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      1 /*
      2  * Copyright 2011 Google Inc.
      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 #include "SkDevice.h"
      9 #include "SkColorFilter.h"
     10 #include "SkDraw.h"
     11 #include "SkDrawFilter.h"
     12 #include "SkImageCacherator.h"
     13 #include "SkImageFilter.h"
     14 #include "SkImageFilterCache.h"
     15 #include "SkImagePriv.h"
     16 #include "SkImage_Base.h"
     17 #include "SkLatticeIter.h"
     18 #include "SkPatchUtils.h"
     19 #include "SkPathMeasure.h"
     20 #include "SkPathPriv.h"
     21 #include "SkRSXform.h"
     22 #include "SkRasterClip.h"
     23 #include "SkShader.h"
     24 #include "SkSpecialImage.h"
     25 #include "SkTLazy.h"
     26 #include "SkTextBlobRunIterator.h"
     27 #include "SkTextToPathIter.h"
     28 #include "SkVertices.h"
     29 
     30 SkBaseDevice::SkBaseDevice(const SkImageInfo& info, const SkSurfaceProps& surfaceProps)
     31     : fInfo(info)
     32     , fSurfaceProps(surfaceProps)
     33 {
     34     fOrigin.setZero();
     35     fCTM.reset();
     36 }
     37 
     38 void SkBaseDevice::setOrigin(const SkMatrix& globalCTM, int x, int y) {
     39     fOrigin.set(x, y);
     40     fCTM = globalCTM;
     41     fCTM.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
     42 }
     43 
     44 void SkBaseDevice::setGlobalCTM(const SkMatrix& ctm) {
     45     fCTM = ctm;
     46     if (fOrigin.fX | fOrigin.fY) {
     47         fCTM.postTranslate(-SkIntToScalar(fOrigin.fX), -SkIntToScalar(fOrigin.fY));
     48     }
     49 }
     50 
     51 bool SkBaseDevice::clipIsWideOpen() const {
     52     if (kRect_ClipType == this->onGetClipType()) {
     53         SkRegion rgn;
     54         this->onAsRgnClip(&rgn);
     55         SkASSERT(rgn.isRect());
     56         return rgn.getBounds() == SkIRect::MakeWH(this->width(), this->height());
     57     } else {
     58         return false;
     59     }
     60 }
     61 
     62 SkPixelGeometry SkBaseDevice::CreateInfo::AdjustGeometry(const SkImageInfo& info,
     63                                                          TileUsage tileUsage,
     64                                                          SkPixelGeometry geo,
     65                                                          bool preserveLCDText) {
     66     switch (tileUsage) {
     67         case kPossible_TileUsage:
     68             // (we think) for compatibility with old clients, we assume this layer can support LCD
     69             // even though they may not have marked it as opaque... seems like we should update
     70             // our callers (reed/robertphilips).
     71             break;
     72         case kNever_TileUsage:
     73             if (!preserveLCDText) {
     74                 geo = kUnknown_SkPixelGeometry;
     75             }
     76             break;
     77     }
     78     return geo;
     79 }
     80 
     81 static inline bool is_int(float x) {
     82     return x == (float) sk_float_round2int(x);
     83 }
     84 
     85 void SkBaseDevice::drawRegion(const SkRegion& region, const SkPaint& paint) {
     86     const SkMatrix& ctm = this->ctm();
     87     bool isNonTranslate = ctm.getType() & ~(SkMatrix::kTranslate_Mask);
     88     bool complexPaint = paint.getStyle() != SkPaint::kFill_Style || paint.getMaskFilter() ||
     89                         paint.getPathEffect();
     90     bool antiAlias = paint.isAntiAlias() && (!is_int(ctm.getTranslateX()) ||
     91                                              !is_int(ctm.getTranslateY()));
     92     if (isNonTranslate || complexPaint || antiAlias) {
     93         SkPath path;
     94         region.getBoundaryPath(&path);
     95         return this->drawPath(path, paint, nullptr, false);
