| /* |
| * 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}; |
| } |