epoger@google.com | ec3ed6a | 2011-07-28 14:26:00 +0000 | [diff] [blame] | 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 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 8 | #include "SkRegionPriv.h" |
| 9 | #include "SkBlitter.h" |
| 10 | #include "SkScan.h" |
| 11 | #include "SkTDArray.h" |
| 12 | #include "SkPath.h" |
| 13 | |
reed | b8f0798 | 2014-06-20 13:59:15 -0700 | [diff] [blame] | 14 | // The rgnbuilder caller *seems* to pass short counts, possible often seens early failure, so |
| 15 | // we may not want to promote this to a "std" routine just yet. |
| 16 | static bool sk_memeq32(const int32_t* SK_RESTRICT a, const int32_t* SK_RESTRICT b, int count) { |
| 17 | for (int i = 0; i < count; ++i) { |
| 18 | if (a[i] != b[i]) { |
| 19 | return false; |
| 20 | } |
| 21 | } |
| 22 | return true; |
| 23 | } |
| 24 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 25 | class SkRgnBuilder : public SkBlitter { |
| 26 | public: |
commit-bot@chromium.org | 73be1fc | 2013-12-30 16:21:06 +0000 | [diff] [blame] | 27 | SkRgnBuilder(); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 28 | virtual ~SkRgnBuilder(); |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 29 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 30 | // returns true if it could allocate the working storage needed |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 31 | bool init(int maxHeight, int maxTransitions, bool pathIsInverse); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 32 | |
| 33 | void done() { |
| 34 | if (fCurrScanline != NULL) { |
| 35 | fCurrScanline->fXCount = (SkRegion::RunType)((int)(fCurrXPtr - fCurrScanline->firstX())); |
| 36 | if (!this->collapsWithPrev()) { // flush the last line |
| 37 | fCurrScanline = fCurrScanline->nextScanline(); |
| 38 | } |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | int computeRunCount() const; |
| 43 | void copyToRect(SkIRect*) const; |
| 44 | void copyToRgn(SkRegion::RunType runs[]) const; |
| 45 | |
| 46 | virtual void blitH(int x, int y, int width); |
| 47 | |
| 48 | #ifdef SK_DEBUG |
| 49 | void dump() const { |
| 50 | SkDebugf("SkRgnBuilder: Top = %d\n", fTop); |
| 51 | const Scanline* line = (Scanline*)fStorage; |
| 52 | while (line < fCurrScanline) { |
| 53 | SkDebugf("SkRgnBuilder::Scanline: LastY=%d, fXCount=%d", line->fLastY, line->fXCount); |
| 54 | for (int i = 0; i < line->fXCount; i++) { |
| 55 | SkDebugf(" %d", line->firstX()[i]); |
| 56 | } |
| 57 | SkDebugf("\n"); |
| 58 | |
| 59 | line = line->nextScanline(); |
| 60 | } |
| 61 | } |
| 62 | #endif |
| 63 | private: |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 64 | /* |
| 65 | * Scanline mimics a row in the region, nearly. A row in a region is: |
| 66 | * [Bottom IntervalCount [L R]... Sentinel] |
| 67 | * while a Scanline is |
| 68 | * [LastY XCount [L R]... uninitialized] |
| 69 | * The two are the same length (which is good), but we have to transmute |
| 70 | * the scanline a little when we convert it to a region-row. |
| 71 | * |
| 72 | * Potentially we could recode this to exactly match the row format, in |
| 73 | * which case copyToRgn() could be a single memcpy. Not sure that is worth |
| 74 | * the effort. |
| 75 | */ |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 76 | struct Scanline { |
| 77 | SkRegion::RunType fLastY; |
| 78 | SkRegion::RunType fXCount; |
| 79 | |
| 80 | SkRegion::RunType* firstX() const { return (SkRegion::RunType*)(this + 1); } |
| 81 | Scanline* nextScanline() const { |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 82 | // add final +1 for the x-sentinel |
| 83 | return (Scanline*)((SkRegion::RunType*)(this + 1) + fXCount + 1); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 84 | } |
