diff options
Diffstat (limited to 'gfx/skia/skia/src/pdf/SkClusterator.cpp')
-rw-r--r-- | gfx/skia/skia/src/pdf/SkClusterator.cpp | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/pdf/SkClusterator.cpp b/gfx/skia/skia/src/pdf/SkClusterator.cpp new file mode 100644 index 0000000000..5eaed752da --- /dev/null +++ b/gfx/skia/skia/src/pdf/SkClusterator.cpp @@ -0,0 +1,64 @@ +/* + * Copyright 2018 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "src/pdf/SkClusterator.h" + +#include "include/private/base/SkTo.h" +#include "src/base/SkUTF.h" +#include "src/text/GlyphRun.h" + +static bool is_reversed(const uint32_t* clusters, uint32_t count) { + // "ReversedChars" is how PDF deals with RTL text. + // return true if more than one cluster and monotonicly decreasing to zero. + if (count < 2 || clusters[0] == 0 || clusters[count - 1] != 0) { + return false; + } + for (uint32_t i = 0; i + 1 < count; ++i) { + if (clusters[i + 1] > clusters[i]) { + return false; + } + } + return true; +} + +SkClusterator::SkClusterator(const sktext::GlyphRun& run) + : fClusters(run.clusters().data()) + , fUtf8Text(run.text().data()) + , fGlyphCount(SkToU32(run.glyphsIDs().size())) + , fTextByteLength(SkToU32(run.text().size())) + , fReversedChars(fClusters ? is_reversed(fClusters, fGlyphCount) : false) +{ + if (fClusters) { + SkASSERT(fUtf8Text && fTextByteLength > 0 && fGlyphCount > 0); + } else { + SkASSERT(!fUtf8Text && fTextByteLength == 0); + } +} + +SkClusterator::Cluster SkClusterator::next() { + if (fCurrentGlyphIndex >= fGlyphCount) { + return Cluster{nullptr, 0, 0, 0}; + } + if (!fClusters || !fUtf8Text) { + return Cluster{nullptr, 0, fCurrentGlyphIndex++, 1}; + } + uint32_t clusterGlyphIndex = fCurrentGlyphIndex; + uint32_t cluster = fClusters[clusterGlyphIndex]; + do { + ++fCurrentGlyphIndex; + } while (fCurrentGlyphIndex < fGlyphCount && cluster == fClusters[fCurrentGlyphIndex]); + uint32_t clusterGlyphCount = fCurrentGlyphIndex - clusterGlyphIndex; + uint32_t clusterEnd = fTextByteLength; + for (unsigned i = 0; i < fGlyphCount; ++i) { + uint32_t c = fClusters[i]; + if (c > cluster && c < clusterEnd) { + clusterEnd = c; + } + } + uint32_t clusterLen = clusterEnd - cluster; + return Cluster{fUtf8Text + cluster, clusterLen, clusterGlyphIndex, clusterGlyphCount}; +} |