blob: 4df0edaed15dd67c3b1d79a478986a4f02399ca0 (
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
|
// Copyright 2020 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_STRETCHY_OPERATOR_SHAPER_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_STRETCHY_OPERATOR_SHAPER_H_
#include <base/memory/scoped_refptr.h>
#include <unicode/uchar.h>
#include "third_party/blink/renderer/platform/fonts/glyph.h"
#include "third_party/blink/renderer/platform/fonts/opentype/open_type_math_support.h"
#include "third_party/blink/renderer/platform/text/text_direction.h"
#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
namespace blink {
class Font;
class ShapeResult;
class StretchyOperatorShaper;
// TODO(https://crbug.com/1057589): Add a TextDirection parameter, so that it's
// possible to perform glyph-level (rtlm feature) or character-level mirroring
// before stretching.
// https://mathml-refresh.github.io/mathml-core/#algorithms-for-glyph-stretching
class PLATFORM_EXPORT StretchyOperatorShaper final {
DISALLOW_NEW();
public:
StretchyOperatorShaper(UChar stretchy_character,
OpenTypeMathStretchData::StretchAxis stretch_axis)
: stretchy_character_(stretchy_character), stretch_axis_(stretch_axis) {}
// Returns the metrics of the stretched operator for layout purpose.
// May be called multiple times; font and direction may vary between calls.
// https://mathml-refresh.github.io/mathml-core/#dfn-box-metrics-of-a-stretchy-glyph
struct Metrics {
float advance;
float ascent;
float descent;
// TODO(https://crbug.com/1057592): Add italic correction.
};
Metrics GetMetrics(const Font*, float target_size) const;
// Shape the stretched operator. The coordinates of the glyph(s) use the same
// origin as the rectangle returned by GetMetrics.
// May be called multiple times; font and direction may vary between calls.
// https://mathml-refresh.github.io/mathml-core/#dfn-shape-a-stretchy-glyph
scoped_refptr<ShapeResult> Shape(const Font*, float target_size) const;
~StretchyOperatorShaper() = default;
private:
const UChar stretchy_character_;
const OpenTypeMathStretchData::StretchAxis stretch_axis_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_STRETCHY_OPERATOR_SHAPER_H_
|
