| /* |
| * Copyright 2014 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkTextBlob.h" |
| |
| #include "SkReadBuffer.h" |
| #include "SkWriteBuffer.h" |
| |
| // |
| // Textblob data is laid out into externally-managed storage as follows: |
| // |
| // ----------------------------------------------------------------------------- |
| // | SkTextBlob | RunRecord | Glyphs[] | Pos[] | RunRecord | Glyphs[] | Pos[] | ... |
| // ----------------------------------------------------------------------------- |
| // |
| // Each run record describes a text blob run, and can be used to determine the (implicit) |
| // location of the following record. |
| |
| SkDEBUGCODE(static const unsigned kRunRecordMagic = 0xb10bcafe;) |
| |
| class SkTextBlob::RunRecord { |
| public: |
| RunRecord(uint32_t count, const SkPoint& offset, const SkPaint& font, GlyphPositioning pos) |
| : fCount(count) |
| , fOffset(offset) |
| , fFont(font) |
| , fPositioning(pos) { |
| SkDEBUGCODE(fMagic = kRunRecordMagic); |
| } |
| |
| uint32_t glyphCount() const { |
| return fCount; |
| } |
| |
| const SkPoint& offset() const { |
| return fOffset; |
| } |
| |
| const SkPaint& font() const { |
| return fFont; |
| } |
| |
| GlyphPositioning positioning() const { |
| return fPositioning; |
| } |
| |
| uint16_t* glyphBuffer() const { |
| // Glyph are stored immediately following the record. |
| return reinterpret_cast<uint16_t*>(const_cast<RunRecord*>(this) + 1); |
| } |
| |
| SkScalar* posBuffer() const { |
| // Position scalars follow the (aligned) glyph buffer. |
| return reinterpret_cast<SkScalar*>(reinterpret_cast<uint8_t*>(this->glyphBuffer()) + |
| SkAlign4(fCount * sizeof(uint16_t))); |
| } |
| |
| static size_t StorageSize(int glyphCount, SkTextBlob::GlyphPositioning positioning) { |
| // RunRecord object + (aligned) glyph buffer + position buffer |
| return SkAlignPtr(sizeof(SkTextBlob::RunRecord) |
| + SkAlign4(glyphCount* sizeof(uint16_t)) |
| + glyphCount * sizeof(SkScalar) * ScalarsPerGlyph(positioning)); |
| } |
| |
| static const RunRecord* First(const SkTextBlob* blob) { |
| // The first record (if present) is stored following the blob object. |
| return reinterpret_cast<const RunRecord*>(blob + 1); |
| } |
| |
| static const RunRecord* Next(const RunRecord* run) { |
| return reinterpret_cast<const RunRecord*>(reinterpret_cast<const uint8_t*>(run) |
| + StorageSize(run->glyphCount(), run->positioning())); |
| } |
| |
| void validate(uint8_t* storageTop) const { |
| SkASSERT(kRunRecordMagic == fMagic); |
| SkASSERT((uint8_t*)Next(this) <= storageTop); |
| SkASSERT(glyphBuffer() + fCount <= (uint16_t*)posBuffer()); |
| SkASSERT(posBuffer() + fCount * ScalarsPerGlyph(fPositioning) <= (SkScalar*)Next(this)); |
| } |
| |
| private: |
| friend class SkTextBlobBuilder; |
| |
| void grow(uint32_t count) { |
| SkScalar* initialPosBuffer = posBuffer(); |
| uint32_t initialCount = fCount; |
| fCount += count; |
| |
| // Move the initial pos scalars to their new location. |
| size_t copySize = initialCount * sizeof(SkScalar) * ScalarsPerGlyph(fPositioning); |
| SkASSERT((uint8_t*)posBuffer() + copySize <= (uint8_t*)Next(this)); |
| |
| // memmove, as the buffers may overlap |
| memmove(posBuffer(), initialPosBuffer, copySize); |
| } |
| |
| uint32_t fCount; |
| SkPoint fOffset; |
| SkPaint fFont; |
| GlyphPositioning fPositioning; |
| |
| SkDEBUGCODE(unsigned fMagic;) |
| }; |
| |
| SkTextBlob::SkTextBlob(int runCount, const SkRect& bounds) |
| : fRunCount(runCount) |
| , fBounds(bounds) { |
| } |
| |
| SkTextBlob::~SkTextBlob() { |
| const RunRecord* run = RunRecord::First(this); |
| for (int i = 0; i < fRunCount; ++i) { |
| const RunRecord* nextRun = RunRecord::Next(run); |
| SkDEBUGCODE(run->validate((uint8_t*)this + fStorageSize);) |
