1
2 /*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10 #include "SkUtils.h"
11 #include "SkLazyFnPtr.h"
12
13 #if 0
14 #define assign_16_longs(dst, value) \
15 do { \
16 (dst)[0] = value; (dst)[1] = value; \
17 (dst)[2] = value; (dst)[3] = value; \
18 (dst)[4] = value; (dst)[5] = value; \
19 (dst)[6] = value; (dst)[7] = value; \
20 (dst)[8] = value; (dst)[9] = value; \
21 (dst)[10] = value; (dst)[11] = value; \
22 (dst)[12] = value; (dst)[13] = value; \
23 (dst)[14] = value; (dst)[15] = value; \
24 } while (0)
25 #else
26 #define assign_16_longs(dst, value) \
27 do { \
28 *(dst)++ = value; *(dst)++ = value; \
29 *(dst)++ = value; *(dst)++ = value; \
30 *(dst)++ = value; *(dst)++ = value; \
31 *(dst)++ = value; *(dst)++ = value; \
32 *(dst)++ = value; *(dst)++ = value; \
33 *(dst)++ = value; *(dst)++ = value; \
34 *(dst)++ = value; *(dst)++ = value; \
35 *(dst)++ = value; *(dst)++ = value; \
36 } while (0)
37 #endif
38
39 ///////////////////////////////////////////////////////////////////////////////
40
sk_memset16_portable(uint16_t dst[],uint16_t value,int count)41 static void sk_memset16_portable(uint16_t dst[], uint16_t value, int count) {
42 SkASSERT(dst != NULL && count >= 0);
43
44 if (count <= 0) {
45 return;
46 }
47
48 // not sure if this helps to short-circuit on small values of count
49 if (count < 8) {
50 do {
51 *dst++ = (uint16_t)value;
52 } while (--count != 0);
53 return;
54 }
55
56 // ensure we're on a long boundary
57 if ((size_t)dst & 2) {
58 *dst++ = (uint16_t)value;
59 count -= 1;
60 }
61
62 uint32_t value32 = ((uint32_t)value << 16) | value;
63
64 // handle the bulk with our unrolled macro
65 {
66 int sixteenlongs = count >> 5;
67 if (sixteenlongs) {
68 uint32_t* dst32 = (uint32_t*)dst;
69 do {
70 assign_16_longs(dst32, value32);
71 } while (--sixteenlongs != 0);
72 dst = (uint16_t*)dst32;
73 count &= 31;
74 }
75 }
76
77 // handle (most) of the rest
78 {
79 int longs = count >> 1;
80 if (longs) {
81 do {
82 *(uint32_t*)dst = value32;
83 dst += 2;
84 } while (--longs != 0);
85 }
86 }
87
88 // cleanup a possible trailing short
89 if (count & 1) {
90 *dst = (uint16_t)value;
91 }
92 }
93
sk_memset32_portable(uint32_t dst[],uint32_t value,int count)94 static void sk_memset32_portable(uint32_t dst[], uint32_t value, int count) {
95 SkASSERT(dst != NULL && count >= 0);
96
97 int sixteenlongs = count >> 4;
98 if (sixteenlongs) {
99 do {
100 assign_16_longs(dst, value);
101 } while (--sixteenlongs != 0);
102 count &= 15;
103 }
104
105 if (count) {
106 do {
107 *dst++ = value;
108 } while (--count != 0);
109 }
110 }
111
sk_memcpy32_portable(uint32_t dst[],const uint32_t src[],int count)112 static void sk_memcpy32_portable(uint32_t dst[], const uint32_t src[], int count) {
113 memcpy(dst, src, count * sizeof(uint32_t));
114 }
115
116 namespace {
117 // These three methods technically need external linkage to be passed as template parameters.
118 // Since they can't be static, we hide them in an anonymous namespace instead.
