Codechange: Rename CenterBounds to CentreBounds and move to geometry header. (#14002)

src/core/geometry_type.hpp

@@ -16,6 +16,17 @@
 #	define Point OTTD_Point
 #endif /* __APPLE__ */
 
+/**
+ * Determine where to position a centred object.
+ * @param min The top or left coordinate.
+ * @param max The bottom or right coordinate.
+ * @param size The height or width of the object to draw.
+ * @return Offset of where to position the object.
+ */
+inline int CentreBounds(int min, int max, int size)
+{
+	return (min + max - size + 1) / 2;
+}
 
 /** Coordinates of a point in 2D */
 struct Point {