text: // Copyright 2014 PDFium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
  
  #ifndef CORE_FXCRT_FX_EXT_H_
  #define CORE_FXCRT_FX_EXT_H_
  
  #include <cctype>
  #include <cwctype>
  
  #include "core/fxcrt/fx_basic.h"
  
  #define FX_INVALID_OFFSET static_cast<uint32_t>(-1)
  
  // TODO(thestig) Using unique_ptr with ReleaseDeleter is still not ideal.
  // Come up or wait for something better. This appears in this file rather
  // than fx_stream.h due to include ordering restrictions.
  using ScopedFileStream =
      std::unique_ptr<IFX_SeekableStream, ReleaseDeleter<IFX_SeekableStream>>;
  
  FX_FLOAT FXSYS_tan(FX_FLOAT a);
  FX_FLOAT FXSYS_logb(FX_FLOAT b, FX_FLOAT x);
  FX_FLOAT FXSYS_strtof(const FX_CHAR* pcsStr,
                        int32_t iLength = -1,
                        int32_t* pUsedLen = nullptr);
  FX_FLOAT FXSYS_wcstof(const FX_WCHAR* pwsStr,
                        int32_t iLength = -1,
                        int32_t* pUsedLen = nullptr);
  FX_WCHAR* FXSYS_wcsncpy(FX_WCHAR* dstStr, const FX_WCHAR* srcStr, size_t count);
  int32_t FXSYS_wcsnicmp(const FX_WCHAR* s1, const FX_WCHAR* s2, size_t count);
  int32_t FXSYS_strnicmp(const FX_CHAR* s1, const FX_CHAR* s2, size_t count);
  
  inline bool FXSYS_islower(int32_t ch) {
    return ch >= 'a' && ch <= 'z';
  }
  inline bool FXSYS_isupper(int32_t ch) {
    return ch >= 'A' && ch <= 'Z';
  }
  inline int32_t FXSYS_tolower(int32_t ch) {
    return ch < 'A' || ch > 'Z' ? ch : (ch + 0x20);
  }
  inline int32_t FXSYS_toupper(int32_t ch) {
    return ch < 'a' || ch > 'z' ? ch : (ch - 0x20);
  }
  inline bool FXSYS_iswalpha(wchar_t wch) {
    return (wch >= L'A' && wch <= L'Z') || (wch >= L'a' && wch <= L'z');
  }
  inline bool FXSYS_iswdigit(wchar_t wch) {
    return wch >= L'0' && wch <= L'9';
  }
  inline bool FXSYS_iswalnum(wchar_t wch) {
    return FXSYS_iswalpha(wch) || FXSYS_iswdigit(wch);
  }
  inline bool FXSYS_iswspace(FX_WCHAR c) {
    return (c == 0x20) || (c == 0x0d) || (c == 0x0a) || (c == 0x09);
  }
  
  inline int FXSYS_toHexDigit(const FX_CHAR c) {
    if (!std::isxdigit(c))
      return 0;
    char upchar = std::toupper(c);
    return upchar > '9' ? upchar - 'A' + 10 : upchar - '0';
  }
  
  inline bool FXSYS_isDecimalDigit(const FX_CHAR c) {
    return !!std::isdigit(c);
  }
  
  inline bool FXSYS_isDecimalDigit(const FX_WCHAR c) {
    return !!std::iswdigit(c);
  }
  
  inline int FXSYS_toDecimalDigit(const FX_CHAR c) {
    return std::isdigit(c) ? c - '0' : 0;
  }
  
  inline int FXSYS_toDecimalDigit(const FX_WCHAR c) {
    return std::iswdigit(c) ? c - L'0' : 0;
  }
  
  FX_FLOAT FXSYS_FractionalScale(size_t scale_factor, int value);
  int FXSYS_FractionalScaleCount();
  
  void* FX_Random_MT_Start(uint32_t dwSeed);
  void FX_Random_MT_Close(void* pContext);
  uint32_t FX_Random_MT_Generate(void* pContext);
  void FX_Random_GenerateBase(uint32_t* pBuffer, int32_t iCount);
  void FX_Random_GenerateMT(uint32_t* pBuffer, int32_t iCount);
  void FX_Random_GenerateCrypto(uint32_t* pBuffer, int32_t iCount);
  
  #ifdef PDF_ENABLE_XFA
  typedef struct FX_GUID {
    uint32_t data1;
    uint16_t data2;
    uint16_t data3;
    uint8_t data4[8];
  } FX_GUID, *FX_LPGUID;
  typedef FX_GUID const* FX_LPCGUID;
  void FX_GUID_CreateV4(FX_LPGUID pGUID);
  void FX_GUID_ToString(FX_LPCGUID pGUID,
                        CFX_ByteString& bsStr,
                        bool bSeparator = true);
  #endif  // PDF_ENABLE_XFA
  
  template <class baseType>
  class CFX_SSortTemplate {
   public:
    void ShellSort(baseType* pArray, int32_t iCount) {
      ASSERT(pArray && iCount > 0);
      int32_t i, j, gap;
      baseType v1, v2;
      gap = iCount >> 1;
      while (gap > 0) {
        for (i = gap; i < iCount; i++) {
          j = i - gap;
          v1 = pArray[i];
          while (j > -1 && (v2 = pArray[j]) > v1) {
            pArray[j + gap] = v2;
            j -= gap;
          }
          pArray[j + gap] = v1;
        }
        gap >>= 1;
      }
    }
  };
  
  #endif  // CORE_FXCRT_FX_EXT_H_
  