119
choose_memset16()120 SkMemset16Proc choose_memset16() {
121 SkMemset16Proc proc = SkMemset16GetPlatformProc();
122 return proc ? proc : sk_memset16_portable;
123 }
124
choose_memset32()125 SkMemset32Proc choose_memset32() {
126 SkMemset32Proc proc = SkMemset32GetPlatformProc();
127 return proc ? proc : sk_memset32_portable;
128 }
129
choose_memcpy32()130 SkMemcpy32Proc choose_memcpy32() {
131 SkMemcpy32Proc proc = SkMemcpy32GetPlatformProc();
132 return proc ? proc : sk_memcpy32_portable;
133 }
134
135 } // namespace
136
sk_memset16_large(uint16_t dst[],uint16_t value,int count)137 void sk_memset16_large(uint16_t dst[], uint16_t value, int count) {
138 SK_DECLARE_STATIC_LAZY_FN_PTR(SkMemset16Proc, proc, choose_memset16);
139 proc.get()(dst, value, count);
140 }
141
sk_memset32_large(uint32_t dst[],uint32_t value,int count)142 void sk_memset32_large(uint32_t dst[], uint32_t value, int count) {
143 SK_DECLARE_STATIC_LAZY_FN_PTR(SkMemset32Proc, proc, choose_memset32);
144 proc.get()(dst, value, count);
145 }
146
sk_memcpy32(uint32_t dst[],const uint32_t src[],int count)147 void sk_memcpy32(uint32_t dst[], const uint32_t src[], int count) {
148 SK_DECLARE_STATIC_LAZY_FN_PTR(SkMemcpy32Proc, proc, choose_memcpy32);
149 proc.get()(dst, src, count);
150 }
151
152 ///////////////////////////////////////////////////////////////////////////////
153
154 /* 0xxxxxxx 1 total
155 10xxxxxx // never a leading byte
156 110xxxxx 2 total
157 1110xxxx 3 total
158 11110xxx 4 total
159
160 11 10 01 01 xx xx xx xx 0...
161 0xE5XX0000
162 0xE5 << 24
163 */
164
165 #ifdef SK_DEBUG
assert_utf8_leadingbyte(unsigned c)166 static void assert_utf8_leadingbyte(unsigned c) {
167 SkASSERT(c <= 0xF7); // otherwise leading byte is too big (more than 4 bytes)
168 SkASSERT((c & 0xC0) != 0x80); // can't begin with a middle char
169 }
170
SkUTF8_LeadByteToCount(unsigned c)171 int SkUTF8_LeadByteToCount(unsigned c) {
172 assert_utf8_leadingbyte(c);
173 return (((0xE5 << 24) >> (c >> 4 << 1)) & 3) + 1;
174 }
175 #else
176 #define assert_utf8_leadingbyte(c)
177 #endif
178
SkUTF8_CountUnichars(const char utf8[])179 int SkUTF8_CountUnichars(const char utf8[]) {
180 SkASSERT(utf8);
181
182 int count = 0;
183
184 for (;;) {
185 int c = *(const uint8_t*)utf8;
186 if (c == 0) {
187 break;
188 }
189 utf8 += SkUTF8_LeadByteToCount(c);
190 count += 1;
191 }
192 return count;
193 }
194
SkUTF8_CountUnichars(const char utf8[],size_t byteLength)195 int SkUTF8_CountUnichars(const char utf8[], size_t byteLength) {
196 SkASSERT(utf8 || 0 == byteLength);
197
198 int count = 0;
199 const char* stop = utf8 + byteLength;
200
201 while (utf8 < stop) {
202 utf8 += SkUTF8_LeadByteToCount(*(const uint8_t*)utf8);
203 count += 1;
204 }
