From da7563c7c92dbf9bb7c35fb4dfe01067e8ab79a1 Mon Sep 17 00:00:00 2001
From: IntelOrca <ted@brambles.org>
Date: Sun, 4 May 2014 18:51:36 +0100
Subject: [PATCH] add unknown map element function

---
 src/game.c |  2 +-
 src/map.c  | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/map.h  |  1 +
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/src/game.c b/src/game.c
index 43e55f9e25..c20491046e 100644
--- a/src/game.c
+++ b/src/game.c
@@ -140,7 +140,7 @@ void game_logic_update()
 	if (RCT2_GLOBAL(0x009DEA66, sint16) == 0)
 		RCT2_GLOBAL(0x009DEA66, sint16)--;
 
-	RCT2_CALLPROC_EBPSAFE(0x0068B089);
+	sub_68B089();
 	scenario_update();
 	climate_update();
 	RCT2_CALLPROC_EBPSAFE(0x006646E1);
diff --git a/src/map.c b/src/map.c
index 3a62c79253..581eabdf30 100644
--- a/src/map.c
+++ b/src/map.c
@@ -280,3 +280,53 @@ int map_element_height(int x, int y)
 
 	return height;
 }
+
+/**
+ *
+ *  rct2: 0x0068B089
+ */
+void sub_68B089()
+{
+	int i;
+	rct_map_element *mapElementFirst, *mapElement;
+
+	if (RCT2_GLOBAL(0x009DEA6F, uint8) & 1)
+		return;
+
+	i = RCT2_GLOBAL(0x0010E63B8, uint32);
+	do {
+		i++;
+		if (i >= MAX_TILE_MAP_ELEMENT_POINTERS)
+			i = 0;
+	} while (TILE_MAP_ELEMENT_POINTER(i) == 0xFFFFFFFF);
+	RCT2_GLOBAL(0x0010E63B8, uint32) = i;
+
+	mapElementFirst = mapElement = TILE_MAP_ELEMENT_POINTER(i);
+	do {
+		mapElement--;
+		if (mapElement < RCT2_ADDRESS_MAP_ELEMENTS)
+			break;
+	} while (mapElement->base_height == 255);
+	mapElement++;
+
+	if (mapElement == mapElementFirst)
+		return;
+
+	// 
+	TILE_MAP_ELEMENT_POINTER(i) = mapElement;
+	do {
+		*mapElement = *mapElementFirst;
+		mapElementFirst->base_height = 255;
+
+		mapElement++;
+		mapElementFirst++;
+	} while (!((mapElement - 1)->flags & MAP_ELEMENT_FLAG_LAST_TILE));
+
+	// Update next free element?
+	mapElement = RCT2_GLOBAL(0x0140E9A4, rct_map_element*);
+	do {
+		mapElement--;
+	} while (mapElement->base_height == 255);
+	mapElement++;
+	RCT2_GLOBAL(0x0140E9A4, rct_map_element*) = mapElement;
+}
\ No newline at end of file
diff --git a/src/map.h b/src/map.h
index 5d0f1a655b..88e76d7e11 100644
--- a/src/map.h
+++ b/src/map.h
@@ -185,5 +185,6 @@ enum {
 void map_init();
 void map_update_tile_pointers();
 int map_element_height(int x, int y);
+void sub_68B089();
 
 #endif