| 85 | }; |
| 86 | SkRegion::RunType* fStorage; |
| 87 | Scanline* fCurrScanline; |
| 88 | Scanline* fPrevScanline; |
| 89 | // points at next avialable x[] in fCurrScanline |
| 90 | SkRegion::RunType* fCurrXPtr; |
| 91 | SkRegion::RunType fTop; // first Y value |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 92 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 93 | int fStorageCount; |
| 94 | |
| 95 | bool collapsWithPrev() { |
| 96 | if (fPrevScanline != NULL && |
| 97 | fPrevScanline->fLastY + 1 == fCurrScanline->fLastY && |
| 98 | fPrevScanline->fXCount == fCurrScanline->fXCount && |
reed | b8f0798 | 2014-06-20 13:59:15 -0700 | [diff] [blame] | 99 | sk_memeq32(fPrevScanline->firstX(), fCurrScanline->firstX(), fCurrScanline->fXCount)) |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 100 | { |
| 101 | // update the height of fPrevScanline |
| 102 | fPrevScanline->fLastY = fCurrScanline->fLastY; |
| 103 | return true; |
| 104 | } |
| 105 | return false; |
| 106 | } |
| 107 | }; |
| 108 | |
commit-bot@chromium.org | 73be1fc | 2013-12-30 16:21:06 +0000 | [diff] [blame] | 109 | SkRgnBuilder::SkRgnBuilder() |
| 110 | : fStorage(NULL) { |
| 111 | } |
| 112 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 113 | SkRgnBuilder::~SkRgnBuilder() { |
| 114 | sk_free(fStorage); |
| 115 | } |
| 116 | |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 117 | bool SkRgnBuilder::init(int maxHeight, int maxTransitions, bool pathIsInverse) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 118 | if ((maxHeight | maxTransitions) < 0) { |
| 119 | return false; |
| 120 | } |
| 121 | |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 122 | if (pathIsInverse) { |
| 123 | // allow for additional X transitions to "invert" each scanline |
| 124 | // [ L' ... normal transitions ... R' ] |
| 125 | // |
| 126 | maxTransitions += 2; |
| 127 | } |
| 128 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 129 | // compute the count with +1 and +3 slop for the working buffer |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 130 | int64_t count = sk_64_mul(maxHeight + 1, 3 + maxTransitions); |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 131 | |
| 132 | if (pathIsInverse) { |
| 133 | // allow for two "empty" rows for the top and bottom |
| 134 | // [ Y, 1, L, R, S] == 5 (*2 for top and bottom) |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 135 | count += 10; |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 136 | } |
| 137 | |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 138 | if (count < 0 || !sk_64_isS32(count)) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 139 | return false; |
| 140 | } |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 141 | fStorageCount = sk_64_asS32(count); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 142 | |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 143 | int64_t size = sk_64_mul(fStorageCount, sizeof(SkRegion::RunType)); |
| 144 | if (size < 0 || !sk_64_isS32(size)) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 145 | return false; |
| 146 | } |
skia.committer@gmail.com | 4726291 | 2013-10-16 07:02:24 +0000 | [diff] [blame] | 147 | |
reed@google.com | 57212f9 | 2013-12-30 14:40:38 +0000 | [diff] [blame] | 148 | fStorage = (SkRegion::RunType*)sk_malloc_flags(sk_64_asS32(size), 0); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 149 | if (NULL == fStorage) { |
| 150 | return false; |
| 151 | } |
| 152 | |
| 153 | fCurrScanline = NULL; // signal empty collection |
| 154 | fPrevScanline = NULL; // signal first scanline |
| 155 | return true; |
| 156 | } |
| 157 | |
| 158 | void SkRgnBuilder::blitH(int x, int y, int width) { |
| 159 | if (fCurrScanline == NULL) { // first time |