     96     }
     97 
     98     SkRegion::Iterator it(region);
     99     while (!it.done()) {
    100         this->drawRect(SkRect::Make(it.rect()), paint);
    101         it.next();
    102     }
    103 }
    104 
    105 void SkBaseDevice::drawArc(const SkRect& oval, SkScalar startAngle,
    106                            SkScalar sweepAngle, bool useCenter, const SkPaint& paint) {
    107     SkPath path;
    108     bool isFillNoPathEffect = SkPaint::kFill_Style == paint.getStyle() && !paint.getPathEffect();
    109     SkPathPriv::CreateDrawArcPath(&path, oval, startAngle, sweepAngle, useCenter,
    110                                   isFillNoPathEffect);
    111     this->drawPath(path, paint);
    112 }
    113 
    114 void SkBaseDevice::drawDRRect(const SkRRect& outer,
    115                               const SkRRect& inner, const SkPaint& paint) {
    116     SkPath path;
    117     path.addRRect(outer);
    118     path.addRRect(inner);
    119     path.setFillType(SkPath::kEvenOdd_FillType);
    120     path.setIsVolatile(true);
    121 
    122     const SkMatrix* preMatrix = nullptr;
    123     const bool pathIsMutable = true;
    124     this->drawPath(path, paint, preMatrix, pathIsMutable);
    125 }
    126 
    127 void SkBaseDevice::drawPatch(const SkPoint cubics[12], const SkColor colors[4],
    128                              const SkPoint texCoords[4], SkBlendMode bmode, const SkPaint& paint) {
    129     SkPatchUtils::VertexData data;
    130 
    131     SkISize lod = SkPatchUtils::GetLevelOfDetail(cubics, &this->ctm());
    132     auto vertices = SkPatchUtils::MakeVertices(cubics, colors, texCoords, lod.width(), lod.height());
    133     if (vertices) {
    134         this->drawVertices(vertices.get(), bmode, paint);
    135     }
    136 }
    137 
    138 void SkBaseDevice::drawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
    139                                 const SkPaint &paint, SkDrawFilter* drawFilter) {
    140 
    141     SkPaint runPaint = paint;
    142 
    143     SkTextBlobRunIterator it(blob);
    144     for (;!it.done(); it.next()) {
    145         size_t textLen = it.glyphCount() * sizeof(uint16_t);
    146         const SkPoint& offset = it.offset();
    147         // applyFontToPaint() always overwrites the exact same attributes,
    148         // so it is safe to not re-seed the paint for this reason.
    149         it.applyFontToPaint(&runPaint);
    150 
    151         if (drawFilter && !drawFilter->filter(&runPaint, SkDrawFilter::kText_Type)) {
    152             // A false return from filter() means we should abort the current draw.
    153             runPaint = paint;
    154             continue;
    155         }
    156 
    157         runPaint.setFlags(this->filterTextFlags(runPaint));
    158 
    159         switch (it.positioning()) {
    160         case SkTextBlob::kDefault_Positioning:
    161             this->drawText(it.glyphs(), textLen, x + offset.x(), y + offset.y(), runPaint);
    162             break;
    163         case SkTextBlob::kHorizontal_Positioning:
    164             this->drawPosText(it.glyphs(), textLen, it.pos(), 1,
    165                               SkPoint::Make(x, y + offset.y()), runPaint);
    166             break;
    167         case SkTextBlob::kFull_Positioning:
    168             this->drawPosText(it.glyphs(), textLen, it.pos(), 2,
    169                               SkPoint::Make(x, y), runPaint);
    170             break;
    171         default:
    172             SkFAIL("unhandled positioning mode");
    173         }
    174 
    175         if (drawFilter) {
    176             // A draw filter may change the paint arbitrarily, so we must re-seed in this case.
