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      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 
     13 /** Similar to memset(), but it assigns a 16bit value into the buffer.
     14     @param buffer   The memory to have value copied into it
     15     @param value    The 16bit value to be copied into buffer
     16     @param count    The number of times value should be copied into the buffer.
     17 */
     18 static inline void sk_memset16(uint16_t buffer[], uint16_t value, int count) {
     19     for (int i = 0; i < count; i++) {
     20         buffer[i] = value;
     21     }
     22 }
     23 
     24 /** Similar to memset(), but it assigns a 32bit value into the buffer.
     25     @param buffer   The memory to have value copied into it
     26     @param value    The 32bit value to be copied into buffer
     27     @param count    The number of times value should be copied into the buffer.
     28 */
     29 static inline void sk_memset32(uint32_t buffer[], uint32_t value, int count) {
     30     for (int i = 0; i < count; i++) {
     31         buffer[i] = value;
     32     }
     33 }
     34 
     35 ///////////////////////////////////////////////////////////////////////////////
     36 
     37 #define kMaxBytesInUTF8Sequence     4
     38 
     39 #ifdef SK_DEBUG
     40     int SkUTF8_LeadByteToCount(unsigned c);
     41 #else
     42     #define SkUTF8_LeadByteToCount(c)   ((((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1)
     43 #endif
     44 
     45 inline int SkUTF8_CountUTF8Bytes(const char utf8[]) {
     46     SkASSERT(utf8);
     47     return SkUTF8_LeadByteToCount(*(const uint8_t*)utf8);
     48 }
     49 
     50 int         SkUTF8_CountUnichars(const char utf8[]);
     51 int         SkUTF8_CountUnichars(const char utf8[], size_t byteLength);
     52 SkUnichar   SkUTF8_ToUnichar(const char utf8[]);
     53 SkUnichar   SkUTF8_NextUnichar(const char**);
     54 SkUnichar   SkUTF8_PrevUnichar(const char**);
     55 
     56 /** Return the number of bytes need to convert a unichar
     57     into a utf8 sequence. Will be 1..kMaxBytesInUTF8Sequence,
     58     or 0 if uni is illegal.
     59 */
     60 size_t      SkUTF8_FromUnichar(SkUnichar uni, char utf8[] = NULL);
     61 
     62 ///////////////////////////////////////////////////////////////////////////////
     63 
     64 #define SkUTF16_IsHighSurrogate(c)  (((c) & 0xFC00) == 0xD800)
     65 #define SkUTF16_IsLowSurrogate(c)   (((c) & 0xFC00) == 0xDC00)
     66 
     67 int SkUTF16_CountUnichars(const uint16_t utf16[]);
     68 int SkUTF16_CountUnichars(const uint16_t utf16[], int numberOf16BitValues);
     69 // returns the current unichar and then moves past it (*p++)
     70 SkUnichar SkUTF16_NextUnichar(const uint16_t**);
     71 // this guy backs up to the previus unichar value, and returns it (*--p)
     72 SkUnichar SkUTF16_PrevUnichar(const uint16_t**);
     73 size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t utf16[] = NULL);
     74 
     75 size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues,
     76                       char utf8[] = NULL);
     77 
     78 inline bool SkUnichar_IsVariationSelector(SkUnichar uni) {
     79 /*  The 'true' ranges are:
     80  *      0x180B  <= uni <=  0x180D
     81  *      0xFE00  <= uni <=  0xFE0F
     82  *      0xE0100 <= uni <= 0xE01EF
     83  */
     84     if (uni < 0x180B || uni > 0xE01EF) {
     85         return false;
     86     }
     87     if ((uni > 0x180D && uni < 0xFE00) || (uni > 0xFE0F && uni < 0xE0100)) {
     88         return false;
     89     }
     90     return true;
     91 }
     92 
     93 #endif
     94