left = tr->Left + (tr->Right - tr->Left)
* (tr->CurrentColumn * tr->TileWidthNB - border) / tr->ImageWidth;
right = left + (tr->Right - tr->Left) * tileWidth / tr->ImageWidth;
left = tr->Left + (tr->Right - tr->Left)
* (tr->CurrentColumn * tr->TileWidthNB - border) / tr->ImageWidth;
right = left + (tr->Right - tr->Left) * tileWidth / tr->ImageWidth;