205 return count;
206 }
207
SkUTF8_ToUnichar(const char utf8[])208 SkUnichar SkUTF8_ToUnichar(const char utf8[]) {
209 SkASSERT(utf8);
210
211 const uint8_t* p = (const uint8_t*)utf8;
212 int c = *p;
213 int hic = c << 24;
214
215 assert_utf8_leadingbyte(c);
216
217 if (hic < 0) {
218 uint32_t mask = (uint32_t)~0x3F;
219 hic <<= 1;
220 do {
221 c = (c << 6) | (*++p & 0x3F);
222 mask <<= 5;
223 } while ((hic <<= 1) < 0);
224 c &= ~mask;
225 }
226 return c;
227 }
228
SkUTF8_NextUnichar(const char ** ptr)229 SkUnichar SkUTF8_NextUnichar(const char** ptr) {
230 SkASSERT(ptr && *ptr);
231
232 const uint8_t* p = (const uint8_t*)*ptr;
233 int c = *p;
234 int hic = c << 24;
235
236 assert_utf8_leadingbyte(c);
237
238 if (hic < 0) {
239 uint32_t mask = (uint32_t)~0x3F;
240 hic <<= 1;
241 do {
242 c = (c << 6) | (*++p & 0x3F);
243 mask <<= 5;
244 } while ((hic <<= 1) < 0);
245 c &= ~mask;
246 }
247 *ptr = (char*)p + 1;
248 return c;
249 }
250
SkUTF8_PrevUnichar(const char ** ptr)251 SkUnichar SkUTF8_PrevUnichar(const char** ptr) {
252 SkASSERT(ptr && *ptr);
253
254 const char* p = *ptr;
255
256 if (*--p & 0x80) {
257 while (*--p & 0x40) {
258 ;
259 }
260 }
261
262 *ptr = (char*)p;
263 return SkUTF8_NextUnichar(&p);
264 }
265
SkUTF8_FromUnichar(SkUnichar uni,char utf8[])266 size_t SkUTF8_FromUnichar(SkUnichar uni, char utf8[]) {
267 if ((uint32_t)uni > 0x10FFFF) {
268 SkDEBUGFAIL("bad unichar");
269 return 0;
270 }
271
272 if (uni <= 127) {
273 if (utf8) {
274 *utf8 = (char)uni;
275 }
276 return 1;
277 }
278
279 char tmp[4];
280 char* p = tmp;
281 size_t count = 1;
282
283 SkDEBUGCODE(SkUnichar orig = uni;)
284
285 while (uni > 0x7F >> count) {
286 *p++ = (char)(0x80 | (uni & 0x3F));
287 uni >>= 6;
288 count += 1;
289 }
290
291 if (utf8) {
292 p = tmp;
293 utf8 += count;
294 while (p < tmp + count - 1) {
295 *--utf8 = *p++;
296 }
297 *--utf8 = (char)(~(0xFF >> count) | uni);
298 }
299
300 SkASSERT(utf8 == NULL || orig == SkUTF8_ToUnichar(utf8));
301 return count;
302 }
303
304 ///////////////////////////////////////////////////////////////////////////////
305
SkUTF16_CountUnichars(const uint16_t src[])306 int SkUTF16_CountUnichars(const uint16_t src[]) {
307 SkASSERT(src);
308
309 int count = 0;
310 unsigned c;
311 while ((c = *src++) != 0) {
312 SkASSERT(!SkUTF16_IsLowSurrogate(c));
313 if (SkUTF16_IsHighSurrogate(c)) {
314 c = *src++;
315 SkASSERT(SkUTF16_IsLowSurrogate(c));
316 }
317 count += 1;
318 }
319 return count;
320 }
321
SkUTF16_CountUnichars(const uint16_t src[],int numberOf16BitValues)322 int SkUTF16_CountUnichars(const uint16_t src[], int numberOf16BitValues) {
323 SkASSERT(src);
324
325 const uint16_t* stop = src + numberOf16BitValues;
326 int count = 0;
327 while (src < stop) {
