Method ClearScreen

rEFIt_UEFI/libeg/XTheme.cpp:329–456

}

void XTheme::ClearScreen() //and restore background and banner
{
  if ( UGAWidth == 0 || UGAHeight == 0 ) {
      // jief : I had the case where no graphic protocol were availbale. So UGAWidth == 0 && UGAHeight == 0 which panic because Background would be empty.
      //        Background.GetPixelPtr(0, 0) panic on an empty image because there is no pixel at x=0 y=0
      // test could be "if ( UGAWidth == 0 && UGAHeight == 0 )" (&& instead of ||), but I feel like if one of the dimension is 0, we have a graphic problem.
      // also, should we implement the case if we are in text mode ?
      return;
  }
  EFI_GRAPHICS_OUTPUT_BLT_PIXEL FirstBannerPixel = MenuBackgroundPixel;
  if (BanHeight < 2) {
    BanHeight = ((UGAHeight - (int)(LayoutHeight * Scale)) >> 1);
  }
  if (!(HideUIFlags & HIDEUI_FLAG_BANNER)) {
    //Banner image prepared before
    if (!Banner.isEmpty()) {
      FirstBannerPixel = Banner.GetPixel(0,0);

      BannerPlace.Width = Banner.GetWidth();
      BannerPlace.Height = (BanHeight >= Banner.GetHeight()) ? Banner.GetHeight() : BanHeight;
      BannerPlace.XPos = BannerPosX;
      BannerPlace.YPos = BannerPosY;
      if (!TypeSVG) {
        // Check if new style placement value was used for banner in theme.plist
        
        if ((BannerPosX >=0 && BannerPosX <=1000) && (BannerPosY >=0 && BannerPosY <=1000)) {
          // Check if screen size being used is different from theme origination size.
          // If yes, then recalculate the placement % value.
          // This is necessary because screen can be a different size, but banner is not scaled.
          BannerPlace.XPos = HybridRepositioning(BannerEdgeHorizontal, BannerPosX, BannerPlace.Width,  UGAWidth,  ThemeDesignWidth );
          BannerPlace.YPos = HybridRepositioning(BannerEdgeVertical, BannerPosY, BannerPlace.Height, UGAHeight, ThemeDesignHeight);
          // Check if banner is required to be nudged.
          BannerPlace.XPos = CalculateNudgePosition(BannerPlace.XPos, BannerNudgeX, Banner.GetWidth(),  UGAWidth);
          BannerPlace.YPos = CalculateNudgePosition(BannerPlace.YPos, BannerNudgeY, Banner.GetHeight(), UGAHeight);
          //         DBG("banner position new style\n");
        } else {
          // Use rEFIt default (no placement values speicifed)
          BannerPlace.XPos = (UGAWidth  >= Banner.GetWidth() ) ? (UGAWidth  - Banner.GetWidth() ) >> 1 : 0;
          BannerPlace.YPos = (BanHeight >= Banner.GetHeight()) ? (BanHeight - Banner.GetHeight())      : 0;
          //        DBG("banner position old style\n");
        }
      }
    }
  }
  DBG("BannerPlace at Clear Screen [%lld,%lld]\n",  BannerPlace.XPos, BannerPlace.YPos);
  //Then prepare Background from BigBack
  if (Background.GetWidth() != UGAWidth || Background.GetHeight() != UGAHeight) { // should we type UGAWidth and UGAHeight as UINTN to avoid cast ?
    // Resolution changed or empty background
    Background = XImage(UGAWidth, UGAHeight);
  }
// now we are sure Background has UGA sizes
  float BigScale;
  float BigScaleY;
  if (!BigBack.isEmpty()) {
    switch (BackgroundScale) {
    case imScale:
      BigScale = (float)UGAWidth/BigBack.GetWidth();
      BigScaleY = (float)UGAHeight/BigBack.GetHeight();