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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 "include/core/SkFontTypes.h"
12 #include "src/core/SkOpts.h"
13 #include "src/utils/SkUTF.h"
14 
15 /** Similar to memset(), but it assigns a 16, 32, or 64-bit value into the buffer.
16     @param buffer   The memory to have value copied into it
17     @param value    The value to be copied into buffer
18     @param count    The number of times value should be copied into the buffer.
19 */
sk_memset16(uint16_t buffer[],uint16_t value,int count)20 static inline void sk_memset16(uint16_t buffer[], uint16_t value, int count) {
21     SkOpts::memset16(buffer, value, count);
22 }
sk_memset32(uint32_t buffer[],uint32_t value,int count)23 static inline void sk_memset32(uint32_t buffer[], uint32_t value, int count) {
24     SkOpts::memset32(buffer, value, count);
25 }
sk_memset64(uint64_t buffer[],uint64_t value,int count)26 static inline void sk_memset64(uint64_t buffer[], uint64_t value, int count) {
27     SkOpts::memset64(buffer, value, count);
28 }
29 
30 ///////////////////////////////////////////////////////////////////////////////
31 
32 // Unlike the functions in SkUTF.h, these two functions do not take an array
33 // length parameter.  When possible, use SkUTF::NextUTF{8,16} instead.
34 SkUnichar SkUTF8_NextUnichar(const char**);
35 SkUnichar SkUTF16_NextUnichar(const uint16_t**);
36 
37 ///////////////////////////////////////////////////////////////////////////////
38 
SkUTF16_IsLeadingSurrogate(uint16_t c)39 static inline bool SkUTF16_IsLeadingSurrogate(uint16_t c) { return ((c) & 0xFC00) == 0xD800; }
40 
SkUTF16_IsTrailingSurrogate(uint16_t c)41 static inline bool SkUTF16_IsTrailingSurrogate (uint16_t c) { return ((c) & 0xFC00) == 0xDC00; }
42 
43 ///////////////////////////////////////////////////////////////////////////////
44 
SkUTFN_CountUnichars(SkTextEncoding enc,const void * utfN,size_t bytes)45 static inline int SkUTFN_CountUnichars(SkTextEncoding enc, const void* utfN, size_t bytes) {
46     switch (enc) {
47         case SkTextEncoding::kUTF8:  return SkUTF::CountUTF8((const char*)utfN, bytes);
48         case SkTextEncoding::kUTF16: return SkUTF::CountUTF16((const uint16_t*)utfN, bytes);
49         case SkTextEncoding::kUTF32: return SkUTF::CountUTF32((const int32_t*)utfN, bytes);
50         default: SkDEBUGFAIL("unknown text encoding"); return -1;
51     }
52 }
53 
SkUTFN_Next(SkTextEncoding enc,const void ** ptr,const void * stop)54 static inline SkUnichar SkUTFN_Next(SkTextEncoding enc, const void** ptr, const void* stop) {
55     switch (enc) {
56         case SkTextEncoding::kUTF8:
57             return SkUTF::NextUTF8((const char**)ptr, (const char*)stop);
58         case SkTextEncoding::kUTF16:
59             return SkUTF::NextUTF16((const uint16_t**)ptr, (const uint16_t*)stop);
60         case SkTextEncoding::kUTF32:
61             return SkUTF::NextUTF32((const int32_t**)ptr, (const int32_t*)stop);
62         default: SkDEBUGFAIL("unknown text encoding"); return -1;
63     }
64 }
65 
66 ///////////////////////////////////////////////////////////////////////////////
67 
68 namespace SkHexadecimalDigits {
69     extern const char gUpper[16];  // 0-9A-F
70     extern const char gLower[16];  // 0-9a-f
71 }  // namespace SkHexadecimalDigits
72 
73 ///////////////////////////////////////////////////////////////////////////////
74 
75 // If T is an 8-byte GCC or Clang vector extension type, it would naturally
76 // pass or return in the MMX mm0 register on 32-bit x86 builds.  This has the
77 // fun side effect of clobbering any state in the x87 st0 register.  (There is
78 // no ABI governing who should preserve mm?/st? registers, so no one does!)
79 //
80 // We force-inline sk_unaligned_load() and sk_unaligned_store() to avoid that,
81 // making them safe to use for all types on all platforms, thus solving the
82 // problem once and for all!
83 
84 template <typename T, typename P>
sk_unaligned_load(const P * ptr)85 static SK_ALWAYS_INLINE T sk_unaligned_load(const P* ptr) {
86     static_assert(std::is_trivially_copyable<T>::value);
87     static_assert(std::is_trivially_copyable<P>::value);
88     T val;
89     memcpy(&val, ptr, sizeof(val));
90     return val;
91 }
92 
93 template <typename T, typename P>
sk_unaligned_store(P * ptr,T val)94 static SK_ALWAYS_INLINE void sk_unaligned_store(P* ptr, T val) {
95     static_assert(std::is_trivially_copyable<T>::value);
96     static_assert(std::is_trivially_copyable<P>::value);
97     memcpy(ptr, &val, sizeof(val));
98 }
99 
100 template <typename Dst, typename Src>
sk_bit_cast(const Src & src)101 static SK_ALWAYS_INLINE Dst sk_bit_cast(const Src& src) {
102     static_assert(sizeof(Dst) == sizeof(Src));
103     return sk_unaligned_load<Dst>(&src);
104 }
105 
106 #endif
107