Chess+GamesSettings: Give chess pieces some breathing room

Draw pieces around 80% of the size of a square, instead of 100%, so that
there is a nice gap around them. This feels more comfy, and makes it
actually possible to read the coordinates while a piece is on their
square.

Userland/Applications/GamesSettings/ChessSettingsWidget.cpp

@@ -163,6 +163,7 @@ class ChessGamePreview final : public GUI::Frame {
  // With the same preview size as we use for card games, a nice fit is 2 ranks of 6.
  // There are definitely better ways of doing this, but it'll do. ;^)
  auto square_size = 61;
+ auto square_margin = square_size / 10;
 
  auto rect_for_square = [&](Chess::Square const& square) {
  return Gfx::IntRect {
@@ -196,7 +197,7 @@ class ChessGamePreview final : public GUI::Frame {
  auto draw_piece = [&](Chess::Piece const& piece, Chess::Square const& square) {
  auto& bitmap = *m_piece_images.get(piece).value();
  painter.draw_scaled_bitmap(
- rect_for_square(square),
+ rect_for_square(square).shrunken(square_margin, square_margin, square_margin, square_margin),
  bitmap,
  bitmap.rect(),
  1.0f,

Userland/Games/Chess/ChessWidget.cpp

@@ -41,6 +41,7 @@ void ChessWidget::paint_event(GUI::PaintEvent& event)
 
  auto square_width = min_size / 8;
  auto square_height = min_size / 8;
+ auto square_margin = square_width / 10;
  int coord_rank_file = (side() == Chess::Color::White) ? 0 : 7;
 
  Chess::Board& active_board = (m_playback ? board_playback() : board());
@@ -84,7 +85,7 @@ void ChessWidget::paint_event(GUI::PaintEvent& event)
  if (!(m_dragging_piece && sq == m_moving_square)) {
  auto bmp = m_pieces.get(active_board.get_piece(sq));
  if (bmp.has_value()) {
- painter.draw_scaled_bitmap(tile_rect, *bmp.value(), bmp.value()->rect(), 1.0f, Gfx::Painter::ScalingMode::BilinearBlend);
+ painter.draw_scaled_bitmap(tile_rect.shrunken(square_margin, square_margin, square_margin, square_margin), *bmp.value(), bmp.value()->rect(), 1.0f, Gfx::Painter::ScalingMode::BilinearBlend);
  }
  }