Function ApplyLayoutToGlyphInfos

src/rendering/renderers/TextRenderer.cpp:292–354

}

static std::vector<std::vector<GlyphInfo*>> ApplyLayoutToGlyphInfos(
    const TextLayout& layout, std::vector<GlyphInfo>* glyphInfos, tgfx::Rect* bounds,
    float* firstLineMiniAscent) {
  float maxWidth, maxY;
  if (layout.boxRect.isEmpty()) {
    maxWidth = std::numeric_limits<float>::infinity();
    maxY = std::numeric_limits<float>::infinity();
  } else {
    maxWidth = layout.boxRect.width();
    maxY = layout.boxRect.bottom;
  }

  std::vector<std::vector<GlyphInfo*>> lineList = {};
  auto glyphCount = glyphInfos->size();
  size_t index = 0;
  int lineIndex = 0;
  auto baseLine = layout.firstBaseLine;
  while (index < glyphCount) {
    if (baseLine > maxY) {
      break;
    }
    auto lineGlyphStart = index;
    auto lineWidth = 0.0f;
    auto nextLineIndex =
        CalculateNextLineIndex(*glyphInfos, index, 1.0f, maxWidth, layout.tracking, &lineWidth);
    auto hasLineBreaker = (*glyphInfos)[nextLineIndex - 1].name[0] == '\n';  // 换行符
    auto lineGlyphEnd = nextLineIndex - (hasLineBreaker ? 1 : 0);
    index = nextLineIndex;
    bool isLastLine = (index == glyphCount);
    auto drawX = CalculateDrawX(layout.justification, lineWidth, isLastLine || hasLineBreaker,
                                layout.boxRect);
    auto drawY = baseLine - layout.baselineShift;
    float letterSpacing = CalculateLetterSpacing(layout.justification, layout.tracking, lineWidth,
                                                 lineGlyphEnd - lineGlyphStart,
                                                 isLastLine || hasLineBreaker, layout.boxRect);
    std::vector<GlyphInfo*> glyphLine = {};
    for (size_t i = lineGlyphStart; i < lineGlyphEnd; i++) {
      auto& glyph = (*glyphInfos)[i];
      glyph.position.x = drawX;
      glyph.position.y = drawY;
      glyph.bounds.offset(drawX, drawY);
      glyphLine.push_back(&glyph);
      bounds->join(glyph.bounds);
      drawX += glyph.advance + letterSpacing;
    }
    if (!glyphLine.empty()) {
      lineList.push_back(glyphLine);
    } else {
      auto emptyLineBounds = tgfx::Rect::MakeLTRB(
          drawX, drawY + layout.fontTop, drawX + EMPTY_LINE_WIDTH, drawY + layout.fontBottom);
      bounds->join(emptyLineBounds);
    }

    if (firstLineMiniAscent && lineIndex == 0) {
      *firstLineMiniAscent = glyphLine.empty() ? layout.fontTop : FindMiniAscent(glyphLine);
    }

    baseLine += layout.lineGap;