| 160 | fTop = (SkRegion::RunType)(y); |
| 161 | fCurrScanline = (Scanline*)fStorage; |
| 162 | fCurrScanline->fLastY = (SkRegion::RunType)(y); |
| 163 | fCurrXPtr = fCurrScanline->firstX(); |
| 164 | } else { |
| 165 | SkASSERT(y >= fCurrScanline->fLastY); |
| 166 | |
| 167 | if (y > fCurrScanline->fLastY) { |
| 168 | // if we get here, we're done with fCurrScanline |
| 169 | fCurrScanline->fXCount = (SkRegion::RunType)((int)(fCurrXPtr - fCurrScanline->firstX())); |
| 170 | |
| 171 | int prevLastY = fCurrScanline->fLastY; |
| 172 | if (!this->collapsWithPrev()) { |
| 173 | fPrevScanline = fCurrScanline; |
| 174 | fCurrScanline = fCurrScanline->nextScanline(); |
| 175 | |
| 176 | } |
| 177 | if (y - 1 > prevLastY) { // insert empty run |
| 178 | fCurrScanline->fLastY = (SkRegion::RunType)(y - 1); |
| 179 | fCurrScanline->fXCount = 0; |
| 180 | fCurrScanline = fCurrScanline->nextScanline(); |
| 181 | } |
| 182 | // setup for the new curr line |
| 183 | fCurrScanline->fLastY = (SkRegion::RunType)(y); |
| 184 | fCurrXPtr = fCurrScanline->firstX(); |
| 185 | } |
| 186 | } |
| 187 | // check if we should extend the current run, or add a new one |
| 188 | if (fCurrXPtr > fCurrScanline->firstX() && fCurrXPtr[-1] == x) { |
| 189 | fCurrXPtr[-1] = (SkRegion::RunType)(x + width); |
| 190 | } else { |
| 191 | fCurrXPtr[0] = (SkRegion::RunType)(x); |
| 192 | fCurrXPtr[1] = (SkRegion::RunType)(x + width); |
| 193 | fCurrXPtr += 2; |
| 194 | } |
| 195 | SkASSERT(fCurrXPtr - fStorage < fStorageCount); |
| 196 | } |
| 197 | |
| 198 | int SkRgnBuilder::computeRunCount() const { |
| 199 | if (fCurrScanline == NULL) { |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | const SkRegion::RunType* line = fStorage; |
| 204 | const SkRegion::RunType* stop = (const SkRegion::RunType*)fCurrScanline; |
| 205 | |
| 206 | return 2 + (int)(stop - line); |
| 207 | } |
| 208 | |
| 209 | void SkRgnBuilder::copyToRect(SkIRect* r) const { |
| 210 | SkASSERT(fCurrScanline != NULL); |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 211 | // A rect's scanline is [bottom intervals left right sentinel] == 5 |
| 212 | SkASSERT((const SkRegion::RunType*)fCurrScanline - fStorage == 5); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 213 | |
| 214 | const Scanline* line = (const Scanline*)fStorage; |
| 215 | SkASSERT(line->fXCount == 2); |
| 216 | |
| 217 | r->set(line->firstX()[0], fTop, line->firstX()[1], line->fLastY + 1); |
| 218 | } |
| 219 | |
| 220 | void SkRgnBuilder::copyToRgn(SkRegion::RunType runs[]) const { |
| 221 | SkASSERT(fCurrScanline != NULL); |
| 222 | SkASSERT((const SkRegion::RunType*)fCurrScanline - fStorage > 4); |
| 223 | |
| 224 | const Scanline* line = (const Scanline*)fStorage; |
| 225 | const Scanline* stop = fCurrScanline; |
| 226 | |
| 227 | *runs++ = fTop; |
| 228 | do { |
| 229 | *runs++ = (SkRegion::RunType)(line->fLastY + 1); |
| 230 | int count = line->fXCount; |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 231 | *runs++ = count >> 1; // intervalCount |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 232 | if (count) { |
| 233 | memcpy(runs, line->firstX(), count * sizeof(SkRegion::RunType)); |
| 234 | runs += count; |
| 235 | } |
| 236 | *runs++ = SkRegion::kRunTypeSentinel; |
| 237 | line = line->nextScanline(); |
| 238 | } while (line < stop); |
| 239 | SkASSERT(line == stop); |
| 240 | *runs = SkRegion::kRunTypeSentinel; |
| 241 | } |
| 242 | |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 243 | static unsigned verb_to_initial_last_index(unsigned verb) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 244 | static const uint8_t gPathVerbToInitialLastIndex[] = { |
| 245 | 0, // kMove_Verb |
| 246 | 1, // kLine_Verb |
