Function DrawTileSelectionRect

src/viewport.cpp:914–935

* Draws a selection rectangle on a tile. * * @param ti TileInfo Tile that is being drawn * @param pal Palette to apply. */

 * @param pal Palette to apply.
 */
static void DrawTileSelectionRect(const TileInfo *ti, PaletteID pal)
{
	if (!IsValidTile(ti->tile)) return;

	SpriteID sel;
	if (IsHalftileSlope(ti->tileh)) {
		Corner halftile_corner = GetHalftileSlopeCorner(ti->tileh);
		SpriteID sel2 = SPR_HALFTILE_SELECTION_FLAT + halftile_corner;
		DrawSelectionSprite(sel2, pal, ti, 7 + TILE_HEIGHT, FOUNDATION_PART_HALFTILE);

		Corner opposite_corner = OppositeCorner(halftile_corner);
		if (IsSteepSlope(ti->tileh)) {
			sel = SPR_HALFTILE_SELECTION_DOWN;
		} else {
			sel = ((ti->tileh & SlopeWithOneCornerRaised(opposite_corner)) != 0 ? SPR_HALFTILE_SELECTION_UP : SPR_HALFTILE_SELECTION_FLAT);
		}
		sel += opposite_corner;
	} else {
		sel = SPR_SELECT_TILE + SlopeToSpriteOffset(ti->tileh);
	}
	DrawSelectionSprite(sel, pal, ti, 7, FOUNDATION_PART_NORMAL);
}

static bool IsPartOfAutoLine(int px, int py)
{