| run->~RunRecord(); |
| run = nextRun; |
| } |
| } |
| |
| void SkTextBlob::internal_dispose() const { |
| // SkTextBlobs use externally-managed storage. |
| this->internal_dispose_restore_refcnt_to_1(); |
| this->~SkTextBlob(); |
| sk_free(const_cast<SkTextBlob*>(this)); |
| } |
| |
| uint32_t SkTextBlob::uniqueID() const { |
| static int32_t gTextBlobGenerationID; // = 0; |
| |
| // loop in case our global wraps around, as we never want to return SK_InvalidGenID |
| while (SK_InvalidGenID == fUniqueID) { |
| fUniqueID = sk_atomic_inc(&gTextBlobGenerationID) + 1; |
| } |
| |
| return fUniqueID; |
| } |
| |
| void SkTextBlob::flatten(SkWriteBuffer& buffer) const { |
| int runCount = fRunCount; |
| |
| buffer.write32(runCount); |
| buffer.writeRect(fBounds); |
| |
| SkPaint runPaint; |
| RunIterator it(this); |
| while (!it.done()) { |
| SkASSERT(it.glyphCount() > 0); |
| |
| buffer.write32(it.glyphCount()); |
| buffer.write32(it.positioning()); |
| buffer.writePoint(it.offset()); |
| // This should go away when switching to SkFont |
| it.applyFontToPaint(&runPaint); |
| buffer.writePaint(runPaint); |
| |
| buffer.writeByteArray(it.glyphs(), it.glyphCount() * sizeof(uint16_t)); |
| buffer.writeByteArray(it.pos(), |
| it.glyphCount() * sizeof(SkScalar) * ScalarsPerGlyph(it.positioning())); |
| |
| it.next(); |
| SkDEBUGCODE(runCount--); |
| } |
| SkASSERT(0 == runCount); |
| } |
| |
| const SkTextBlob* SkTextBlob::CreateFromBuffer(SkReadBuffer& reader) { |
| int runCount = reader.read32(); |
| if (runCount < 0) { |
| return NULL; |
| } |
| |
| SkRect bounds; |
| reader.readRect(&bounds); |
| |
| SkTextBlobBuilder blobBuilder; |
| for (int i = 0; i < runCount; ++i) { |
| int glyphCount = reader.read32(); |
| GlyphPositioning pos = static_cast<GlyphPositioning>(reader.read32()); |
| if (glyphCount <= 0 || pos > kFull_Positioning) { |
| return NULL; |
| } |
| |
| SkPoint offset; |
| reader.readPoint(&offset); |
| SkPaint font; |
| reader.readPaint(&font); |
| |
| const SkTextBlobBuilder::RunBuffer* buf = NULL; |
| switch (pos) { |
| case kDefault_Positioning: |
| buf = &blobBuilder.allocRun(font, glyphCount, offset.x(), offset.y(), &bounds); |
| break; |
| case kHorizontal_Positioning: |
| buf = &blobBuilder.allocRunPosH(font, glyphCount, offset.y(), &bounds); |
| break; |
| case kFull_Positioning: |
| buf = &blobBuilder.allocRunPos(font, glyphCount, &bounds); |
| break; |
| default: |
| return NULL; |
| } |
| |
| if (!reader.readByteArray(buf->glyphs, glyphCount * sizeof(uint16_t)) || |
| !reader.readByteArray(buf->pos, |
| glyphCount * sizeof(SkScalar) * ScalarsPerGlyph(pos))) { |
| return NULL; |
| } |
| } |
| |
| return blobBuilder.build(); |
| } |
| |
| unsigned SkTextBlob::ScalarsPerGlyph(GlyphPositioning pos) { |
| // GlyphPositioning values are directly mapped to scalars-per-glyph. |
| SkASSERT(pos <= 2); |
| return pos; |
| } |
| |
| SkTextBlob::RunIterator::RunIterator(const SkTextBlob* blob) |
| : fCurrentRun(RunRecord::First(blob)) |
| , fRemainingRuns(blob->fRunCount) { |
| SkDEBUGCODE(fStorageTop = (uint8_t*)blob + blob->fStorageSize;) |
| } |
| |
| bool SkTextBlob::RunIterator::done() const { |
| return fRemainingRuns <= 0; |
| } |
| |
| void SkTextBlob::RunIterator::next() { |
| SkASSERT(!this->done()); |
| |
| if (!this->done()) { |
| SkDEBUGCODE(fCurrentRun->validate(fStorageTop);) |
| fCurrentRun = RunRecord::Next(fCurrentRun); |
| fRemainingRuns--; |
| } |
| } |
| |
| uint32_t SkTextBlob::RunIterator::glyphCount() const { |
| SkASSERT(!this->done()); |
| return fCurrentRun->glyphCount(); |
| } |
| |
| const uint16_t* SkTextBlob::RunIterator::glyphs() const { |
| SkASSERT(!this->done()); |
| return fCurrentRun->glyphBuffer(); |
| } |
| |
| const SkScalar* SkTextBlob::RunIterator::pos() const { |
