From caa6547650d3eab9f05d121a0ec84f02077662e1 Mon Sep 17 00:00:00 2001
From: Duncan Frost <duncans_pumpkin@hotmail.co.uk>
Date: Wed, 13 May 2015 20:15:48 +0100
Subject: [PATCH] Started implementing track_mirror.

Ride and maze mirror already works.
Scenery still requires work.
---
 src/ride/track.c          | 70 ++++++++++++++++++++++++++++++++++++++-
 src/ride/track.h          |  1 +
 src/windows/track_place.c |  2 +-
 3 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/src/ride/track.c b/src/ride/track.c
index a99fc1b884..fce13d3152 100644
--- a/src/ride/track.c
+++ b/src/ride/track.c
@@ -721,7 +721,7 @@ void blank_map(){
 		map_element->flags = MAP_ELEMENT_FLAG_LAST_TILE;
 		map_element->base_height = 2;
 		map_element->clearance_height = 0;
-		map_element->properties.surface.slope = 0;		
+		map_element->properties.surface.slope = 0;
 		map_element->properties.surface.terrain = 0;
 		map_element->properties.surface.grass_length = 1;
 		map_element->properties.surface.ownership = OWNERSHIP_OWNED;
@@ -774,6 +774,74 @@ void load_track_scenery_objects(){
 	reset_loaded_objects();
 }
 
+/* rct2: 0x006D247A */
+void track_mirror_scenery(uint8** track_elements){
+	rct_track_scenery* scenery = (rct_track_scenery*)*track_elements;
+	for (; (scenery->scenery_object.flags & 0xFF) != 0xFF; scenery++){
+		//0x006d2484
+	}
+}
+
+/* rct2: 0x006D2443 */
+void track_mirror_ride(uint8** track_elements){
+	rct_track_element* track = (rct_track_element*)*track_elements;
+	for (; track->type != 0xFF; track++){
+		track->type = RCT2_ADDRESS(0x0099EA1C, uint8)[track->type];
+	}
+	*track_elements = (uint8*)track + 1;
+
+	rct_track_entrance* entrance = (rct_track_entrance*)*track_elements;
+	for (; entrance->z != -1; entrance++){
+		entrance->y = -entrance->y;
+		if (entrance->direction & 1){
+			entrance->direction ^= (1 << 1);
+		}
+	}
+	*track_elements = (uint8*)entrance + 1;
+}
+
+/* rct2: 0x006D25FA */
+void track_mirror_maze(uint8** track_elements){
+	rct_maze_element* maze = (rct_maze_element*)*track_elements;
+	for (; maze->all != 0; maze++){
+		maze->y = -maze->y;
+
+		if (maze->type == 0x8 || maze->type == 0x80){
+			if (maze->unk_2 & 1){
+				maze->unk_2 ^= (1 << 1);
+			}
+			continue;
+		}
+
+		uint16 maze_entry = maze->maze_entry;
+		uint16 new_entry = 0;
+		for (uint8 position = bitscanforward(maze_entry);
+			position != 0xFF;
+			position = bitscanforward(maze_entry)){
+			maze_entry &= ~(1 << position);
+			new_entry |= (1 << RCT2_ADDRESS(0x00993EDC, uint8)[position]);
+		}
+		maze->maze_entry = new_entry;
+	}
+	*track_elements = (uint8*)maze + 4;
+}
+
+/* rct2: 0x006D2436 */
+void track_mirror(){
+	uint8* track_elements = RCT2_ADDRESS(0x009D821B, uint8);
+
+	rct_track_td6* track_design = RCT2_ADDRESS(0x009D8178, rct_track_td6);
+
+	if (track_design->type == RIDE_TYPE_MAZE){
+		track_mirror_maze(&track_elements);
+	}
+	else{
+		track_mirror_ride(&track_elements);
+	}
+
+	track_mirror_scenery(&track_elements);
+}
+
 void track_update_max_min_coordinates(sint16 x, sint16 y, sint16 z){
 	if (x < RCT2_GLOBAL(RCT2_ADDRESS_TRACK_PREVIEW_X_MIN, sint16)){
 		RCT2_GLOBAL(RCT2_ADDRESS_TRACK_PREVIEW_X_MIN, sint16) = x;
diff --git a/src/ride/track.h b/src/ride/track.h
index 18db3dbe53..cac426850a 100644
--- a/src/ride/track.h
+++ b/src/ride/track.h
@@ -433,6 +433,7 @@ rct_track_design *temp_track_get_info(char* path, uint8** preview);
 rct_track_td6* load_track_design(const char *path);
 int track_rename(const char *text);
 int track_delete();
+void track_mirror();
 void reset_track_list_cache();
 int track_is_connected_by_shape(rct_map_element *a, rct_map_element *b);
 int sub_6D01B3(uint8 bl, uint8 rideIndex, int x, int y, int z);
diff --git a/src/windows/track_place.c b/src/windows/track_place.c
index da72df7855..6ac32ddad2 100644
--- a/src/windows/track_place.c
+++ b/src/windows/track_place.c
@@ -428,7 +428,7 @@ static void window_track_place_mouseup()
 		window_track_place_draw_mini_preview();
 		break;
 	case WIDX_MIRROR:
-		RCT2_CALLPROC_EBPSAFE(0x006D2436);
+		track_mirror();
 		RCT2_GLOBAL(RCT2_ADDRESS_TRACK_PREVIEW_ROTATION, uint16) = (-RCT2_GLOBAL(RCT2_ADDRESS_TRACK_PREVIEW_ROTATION, uint16)) & 3;
 		window_invalidate(w);
 		_window_track_place_last_x = 0xFFFF;