glyph_atlas.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "impeller/typographer/glyph_atlas.h"
 
#include <numeric>
#include <utility>
 
namespace impeller {
 
GlyphAtlasContext::GlyphAtlasContext(GlyphAtlas::Type type)
    : atlas_(std::make_shared<GlyphAtlas>(type)), atlas_size_(ISize(0, 0)) {}
 
GlyphAtlasContext::~GlyphAtlasContext() {}
 
std::shared_ptr<GlyphAtlas> GlyphAtlasContext::GetGlyphAtlas() const {
  return atlas_;
}
 
const ISize& GlyphAtlasContext::GetAtlasSize() const {
  return atlas_size_;
}
 
int64_t GlyphAtlasContext::GetHeightAdjustment() const {
  return height_adjustment_;
}
 
std::shared_ptr<RectanglePacker> GlyphAtlasContext::GetRectPacker() const {
  return rect_packer_;
}
 
void GlyphAtlasContext::UpdateGlyphAtlas(std::shared_ptr<GlyphAtlas> atlas,
                                         ISize size,
                                         int64_t height_adjustment) {
  atlas_ = std::move(atlas);
  atlas_size_ = size;
  height_adjustment_ = height_adjustment;
}
 
void GlyphAtlasContext::UpdateRectPacker(
    std::shared_ptr<RectanglePacker> rect_packer) {
  rect_packer_ = std::move(rect_packer);
}
 
GlyphAtlas::GlyphAtlas(Type type) : type_(type) {}
 
GlyphAtlas::~GlyphAtlas() = default;
 
bool GlyphAtlas::IsValid() const {
  return !!texture_;
}
 
GlyphAtlas::Type GlyphAtlas::GetType() const {
  return type_;
}
 
const std::shared_ptr<Texture>& GlyphAtlas::GetTexture() const {
  return texture_;
}
 
void GlyphAtlas::SetTexture(std::shared_ptr<Texture> texture) {
  texture_ = std::move(texture);
}
 
void GlyphAtlas::AddTypefaceGlyphPositionAndBounds(const FontGlyphPair& pair,
                                                   Rect position,
                                                   Rect bounds) {
  font_atlas_map_[pair.scaled_font].positions_[pair.glyph] =
      std::make_pair(position, bounds);
}
 
std::optional<std::pair<Rect, Rect>> GlyphAtlas::FindFontGlyphBounds(
    const FontGlyphPair& pair) const {
  const auto& found = font_atlas_map_.find(pair.scaled_font);
  if (found == font_atlas_map_.end()) {
    return std::nullopt;
  }
  return found->second.FindGlyphBounds(pair.glyph);
}
 
const FontGlyphAtlas* GlyphAtlas::GetFontGlyphAtlas(const Font& font,
                                                    Scalar scale) const {
  const auto& found = font_atlas_map_.find(ScaledFont{font, scale});
  if (found == font_atlas_map_.end()) {
    return nullptr;
  }
  return &found->second;
}
 
size_t GlyphAtlas::GetGlyphCount() const {
  return std::accumulate(font_atlas_map_.begin(), font_atlas_map_.end(), 0,
                         [](const int a, const auto& b) {
                           return a + b.second.positions_.size();
                         });
}
 
size_t GlyphAtlas::IterateGlyphs(
    const std::function<bool(const ScaledFont& scaled_font,
                             const SubpixelGlyph& glyph,
                             const Rect& rect)>& iterator) const {
  if (!iterator) {
    return 0u;
  }
 
  size_t count = 0u;
  for (const auto& font_value : font_atlas_map_) {
    for (const auto& glyph_value : font_value.second.positions_) {
      count++;
      if (!iterator(font_value.first, glyph_value.first,
                    glyph_value.second.first)) {
        return count;
      }
    }
  }
  return count;
}
 
std::optional<std::pair<Rect, Rect>> FontGlyphAtlas::FindGlyphBounds(
    const SubpixelGlyph& glyph) const {
  const auto& found = positions_.find(glyph);
  if (found == positions_.end()) {
    return std::nullopt;
  }
  return found->second;
}
 
}  // namespace impeller