| SkASSERT(!this->done()); |
| return fCurrentRun->posBuffer(); |
| } |
| |
| const SkPoint& SkTextBlob::RunIterator::offset() const { |
| SkASSERT(!this->done()); |
| return fCurrentRun->offset(); |
| } |
| |
| SkTextBlob::GlyphPositioning SkTextBlob::RunIterator::positioning() const { |
| SkASSERT(!this->done()); |
| return fCurrentRun->positioning(); |
| } |
| |
| void SkTextBlob::RunIterator::applyFontToPaint(SkPaint* paint) const { |
| SkASSERT(!this->done()); |
| |
| const SkPaint& font = fCurrentRun->font(); |
| |
| paint->setTypeface(font.getTypeface()); |
| paint->setTextEncoding(font.getTextEncoding()); |
| paint->setTextSize(font.getTextSize()); |
| paint->setTextScaleX(font.getTextScaleX()); |
| paint->setTextSkewX(font.getTextSkewX()); |
| paint->setHinting(font.getHinting()); |
| |
| uint32_t flagsMask = SkPaint::kAntiAlias_Flag |
| | SkPaint::kUnderlineText_Flag |
| | SkPaint::kStrikeThruText_Flag |
| | SkPaint::kFakeBoldText_Flag |
| | SkPaint::kLinearText_Flag |
| | SkPaint::kSubpixelText_Flag |
| | SkPaint::kDevKernText_Flag |
| | SkPaint::kLCDRenderText_Flag |
| | SkPaint::kEmbeddedBitmapText_Flag |
| | SkPaint::kAutoHinting_Flag |
| | SkPaint::kVerticalText_Flag |
| | SkPaint::kGenA8FromLCD_Flag |
| | SkPaint::kDistanceFieldTextTEMP_Flag; |
| paint->setFlags((paint->getFlags() & ~flagsMask) | (font.getFlags() & flagsMask)); |
| } |
| |
| SkTextBlobBuilder::SkTextBlobBuilder() |
| : fStorageSize(0) |
| , fStorageUsed(0) |
| , fRunCount(0) |
| , fDeferredBounds(false) |
| , fLastRun(0) { |
| fBounds.setEmpty(); |
| } |
| |
| SkTextBlobBuilder::~SkTextBlobBuilder() { |
| if (NULL != fStorage.get()) { |
| // We are abandoning runs and must destruct the associated font data. |
| // The easiest way to accomplish that is to use the blob destructor. |
| build()->unref(); |
| } |
| } |
| |
| void SkTextBlobBuilder::updateDeferredBounds() { |
| SkASSERT(!fDeferredBounds || fRunCount > 0); |
| |
| if (!fDeferredBounds) { |
| return; |
| } |
| |
| // FIXME: measure the current run & union bounds |
| fDeferredBounds = false; |
| } |
| |
| void SkTextBlobBuilder::reserve(size_t size) { |
| // We don't currently pre-allocate, but maybe someday... |
| if (fStorageUsed + size <= fStorageSize) { |
| return; |
| } |
| |
| if (0 == fRunCount) { |
| SkASSERT(NULL == fStorage.get()); |
| SkASSERT(0 == fStorageSize); |
| SkASSERT(0 == fStorageUsed); |
| |
| // the first allocation also includes blob storage |
| fStorageUsed += sizeof(SkTextBlob); |
| } |
| |
| fStorageSize = fStorageUsed + size; |
| // FYI: This relies on everything we store being relocatable, particularly SkPaint. |
| fStorage.realloc(fStorageSize); |
| } |
| |
| bool SkTextBlobBuilder::mergeRun(const SkPaint &font, SkTextBlob::GlyphPositioning positioning, |
| int count, SkPoint offset) { |
| if (0 == fLastRun) { |
| SkASSERT(0 == fRunCount); |
| return false; |
| } |
| |
| SkASSERT(fLastRun >= sizeof(SkTextBlob)); |
| SkTextBlob::RunRecord* run = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() + |
| fLastRun); |
| SkASSERT(run->glyphCount() > 0); |
| |
| if (run->positioning() != positioning |
| || run->font() != font |
| || (run->glyphCount() + count < run->glyphCount())) { |
| return false; |
| } |
| |
| // we can merge same-font/same-positioning runs in the following cases: |
| // * fully positioned run following another fully positioned run |
| // * horizontally postioned run following another horizontally positioned run with the same |
| // y-offset |
| if (SkTextBlob::kFull_Positioning != positioning |
| && (SkTextBlob::kHorizontal_Positioning != positioning |
| || run->offset().y() != offset.y())) { |
| return false; |
| } |
| |
| size_t sizeDelta = SkTextBlob::RunRecord::StorageSize(run->glyphCount() + count, positioning) - |
