1 // Copyright 2017 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "core/fxcrt/cfx_utf8decoder.h"
8 
Clear()9 void CFX_UTF8Decoder::Clear() {
10   m_Buffer.Clear();
11   m_PendingBytes = 0;
12 }
13 
AppendCodePoint(uint32_t ch)14 void CFX_UTF8Decoder::AppendCodePoint(uint32_t ch) {
15   m_Buffer.AppendChar(static_cast<wchar_t>(ch));
16 }
17 
Input(uint8_t byte)18 void CFX_UTF8Decoder::Input(uint8_t byte) {
19   if (byte < 0x80) {
20     m_PendingBytes = 0;
21     m_Buffer.AppendChar(byte);
22   } else if (byte < 0xc0) {
23     if (m_PendingBytes == 0) {
24       return;
25     }
26     m_PendingBytes--;
27     m_PendingChar |= (byte & 0x3f) << (m_PendingBytes * 6);
28     if (m_PendingBytes == 0) {
29       AppendCodePoint(m_PendingChar);
30     }
31   } else if (byte < 0xe0) {
32     m_PendingBytes = 1;
33     m_PendingChar = (byte & 0x1f) << 6;
34   } else if (byte < 0xf0) {
35     m_PendingBytes = 2;
36     m_PendingChar = (byte & 0x0f) << 12;
37   } else if (byte < 0xf8) {
38     m_PendingBytes = 3;
39     m_PendingChar = (byte & 0x07) << 18;
40   } else if (byte < 0xfc) {
41     m_PendingBytes = 4;
42     m_PendingChar = (byte & 0x03) << 24;
43   } else if (byte < 0xfe) {
44     m_PendingBytes = 5;
45     m_PendingChar = (byte & 0x01) << 30;
46   }
47 }
48