Line data    Source code

       1             : /*
       2             :  * Copyright 2006 The Android Open Source Project
       3             :  *
       4             :  * Use of this source code is governed by a BSD-style license that can be
       5             :  * found in the LICENSE file.
       6             :  */
       7             : 
       8             : #ifndef SkUtils_DEFINED
       9             : #define SkUtils_DEFINED
      10             : 
      11             : #include "SkTypes.h"
      12             : #include "SkMath.h"
      13             : 
      14             : /** Similar to memset(), but it assigns a 16, 32, or 64-bit value into the buffer.
      15             :     @param buffer   The memory to have value copied into it
      16             :     @param value    The value to be copied into buffer
      17             :     @param count    The number of times value should be copied into the buffer.
      18             : */
      19             : void sk_memset16(uint16_t buffer[], uint16_t value, int count);
      20             : void sk_memset32(uint32_t buffer[], uint32_t value, int count);
      21             : void sk_memset64(uint64_t buffer[], uint64_t value, int count);
      22             : ///////////////////////////////////////////////////////////////////////////////
      23             : 
      24             : #define kMaxBytesInUTF8Sequence     4
      25             : 
      26             : #ifdef SK_DEBUG
      27             :     int SkUTF8_LeadByteToCount(unsigned c);
      28             : #else
      29             :     #define SkUTF8_LeadByteToCount(c)   ((((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1)
      30             : #endif
      31             : 
      32           0 : inline int SkUTF8_CountUTF8Bytes(const char utf8[]) {
      33           0 :     SkASSERT(utf8);
      34           0 :     return SkUTF8_LeadByteToCount(*(const uint8_t*)utf8);
      35             : }
      36             : 
      37             : int         SkUTF8_CountUnichars(const char utf8[]);
      38             : 
      39             : /** This function is safe: invalid UTF8 sequences will return -1; */
      40             : int         SkUTF8_CountUnicharsWithError(const char utf8[], size_t byteLength);
      41             : 
      42             : /** This function is safe: invalid UTF8 sequences will return 0; */
      43           0 : inline int  SkUTF8_CountUnichars(const char utf8[], size_t byteLength) {
      44           0 :     return SkClampPos(SkUTF8_CountUnicharsWithError(utf8, byteLength));
      45             : }
      46             : 
      47             : /** This function is safe: invalid UTF8 sequences will return -1
      48             :  *  When -1 is returned, ptr is unchanged.
      49             :  *  Precondition: *ptr < end;
      50             :  */
      51             : SkUnichar SkUTF8_NextUnicharWithError(const char** ptr, const char* end);
      52             : 
      53             : /** this version replaces invalid utf-8 sequences with code point U+FFFD. */
      54             : inline SkUnichar SkUTF8_NextUnichar(const char** ptr, const char* end) {
      55             :     SkUnichar val = SkUTF8_NextUnicharWithError(ptr, end);
      56             :     if (val < 0) {
      57             :         *ptr = end;
      58             :         return 0xFFFD;  // REPLACEMENT CHARACTER
      59             :     }
      60             :     return val;
      61             : }
      62             : 
      63             : SkUnichar   SkUTF8_ToUnichar(const char utf8[]);
      64             : SkUnichar   SkUTF8_NextUnichar(const char**);
      65             : SkUnichar   SkUTF8_PrevUnichar(const char**);
      66             : 
      67             : /** Return the number of bytes need to convert a unichar
      68             :     into a utf8 sequence. Will be 1..kMaxBytesInUTF8Sequence,
      69             :     or 0 if uni is illegal.
      70             : */
      71             : size_t      SkUTF8_FromUnichar(SkUnichar uni, char utf8[] = NULL);
      72             : 
      73             : ///////////////////////////////////////////////////////////////////////////////
      74             : 
      75             : #define SkUTF16_IsHighSurrogate(c)  (((c) & 0xFC00) == 0xD800)
      76             : #define SkUTF16_IsLowSurrogate(c)   (((c) & 0xFC00) == 0xDC00)
      77             : 
      78             : int SkUTF16_CountUnichars(const uint16_t utf16[]);
      79             : int SkUTF16_CountUnichars(const uint16_t utf16[], int numberOf16BitValues);
      80             : // returns the current unichar and then moves past it (*p++)
      81             : SkUnichar SkUTF16_NextUnichar(const uint16_t**);
      82             : // this guy backs up to the previus unichar value, and returns it (*--p)
      83             : SkUnichar SkUTF16_PrevUnichar(const uint16_t**);
      84             : size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t utf16[] = NULL);
      85             : 
      86             : size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues,
      87             :                       char utf8[] = NULL);
      88             : 
      89             : inline bool SkUnichar_IsVariationSelector(SkUnichar uni) {
      90             : /*  The 'true' ranges are:
      91             :  *      0x180B  <= uni <=  0x180D
      92             :  *      0xFE00  <= uni <=  0xFE0F
      93             :  *      0xE0100 <= uni <= 0xE01EF
      94             :  */
      95             :     if (uni < 0x180B || uni > 0xE01EF) {
      96             :         return false;
      97             :     }
      98             :     if ((uni > 0x180D && uni < 0xFE00) || (uni > 0xFE0F && uni < 0xE0100)) {
      99             :         return false;
     100             :     }
     101             :     return true;
     102             : }
     103             : #endif