| SkTextBlob::RunRecord::StorageSize(run->glyphCount(), positioning); |
| this->reserve(sizeDelta); |
| |
| // reserve may have realloced |
| run = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() + fLastRun); |
| uint32_t preMergeCount = run->glyphCount(); |
| run->grow(count); |
| |
| // Callers expect the buffers to point at the newly added slice, ant not at the beginning. |
| fCurrentRunBuffer.glyphs = run->glyphBuffer() + preMergeCount; |
| fCurrentRunBuffer.pos = run->posBuffer() |
| + preMergeCount * SkTextBlob::ScalarsPerGlyph(positioning); |
| |
| fStorageUsed += sizeDelta; |
| |
| SkASSERT(fStorageUsed <= fStorageSize); |
| run->validate(fStorage.get() + fStorageUsed); |
| |
| return true; |
| } |
| |
| void SkTextBlobBuilder::allocInternal(const SkPaint &font, |
| SkTextBlob::GlyphPositioning positioning, |
| int count, SkPoint offset, const SkRect* bounds) { |
| SkASSERT(count > 0); |
| SkASSERT(SkPaint::kGlyphID_TextEncoding == font.getTextEncoding()); |
| |
| if (!this->mergeRun(font, positioning, count, offset)) { |
| updateDeferredBounds(); |
| |
| size_t runSize = SkTextBlob::RunRecord::StorageSize(count, positioning); |
| this->reserve(runSize); |
| |
| SkASSERT(fStorageUsed >= sizeof(SkTextBlob)); |
| SkASSERT(fStorageUsed + runSize <= fStorageSize); |
| |
| SkTextBlob::RunRecord* run = new (fStorage.get() + fStorageUsed) |
| SkTextBlob::RunRecord(count, offset, font, positioning); |
| |
| fCurrentRunBuffer.glyphs = run->glyphBuffer(); |
| fCurrentRunBuffer.pos = run->posBuffer(); |
| |
| fLastRun = fStorageUsed; |
| fStorageUsed += runSize; |
| fRunCount++; |
| |
| SkASSERT(fStorageUsed <= fStorageSize); |
| run->validate(fStorage.get() + fStorageUsed); |
| } |
| |
| if (!fDeferredBounds) { |
| if (bounds) { |
| fBounds.join(*bounds); |
| } else { |
| fDeferredBounds = true; |
| } |
| } |
| } |
| |
| const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRun(const SkPaint& font, int count, |
| SkScalar x, SkScalar y, |
| const SkRect* bounds) { |
| this->allocInternal(font, SkTextBlob::kDefault_Positioning, count, SkPoint::Make(x, y), bounds); |
| |
| return fCurrentRunBuffer; |
| } |
| |
| const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunPosH(const SkPaint& font, int count, |
| SkScalar y, |
| const SkRect* bounds) { |
| this->allocInternal(font, SkTextBlob::kHorizontal_Positioning, count, SkPoint::Make(0, y), |
| bounds); |
| |
| return fCurrentRunBuffer; |
| } |
| |
| const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunPos(const SkPaint& font, int count, |
| const SkRect *bounds) { |
| this->allocInternal(font, SkTextBlob::kFull_Positioning, count, SkPoint::Make(0, 0), bounds); |
| |
| return fCurrentRunBuffer; |
| } |
| |
| const SkTextBlob* SkTextBlobBuilder::build() { |
| SkASSERT((fRunCount > 0) == (NULL != fStorage.get())); |
| |
| this->updateDeferredBounds(); |
| |
| if (0 == fRunCount) { |
| SkASSERT(NULL == fStorage.get()); |
| fStorageUsed = sizeof(SkTextBlob); |
| fStorage.realloc(fStorageUsed); |
| } |
| |
| SkDEBUGCODE( |
| size_t validateSize = sizeof(SkTextBlob); |
| const SkTextBlob::RunRecord* run = |
| SkTextBlob::RunRecord::First(reinterpret_cast<const SkTextBlob*>(fStorage.get())); |
| for (int i = 0; i < fRunCount; ++i) { |
| validateSize += SkTextBlob::RunRecord::StorageSize(run->fCount, run->fPositioning); |
| run->validate(fStorage.get() + fStorageUsed); |
| run = SkTextBlob::RunRecord::Next(run); |
| } |
| SkASSERT(validateSize == fStorageUsed); |
| ) |
| |
| const SkTextBlob* blob = new (fStorage.detach()) SkTextBlob(fRunCount, fBounds); |
| SkDEBUGCODE(const_cast<SkTextBlob*>(blob)->fStorageSize = fStorageSize;) |
| |
| fStorageUsed = 0; |
| fStorageSize = 0; |
| fRunCount = 0; |
| fLastRun = 0; |
| fBounds.setEmpty(); |
| |
| return blob; |
| } |
| |