1 files changed, 47 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/pdf/SkClusterator.h b/gfx/skia/skia/src/pdf/SkClusterator.h
new file mode 100644
index 0000000000..86fd6cdfdf
--- /dev/null
+++ b/gfx/skia/skia/src/pdf/SkClusterator.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkClusterator_DEFINED
+#define SkClusterator_DEFINED
+
+#include <cstdint>
+#include <vector>
+
+namespace sktext {
+class GlyphRun;
+}
+
+/** Given the m-to-n glyph-to-character mapping data (as returned by
+    harfbuzz), iterate over the clusters. */
+class SkClusterator {
+public:
+    SkClusterator(const sktext::GlyphRun& run);
+    uint32_t glyphCount() const { return fGlyphCount; }
+    bool reversedChars() const { return fReversedChars; }
+    struct Cluster {
+        const char* fUtf8Text;
+        uint32_t fTextByteLength;
+        uint32_t fGlyphIndex;
+        uint32_t fGlyphCount;
+        explicit operator bool() const { return fGlyphCount != 0; }
+        bool operator==(const SkClusterator::Cluster& o) {
+            return fUtf8Text       == o.fUtf8Text
+                && fTextByteLength == o.fTextByteLength
+                && fGlyphIndex     == o.fGlyphIndex
+                && fGlyphCount     == o.fGlyphCount;
+        }
+    };
+    Cluster next();
+
+private:
+    uint32_t const * const fClusters;
+    char const * const fUtf8Text;
+    uint32_t const fGlyphCount;
+    uint32_t const fTextByteLength;
+    bool const fReversedChars;
+    uint32_t fCurrentGlyphIndex = 0;
+};
+#endif  // SkClusterator_DEFINED