Function RenderTextBackground

src/rendering/renderers/TextRenderer.cpp:436–472

}

std::shared_ptr<Graphic> RenderTextBackground(ID assetID,
                                              const std::vector<std::vector<GlyphHandle>>& lines,
                                              const TextDocument* textDocument) {
  float strokeWidth = textDocument->strokeWidth;
  auto margin = textDocument->fontSize * 0.4f;
  if (margin < strokeWidth) {
    margin = strokeWidth;
  }
  auto isVertical = textDocument->direction == TextDirection::Vertical;
  float lineTop = 0, lineBottom = 0;
  for (auto& line : lines) {
    for (auto& glyph : line) {
      if (isVertical) {
        lineTop = std::min(lineTop, -glyph->getBounds().right);
        lineBottom = std::max(lineBottom, -glyph->getBounds().left);
      } else {
        lineTop = std::min(lineTop, glyph->getBounds().top);
        lineBottom = std::max(lineBottom, glyph->getBounds().bottom);
      }
    }
  }

  auto backgroundPath = RenderBackgroundPath(lines, margin, lineTop, lineBottom, isVertical);
  auto bounds = backgroundPath.getBounds();
  float maxRadius = std::min(bounds.width(), bounds.height()) / 3.0f;
  if (maxRadius >= 25.0f) {
    maxRadius = 25.0f;
  }
  auto effect = tgfx::PathEffect::MakeCorner(maxRadius);
  if (effect) {
    effect->filterPath(&backgroundPath);
  }
  auto graphic = Shape::MakeFrom(assetID, backgroundPath, ToTGFX(textDocument->backgroundColor));
  auto modifier =
      Modifier::MakeBlend(ToAlpha(textDocument->backgroundAlpha), tgfx::BlendMode::SrcOver);
  return Graphic::MakeCompose(graphic, modifier);
}

static std::vector<GlyphHandle> BuildGlyphs(const TextDocument* textDocument) {
  TextPaint textPaint = {};