| 247 | 2, // kQuad_Verb |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 248 | 2, // kConic_Verb |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 249 | 3, // kCubic_Verb |
| 250 | 0, // kClose_Verb |
| 251 | 0 // kDone_Verb |
| 252 | }; |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 253 | SkASSERT((unsigned)verb < SK_ARRAY_COUNT(gPathVerbToInitialLastIndex)); |
| 254 | return gPathVerbToInitialLastIndex[verb]; |
| 255 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 256 | |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 257 | static unsigned verb_to_max_edges(unsigned verb) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 258 | static const uint8_t gPathVerbToMaxEdges[] = { |
| 259 | 0, // kMove_Verb |
| 260 | 1, // kLine_Verb |
| 261 | 2, // kQuad_VerbB |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 262 | 2, // kConic_VerbB |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 263 | 3, // kCubic_Verb |
| 264 | 0, // kClose_Verb |
| 265 | 0 // kDone_Verb |
| 266 | }; |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 267 | SkASSERT((unsigned)verb < SK_ARRAY_COUNT(gPathVerbToMaxEdges)); |
| 268 | return gPathVerbToMaxEdges[verb]; |
| 269 | } |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 270 | |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 271 | |
| 272 | static int count_path_runtype_values(const SkPath& path, int* itop, int* ibot) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 273 | SkPath::Iter iter(path, true); |
| 274 | SkPoint pts[4]; |
| 275 | SkPath::Verb verb; |
| 276 | |
| 277 | int maxEdges = 0; |
| 278 | SkScalar top = SkIntToScalar(SK_MaxS16); |
| 279 | SkScalar bot = SkIntToScalar(SK_MinS16); |
| 280 | |
reed@google.com | 4a3b714 | 2012-05-16 17:16:46 +0000 | [diff] [blame] | 281 | while ((verb = iter.next(pts, false)) != SkPath::kDone_Verb) { |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 282 | maxEdges += verb_to_max_edges(verb); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 283 | |
reed@google.com | 277c3f8 | 2013-05-31 15:17:50 +0000 | [diff] [blame] | 284 | int lastIndex = verb_to_initial_last_index(verb); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 285 | if (lastIndex > 0) { |
| 286 | for (int i = 1; i <= lastIndex; i++) { |
| 287 | if (top > pts[i].fY) { |
| 288 | top = pts[i].fY; |
| 289 | } else if (bot < pts[i].fY) { |
| 290 | bot = pts[i].fY; |
| 291 | } |
| 292 | } |
| 293 | } else if (SkPath::kMove_Verb == verb) { |
| 294 | if (top > pts[0].fY) { |
| 295 | top = pts[0].fY; |
| 296 | } else if (bot < pts[0].fY) { |
| 297 | bot = pts[0].fY; |
| 298 | } |
| 299 | } |
| 300 | } |
| 301 | SkASSERT(top <= bot); |
| 302 | |
reed@google.com | e1ca705 | 2013-12-17 19:22:07 +0000 | [diff] [blame] | 303 | *itop = SkScalarRoundToInt(top); |
| 304 | *ibot = SkScalarRoundToInt(bot); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 305 | return maxEdges; |
| 306 | } |
| 307 | |
| 308 | bool SkRegion::setPath(const SkPath& path, const SkRegion& clip) { |
| 309 | SkDEBUGCODE(this->validate();) |
| 310 | |
| 311 | if (clip.isEmpty()) { |
| 312 | return this->setEmpty(); |
| 313 | } |
| 314 | |
| 315 | if (path.isEmpty()) { |
| 316 | if (path.isInverseFillType()) { |
| 317 | return this->set(clip); |
| 318 | } else { |
| 319 | return this->setEmpty(); |
| 320 | } |
| 321 | } |
| 322 | |
| 323 | // compute worst-case rgn-size for the path |
| 324 | int pathTop, pathBot; |
| 325 | int pathTransitions = count_path_runtype_values(path, &pathTop, &pathBot); |
| 326 | int clipTop, clipBot; |
| 327 | int clipTransitions; |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 328 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 329 | clipTransitions = clip.count_runtype_values(&clipTop, &clipBot); |
