skia/src/codec/SkSampler.h
new file mode 100644
index 0000000000..ac3b27c441
--- /dev/null
+++ b/gfx/skia/skia/src/codec/SkSampler.h
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkSampler_DEFINED
+#define SkSampler_DEFINED
+
+#include "include/codec/SkCodec.h"
+#include "include/core/SkTypes.h"
+#include "include/private/base/SkNoncopyable.h"
+#include "src/codec/SkCodecPriv.h"
+
+#include <cstddef>
+
+struct SkImageInfo;
+
+class SkSampler : public SkNoncopyable {
+public:
+    /**
+     *  Update the sampler to sample every sampleX'th pixel. Returns the
+     *  width after sampling.
+     */
+    int setSampleX(int sampleX) {
+        return this->onSetSampleX(sampleX);
+    }
+
+    /**
+     *  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 in the subset.
+     */
+    bool rowNeeded(int row) const {
+        return (row - get_start_coord(fSampleY)) % fSampleY == 0;
+    }
+
+    /**
+     * Fill the remainder of the destination with 0.
+     *
+     * 0 has a different meaning depending on the SkColorType. For color types
+     * with transparency, this means transparent. For k565 and kGray, 0 is
+     * black.
+     *
+     * @param info
+     * Contains the color type of the rows to fill.
+     * Contains the pixel width of the destination rows to fill
+     * Contains the number of rows that we need to fill.
+     *
+     * @param dst
+     * The destination row to fill.
+     *
+     * @param rowBytes
+     * Stride in bytes of the destination.
+     *
+     * @param zeroInit
+     * Indicates whether memory is already zero initialized.
+     */
+    static void Fill(const SkImageInfo& info, void* dst, size_t rowBytes,
+                     SkCodec::ZeroInitialized zeroInit);
+
+    virtual int fillWidth() const = 0;
+
+    SkSampler()
+        : fSampleY(1)
+    {}
+
+    virtual ~SkSampler() {}
+private:
+    int fSampleY;
+
+    virtual int onSetSampleX(int) = 0;
+};
+
+#endif // SkSampler_DEFINED