1 files changed, 37 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/core/SkMaskBlurFilter.h b/gfx/skia/skia/src/core/SkMaskBlurFilter.h
new file mode 100644
index 0000000000..fe10cf4abb
--- /dev/null
+++ b/gfx/skia/skia/src/core/SkMaskBlurFilter.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkMaskBlurFilter_DEFINED
+#define SkMaskBlurFilter_DEFINED
+
+#include <algorithm>
+#include <memory>
+#include <tuple>
+
+#include "include/core/SkTypes.h"
+#include "src/core/SkMask.h"
+
+// Implement a single channel Gaussian blur. The specifics for implementation are taken from:
+// https://drafts.fxtf.org/filters/#feGaussianBlurElement
+class SkMaskBlurFilter {
+public:
+    // Create an object suitable for filtering an SkMask using a filter with width sigmaW and
+    // height sigmaH.
+    SkMaskBlurFilter(double sigmaW, double sigmaH);
+
+    // returns true iff the sigmas will result in an identity mask (no blurring)
+    bool hasNoBlur() const;
+
+    // Given a src SkMask, generate dst SkMask returning the border width and height.
+    SkIPoint blur(const SkMask& src, SkMask* dst) const;
+
+private:
+    const double fSigmaW;
+    const double fSigmaH;
+};
+
+#endif  // SkBlurMaskFilter_DEFINED