| 330 | |
| 331 | int top = SkMax32(pathTop, clipTop); |
| 332 | int bot = SkMin32(pathBot, clipBot); |
| 333 | |
| 334 | if (top >= bot) |
| 335 | return this->setEmpty(); |
| 336 | |
| 337 | SkRgnBuilder builder; |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 338 | |
reed@google.com | b58ba89 | 2013-10-15 15:44:35 +0000 | [diff] [blame] | 339 | if (!builder.init(bot - top, |
| 340 | SkMax32(pathTransitions, clipTransitions), |
| 341 | path.isInverseFillType())) { |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 342 | // can't allocate working space, so return false |
| 343 | return this->setEmpty(); |
| 344 | } |
| 345 | |
| 346 | SkScan::FillPath(path, clip, &builder); |
| 347 | builder.done(); |
| 348 | |
| 349 | int count = builder.computeRunCount(); |
| 350 | if (count == 0) { |
| 351 | return this->setEmpty(); |
| 352 | } else if (count == kRectRegionRuns) { |
| 353 | builder.copyToRect(&fBounds); |
| 354 | this->setRect(fBounds); |
| 355 | } else { |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 356 | SkRegion tmp; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 357 | |
| 358 | tmp.fRunHead = RunHead::Alloc(count); |
| 359 | builder.copyToRgn(tmp.fRunHead->writable_runs()); |
reed@google.com | 9c36a76 | 2012-05-02 18:07:33 +0000 | [diff] [blame] | 360 | tmp.fRunHead->computeRunBounds(&tmp.fBounds); |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 361 | this->swap(tmp); |
| 362 | } |
| 363 | SkDEBUGCODE(this->validate();) |
| 364 | return true; |
| 365 | } |
| 366 | |
| 367 | ///////////////////////////////////////////////////////////////////////////////////////////////// |
| 368 | ///////////////////////////////////////////////////////////////////////////////////////////////// |
| 369 | |
| 370 | struct Edge { |
| 371 | enum { |
| 372 | kY0Link = 0x01, |
| 373 | kY1Link = 0x02, |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 374 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 375 | kCompleteLink = (kY0Link | kY1Link) |
| 376 | }; |
| 377 | |
| 378 | SkRegion::RunType fX; |
| 379 | SkRegion::RunType fY0, fY1; |
| 380 | uint8_t fFlags; |
| 381 | Edge* fNext; |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 382 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 383 | void set(int x, int y0, int y1) { |
| 384 | SkASSERT(y0 != y1); |
| 385 | |
| 386 | fX = (SkRegion::RunType)(x); |
| 387 | fY0 = (SkRegion::RunType)(y0); |
| 388 | fY1 = (SkRegion::RunType)(y1); |
| 389 | fFlags = 0; |
| 390 | SkDEBUGCODE(fNext = NULL;) |
| 391 | } |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 392 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 393 | int top() const { |
| 394 | return SkFastMin32(fY0, fY1); |
| 395 | } |
| 396 | }; |
| 397 | |
| 398 | static void find_link(Edge* base, Edge* stop) { |
| 399 | SkASSERT(base < stop); |
| 400 | |
| 401 | if (base->fFlags == Edge::kCompleteLink) { |
| 402 | SkASSERT(base->fNext); |
| 403 | return; |
| 404 | } |
| 405 | |
| 406 | SkASSERT(base + 1 < stop); |
| 407 | |
| 408 | int y0 = base->fY0; |
| 409 | int y1 = base->fY1; |
| 410 | |
| 411 | Edge* e = base; |
| 412 | if ((base->fFlags & Edge::kY0Link) == 0) { |
| 413 | for (;;) { |
| 414 | e += 1; |
| 415 | if ((e->fFlags & Edge::kY1Link) == 0 && y0 == e->fY1) { |
| 416 | SkASSERT(NULL == e->fNext); |
| 417 | e->fNext = base; |
| 418 | e->fFlags = SkToU8(e->fFlags | Edge::kY1Link); |
| 419 | break; |
| 420 | } |
| 421 | } |
| 422 | } |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 423 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 424 | e = base; |
| 425 | if ((base->fFlags & Edge::kY1Link) == 0) { |
| 426 | for (;;) { |
| 427 | e += 1; |
| 428 | if ((e->fFlags & Edge::kY0Link) == 0 && y1 == e->fY0) { |