328 unsigned c = *src++;
329 SkASSERT(!SkUTF16_IsLowSurrogate(c));
330 if (SkUTF16_IsHighSurrogate(c)) {
331 SkASSERT(src < stop);
332 c = *src++;
333 SkASSERT(SkUTF16_IsLowSurrogate(c));
334 }
335 count += 1;
336 }
337 return count;
338 }
339
SkUTF16_NextUnichar(const uint16_t ** srcPtr)340 SkUnichar SkUTF16_NextUnichar(const uint16_t** srcPtr) {
341 SkASSERT(srcPtr && *srcPtr);
342
343 const uint16_t* src = *srcPtr;
344 SkUnichar c = *src++;
345
346 SkASSERT(!SkUTF16_IsLowSurrogate(c));
347 if (SkUTF16_IsHighSurrogate(c)) {
348 unsigned c2 = *src++;
349 SkASSERT(SkUTF16_IsLowSurrogate(c2));
350
351 // c = ((c & 0x3FF) << 10) + (c2 & 0x3FF) + 0x10000
352 // c = (((c & 0x3FF) + 64) << 10) + (c2 & 0x3FF)
353 c = (c << 10) + c2 + (0x10000 - (0xD800 << 10) - 0xDC00);
354 }
355 *srcPtr = src;
356 return c;
357 }
358
SkUTF16_PrevUnichar(const uint16_t ** srcPtr)359 SkUnichar SkUTF16_PrevUnichar(const uint16_t** srcPtr) {
360 SkASSERT(srcPtr && *srcPtr);
361
362 const uint16_t* src = *srcPtr;
363 SkUnichar c = *--src;
364
365 SkASSERT(!SkUTF16_IsHighSurrogate(c));
366 if (SkUTF16_IsLowSurrogate(c)) {
367 unsigned c2 = *--src;
368 SkASSERT(SkUTF16_IsHighSurrogate(c2));
369 c = (c2 << 10) + c + (0x10000 - (0xD800 << 10) - 0xDC00);
370 }
371 *srcPtr = src;
372 return c;
373 }
374
SkUTF16_FromUnichar(SkUnichar uni,uint16_t dst[])375 size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t dst[]) {
376 SkASSERT((unsigned)uni <= 0x10FFFF);
377
378 int extra = (uni > 0xFFFF);
379
380 if (dst) {
381 if (extra) {
382 // dst[0] = SkToU16(0xD800 | ((uni - 0x10000) >> 10));
383 // dst[0] = SkToU16(0xD800 | ((uni >> 10) - 64));
384 dst[0] = SkToU16((0xD800 - 64) + (uni >> 10));
385 dst[1] = SkToU16(0xDC00 | (uni & 0x3FF));
386
387 SkASSERT(SkUTF16_IsHighSurrogate(dst[0]));
388 SkASSERT(SkUTF16_IsLowSurrogate(dst[1]));
389 } else {
390 dst[0] = SkToU16(uni);
391 SkASSERT(!SkUTF16_IsHighSurrogate(dst[0]));
392 SkASSERT(!SkUTF16_IsLowSurrogate(dst[0]));
393 }
394 }
395 return 1 + extra;
396 }
397
SkUTF16_ToUTF8(const uint16_t utf16[],int numberOf16BitValues,char utf8[])398 size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues,
399 char utf8[]) {
400 SkASSERT(numberOf16BitValues >= 0);
401 if (numberOf16BitValues <= 0) {
402 return 0;
403 }
404
405 SkASSERT(utf16 != NULL);
406
407 const uint16_t* stop = utf16 + numberOf16BitValues;
408 size_t size = 0;
409
410 if (utf8 == NULL) { // just count
411 while (utf16 < stop) {
412 size += SkUTF8_FromUnichar(SkUTF16_NextUnichar(&utf16), NULL);
413 }
414 } else {
415 char* start = utf8;
416 while (utf16 < stop) {
417 utf8 += SkUTF8_FromUnichar(SkUTF16_NextUnichar(&utf16), utf8);
418 }
419 size = utf8 - start;
420 }
421 return size;
422 }
423