blob: cfaf803f75e8a3398eab516115b5d180e3011d8d (
plain)
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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
#include <mbgl/text/glyph_pbf.hpp>
#include <protozero/pbf_reader.hpp>
namespace mbgl {
std::vector<Glyph> parseGlyphPBF(const GlyphRange& glyphRange, const std::string& data) {
std::vector<Glyph> result;
result.reserve(256);
protozero::pbf_reader glyphs_pbf(data);
while (glyphs_pbf.next(1)) {
auto fontstack_pbf = glyphs_pbf.get_message();
while (fontstack_pbf.next(3)) {
auto glyph_pbf = fontstack_pbf.get_message();
Glyph glyph;
protozero::data_view glyphData;
bool hasID = false, hasWidth = false, hasHeight = false, hasLeft = false,
hasTop = false, hasAdvance = false;
while (glyph_pbf.next()) {
switch (glyph_pbf.tag()) {
case 1: // id
glyph.id = glyph_pbf.get_uint32();
hasID = true;
break;
case 2: // bitmap
glyphData = glyph_pbf.get_view();
break;
case 3: // width
glyph.metrics.width = glyph_pbf.get_uint32();
hasWidth = true;
break;
case 4: // height
glyph.metrics.height = glyph_pbf.get_uint32();
hasHeight = true;
break;
case 5: // left
glyph.metrics.left = glyph_pbf.get_sint32();
hasLeft = true;
break;
case 6: // top
glyph.metrics.top = glyph_pbf.get_sint32();
hasTop = true;
break;
case 7: // advance
glyph.metrics.advance = glyph_pbf.get_uint32();
hasAdvance = true;
break;
default:
glyph_pbf.skip();
break;
}
}
// Only treat this glyph as a correct glyph if it has all required fields. It also
// needs to satisfy a few metrics conditions that ensure that the glyph isn't bogus.
// All other glyphs are malformed. We're also discarding all glyphs that are outside
// the expected glyph range.
if (!hasID || !hasWidth || !hasHeight || !hasLeft || !hasTop || !hasAdvance ||
glyph.metrics.width >= 256 || glyph.metrics.height >= 256 ||
glyph.metrics.left < -128 || glyph.metrics.left >= 128 ||
glyph.metrics.top < -128 || glyph.metrics.top >= 128 ||
glyph.metrics.advance >= 256 ||
glyph.id < glyphRange.first || glyph.id > glyphRange.second) {
continue;
}
// If the area of width/height is non-zero, we need to adjust the expected size
// with the implicit border size, otherwise we expect there to be no bitmap at all.
if (glyph.metrics.width && glyph.metrics.height) {
const Size size {
glyph.metrics.width + 2 * Glyph::borderSize,
glyph.metrics.height + 2 * Glyph::borderSize
};
if (size.area() != glyphData.size()) {
continue;
}
glyph.bitmap = AlphaImage(size, reinterpret_cast<const uint8_t*>(glyphData.data()), glyphData.size());
}
result.push_back(std::move(glyph));
}
}
return result;
}
} // namespace mbgl
|
