From 9ca929c812fe06cab248feb00fc830e00363ea95 Mon Sep 17 00:00:00 2001
From: peter1138 <peter1138@openttd.org>
Date: Sun, 20 Jan 2008 18:30:53 +0000
Subject: [PATCH] (svn r11934) -Codechange: add persistent random data for
 river and canal tiles.

---
 docs/landscape.html  |  8 +++++++-
 src/newgrf_canal.cpp |  6 +++++-
 src/openttd.cpp      |  2 +-
 src/water_cmd.cpp    | 10 +++++-----
 src/water_map.h      | 13 +++++++++----
 5 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/docs/landscape.html b/docs/landscape.html
index cd6a0cf12d..ec208b944b 100644
--- a/docs/landscape.html
+++ b/docs/landscape.html
@@ -864,6 +864,11 @@
         <td align=left>coast or riverbank</td>
        </tr>
 
+       <tr>
+        <td noswap valign=top><tt>02</tt>&nbsp; </td>
+        <td align=left>river</td>
+       </tr>
+
        <tr>
         <td nowrap valign=top><tt>10</tt>..<tt>1B</tt>&nbsp; </td>
         <td align=left>canal locks
@@ -945,7 +950,8 @@
        </tr>
       </table>
      </li>
-     <li>m4: Owner of the water</li>
+     <li>m4: Owner of the water when ship depot</li>
+     <li>m4: Random data for canal or river tiles</li>
      <li>m6 bits 7..6 : Possibility of a bridge above, in the <a href="#bridge_direction">direction specified</a></li>
      <li>m6 bits 1..0 : <a href="#tropic_zone">Tropic zone definition</a></li>
     </ul>
diff --git a/src/newgrf_canal.cpp b/src/newgrf_canal.cpp
index f7cc633d7e..a2a89d13b8 100644
--- a/src/newgrf_canal.cpp
+++ b/src/newgrf_canal.cpp
@@ -11,6 +11,7 @@
 #include "newgrf_spritegroup.h"
 #include "newgrf_canal.h"
 #include "tile_map.h"
+#include "water_map.h"
 
 
 /** Table of canal 'feature' sprite groups */
@@ -21,7 +22,7 @@ const SpriteGroup *_canal_sg[CF_END];
  * three functions are stubs. */
 static uint32 CanalGetRandomBits(const ResolverObject *object)
 {
-	return 0;
+	return GetWaterTileRandomBits(object->u.canal.tile);
 }
 
 
@@ -47,6 +48,9 @@ static uint32 CanalGetVariable(const ResolverObject *object, byte variable, byte
 
 		case 0x81:
 			return GetTerrainType(tile);
+
+		case 0x83:
+			return GetWaterTileRandomBits(tile);
 	}
 
 	DEBUG(grf, 1, "Unhandled canal property 0x%02X", variable);
diff --git a/src/openttd.cpp b/src/openttd.cpp
index cff06481b5..19436ea1e0 100644
--- a/src/openttd.cpp
+++ b/src/openttd.cpp
@@ -1710,7 +1710,7 @@ bool AfterLoadGame()
 						if (GB(_m[t].m5, 3, 2) == 0) {
 							MakeClear(t, CLEAR_GRASS, 3);
 						} else {
-							MakeCanal(t, (GetTileOwner(t) == OWNER_WATER) ? OWNER_NONE : GetTileOwner(t));
+							MakeCanal(t, (GetTileOwner(t) == OWNER_WATER) ? OWNER_NONE : GetTileOwner(t), Random());
 						}
 					}
 					SetBridgeMiddle(t, axis);
diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index ac90ef20d0..eeed4a6968 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -56,7 +56,7 @@ void MakeWaterOrCanalDependingOnSurroundings(TileIndex t, Owner o)
 
 	/* Non-sealevel -> canal */
 	if (TileHeight(t) != 0) {
-		MakeCanal(t, o);
+		MakeCanal(t, o, Random());
 		return;
 	}
 
@@ -71,7 +71,7 @@ void MakeWaterOrCanalDependingOnSurroundings(TileIndex t, Owner o)
 		}
 	}
 	if (has_canal || !has_water) {
-		MakeCanal(t, o);
+		MakeCanal(t, o, Random());
 	} else {
 		MakeWater(t);
 	}
@@ -128,7 +128,7 @@ void MakeWaterOrCanalDependingOnOwner(TileIndex tile, Owner o)
 	if (o == OWNER_WATER) {
 		MakeWater(tile);
 	} else {
-		MakeCanal(tile, o);
+		MakeCanal(tile, o, Random());
 	}
 }
 
@@ -305,9 +305,9 @@ CommandCost CmdBuildCanal(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 			if (TileHeight(tile) == 0 && p2 == 1) {
 				MakeWater(tile);
 			} else if (p2 == 2) {
-				MakeRiver(tile);
+				MakeRiver(tile, Random());
 			} else {
-				MakeCanal(tile, _current_player);
+				MakeCanal(tile, _current_player, Random());
 			}
 			MarkTileDirtyByTile(tile);
 			MarkTilesAroundDirty(tile);
diff --git a/src/water_map.h b/src/water_map.h
index 98177631be..93ec67a9dc 100644
--- a/src/water_map.h
+++ b/src/water_map.h
@@ -108,6 +108,11 @@ static inline byte GetSection(TileIndex t)
 	return GB(_m[t].m5, 0, 4);
 }
 
+static inline byte GetWaterTileRandomBits(TileIndex t)
+{
+	return _m[t].m4;
+}
+
 
 static inline void MakeWater(TileIndex t)
 {
@@ -129,24 +134,24 @@ static inline void MakeShore(TileIndex t)
 	_m[t].m5 = 1;
 }
 
-static inline void MakeRiver(TileIndex t)
+static inline void MakeRiver(TileIndex t, uint8 random_bits)
 {
 	SetTileType(t, MP_WATER);
 	SetTileOwner(t, OWNER_WATER);
 	_m[t].m2 = 0;
 	_m[t].m3 = 0;
-	_m[t].m4 = 0;
+	_m[t].m4 = random_bits;
 	_m[t].m5 = 2;
 }
 
-static inline void MakeCanal(TileIndex t, Owner o)
+static inline void MakeCanal(TileIndex t, Owner o, uint8 random_bits)
 {
 	assert(o != OWNER_WATER);
 	SetTileType(t, MP_WATER);
 	SetTileOwner(t, o);
 	_m[t].m2 = 0;
 	_m[t].m3 = 0;
-	_m[t].m4 = 0;
+	_m[t].m4 = random_bits;
 	_m[t].m5 = 0;
 }