diff options
Diffstat (limited to 'src/core/SkUtils.cpp')
| -rw-r--r-- | src/core/SkUtils.cpp | 428 |
1 files changed, 12 insertions, 416 deletions
diff --git a/src/core/SkUtils.cpp b/src/core/SkUtils.cpp index f0c1f60a09..9754da662c 100644 --- a/src/core/SkUtils.cpp +++ b/src/core/SkUtils.cpp @@ -7,431 +7,27 @@ #include "SkUtils.h" -#include "SkTo.h" - -/* 0xxxxxxx 1 total - 10xxxxxx // never a leading byte - 110xxxxx 2 total - 1110xxxx 3 total - 11110xxx 4 total - - 11 10 01 01 xx xx xx xx 0... - 0xE5XX0000 - 0xE5 << 24 -*/ - -static bool utf8_byte_is_valid(uint8_t c) { - return c < 0xF5 && (c & 0xFE) != 0xC0; -} -static bool utf8_byte_is_continuation(uint8_t c) { - return (c & 0xC0) == 0x80; -} -static bool utf8_byte_is_leading_byte(uint8_t c) { - return utf8_byte_is_valid(c) && !utf8_byte_is_continuation(c); -} - -#ifdef SK_DEBUG - static void assert_utf8_leadingbyte(unsigned c) { - SkASSERT(utf8_byte_is_leading_byte(SkToU8(c))); - } - - int SkUTF8_LeadByteToCount(unsigned c) { - assert_utf8_leadingbyte(c); - return (((0xE5 << 24) >> (c >> 4 << 1)) & 3) + 1; - } -#else - #define assert_utf8_leadingbyte(c) -#endif - -/** - * @returns -1 iff invalid UTF8 byte, - * 0 iff UTF8 continuation byte, - * 1 iff ASCII byte, - * 2 iff leading byte of 2-byte sequence, - * 3 iff leading byte of 3-byte sequence, and - * 4 iff leading byte of 4-byte sequence. - * - * I.e.: if return value > 0, then gives length of sequence. -*/ -static int utf8_byte_type(uint8_t c) { - if (c < 0x80) { - return 1; - } else if (c < 0xC0) { - return 0; - } else if (c < 0xF5 && (c & 0xFE) != 0xC0) { // "octet values C0, C1, F5 to FF never appear" - return (((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1; - } else { - return -1; - } -} -static bool utf8_type_is_valid_leading_byte(int type) { return type > 0; } - -int SkUTF8_CountUnichars(const char utf8[]) { - SkASSERT(utf8); - - int count = 0; - - for (;;) { - int c = *(const uint8_t*)utf8; - if (c == 0) { - break; - } - utf8 += SkUTF8_LeadByteToCount(c); - count += 1; - } - return count; -} - -// SAFE: returns -1 if invalid UTF-8 -int SkUTF8_CountUnichars(const void* text, size_t byteLength) { - SkASSERT(text); - const char* utf8 = static_cast<const char*>(text); - int count = 0; - const char* stop = utf8 + byteLength; - - while (utf8 < stop) { - int type = utf8_byte_type(*(const uint8_t*)utf8); - SkASSERT(type >= -1 && type <= 4); - if (!utf8_type_is_valid_leading_byte(type) || utf8 + type > stop) { - // Sequence extends beyond end. - return -1; - } - while(type-- > 1) { - ++utf8; - if (!utf8_byte_is_continuation(*(const uint8_t*)utf8)) { - return -1; - } - } - ++utf8; - ++count; - } - return count; -} - -SkUnichar SkUTF8_ToUnichar(const char utf8[]) { - SkASSERT(utf8); - - const uint8_t* p = (const uint8_t*)utf8; - int c = *p; - int hic = c << 24; - - assert_utf8_leadingbyte(c); - - if (hic < 0) { - uint32_t mask = (uint32_t)~0x3F; - hic = SkLeftShift(hic, 1); - do { - c = (c << 6) | (*++p & 0x3F); - mask <<= 5; - } while ((hic = SkLeftShift(hic, 1)) < 0); - c &= ~mask; - } - return c; -} - -// SAFE: returns -1 on invalid UTF-8 sequence. -SkUnichar SkUTF8_NextUnicharWithError(const char** ptr, const char* end) { - SkASSERT(ptr && *ptr); - SkASSERT(*ptr < end); - const uint8_t* p = (const uint8_t*)*ptr; - int c = *p; - int hic = c << 24; - - if (!utf8_byte_is_leading_byte(c)) { - return -1; - } - if (hic < 0) { - uint32_t mask = (uint32_t)~0x3F; - hic = SkLeftShift(hic, 1); - do { - ++p; - if (p >= (const uint8_t*)end) { - return -1; - } - // check before reading off end of