Cocos2d-x Multicolored Label

gistfile1.cpp

class LabelBMColoredFont : public cocos2d::Label
{
private:
  struct ColorIndex
  {
    const cocos2d::Color3B& color;
    size_t index;
  };
  
  LabelBMColoredFont(cocos2d::FontAtlas *atlas = nullptr, cocos2d::TextHAlignment hAlignment = cocos2d::TextHAlignment::LEFT,
        cocos2d::TextVAlignment vAlignment = cocos2d::TextVAlignment::TOP,bool useDistanceField = false,bool useA8Shader = false);
  
  std::vector<ColorIndex> colors;

public:
  static LabelBMColoredFont * create(const std::string& str, const std::string& fntFile, float width = 0, cocos2d::TextHAlignment alignment = cocos2d::TextHAlignment::LEFT,const cocos2d::Vec2& imageOffset = cocos2d::Vec2::ZERO);

  void setString(const std::string& string) override;
  
  void updateColor() override;

};

LabelBMColoredFont::LabelBMColoredFont(cocos2d::FontAtlas *atlas, cocos2d::TextHAlignment hAlignment, cocos2d::TextVAlignment vAlignment,bool useDistanceField,bool useA8Shader) : Label(atlas,hAlignment,vAlignment,useDistanceField,useA8Shader) { }

LabelBMColoredFont *LabelBMColoredFont::create(const std::string& str, const std::string& fntFile, float width /* = 0 */, TextHAlignment alignment /* = TextHAlignment::LEFT */,const Vec2& imageOffset /* = Vec2::ZERO */)
{
  auto ret = new LabelBMColoredFont(nullptr,alignment);
  
  if (ret && ret->setBMFontFilePath(fntFile,imageOffset))
  {
    ret->setMaxLineWidth(width);
    ret->setString(str);
    ret->autorelease();
    
    return ret;
  }
  
  delete ret;
  return nullptr;
}

static const Color3B scolors[] = {
  Color3B(255,255,255), // 0
  Color3B(0,0,0), // 1
  Color3B(208,25,27), // 2
  Color3B(43,167,68), // 3
  Color3B(165,24,217), // v (purple)
  Color3B(233,181,31), // y (yellow)
  Color3B(28,134,222), // b
  Color3B(245,19,147), // m
  Color3B(255,128,0), // o (orange)
};

void LabelBMColoredFont::setString(const string &text)
{
  colors.clear();
  
  u16string text16;
  StringUtils::UTF8ToUTF16(text, text16);
  
  _currentUTF16String.clear();
  const size_t length = text16.length();
  text16.reserve(length);
  
  Color3B baseColor = getColor();

  size_t tindex = 0;
  
  for (size_t i = 0; i < length; ++i)
  {
    if (text16[i] == '^')
    {
      char mapping = text16[i+1];
      s8 colorIndex = -1;
      
      switch (mapping) {
        case '0': colorIndex = 0; break;
        case '1': colorIndex = 1; break;
        case '2': colorIndex = 2; break;
        case '3': colorIndex = 3; break;
        case 'v': colorIndex = 4; break;
        case 'y': colorIndex = 5; break;
        case 'b': colorIndex = 6; break;
        case 'm': colorIndex = 7; break;
        case 'o': colorIndex = 8; break;
        case 's': colors.push_back({baseColor,tindex}); break;
      }
    
      if (colorIndex != -1)
        colors.push_back({scolors[colorIndex], tindex});
      
      ++i;
      continue;
    }
    else if (text[i] == '\n')
      --tindex;
    else if (i == 0)
      colors.push_back({baseColor,0});
    
    ++tindex;
    _currentUTF16String.push_back(text16[i]);
  }

  _originalUTF8String.clear();
  StringUtils::UTF16ToUTF8(_currentUTF16String, _originalUTF8String);
  _contentDirty = true;
}

void LabelBMColoredFont::updateColor()
{
  if (nullptr == _textureAtlas)
  {
    return;
  }
  
  cocos2d::TextureAtlas* textureAtlas;
  V3F_C4B_T2F_Quad *quads;
  
  for (const auto& batchNode:_batchNodes)
  {
    textureAtlas = batchNode->getTextureAtlas();
    quads = textureAtlas->getQuads();
    auto count = textureAtlas->getTotalQuads();
    
    size_t cindex = 0;
    for (size_t i = 0; i < count; ++i)
    {
      if (cindex < colors.size() - 1 && i == colors[cindex+1].index)
        ++cindex;

      Color4B color(colors[cindex].color);
      color.a = _displayedOpacity;
      
      if (_isOpacityModifyRGB)
      {
        color.r *= _displayedOpacity/255.0f;
        color.g *= _displayedOpacity/255.0f;
        color.b *= _displayedOpacity/255.0f;
      }
      else
        color.a = _displayedOpacity;
      
      quads[i].bl.colors = color;
      quads[i].br.colors = color;
      quads[i].tl.colors = color;
      quads[i].tr.colors = color;
      textureAtlas->updateQuad(&quads[i], i);
    }
  }
}