(svn r12020) -Documentation: Correct description of TropicZone.

1 files changed, 12 insertions, 3 deletions

diff --git a/src/tile_type.h b/src/tile_type.h
index e954aa1fb..2d46a74d5 100644
--- a/src/tile_type.h
+++ b/src/tile_type.h
@@ -41,11 +41,20 @@ enum TileType {
 /**
  * Additional infos of a tile on a tropic game.
  *
- * Each non-water tile in a tropic game is either a rainforest tile or a
- * desert one.
+ * The tropiczone is not modified during gameplay. It mainly affects tree growth. (desert tiles are visible though)
+ *
+ * In randomly generated maps:
+ *  TROPICZONE_DESERT: Generated everywhere, if there is neither water nor mountains (TileHeight >= 4) in a certain distance from the tile.
+ *  TROPICZONE_RAINFOREST: Genereated everywhere, if there is no desert in a certain distance from the tile.
+ *  TROPICZONE_NORMAL: Everywhere else, i.e. between desert and rainforest and on sea (if you clear the water).
+ *
+ * In scenarios:
+ *  TROPICZONE_NORMAL: Default value.
+ *  TROPICZONE_DESERT: Placed manually.
+ *  TROPICZONE_RAINFOREST: Placed if you plant certain rainforest-trees.
  */
 enum TropicZone {
-	TROPICZONE_INVALID    = 0,      ///< Invalid tropiczone-type
+	TROPICZONE_NORMAL     = 0,      ///< Normal tropiczone
 	TROPICZONE_DESERT     = 1,      ///< Tile is desert
 	TROPICZONE_RAINFOREST = 2,      ///< Rainforest tile
 };