SkTextBlob

src/core/SkTextBlob.cpp

+/*
+ * 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"
+
+SkTextBlob::SkTextBlob(const uint16_t *glyphs, const SkScalar *pos, const SkTArray<Run> *runs,
+                       const SkRect& bounds)
+    : fGlyphBuffer(glyphs)
+    , fPosBuffer(pos)
+    , fRuns(runs)
+    , fBounds(bounds) {
+}
+
+SkTextBlob::~SkTextBlob() {
+    sk_free(const_cast<uint16_t*>(fGlyphBuffer));
+    sk_free(const_cast<SkScalar*>(fPosBuffer));
+    SkDELETE(fRuns);
+}
+
+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;
+}
+
+const SkTextBlob::RunInfo SkTextBlob::runInfo(unsigned runIndex) const {
+    SkASSERT(NULL != fRuns && runIndex < (unsigned)fRuns->count());
+
+    const Run& run = (*fRuns)[runIndex];
+    return RunInfo(run.count, run.positioning, fGlyphBuffer + run.glyphStart,
+                   fPosBuffer + run.posStart, &run.font);
+}
+
+SkTextBlobBuilder::SkTextBlobBuilder(unsigned runs)
+    : fRuns(NULL)
+    , fDeferredRunBounds(false) {
+
+    if (runs > 0) {
+        // if the number of runs is known, size our run storage accordingly.
+        fRuns = SkNEW(SkTArray<SkTextBlob::Run>(runs));
+    }
+    fBounds.setEmpty();
+}
+
+SkTextBlobBuilder::~SkTextBlobBuilder() {
+    // unused runs
+    SkDELETE(fRuns);
+}
+
+void SkTextBlobBuilder::updateRunBounds() {
+    if (!fDeferredRunBounds) {
+        // Run bounds are up to date.
+        return;
+    }
+
+    SkASSERT(NULL != fRuns && !fRuns->empty());
+
+    // FIXME: compute run bounds.
+    SkRect runBounds = SkRect::MakeEmpty();
+
+    fBounds.join(runBounds);
+    fDeferredRunBounds = false;
+}
+
+void SkTextBlobBuilder::ensureRun(const SkPaint& font, SkTextBlob::Positioning pos,
+                                  unsigned count, const SkRect* runBounds) {
+    SkASSERT(SkPaint::kGlyphID_TextEncoding == font.getTextEncoding());
+
+    if (NULL == fRuns) {
+        fRuns = SkNEW(SkTArray<SkTextBlob::Run>());
+    }
+
+    // same-font/same-positioning runs are merged
+    if (fRuns->empty() || fRuns->back().positioning != pos || fRuns->back().font != font) {
+        // former run bounds may need updating
+        updateRunBounds();
+
+        // start a new run
+        SkTextBlob::Run& newRun = fRuns->push_back();
+        newRun.count = 0;
+        newRun.glyphStart = fGlyphBuffer.count();
+        newRun.posStart = fPosBuffer.count();
+        newRun.font = font;
+        newRun.positioning = pos;
+    }
+
+    // reserve buffer storage upfront if the glyph count is known
+    if (count > 0) {
+        fGlyphBuffer.setReserve(fGlyphBuffer.count() + count);
+        SkASSERT(pos <= 2);
+        fPosBuffer.setReserve(fPosBuffer.count() + count * pos);
+    }
+
+    fDeferredRunBounds |= (NULL == runBounds);
+    // when in deferred bounds mode, we'll compute the bounds at a later time.
+    if (!fDeferredRunBounds) {
+        fBounds.join(*runBounds);
+    }
+}
+
+const SkTextBlob* SkTextBlobBuilder::build() {
+    const SkTextBlob* leBlob;
+
+    if (fGlyphBuffer.count() > 0) {
+        // we have some glyphs, construct a real blob
+        SkASSERT(NULL != fRuns && !fRuns->empty());
+
+        // last run may require deferred bounds computation
+        updateRunBounds();
+
+        // ownership of all buffers is transferred to the blob
+        leBlob = SkNEW_ARGS(SkTextBlob, (fGlyphBuffer.detach(),
+                                         fPosBuffer.detach(),
+                                         fRuns,
+                                         fBounds));
+        fRuns = NULL;
+        fBounds.setEmpty();
+    } else {
+        // empty blob
+        SkASSERT(NULL == fRuns || fRuns->empty());
+        SkASSERT(fBounds.isEmpty());
+
+        leBlob = SkNEW_ARGS(SkTextBlob, (NULL, NULL, NULL, SkRect::MakeEmpty()));
+    }
+
+    return leBlob;
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kDefault_Positioning>::addGlyph(uint16_t glyph) {
+    SkASSERT(NULL != fBlobBuilder->fRuns);
+    SkASSERT(fBlobBuilder->fRuns->count() > 0);
+    SkASSERT(fBlobBuilder->fRuns->back().positioning == SkTextBlob::kDefault_Positioning);
+
+    *fBlobBuilder->fGlyphBuffer.append() = glyph;
+
+    fBlobBuilder->fRuns->back().count += 1;
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kDefault_Positioning>::addGlyphs(
+        const uint16_t glyphs[], size_t count) {
+
+    for (size_t i = 0; i < count; ++i) {
+        this->addGlyph(glyphs[i]);
+    }
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kHorizontal_Positioning>::addGlyph(uint16_t glyph,
+                                                                              SkScalar x) {
+    SkASSERT(NULL != fBlobBuilder->fRuns);
+    SkASSERT(fBlobBuilder->fRuns->count() > 0);
+    SkASSERT(fBlobBuilder->fRuns->back().positioning == SkTextBlob::kHorizontal_Positioning);
+
+    *fBlobBuilder->fGlyphBuffer.append() = glyph;
+    *fBlobBuilder->fPosBuffer.append() = x;
+
+    fBlobBuilder->fRuns->back().count += 1;
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kHorizontal_Positioning>::addGlyphs(
+        const uint16_t glyphs[], const SkScalar xPos[], size_t count) {
+
+    for (size_t i = 0; i < count; ++i) {
+        this->addGlyph(glyphs[i], xPos[i]);
+    }
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kFull_Positioning>::addGlyph(uint16_t glyph,
+                                                                             SkScalar x,
+                                                                             SkScalar y) {
+    SkASSERT(NULL != fBlobBuilder->fRuns);
+    SkASSERT(fBlobBuilder->fRuns->count() > 0);
+    SkASSERT(fBlobBuilder->fRuns->back().positioning == SkTextBlob::kFull_Positioning);
+
+    *fBlobBuilder->fGlyphBuffer.append() = glyph;
+    *fBlobBuilder->fPosBuffer.append() = x;
+    *fBlobBuilder->fPosBuffer.append() = y;
+
+    fBlobBuilder->fRuns->back().count += 1;
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kFull_Positioning>::addGlyph(uint16_t glyph,
+                                                                            SkPoint pos) {
+    this->addGlyph(glyph, pos.x(), pos.y());
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kFull_Positioning>::addGlyphs(
+        const uint16_t glyphs[], const SkScalar xPos[], const SkScalar yPos[], size_t count) {
+
+    for (size_t i = 0; i < count; ++i) {
+        this->addGlyph(glyphs[i], xPos[i], yPos[i]);
+    }
+}
+
+void SkTextBlobBuilder::RunBuilder<SkTextBlob::kFull_Positioning>::addGlyphs(
+        const uint16_t glyphs[], const SkPoint pos[], size_t count) {
+
+    for (size_t i = 0; i < count; ++i) {
+        this->addGlyph(glyphs[i], pos[i].x(), pos[i].y());
+    }
+}