1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/*
* 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 "SkClusterator.h"
#include "SkGlyphRun.h"
#include "SkTo.h"
#include "SkUtils.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 SkGlyphRun& run)
: fClusters(run.clusters().data())
, fUtf8Text(run.text().data())
, fGlyphCount(SkToU32(run.shuntGlyphsIDs().size()))
, fTextByteLength(SkToU32(run.text().size()))
{
SkASSERT(SkPaint::kGlyphID_TextEncoding == run.paint().getTextEncoding());
if (fClusters) {
SkASSERT(fUtf8Text && fTextByteLength > 0 && fGlyphCount > 0);
fReversedChars = is_reversed(fClusters, fGlyphCount);
} 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};
}
|