array. - uint8_t nextByte = *p; - if (!utf8_byte_is_continuation(nextByte)) { - return -1; - } - c = (c << 6) | (nextByte & 0x3F); - mask <<= 5; - } while ((hic = SkLeftShift(hic, 1)) < 0); - c &= ~mask; - } - *ptr = (char*)p + 1; - return c; -} - -SkUnichar SkUTF8_NextUnichar(const char** ptr) { - SkASSERT(ptr && *ptr); - - const uint8_t* p = (const uint8_t*)*ptr; - int c = *p; - int hic = c << 24; - - assert_utf8_leadingbyte(c); - - if (hic < 0) { - uint32_t mask = (uint32_t)~0x3F; - hic = SkLeftShift(hic, 1); - do { - c = (c << 6) | (*++p & 0x3F); - mask <<= 5; - } while ((hic = SkLeftShift(hic, 1)) < 0); - c &= ~mask; - } - *ptr = (char*)p + 1; - return c; -} - -SkUnichar SkUTF8_PrevUnichar(const char** ptr) { - SkASSERT(ptr && *ptr); - - const char* p = *ptr; - - if (*--p & 0x80) { - while (*--p & 0x40) { - ; - } - } - - *ptr = (char*)p; - return SkUTF8_NextUnichar(&p); -} - -size_t SkUTF8_FromUnichar(SkUnichar uni, char utf8[]) { - if ((uint32_t)uni > 0x10FFFF) { - SkDEBUGFAIL("bad unichar"); - return 0; - } - - if (uni <= 127) { - if (utf8) { - *utf8 = (char)uni; - } - return 1; - } - - char tmp[4]; - char* p = tmp; - size_t count = 1; - - SkDEBUGCODE(SkUnichar orig = uni;) - - while (uni > 0x7F >> count) { - *p++ = (char)(0x80 | (uni & 0x3F)); - uni >>= 6; - count += 1; - } - - if (utf8) { - p = tmp; - utf8 += count; - while (p < tmp + count - 1) { - *--utf8 = *p++; - } - *--utf8 = (char)(~(0xFF >> count) | uni); - } - - SkASSERT(utf8 == nullptr || orig == SkUTF8_ToUnichar(utf8)); - return count; -} - -/////////////////////////////////////////////////////////////////////////////// - -int SkUTF16_CountUnichars(const uint16_t src[]) { - SkASSERT(src); - - int count = 0; - unsigned c; - while ((c = *src++) != 0) { - SkASSERT(!SkUTF16_IsLowSurrogate(c)); - if (SkUTF16_IsHighSurrogate(c)) { - c = *src++; - SkASSERT(SkUTF16_IsLowSurrogate(c)); - } - count += 1; - } - return count; -} - -// returns -1 on error -int SkUTF16_CountUnichars(const void* text, size_t byteLength) { - SkASSERT(text); - if (!SkIsAlign2(intptr_t(text)) || !SkIsAlign2(byteLength)) { - return -1; - } - - const uint16_t* src = static_cast<const uint16_t*>(text); - const uint16_t* stop = src + (byteLength >> 1); - int count = 0; - while (src < stop) { - unsigned c = *src++; - if (SkUTF16_IsLowSurrogate(c)) { - return -1; - } - if (SkUTF16_IsHighSurrogate(c)) { - if (src >= stop) { - return -1; - } - c = *src++; - if (!SkUTF16_IsLowSurrogate(c)) { - return -1; - } - } - count += 1; - } - return count; -} - -SkUnichar SkUTF16_NextUnichar(const uint16_t** srcPtr, const uint16_t* endPtr) { - if (!srcPtr || !endPtr) { - return -1; - } - const uint16_t* src = *srcPtr; - if (src >= endPtr) { - return -1; - } - uint16_t c = *src++; - SkUnichar result = c; - - if (SkUTF16_IsLowSurrogate(c)) { - return -1; // srcPtr should never point at low surrogate. - } - if (SkUTF16_IsHighSurrogate(c)) { - if (src == endPtr) { - return -1; // Truncated string. - } - uint16_t low = *src++; - if (!SkUTF16_IsLowSurrogate(low)) { - return -1; - } - /* - [paraphrased from wikipedia] - Take the high surrogate and subtract 0xD800, then multiply by 0x400. - Take the low surrogate and subtract 0xDC00. Add these two results - together, and finally add 0x10000 to get the final decoded codepoint. - - unicode = (high - 0xD800) * 0x400 + low - 0xDC00 + 0x10000 - unicode = (high * 0x400) - (0xD800 * 0x400) + low - 0xDC00 + 0x10000 - unicode = (high << 10) - (0xD800 << 10) + low - 0xDC00 + 0x10000 - unicode = (high << 10) + low - ((0xD800 << 10) + 0xDC00 - 0x10000) - */ - result = (result << 10) + (SkUnichar)low - ((0xD800 << 10) + 0xDC00 - 0x10000); - } - *srcPtr = src; - return result; -} - -SkUnichar SkUTF16_NextUnichar(const uint16_t** srcPtr) { - SkUnichar c = SkUTF16_NextUnichar(srcPtr, *srcPtr + 2); +template <typename T> +static SkUnichar next(const T** srcPtr, unsigned N, SkUnichar (*fn)(const T**, const T*)) { + SkASSERT(srcPtr); + const T* ptr = *srcPtr; + SkUnichar c = fn(&ptr, ptr + N); if (c == -1) { SkASSERT(false); ++(*srcPtr); - return 0xFFFD; // REPLACEMENT CHARACTER. - } - return c; -} - -SkUnichar SkUTF16_PrevUnichar(const uint16_t** srcPtr) { - SkASSERT(srcPtr && *srcPtr); - - const uint16_t* src = *srcPtr; - SkUnichar c = *--src; - - SkASSERT(!SkUTF16_IsHighSurrogate(c)); - if (SkUTF16_IsLowSurrogate(c)) { - unsigned c2 = *--src; - SkASSERT(SkUTF16_IsHighSurrogate(c2)); - c = (c2 << 10) + c + (0x10000 - (0xD800 << 10) - 0xDC00); + return 0xFFFD; // REPLACEMENT CHARACTER } - *srcPtr = src; + *srcPtr = ptr; return c; } - -size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t dst[]) { - SkASSERT((unsigned)uni <= 0x10FFFF); - - int extra = (uni > 0xFFFF); - - if (dst) { - if (extra) { - // dst[0] = SkToU16(0xD800 | ((uni - 0x10000) >> 10)); - // dst[0] = SkToU16(0xD800 | ((uni >> 10) - 64)); - dst[0] = SkToU16((0xD800 - 64) + (uni >> 10)); - dst[1] = SkToU16(0xDC00 | (uni & 0x3FF)); - - SkASSERT(SkUTF16_IsHighSurrogate(dst[0])); - SkASSERT(SkUTF16_IsLowSurrogate(dst[1])); - } else { - dst[0] = SkToU16(uni); - SkASSERT(!SkUTF16_IsHighSurrogate(dst[0])); - SkASSERT(!SkUTF16_IsLowSurrogate(dst[0])); - } - } - return 1 + extra; -} - -size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues, - char utf8[]) { - SkASSERT(numberOf16BitValues >= 0); - if (numberOf16BitValues <= 0) { - return 0; - } - - SkASSERT(utf16 != nullptr); - - const uint16_t* stop = utf16 + numberOf16BitValues; - size_t size = 0; - - if (utf8 == nullptr) { // just count - while (utf16 < stop) { - size += SkUTF8_FromUnichar(SkUTF16_NextUnichar(&utf16), nullptr); - } - } else { - char* start = utf8; - while (utf16 < stop) { - utf8 += SkUTF8_FromUnichar(SkUTF16_NextUnichar(&utf16), utf8); - } - size = utf8 - start; - } - return size; +SkUnichar SkUTF8_NextUnichar(const char** p) { + return next<char>(p, SkUTF::kMaxBytesInUTF8Sequence, SkUTF::NextUTF8); } - -// returns -1 on error -int SkUTF32_CountUnichars(const void* text, size_t byteLength) { - if (!SkIsAlign4(intptr_t(text)) || !SkIsAlign4(byteLength)) { - return -1; - } - const uint32_t kInvalidUnicharMask = 0xFF000000; // unichar fits in 24 bits - const uint32_t* ptr = static_cast<const uint32_t*>(text); - const uint32_t* stop = ptr + (byteLength >> 2); - while (ptr < stop) { - if (*ptr & kInvalidUnicharMask) { - return -1; - } - ptr += 1; - } - return SkToInt(byteLength >> 2); +SkUnichar SkUTF16_NextUnichar(const uint16_t** p) { + return next<uint16_t>(p, 2, SkUTF::NextUTF16); } -// returns -1 on error -int SkUTFN_CountUnichars( - SkTypeface::Encoding encoding, const void* utfN, size_t byteLength) { - SkASSERT(utfN != nullptr); - switch (encoding) { - case SkTypeface::kUTF8_Encoding: - return SkUTF8_CountUnichars(utfN, byteLength); - case SkTypeface::kUTF16_Encoding: - return SkUTF16_CountUnichars(utfN, byteLength); - case SkTypeface::kUTF32_Encoding: - return SkUTF32_CountUnichars(utfN, byteLength); - default: - SkDEBUGFAIL("unknown text encoding"); - } - - return -1; -} +/////////////////////////////////////////////////////////////////////////////// const char SkHexadecimalDigits::gUpper[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; |