    177             runPaint = paint;
    178         }
    179     }
    180 }
    181 
    182 void SkBaseDevice::drawImage(const SkImage* image, SkScalar x, SkScalar y,
    183                              const SkPaint& paint) {
    184     SkBitmap bm;
    185     if (as_IB(image)->getROPixels(&bm, this->imageInfo().colorSpace())) {
    186         this->drawBitmap(bm, SkMatrix::MakeTrans(x, y), paint);
    187     }
    188 }
    189 
    190 void SkBaseDevice::drawImageRect(const SkImage* image, const SkRect* src,
    191                                  const SkRect& dst, const SkPaint& paint,
    192                                  SkCanvas::SrcRectConstraint constraint) {
    193     SkBitmap bm;
    194     if (as_IB(image)->getROPixels(&bm, this->imageInfo().colorSpace())) {
    195         this->drawBitmapRect(bm, src, dst, paint, constraint);
    196     }
    197 }
    198 
    199 void SkBaseDevice::drawImageNine(const SkImage* image, const SkIRect& center,
    200                                  const SkRect& dst, const SkPaint& paint) {
    201     SkLatticeIter iter(image->width(), image->height(), center, dst);
    202 
    203     SkRect srcR, dstR;
    204     while (iter.next(&srcR, &dstR)) {
    205         this->drawImageRect(image, &srcR, dstR, paint, SkCanvas::kStrict_SrcRectConstraint);
    206     }
    207 }
    208 
    209 void SkBaseDevice::drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center,
    210                                   const SkRect& dst, const SkPaint& paint) {
    211     SkLatticeIter iter(bitmap.width(), bitmap.height(), center, dst);
    212 
    213     SkRect srcR, dstR;
    214     while (iter.next(&srcR, &dstR)) {
    215         this->drawBitmapRect(bitmap, &srcR, dstR, paint, SkCanvas::kStrict_SrcRectConstraint);
    216     }
    217 }
    218 
    219 void SkBaseDevice::drawImageLattice(const SkImage* image,
    220                                     const SkCanvas::Lattice& lattice, const SkRect& dst,
    221                                     const SkPaint& paint) {
    222     SkLatticeIter iter(lattice, dst);
    223 
    224     SkRect srcR, dstR;
    225     while (iter.next(&srcR, &dstR)) {
    226         this->drawImageRect(image, &srcR, dstR, paint, SkCanvas::kStrict_SrcRectConstraint);
    227     }
    228 }
    229 
    230 void SkBaseDevice::drawBitmapLattice(const SkBitmap& bitmap,
    231                                      const SkCanvas::Lattice& lattice, const SkRect& dst,
    232                                      const SkPaint& paint) {
    233     SkLatticeIter iter(lattice, dst);
    234 
    235     SkRect srcR, dstR;
    236     while (iter.next(&srcR, &dstR)) {
    237         this->drawBitmapRect(bitmap, &srcR, dstR, paint, SkCanvas::kStrict_SrcRectConstraint);
    238     }
    239 }
    240 
    241 void SkBaseDevice::drawAtlas(const SkImage* atlas, const SkRSXform xform[],
    242                              const SkRect tex[], const SkColor colors[], int count,
    243                              SkBlendMode mode, const SkPaint& paint) {
    244     SkPath path;
    245     path.setIsVolatile(true);
    246 
    247     for (int i = 0; i < count; ++i) {
    248         SkPoint quad[4];
    249         xform[i].toQuad(tex[i].width(), tex[i].height(), quad);
    250 
    251         SkMatrix localM;
    252         localM.setRSXform(xform[i]);
    253         localM.preTranslate(-tex[i].left(), -tex[i].top());
    254 
    255         SkPaint pnt(paint);
    256         sk_sp<SkShader> shader = atlas->makeShader(SkShader::kClamp_TileMode,
    257                                                    SkShader::kClamp_TileMode,
    258                                                    &localM);
    259         if (!shader) {
    260             break;
    261         }
    262         pnt.setShader(std::move(shader));