| 429 | SkASSERT(NULL == base->fNext); |
| 430 | base->fNext = e; |
| 431 | e->fFlags = SkToU8(e->fFlags | Edge::kY0Link); |
| 432 | break; |
| 433 | } |
| 434 | } |
| 435 | } |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 436 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 437 | base->fFlags = Edge::kCompleteLink; |
| 438 | } |
| 439 | |
| 440 | static int extract_path(Edge* edge, Edge* stop, SkPath* path) { |
| 441 | while (0 == edge->fFlags) { |
| 442 | edge++; // skip over "used" edges |
| 443 | } |
| 444 | |
| 445 | SkASSERT(edge < stop); |
| 446 | |
| 447 | Edge* base = edge; |
| 448 | Edge* prev = edge; |
| 449 | edge = edge->fNext; |
| 450 | SkASSERT(edge != base); |
| 451 | |
| 452 | int count = 1; |
| 453 | path->moveTo(SkIntToScalar(prev->fX), SkIntToScalar(prev->fY0)); |
| 454 | prev->fFlags = 0; |
| 455 | do { |
| 456 | if (prev->fX != edge->fX || prev->fY1 != edge->fY0) { // skip collinear |
| 457 | path->lineTo(SkIntToScalar(prev->fX), SkIntToScalar(prev->fY1)); // V |
| 458 | path->lineTo(SkIntToScalar(edge->fX), SkIntToScalar(edge->fY0)); // H |
| 459 | } |
| 460 | prev = edge; |
| 461 | edge = edge->fNext; |
| 462 | count += 1; |
| 463 | prev->fFlags = 0; |
| 464 | } while (edge != base); |
| 465 | path->lineTo(SkIntToScalar(prev->fX), SkIntToScalar(prev->fY1)); // V |
| 466 | path->close(); |
| 467 | return count; |
| 468 | } |
| 469 | |
| 470 | #include "SkTSearch.h" |
| 471 | |
| 472 | static int EdgeProc(const Edge* a, const Edge* b) { |
| 473 | return (a->fX == b->fX) ? a->top() - b->top() : a->fX - b->fX; |
| 474 | } |
| 475 | |
| 476 | bool SkRegion::getBoundaryPath(SkPath* path) const { |
tomhudson@google.com | d5d9dad | 2012-01-03 14:52:37 +0000 | [diff] [blame] | 477 | // path could safely be NULL if we're empty, but the caller shouldn't |
| 478 | // *know* that |
| 479 | SkASSERT(path); |
| 480 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 481 | if (this->isEmpty()) { |
| 482 | return false; |
| 483 | } |
| 484 | |
| 485 | const SkIRect& bounds = this->getBounds(); |
| 486 | |
| 487 | if (this->isRect()) { |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 488 | SkRect r; |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 489 | r.set(bounds); // this converts the ints to scalars |
| 490 | path->addRect(r); |
| 491 | return true; |
| 492 | } |
| 493 | |
| 494 | SkRegion::Iterator iter(*this); |
| 495 | SkTDArray<Edge> edges; |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 496 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 497 | for (const SkIRect& r = iter.rect(); !iter.done(); iter.next()) { |
| 498 | Edge* edge = edges.append(2); |
| 499 | edge[0].set(r.fLeft, r.fBottom, r.fTop); |
| 500 | edge[1].set(r.fRight, r.fTop, r.fBottom); |
| 501 | } |
reed@google.com | c7a67cb | 2012-05-07 14:52:12 +0000 | [diff] [blame] | 502 | qsort(edges.begin(), edges.count(), sizeof(Edge), SkCastForQSort(EdgeProc)); |
rmistry@google.com | fbfcd56 | 2012-08-23 18:09:54 +0000 | [diff] [blame] | 503 | |
reed@android.com | 8a1c16f | 2008-12-17 15:59:43 +0000 | [diff] [blame] | 504 | int count = edges.count(); |
| 505 | Edge* start = edges.begin(); |
| 506 | Edge* stop = start + count; |
| 507 | Edge* e; |
| 508 | |
| 509 | for (e = start; e != stop; e++) { |
| 510 | find_link(e, stop); |
| 511 | } |
| 512 | |
| 513 | #ifdef SK_DEBUG |
| 514 | for (e = start; e != stop; e++) { |
| 515 | SkASSERT(e->fNext != NULL); |
| 516 | SkASSERT(e->fFlags == Edge::kCompleteLink); |
| 517 | } |
| 518 | #endif |
| 519 | |
| 520 | path->incReserve(count << 1); |
| 521 | do { |
| 522 | SkASSERT(count > 1); |
| 523 | count -= extract_path(start, stop, path); |
| 524 | } while (count > 0); |
| 525 | |
| 526 | return true; |
| 527 | } |