1 files changed, 68 insertions, 0 deletions
diff --git a/src/utils/SkUTF.h b/src/utils/SkUTF.h
new file mode 100644
index 0000000000..385102aadb
--- /dev/null
+++ b/src/utils/SkUTF.h
@@ -0,0 +1,68 @@
+// Copyright 2018 Google LLC.
+// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
+#ifndef SkUTF_DEFINED
+#define SkUTF_DEFINED
+
+#include <cstddef>
+#include <cstdint>
+
+typedef int32_t SkUnichar;
+
+namespace SkUTF {
+
+/** Given a sequence of UTF-8 bytes, return the number of unicode codepoints.
+    If the sequence is invalid UTF-8, return -1.
+*/
+int CountUTF8(const char* utf8, size_t byteLength);
+
+/** Given a sequence of aligned UTF-16 characters in machine-endian form,
+    return the number of unicode codepoints.  If the sequence is invalid
+    UTF-16, return -1.
+*/
+int CountUTF16(const uint16_t* utf16, size_t byteLength);
+
+/** Given a sequence of aligned UTF-32 characters in machine-endian form,
+    return the number of unicode codepoints.  If the sequence is invalid
+    UTF-32, return -1.
+*/
+int CountUTF32(const int32_t* utf32, size_t byteLength);
+
+/** Given a sequence of UTF-8 bytes, return the first unicode codepoint.
+    The pointer will be incremented to point at the next codepoint's start.  If
+    invalid UTF-8 is encountered, set *ptr to end and return -1.
+*/
+SkUnichar NextUTF8(const char** ptr, const char* end);
+
+/** Given a sequence of aligned UTF-16 characters in machine-endian form,
+    return the first unicode codepoint.  The pointer will be incremented to
+    point at the next codepoint's start.  If invalid UTF-16 is encountered,
+    set *ptr to end and return -1.
+*/
+SkUnichar NextUTF16(const uint16_t** ptr, const uint16_t* end);
+
+/** Given a sequence of aligned UTF-32 characters in machine-endian form,
+    return the first unicode codepoint.  The pointer will be incremented to
+    point at the next codepoint's start.  If invalid UTF-32 is encountered,
+    set *ptr to end and return -1.
+*/
+SkUnichar NextUTF32(const int32_t** ptr, const int32_t* end);
+
+constexpr unsigned kMaxBytesInUTF8Sequence = 4;
+
+/** Convert the unicode codepoint into UTF-8.  If `utf8` is non-null, place the
+    result in that array.  Return the number of bytes in the result.  If `utf8`
+    is null, simply return the number of bytes that would be used.  For invalid
+    unicode codepoints, return 0.
+*/
+size_t ToUTF8(SkUnichar uni, char utf8[kMaxBytesInUTF8Sequence] = nullptr);
+
+/** Convert the unicode codepoint into UTF-16.  If `utf16` is non-null, place
+    the result in that array.  Return the number of UTF-16 code units in the
+    result (1 or 2).  If `utf16` is null, simply return the number of code
+    units that would be used.  For invalid unicode codepoints, return 0.
+*/
+size_t ToUTF16(SkUnichar uni, uint16_t utf16[2] = nullptr);
+
+}  // namespace SkUTF
+
+#endif  // SkUTF_DEFINED