    263 
    264         if (colors) {
    265             pnt.setColorFilter(SkColorFilter::MakeModeFilter(colors[i], (SkBlendMode)mode));
    266         }
    267 
    268         path.rewind();
    269         path.addPoly(quad, 4, true);
    270         path.setConvexity(SkPath::kConvex_Convexity);
    271         this->drawPath(path, pnt, nullptr, true);
    272     }
    273 }
    274 
    275 ///////////////////////////////////////////////////////////////////////////////////////////////////
    276 
    277 void SkBaseDevice::drawSpecial(SkSpecialImage*, int x, int y, const SkPaint&) {}
    278 sk_sp<SkSpecialImage> SkBaseDevice::makeSpecial(const SkBitmap&) { return nullptr; }
    279 sk_sp<SkSpecialImage> SkBaseDevice::makeSpecial(const SkImage*) { return nullptr; }
    280 sk_sp<SkSpecialImage> SkBaseDevice::snapSpecial() { return nullptr; }
    281 
    282 ///////////////////////////////////////////////////////////////////////////////////////////////////
    283 
    284 bool SkBaseDevice::readPixels(const SkImageInfo& info, void* dstP, size_t rowBytes, int x, int y) {
    285     return this->onReadPixels(info, dstP, rowBytes, x, y);
    286 }
    287 
    288 bool SkBaseDevice::writePixels(const SkImageInfo& info, const void* pixels, size_t rowBytes,
    289                                int x, int y) {
    290     return this->onWritePixels(info, pixels, rowBytes, x, y);
    291 }
    292 
    293 bool SkBaseDevice::onWritePixels(const SkImageInfo&, const void*, size_t, int, int) {
    294     return false;
    295 }
    296 
    297 bool SkBaseDevice::onReadPixels(const SkImageInfo&, void*, size_t, int x, int y) {
    298     return false;
    299 }
    300 
    301 bool SkBaseDevice::accessPixels(SkPixmap* pmap) {
    302     SkPixmap tempStorage;
    303     if (nullptr == pmap) {
    304         pmap = &tempStorage;
    305     }
    306     return this->onAccessPixels(pmap);
    307 }
    308 
    309 bool SkBaseDevice::peekPixels(SkPixmap* pmap) {
    310     SkPixmap tempStorage;
    311     if (nullptr == pmap) {
    312         pmap = &tempStorage;
    313     }
    314     return this->onPeekPixels(pmap);
    315 }
    316 
    317 //////////////////////////////////////////////////////////////////////////////////////////
    318 
    319 static void morphpoints(SkPoint dst[], const SkPoint src[], int count,
    320                         SkPathMeasure& meas, const SkMatrix& matrix) {
    321     SkMatrix::MapXYProc proc = matrix.getMapXYProc();
    322 
    323     for (int i = 0; i < count; i++) {
    324         SkPoint pos;
    325         SkVector tangent;
    326 
    327         proc(matrix, src[i].fX, src[i].fY, &pos);
    328         SkScalar sx = pos.fX;
    329         SkScalar sy = pos.fY;
    330 
    331         if (!meas.getPosTan(sx, &pos, &tangent)) {
    332             // set to 0 if the measure failed, so that we just set dst == pos
    333             tangent.set(0, 0);
    334         }
    335 
    336         /*  This is the old way (that explains our approach but is way too slow
    337          SkMatrix    matrix;
    338          SkPoint     pt;
    339 
    340          pt.set(sx, sy);
    341          matrix.setSinCos(tangent.fY, tangent.fX);
    342          matrix.preTranslate(-sx, 0);
    343          matrix.postTranslate(pos.fX, pos.fY);
    344          matrix.mapPoints(&dst[i], &pt, 1);
    345          */
    346         dst[i].set(pos.fX - tangent.fY * sy, pos.fY + tangent.fX * sy);
    347     }
    348 }
    349 
    350 /*  TODO
    351 
    352  Need differentially more subdivisions when the follow-path is curvy. Not sure how to
    353  determine that, but we need it. I guess a cheap answer is let the caller tell us,
    354  but that seems like a cop-out. Another answer is to get Rob Johnson to figure it out.
