Method getTextureDataForText

core/platform/win32/Device-win32.cpp:418–481

}

Data Device::getTextureDataForText(std::string_view text,
                                   const FontDefinition& textDefinition,
                                   TextAlign align,
                                   int& width,
                                   int& height,
                                   bool& hasPremultipliedAlpha)
{
    Data ret;
    do
    {
        BitmapDC& dc = sharedBitmapDC();

        if (!dc.setFont(textDefinition._fontName.c_str(), (int)textDefinition._fontSize, false))
        {
            AXLOGW("Can't found font({}), use system default", textDefinition._fontName);
        }

        // draw text
        // does changing to SIZE here affects the font size by rounding from float?
        SIZE size = {(LONG)textDefinition._dimensions.width, (LONG)textDefinition._dimensions.height};
        AX_BREAK_IF(!dc.drawText(text, size, align, textDefinition._fontName.c_str(), (int)textDefinition._fontSize,
                                 textDefinition._enableWrap, textDefinition._overflow));

        int dataLen            = size.cx * size.cy * 4;
        unsigned char* dataBuf = (unsigned char*)malloc(sizeof(unsigned char) * dataLen);
        AX_BREAK_IF(!dataBuf);

        struct
        {
            BITMAPINFOHEADER bmiHeader;
            int mask[4];
        } bi                = {0};
        bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
        AX_BREAK_IF(!GetDIBits(dc.getDC(), dc.getBitmap(), 0, 0, nullptr, (LPBITMAPINFO)&bi, DIB_RGB_COLORS));

        width  = static_cast<int>(size.cx);
        height = static_cast<int>(size.cy);

        // copy pixel data
        bi.bmiHeader.biHeight = (bi.bmiHeader.biHeight > 0) ? -bi.bmiHeader.biHeight : bi.bmiHeader.biHeight;
        GetDIBits(dc.getDC(), dc.getBitmap(), 0, height, dataBuf, (LPBITMAPINFO)&bi, DIB_RGB_COLORS);

        COLORREF textColor = (textDefinition._fontFillColor.b << 16 | textDefinition._fontFillColor.g << 8 |
                              textDefinition._fontFillColor.r) &
                             0x00ffffff;
        float alpha      = textDefinition._fontAlpha / 255.0f;
        COLORREF* pPixel = nullptr;
        for (int y = 0; y < height; ++y)
        {
            pPixel = (COLORREF*)dataBuf + y * width;
            for (int x = 0; x < width; ++x)
            {
                COLORREF& clr = *pPixel;
                clr           = ((BYTE)(GetRValue(clr) * alpha) << 24) | textColor;
                ++pPixel;
            }
        }