chromium/third_party/blink/renderer/platform/fonts/shaping/glyph_data.h

// Copyright 2024 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_GLYPH_DATA_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_GLYPH_DATA_H_

#include "third_party/blink/renderer/platform/wtf/allocator/allocator.h"
#include "third_party/blink/renderer/platform/wtf/assertions.h"
#include "ui/gfx/geometry/vector2d_f.h"

namespace blink {

// Because glyph offsets are often zero, particularly for Latin runs, we hold it
// in |ShapeResult::RunInfo::GlyphDataCollection::offsets_| for reducing memory
// usage.
struct HarfBuzzRunGlyphData { … };
static_assert …;

GlyphOffset;

// Represents a range of HarfBuzzRunGlyphData. |begin| and |end| follow the
// iterator pattern; i.e., |begin| is lower or equal to |end| in the address
// space regardless of LTR/RTL. |begin| is inclusive, |end| is exclusive.
struct GlyphDataRange { … };

// Find the range of HarfBuzzRunGlyphData for the specified character index
// range. This function uses binary search twice, hence O(2 log n).
inline GlyphDataRange GlyphDataRange::FindGlyphDataRange(
    bool is_rtl,
    unsigned start_character_index,
    unsigned end_character_index) const { … }

// A array of glyph offsets. If all offsets are zero, we don't allocate
// storage for reducing memory usage.
class GlyphOffsetArray final { … };

// For non-zero glyph offset array
template <>
struct GlyphOffsetArray::iterator<true> final { … };

// For zero glyph offset array
template <>
struct GlyphOffsetArray::iterator<false> final { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SHAPING_GLYPH_DATA_H_