    355  */
    356 static void morphpath(SkPath* dst, const SkPath& src, SkPathMeasure& meas,
    357                       const SkMatrix& matrix) {
    358     SkPath::Iter    iter(src, false);
    359     SkPoint         srcP[4], dstP[3];
    360     SkPath::Verb    verb;
    361 
    362     while ((verb = iter.next(srcP)) != SkPath::kDone_Verb) {
    363         switch (verb) {
    364             case SkPath::kMove_Verb:
    365                 morphpoints(dstP, srcP, 1, meas, matrix);
    366                 dst->moveTo(dstP[0]);
    367                 break;
    368             case SkPath::kLine_Verb:
    369                 // turn lines into quads to look bendy
    370                 srcP[0].fX = SkScalarAve(srcP[0].fX, srcP[1].fX);
    371                 srcP[0].fY = SkScalarAve(srcP[0].fY, srcP[1].fY);
    372                 morphpoints(dstP, srcP, 2, meas, matrix);
    373                 dst->quadTo(dstP[0], dstP[1]);
    374                 break;
    375             case SkPath::kQuad_Verb:
    376                 morphpoints(dstP, &srcP[1], 2, meas, matrix);
    377                 dst->quadTo(dstP[0], dstP[1]);
    378                 break;
    379             case SkPath::kCubic_Verb:
    380                 morphpoints(dstP, &srcP[1], 3, meas, matrix);
    381                 dst->cubicTo(dstP[0], dstP[1], dstP[2]);
    382                 break;
    383             case SkPath::kClose_Verb:
    384                 dst->close();
    385                 break;
    386             default:
    387                 SkDEBUGFAIL("unknown verb");
    388                 break;
    389         }
    390     }
    391 }
    392 
    393 void SkBaseDevice::drawTextOnPath(const void* text, size_t byteLength,
    394                                   const SkPath& follow, const SkMatrix* matrix,
    395                                   const SkPaint& paint) {
    396     SkASSERT(byteLength == 0 || text != nullptr);
    397 
    398     // nothing to draw
    399     if (text == nullptr || byteLength == 0) {
    400         return;
    401     }
    402 
    403     SkTextToPathIter    iter((const char*)text, byteLength, paint, true);
    404     SkPathMeasure       meas(follow, false);
    405     SkScalar            hOffset = 0;
    406 
    407     // need to measure first
    408     if (paint.getTextAlign() != SkPaint::kLeft_Align) {
    409         SkScalar pathLen = meas.getLength();
    410         if (paint.getTextAlign() == SkPaint::kCenter_Align) {
    411             pathLen = SkScalarHalf(pathLen);
    412         }
    413         hOffset += pathLen;
    414     }
    415 
    416     const SkPath*   iterPath;
    417     SkScalar        xpos;
    418     SkMatrix        scaledMatrix;
    419     SkScalar        scale = iter.getPathScale();
    420 
    421     scaledMatrix.setScale(scale, scale);
    422 
    423     while (iter.next(&iterPath, &xpos)) {
    424         if (iterPath) {
    425             SkPath      tmp;
    426             SkMatrix    m(scaledMatrix);
    427 
    428             tmp.setIsVolatile(true);
    429             m.postTranslate(xpos + hOffset, 0);
    430             if (matrix) {
    431                 m.postConcat(*matrix);
    432             }
    433             morphpath(&tmp, *iterPath, meas, m);
    434             this->drawPath(tmp, iter.getPaint(), nullptr, true);
    435         }
    436     }
    437 }
    438 
    439 #include "SkUtils.h"
    440 typedef int (*CountTextProc)(const char* text);
    441 static int count_utf16(const char* text) {
    442     const uint16_t* prev = (uint16_t*)text;
    443     (void)SkUTF16_NextUnichar(&prev);
    444     return SkToInt((const char*)prev - text);
    445 }
    446 static int return_4(const char* text) { return 4; }
    447 static int return_2(const char* text) { return 2; }
    448 
    449 void SkBaseDevice::drawTextRSXform(const void* text, size_t len,
    450                                    const SkRSXform xform[], const SkPaint& paint) {
    451     CountTextProc proc = nullptr;
    452     switch (paint.getTextEncoding()) {
    453         case SkPaint::kUTF8_TextEncoding:
    454             proc = SkUTF8_CountUTF8Bytes;
    455             break;
    456         case SkPaint::kUTF16_TextEncoding:
    457             proc = count_utf16;
    458             break;
    459         case SkPaint::kUTF32_TextEncoding:
    460             proc = return_4;
    461             break;
    462         case SkPaint::kGlyphID_TextEncoding:
    463             proc = return_2;
    464             break;
    465     }
    466 
    467     SkMatrix localM, currM;
    468     const void* stopText = (const char*)text + len;
    469     while ((const char*)text < (const char*)stopText) {
    470         localM.setRSXform(*xform++);
    471         currM.setConcat(this->ctm(), localM);
    472         SkAutoDeviceCTMRestore adc(this, currM);
    473 
    474         int subLen = proc((const char*)text);
    475         this->drawText(text, subLen, 0, 0, paint);
    476         text = (const char*)text + subLen;
    477     }
    478 }
    479 
    480 //////////////////////////////////////////////////////////////////////////////////////////
    481 
    482 uint32_t SkBaseDevice::filterTextFlags(const SkPaint& paint) const {
    483     uint32_t flags = paint.getFlags();
    484 
    485     if (!paint.isLCDRenderText() || !paint.isAntiAlias()) {
    486         return flags;
    487     }
    488 
    489     if (kUnknown_SkPixelGeometry == fSurfaceProps.pixelGeometry()
    490         || this->onShouldDisableLCD(paint)) {
    491 
    492         flags &= ~SkPaint::kLCDRenderText_Flag;
    493         flags |= SkPaint::kGenA8FromLCD_Flag;
    494     }
    495 
    496     return flags;
    497 }
    498 
    499 sk_sp<SkSurface> SkBaseDevice::makeSurface(SkImageInfo const&, SkSurfaceProps const&) {
    500     return nullptr;
    501 }
    502 
    503 //////////////////////////////////////////////////////////////////////////////////////////
    504 
    505 void SkBaseDevice::LogDrawScaleFactor(const SkMatrix& matrix, SkFilterQuality filterQuality) {
    506 #if SK_HISTOGRAMS_ENABLED
    507     enum ScaleFactor {
    508         kUpscale_ScaleFactor,
    509         kNoScale_ScaleFactor,
    510         kDownscale_ScaleFactor,
    511         kLargeDownscale_ScaleFactor,
    512 
    513         kLast_ScaleFactor = kLargeDownscale_ScaleFactor
    514     };
    515 
    516     float rawScaleFactor = matrix.getMinScale();
    517 
    518     ScaleFactor scaleFactor;
    519     if (rawScaleFactor < 0.5f) {
    520         scaleFactor = kLargeDownscale_ScaleFactor;
    521     } else if (rawScaleFactor < 1.0f) {
    522         scaleFactor = kDownscale_ScaleFactor;
    523     } else if (rawScaleFactor > 1.0f) {
    524         scaleFactor = kUpscale_ScaleFactor;
    525     } else {
    526         scaleFactor = kNoScale_ScaleFactor;
    527     }
    528 
    529     switch (filterQuality) {
    530         case kNone_SkFilterQuality:
    531             SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.NoneFilterQuality", scaleFactor,
    532                                      kLast_ScaleFactor + 1);
    533             break;
    534         case kLow_SkFilterQuality:
    535             SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.LowFilterQuality", scaleFactor,
    536                                      kLast_ScaleFactor + 1);
    537             break;
    538         case kMedium_SkFilterQuality:
    539             SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.MediumFilterQuality", scaleFactor,
    540                                      kLast_ScaleFactor + 1);
    541             break;
    542         case kHigh_SkFilterQuality:
    543             SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.HighFilterQuality", scaleFactor,
    544                                      kLast_ScaleFactor + 1);
    545             break;
    546     }
    547 
    548     // Also log filter quality independent scale factor.
    549     SK_HISTOGRAM_ENUMERATION("DrawScaleFactor.AnyFilterQuality", scaleFactor,
    550                              kLast_ScaleFactor + 1);
    551 
    552     // Also log an overall histogram of filter quality.
    553     SK_HISTOGRAM_ENUMERATION("FilterQuality", filterQuality, kLast_SkFilterQuality + 1);
    554 #endif
    555 }
    556 
    557